Outline

Hadron accelerators will play a leading role in particle physics during the next 10-15 years. With the Large Hadron Collider (LHC), currently starting to take data at the European research centre for particle physics, CERN, in Geneva, an exploration of the so far unknown TeV energy domain will become possible very soon and answers to key questions of particle physics may become available.

The main topic of the proposed research programme is a test of the Standard Model of particle physics and the search for extensions at present and future hadron accelerators. In a first phase, tests of the electroweak theory and of Quantum Chromodynamics will be carried out with complementary measurements in different experiments. The experimental programme consists in the investigation of deep inelastic lepton nucleon scattering at the experiments ZEUS at DESY in Hamburg and COMPASS at CERN and in the investigation of proton antiproton collisions in the DØ experiment at the US research laboratory Fermilab as well as proton proton collisions in the ATLAS experiment at CERN.

An important part of the proposed programme is the calculation of 2-loop corrections for WW and Higgs production at hadron colliders. These calculations are necessary for a precise comparison between data and theory. Due to a close collaboration between physicists of different experiments on the one side and between experimentalists and theorists on the other side, an extensive analysis of current data can be carried out and the data analysis at the LHC can be prepared in an optimal way.

A summary of the activities of the programme in the years since 2009 is given here in german language.

Faculty Members

eMail

Prof. Dr. Stefan Dittmaier Theory Stefan.Dittmaier_put_here_the_at_physik.uni-freiburg.de
Prof. Dr. Horst Fischer COMPASS horst.fischer_put_here_the_at_cern.ch
Prof. Dr. Gregor Herten ATLAS,DØ herten_put_here_the_at_uni-freiburg.de
JProf. Dr. Harald Ita Theory harald.ita_put_here_the_at_physik.uni-freiburg.de
Prof. Dr. Karl Jakobs (Spokesperson) ATLAS, DØ karl.jakobs_put_here_the_at_uni-freiburg.de
Prof. Dr. Kay Königsmann COMPASS kay.konigsmann_put_here_the_at_ cern.ch
Prof. Dr. Ulrich Landgraf ATLAS landgraf_put_here_the_at_physik.uni-freiburg.de
Prof. Dr. Markus Schumacher ATLAS markus.schumacher_put_here_the_at_physik.uni-freiburg.de
Prof. Dr. Jochum van der Bij Theory jochum_put_here_the_at_phyv1.physik.uni-freiburg.de
Dr. Christian Weiser ATLAS christian.weiser_put_here_the_at_physik.uni-freiburg.de
Dr. Stephanie Zimmermann ATLAS Stephanie.Zimmermann_put_here_the_at_physik.uni-freiburg.de

Postdocs

eMail

Dr. Andrea di Simone ATLAS andrea.di.simone_put_here_the_at_cern.ch
Dr. Stan Lai ATLAS stan.lai_put_here_the_at_cern.ch
Dr. Christian Schill COMPASS christian.schill_put_here_the_at_cern.ch
Dr. Christian Schwinn Theory christian.schwinn_put_here_the_at_physik.uni-freiburg.de

PhD Students

eMail

Lukas Altenkamp Theory lukas.altenkamp_put_here_the_at_physik.uni-freiburg.de
Simone Amoroso ATLAS simone.amoroso_put_here_the_at_physik.uni-freiburg.de
Hannah Arnold
(Speaker for the Students)
ATLAS hannah.arnold_put_here_the_at_cern.ch
Christopher Betancourt ATLAS christopher.betancourt_put_here_the_at_physik.uni-freiburg.de
Felix Bührer ATLAS felix.buehrer_put_here_the_at_physik.uni-freiburg.de
Daniel Büscher ATLAS daniel.buescher_put_here_the_at_physik.uni-freiburg.de
Fabio Cardillo ATLAS fabio.cardillo_put_here_the_at_physik.uni-freiburg.de
Valerio Consorti ATLAS valerio.consorti_put_here_the_at_physik.uni-freiburg.de
Phuong Nguyen Dang ATLAS phuong.dang_put_here_the_at_physik.uni-freiburg.de
Claudia Giuliani ATLAS claudia.giuliani_put_here_the_at_physik.uni-freiburg.de
Markus Hecht
(Speaker for the Students)
Theory markus.hecht_put_here_the_at_physik.uni-freiburg.de
Alexander Huss Theory alexander.huss_put_here_the_at_physik.uni-freiburg.de
Tomas Javurek ATLAS tomas.javurek_put_here_the_at_physik.uni-freiburg.de
Florian Kiß ATLAS florian.kiss_put_here_the_at_physik.uni-freiburg.de
Anna Kopp ATLAS anna.kopp_put_here_the_at_physik.uni-freiburg.de
Luisa Oggero Theory luisa.oggero_put_here_the_at_physik.uni-freiburg.de
Martina Pagáčova' ATLAS martina.pagacova_put_here_the_at_physik.uni-freiburg.de
Manfredi Ronzani ATLAS manfredi.ronzani_put_here_the_at_physik.uni-freiburg.de
Nils Ruthmann ATLAS nils.ruthmann_put_here_the_at_physik.uni-freiburg.de
Christian Schillo ATLAS christian.schillo_put_here_the_at_physik.uni-freiburg.de
Philip Sommer ATLAS philip.sommer_put_here_the_at_physik.uni-freiburg.de
Tobias Szameitat COMPASS tobias.szameitat_put_here_the_at_cern.ch
Johannes ter Wolbeek COMPASS jwolbeek_put_here_the_at_cern.ch
Vakhtang Tsiskaridze ATLAS vakhtang.tsiskaridze_put_here_the_at_physik.uni-freiburg.de
Francesca Ungaro ATLAS francesca.ungaro_put_here_the_at_physik.uni-freiburg.de
Liv Wiik-Fuchs ATLAS lwiik_put_here_the_at_mail.cern.ch

Application

The Graduiertenkolleg started in April 2005. Applications for acceptance into the Graduiertenkolleg may be submitted anytime. Fellowships will be awarded to fill vacant PhD and postdoc position of the Graduiertenkolleg. It is recommended that applicants contact prospective supervisors and discuss their dissertation proposal prior to submitting a formal application. Details on the fellowships can be given on request and can also be inferred from the Deutsche Forschungsgemeinschaft DFG (FAQs in English/German language).

Applicants

Applicants for the fellowships should:

• be no older than 28 years (exceptions are possible if particular reasons exist);
• have an academic degree equivalent to a Diploma or a Master in Physics;
• be prepared to take an active part in the work of the Graduiertenkolleg.

Applications

Applications are accepted in German or English and should contain:

• a letter of application (no formal requirements) ;
• the names, addresses, and e-mail addresses of two persons (typically professors) who would be willing to send a letter of reference;
• a CV with emphasis on the academic career;
• a copy of all university certificates;
• a copy of a written diploma thesis or equivalent

Applications must be sent to this address:

Prof. Dr. Karl Jakobs
University of Freiburg
Physikalisches Institut
Hermann-Herder Str. 3
D-79104 Freiburg im Breisgau

Continuing Education

As a member of the Graduiertenkolleg you may take advantage of the offered programme for continuing education (e.g. language courses)

You may have a look at the following links:

Aktuelle DPG Studie

Die DPG hat eine Studie in Auftrag gegeben, die den Arbeitsmarkt für Physikerinnen und Physiker detailliert untersucht. Den kompletten Bericht könnt Ihr Euch bei Interesse von der Webseite der DPG herunterladen.
Hier gibt es die Zusammenfassung.

• Antrag auf Mitarbeit als Kollegiat/in im Graduiertenkolleg (pdf, doc)
• Statistik Info, für ausscheidende Kollegiaten (pdf)

Social Events

Monday night: Pub Quiz

The pub quiz takes place at O'Kellys (Milchstrasse 1) and all questions are asked in English as well as in German.
The quiz itself starts at 8:30 pm every monday, but in the past usually some of us were there already at 7:30 to have dinner before. Also it's quite crowed at the beginning of the quiz, so I'd recommend to come a bit earlier to get a seat, even if you don't want to eat there.
Since probably none of us will be able to come every week and we try to organize it a little, we ask you to sign up on doodle, so that no one is showing up there and will be on his own the entire night. ;-)

Uni Sport

The University of Freiburg provides a lot of opportunities to do several different kinds of sports. Most activities are for free and some others will cost a small fee, but normally these are also comparably cheap. For some courses you will need to register in the beginning of the semester.
Uni Sport is a nice opportunity not only to do your favorite sport or try something new, you also can meet a lot of new people there and find friends outside the institute. It's no problem to go there on your own, but if you are looking for a partner you can also use our mailing list or a special searching tool, which is provided by the university. As far as I know already some of us are playing Badminton there and if you are interested to join, you can also write me a mail directly.
For a complete list of courses for the current semester, please have a look here.

Professional sport clubs in Freiburg

We have some professional sport clubs in Freiburg and I think it's worth visiting them at least once during the time you live here. Of course you can do this on your own or with some friends, but we also plan to organize something inside the GK and I hope that many of you will take part.

Possible PhD topics

Test of the Standard Model (COMPASS, DØ, ZEUS, theory)

• Measurement of the tt production cross section at the Tevatron
• Study of WW pair production at the Tevatron;
• Measurement of Vtb in single top production at the Tevatron;
• Measurement of the single top quark production cross section;
• Measurement of the W boson helicity in top quark decays;
• Measurement of the Top quark mass;
• Study of jet-jet correlations with BFKL signature at HERA;

The Structure of hadrons (COMPASS, ZEUS, Theory)

• Determination of the gluon polarization in COMPASS;
• Azimuthal asymmetries of pions and kaons in COMPASS;

Search for the Higgs boson (ATLAS, DØ, Theory)

• Search for the Higgs boson at the Tevatron in the H →W W → ℓnu ℓnu decay mode;
• Investigation of the Higgs boson discovery potential at the LHC using NLO Monte Carlo simulations for signals and backgrounds;
• Validation of new Monte Carlo programs, including a comparison to Tevatron data;
• Studies on tau reconstruction  in ATLAS using full simulation;

Search for Physics beyond the Standard Model (ATLAS; DØ, theory)

• Search for charginos and neutralinos in the three-lepton decay mode in the DØ experiment;
• Search for SUSY particles in final states with tau leptons in DØ;
• Determination of SUSY parameters at the LHC;

Research programme

Experiments

The experimental particle physics groups at the University of Freiburg are currently engaged in the following experiments:

• The ATLAS experiment at the LHC:
The focus during the past years was on the detector construction in the areas of the silicon tracking and muon detector systems. In parallel, studies on the physics potential in the search for Higgs bosons and Supersymmetry have been performed.
• The COMPASS experiment at the CERN super proton synchrotron
• The DØ experiment at the Tevatron ppbar Collider:
The activities are concentrated on the analysis of data taken in the ongoing run. Central topics are the search for the Standard Model Higgs boson and for supersymmetric particles as well as the measurement of parameters of the top quark.
• The ZEUS experiment at DESY

Theory

The theory group has a long standing tradition in the computation of higher order corrections to e+e- and hard scattering pp reactions using analytical and/or numerical methods. Special interest lies in the calculation of QCD corrections to the pair production of vector bosons and Higgs bosons.

Within the Graduiertenkolleg  „Physics at Hadron Coliders“ important tests of the Standard Model will be carried out in the experiments at existing hadron colliders.  Perturbative QCD will be tested in deep inelastic scattering at HERA and in the COMPASS experiment. In the DØ experiment, top-quark and vector boson pair production will be studied and the measurements will be compared to QCD predictions. In addition, non-perturbative aspects of QCD will be addressed in the COMPASS experiment. In the electroweak sector, precise measurements of the mass of the top quark and of the coupling parameter Vtb are foreseen to be carried out in the DØ -and later- in the ATLAS experiment.

An important part of our research activities represents the search for the Higgs boson and for extensions beyond the Standard Model, in particular supersymmetry, in both the DØ and the ATLAS experiment. Final states with leptons and missing transverse momentum are considered. This includes the tau-lepton signature, for which efficient reconstruction and tagging algorithms have still to be developed.

On the theoretical side the calculation of higher order corrections for WW and Higgs pair production at hadron colliders is the main focus.

Within the Graduiertenkolleg a close collaboration between the theory and experiment on one side and between the various experiments on the other side is foreseen. An example of such a collaboration is the calculation of higher order QCD corrections for important signal and background processes for Higgs boson searches, their implementation in Monte Carlo generators and a first comparison –at least for the background processes- with Tevatron data. Precise estimates of cross sections at the LHC rely on precise measurements of the proton structure, as  determined at  HERA and COMPASS.

The whole research programme is subdivided into four main areas:

1. Test of the Standard Model  (COMPASS, DØ, ZEUS, theory)
2. The Structure of hadrons  (COMPASS, ZEUS, Theory)
3. Search for the Higgs boson (ATLAS, DØ, Theory)
4. Search for Physics beyond the Standard Model (ATLAS; DØ, theory)

2013:

Monday, September 30 - Wednesday, October 2
Location:
Hotel Saigerhöh
Saiger Höhe 8
79853 Lenzkirch-Saig
Telefon: +49(0)7653 6850
Fax: +49 (0)7653-741
info@saigerhoeh.de
http://www.saigerhoeh.de/

2012:

Location:
Hotel Vier Jahreszeiten Durbach
Almstr. 49
77770 Durbach
Telefon: +49(0)781 / 93 201-0
Fax: +49(0)781 / 93 201-580
info@vierjahreszeiten-durbach.de
http://vierjahreszeiten-durbach.de/hotel.html

2011:

Location:
Best Western Hotel am Münster
Münsterbergstraße 23
79206 Breisach
Telefon: + 49 (0) 7667 / 8380
Fax: + 49 (0) 7667 / 838-100
info@hotelammuenster.bestwestern.de
www.hotelammuenster.bestwestern.de/

2010:

Lectures

Location:
Schwarzwald-Hotel Silberkönig
Familie Birmelin
Silberwaldstraße 24
79261 Gutach im Breisgau - Bleibach
Telefon: + 49 (0) 7685 / 701 -0
Fax: + 49 (0) 7685 / 701 -100
info@silberkoenig.de
www.silberkoenig.de

2009:

 This year's Klausurtagung was held from 10th to 12th December at Feldberg. The preliminary schedule can be downloaded here. You can browse the lectures here.

2008:

This year's Klausurtagung was held at the Feldberg from 11th to 13th December. The program can be downloaded here.

The slides of the students' talks and the lecture can be found here.

NOTE: This material is protected by a password and should only be accessible to members of the Graduiertenkolleg. There is also a gallery of photos taken at the Klausurtagung. Right now they are also protected.
If you want access to these protected materials or if you want to have something removed you should write an email to the Webmaster.

Former Meetings:

Information about former meetings can be found here:

Mentoring Programme "kite-mentoring"

Definition of kite-mentoring

kite-mentoring is a mentoring programme offered by the University of Freiburg aiming at supporting career planning. The programme targets female PhD students who are involved in the cluster of excellence “BrainLinks-BrainTools”, in the doctorate programmes „Von der Zelle zum Organ: Molekulare Mechanismen der Organogenese", "Physik an Hadron-Beschleunigern", "Micro Energy Harvesting" or are members of the Faculty of Biology. The programme offers the opportunity to cooperate with high-profile executives in science as well as companies outside the university (depending on career objectives) over the duration of one year. Additionally networking and career development workshops will promote female researchers who are at the beginning of their business career.
You will be forwarded to the homepage of kite-mentoring

Dr. Marianne Langstrof
Phone: +49(0) 0761.203 67 721
Email: kite-mentoring@uni-freiburg.de

Die Erfolgsgeschichte eines innovativen Graduiertenkollegs der Universität Freiburg

Das an der Universität Freiburg im April 2005 gestartete und von der DFG geförderte Graduiertenkolleg Physik an Hadron-Beschleunigern beschäftigt sich mit hochrelevanten Fragen der Teilchenphysik: So liegt bei den im Graduiertenkolleg durchgeführten Dissertationen der Schwerpunkt auf dem Test des Standardmodells der Teilchenphysik und auf der Suche nach möglichen Erweiterungen am Large Hadron Collider (LHC).

Der Erfolg des Graduiertenkollegs beruht zum einen auf dem besonderen Stellenwert der Freiburger Forschung innerhalb der internationalen Grundlagenforschung am CERN: Eine große Anzahl von Physikern und Doktoranden erbringt hervorragende wissenschaftliche Leistungen etwa in der Analyse der Daten des ATLAS-Experiments, was die Freiburger Forschung in der aus ca. 2500 Physikern bestehenden Kollaboration ATLAS sehr sichtbar macht. Hochmotivierte Freiburger Doktoranden des Kollegs stehen bei solchen am CERN zu verzeichnenden wissenschaftlichen Erfolgen häufig in erster Reihe. So trugen sie – unterstützt von ihren oft auch international renommierten Physik-Professoren – signifikant zur Entdeckung des Higgs-Teilchens bei und waren federführend bei der Suche nach supersymmetrischen Teilchen: Die Freiburger Arbeitsgruppe der experimentellen Teilchenphysik beteiligte sich an den Experimenten ATLAS (Professoren Gregor Herten, Karl Jakobs und Markus Schumacher) und COMPASS (Professoren Horst Fischer und Kay Königsmann). Auf theoretischer Seite trugen die Arbeitsgruppen der Professoren Stefan Dittmaier und Jochum van der Bij präzise Berechnungen zu Teilchenreaktionen bei, die in der Analyse von LHC-Daten verwendet wurden. Neben der Sichtbarkeit der Freiburger Forschung am CERN ist die hervorragende Kooperation von Experimentalphysikern und theoretischen Physikern in Freiburg ein weiterer Grund für den Erfolg des Graduiertenkollegs. Diese Zusammenarbeit ermöglicht einen genauen Abgleich zwischen den am LHC gewonnenen Daten und der Theorie und so die optimale Durchführung der Datenanalyse. Jedem Doktoranden der Experimentalphysik wird ein PostDoc aus der Theorie zugeordnet und umgekehrt. So kann sich jeder mit fachlichen Fragen, die den jeweils anderen Bereich betreffen, direkt an seine Mentorin bzw. seinen Mentor wenden.

Für die Doktorandenstellen des Kollegs werden die besten Physik-Studierenden gesucht mit in der Regel mindestens der Note 1,5 im Diplom oder Master. Die Doktoranden/innen haben zwei gewählte Sprecher, die das Amt für zwei Jahre übernehmen. Jährlich wird ein neuer Sprecher gewählt und der bereits ein Jahr länger amtierende Sprecher abgelöst. Eine wichtige Aufgabe der Sprecher ist es, Seminare und Blockvorlesungen des Kollegs sowie das Vorlesungsprogramm für die jährliche Klausurtagung mit zu organisieren. Beispielweise findet zweiwöchig ein für alle Mitglieder des Kollegs angesetztes Seminar statt, zu dem Experten als Vortragende zu den verschiedensten Themen eingeladen werden. Hierzu befragen die Sprecher die Doktoranden, welche Themen und welche Personen sie besonders interessieren. Die entsprechenden Vorschläge werden von den Professoren nochmals abgestimmt.
Poster-Präsentation der Doktoranden-Sprecherin Claudia Giuliani

Neben der Planung von Veranstaltungen des Graduiertenkollegs und der Informationsvermittlung zwischen Professoren und Doktoranden kümmern sich die Sprecher auch um die Gestaltung der gemeinsamen Freizeitveranstaltungen der Doktoranden. Markus Hecht, neben Claudia Giuliani der aktuelle Sprecher der Doktoranden, liegt die Aufgabe sehr am Herzen, die Doktoranden dazu zu bewegen, auch außerhalb der Universität etwas gemeinsam zu unternehmen, wie zusammen Volleyball zu spielen oder zu grillen: „Dies stärkt die Gemeinschaft und ist auch besonders gut für neue Doktoranden, die in Freiburg vielleicht noch niemanden kennen und so auch die Chance bekommen, sich in die Gruppe zu integrieren. Zum Teil entstehen dort wirklich gute Freundschaften.”

Gegenüber der Einzelbetreuung eines Promovenden hält Markus Hecht die strukturierte Promotion des Kollegs für ausschließlich vorteilhaft. „Man hat einen gewissen Leistungsdruck, da man bei der jährlichen Tagung ein Poster präsentieren oder einen Vortrag halten muss: man zeigt also, was man im letzten Jahr geschafft hat. Nach zwei Jahren muss man einen Statusbericht schreiben. Dadurch bleibt man immer am Ball. Die Professoren haben immer eine offene Tür für Fragen zur Doktorarbeit und der Stand der Doktorarbeit wird regelmäßig in der jeweiligen Arbeitsgruppe besprochen. Man findet immer jemanden, der das eigene aktuelle Problem kennt und einem weiterhelfen kann.”
Teamarbeit im GK – Doktorandinnen und Doktoranden lösen gemeinsam wissenschaftliche Fragen

Der Frauenanteil im Graduiertenkolleg ist mit über 30% überdurchschnittlich hoch. Dr. Susanne Kühn, die bis 2012 Doktorandin im Kolleg war und von 2008 bis 2010 die erste Sprecherin der Doktoranden, hat eine gute Erklärung hierfür: „Wenn bereits Frauen im Kolleg sind, kommen auch weitere Frauen nach. Die Kandidatinnen sehen im Vorfeld, dass bereits Frauen in der Gruppe zurechtkommen und unterstützt werden, was durchaus nicht überall selbstverständlich ist. Die Schwierigkeit besteht vor allem am Anfang, Frauen zu motivieren. Wenn aber bereits zwei Frauen teilnehmen, kommen automatisch weitere hinzu; dann bilden sich relativ schnell Cluster und das Vertrauen wächst untereinander.” Dies bestätigt auch der Sprecher des Kollegs, Prof. Karl Jakobs, der einen weiteren wichtigen Grund für den relativ hohen Frauenanteil im Kolleg anführt: „Der Frauenanteil ist in der Physik in anderen Teilen Europas nicht so niedrig, beispielsweise in Italien oder Spanien. Durch die Sichtbarkeit am CERN ziehen wir auch Ausländerinnen und Ausländer an, auch aus den Südländern, und die heben dann den Durchschnitt.” Mithilfe von auf die Bedürfnisse von Doktorandinnen zugeschnittenen Weiterbildungsveranstaltungen und eines sie in ihrer Karriereplanung unterstützenden Mentoring-Programms wird versucht, diesen Trend zu stärken.

Durch den Erfolg des Graduiertenkollegs und des Forschungsverbunds sowie die jüngsten nobelpreisverdächtigen Entdeckungen am CERN sind die Freiburger Teilchenphysiker sehr motiviert, ein neues Graduiertenkolleg ins Leben zu rufen, wie Karl Jakobs bestätigt: „Wir arbeiten gerade an einem Nachfolgeantrag, der insbesondere die Entdeckung des Higgs-Teilchens berücksichtigt. Auf die neuen Erkenntnisse am ATLAS-Experiment und damit auch auf neue Fragen wird das folgende Graduiertenkolleg ausgerichtet sein. Wir versuchen an diese Forschungsergebnisse anzuknüpfen und gleichzeitig die positiven Strukturen des alten Graduiertenkollegs beizubehalten bzw. noch weiter zu verbessern.” Der zukünftige Sprecher des Kollegs, Prof. Stefan Dittmaier, fügt hinzu: „Die bahnbrechende Entdeckung eines Higgs-Teilchens am LHC im letzten Jahr ist eine Steilvorlage für unseren Neuantrag. Mit unseren fachlichen Expertisen in Freiburg werden wir insbesondere Detailuntersuchungen zum Higgs-Teilchen mit hoher Präzision in Theorie und Experiment durchführen, deren Ergebnisse für die zukünftige Entwicklung der Teilchenphysik richtungsweisend sein werden.”
Marianne Schröder

Contact

Spokesperson:

Prof. Dr. Karl Jakobs

Universität Freiburg
Physikalisches Institut
Hermann-Herder Str. 3
D 79104 Freiburg im Breisgau

Phone: +49 (761) 203-5713
Email: Karl.Jakobs@uni-freiburg.de

Secretary:

Mrs. Christina Skorek

Phone: +49 (761) 203-5715
Fax: +49 (761) 203-5931
Email: christina.skorek@physik.uni-freiburg.de

For the students:

Hannah Arnold

Phone: +49 (761) 203-5751
Email: hannah.arnold at physik.uni-freiburg.de

Felix Anger

Phone: +49 (761) 203-5845
Email: felix.anger at physik.uni-freiburg.de

Seminars:

NEW: The Graduiertenkolleg seminar usually takes place on Wednesday (every two weeks) at 5 pm (c.t.) in HS2.

WS 2014/2015

 Date Speaker Topic Talk 25.11. Abdelhak Djouadi, LPT Orsay Implications of the Higgs discovery for SUSY abstract, pdf 14.01. Shikma Bressler, Weizmann Institute Asymmetric lepton-flavor violating Higgs boson decays abstract 28.01. Jochum J. van der Bij Physics after the discovery of the Higgs boson abstract

SS 2014

 Date Speaker Topic Talk 30.04. Tomas Javurek Boosted W studies for SUSY 0-lepton 2-6 jet channel abstract, pdf 30.04. Phuong Dang Estimation of W+jets background in the ATLAS H->WW->lvlv analysis using a likelihood-based matrix technique abstract, pdf 14.05. Gavin Salam, CERN Towards an Understanding of Jet Substructure 28.05. Jan Plefka, HU Berlin Scattering amplitudes and hidden symmetries in supersymmetric gauge theory and a duality to strings abstract, pdf 04.06. Markus Hecht NLO corrections to W + y production at the LHC abstract, pdf 04.06. Florian Kiß Study of CP violation in VBF H -> yy using Optimal Observables abstract, pdf 02.07. Stefan Weinzierl, Uni Mainz Overview on Top and Single Top production abstract, pdf 09.07. Philipp Sommer Measurement of the W Boson Pair Production in pp Collisions at sqrt(s)=8 TeV with the ATLAS detector abstract, pdf 09.07. Martina Pagacova Measurement of the WWW->lnulnulnu final state in pp collisions at sqrt(s)=8 TeV with the ATLAS detector abstract, pdf 23.07. Christian Schillo Search for the Higgs-Boson decay H -> tau tau -> ll4nu with the ATLAS detector abstract, pdf 23.07. Johannes ter Wolbeek Hard exclusive omega production at COMPASS abstract, pdf

WS 2013/2014

 Date Speaker Topic Talk 06.11. Jochen Dingfelder, Bonn Latest results in B physics abstract, pdf 13.11. Julien Lesgourgues, CERN The Planck satellite results: A Universe so big, but so simple? abstract, pdf 27.11. Michael Spannowsky, Durham Measuring Higgs properties using jet substructure abstract, pdf 15.01. Joerg Jaeckel, Heidelberg Exploring the Hidden Sector @ Low Energies abstract, pdf 21.01. Erez Etzion, Tel Aviv Search for Exotics Physics at the LHC abstract, pdf 29.01. Christian Weinheimer, Münster Direct search for dark matter abstract, pdf 05.02. Dieter Zeppenfeld, KIT NLO QCD corrections for the LHC and Higgs physics abstract, pdf

SS 2013

 Date Speaker Topic Talk 17.04. Laura Covi, Göttingen CP Violation in cosmology and baryogenesis abstract, pdf 08.05. Frank Siegert, Freiburg NLO accuracy in modern Monte-Carlo event generators abstract, pdf 15.05. Kevin Kröninger, Göttingen An introduction to Bayesian reasoning in high-energy physics abstract, pdf 29.05. Talk will be postponed, more information coming up Jochen Dingfelder, Bonn Latest results in B physics abstract 12.06. Klaus Desch, Bonn Towards the ILC: Physics and Detectors abstract , pdf 26.06. Christian Steinwachs, Nottingham Non-minimal Higgs Inflation abstract 10.07. David A. Kosower, Saclay New Methods at Next-to-Leading Order abstract 26.08. Special Seminar 14:00h in HS II Till Eifert (SLAC) Probing Naturalness using top squark searches with the ATLAS detector 28.08. Special Seminar 14:00h in HS II Frederik Rühr (CERN) High-pT Jets at ATLAS: Probing QCD and New Physics 29.08. Special Seminar 14:00h in HS II Will Davey (Bonn) Searches for high-mass di-tau resonances with the ATLAS detector

WS 2012/2013

 Date Speaker Topic Talk 24.10. Prof. Jochum van der Bij Freiburg Considerations on the Standard Model and the Higgs sector abstract , pdf 31.10. Dr. Sasha Glazov DESY Implications of LHC measurements on parton distribution functions abstract , pdf 20.11. Dr. Anselm Vossen Recent Results in Spin Physics at STAR and Belle abstract , pptx 21.11. Prof. Lutz Köpke Mainz Neutrinoastronomy from MeV to PeV energies abstract, pdf 18.12. Dr. Sven Heinemeyer Santander The 126 GeV Discovery: Implications for the SM and MSSM abstract, pdf 16.01. Dr. Gerhard Mallot CERN QCD and the spin structure of the nucleon abstract, pdf 23.01. Prof. Oleg Ruchayskiy CERN Sterile Neutrinos as Dark Matter abstract 31.01. Dr. Stefan Roth Aachen Measurement of Θ₁₃ in Neutrino Oscillation Experiments abstract, pdf 13.02. Dr. Markus Ackermann DESY High-energy γ-ray astronomy. An exciting window into the universe. abstract

SS 2012

 Date Speaker Topic Talk 25.04. Prof. Marco Silari, CERN Particle accelerators in medicine abstract , pdf 06.06. Dr. Jan Hamann Light dark stuff in cosmology: Warm dark matter, hot dark matter and dark radiation abstract, pdf 27.06. Dr. Yvonne Pachmayer, Heidelberg Exploring the Quark-Gluon Plasma with ALICE at the LHC abstract, pdf 04.07. Prof. Markus Diehl, DESY Multi parton interactions in QCD abstract, pdf 18.07. Prof. George Zoupanos, NTUA, CERN Grand Unified Theories and Beyond abstract, pdf 25.07. Prof. Marzio Nessi, CERN LHC and ATLAS upgrade abstract, pdf

WS 2011/12

 Date Speaker Topic Talk 02.11. Students Liv Wiik-Fuchs Search for Seesaw Neutrinos at ATLAS Beyhan Pulice postponed 17.11. Attention Date was changed to Thursday afternoon! Nigel Glover, Durham Prospects for NNLO measurements using jets at the LHC abstract 30.11. Wolfgang Wagner, Wuppertal Measurements of top-quark properties: Tevatron legacy and first LHC results abstract 14.12. Kerstin Hoepfner, Aachen Searches for new, exotic physics at the LHC abstract 11.01. Nicole d'Hose, Saclay Tomography of the Proton using Deeply Virtual Compton scattering to measure Generalized Parton Distributions at COMPASS-II at CERN abstract 25.01 Eilam Gross, Weizmann Institute Higgs Search at LHC 08.02. Attention Lecture from 16:30h - 18.30h with 15 min break + 15 min discussion! Yvonne Wong, Aachen Precision Cosmology abstract

SS 2011

 Date Speaker Topic Talk 06.04. students Evelyn Schmidt Studien von Elektron-Schauerverteilungen in Z->ee Zerfällen mit Daten des ATLAS Experiments Sascha Thoma MSSM A/H/h -> tautau -> lh at ATLAS 13.04. Attention: The seminar starts at 16 ct Christoph Paus, MIT Unveiling the mystery of mass abstract 11.05. Alan Barr, Oxford Summary of first SUSY and BSM results from ATLAS 18.05. Frank Krauss, Durham Looping through Monte Carlo abstract 01.06. Ulrich Uwer, Heidelberg Results from LHCb 29.06 Uwe Oberlack, Mainz Exploring the Nature of Dark Matter with Direct Searches - A XENON Perspective abstract 06.07. Lorenzo Basso, Southampton Phenomenology of the minimal B-L extension of the SM abstract 27.07. students Jochen Hartert Measurement of the W and Z/gamma* production cross sections at sqrt(s)=7 TeV with the ATLAS experiment Felix Braam EXSPECT: Creating a spectrum generator for exceptional SUSY models

WS 2010/11

 Date Speaker Topic Talk 22.10. Sonderseminar Freitag, 22.10.2010 - 15 s.t., Multimediaraum - Westbau Laura Nervo Strategy for an early observation of the ZZ diboson production in the four lepton final states at 10 TeV with the CMS experiment 27.10. Simone Amoroso Measurement of trilinear gauge boson couplings in the WW/WZ → lν jj decay channel with the CDF experiment 03.11. students Oliver Fischer Scalar Multi-Component Dark Matter M. Rammensee Multi lepton (e, mu) final states with missing transverse energy in searches for SUSY at ATLAS 17.11. Philipp Schieferdecker CMS Analysis Results from 7 TeV proton-proton Collisions abstract 15.12. Sven Heinemeyer SUSY predictions for the LHC abstract 22.12. Jahresabschlussvortrag mit anschliessendem Glühweinumtrunk Ulrich Parzefall Silicon Detectors in Particle Physics abstract 14.01. Freitag 14 c.t., Seminarraum GMH Gerhard Brandt Soft QCD measurements in ATLAS 19.01. Alberto Guffanti Monte Carlo techniques, Neural Networks and Parton Densities: the NNPDF approach to PDF fitting 02.02. Michel Janus SUSY mit taus 09.02. Maria Vittoria Garzelli Automatic computation of 1-loop amplitudes for multiparticle production at the LHC abstract 14.02. Sonderseminar 15.15h, Seminarraum GMH Christian Sander Jets and missing transverse momentum at CMS 15.02. Sonderseminar 16.15h, MM-Raum Westbau Alexander Schmidt b-quarks in the CMS experiment, from detector design to physics results

SS 2010

 Date Speaker Topic Talk 21.4. students Holger v. Radziewski Controlling ttbar Background in the VBF H→ττ→ℓℓ+4ν Search with ATLAS 5.5. Oliver Brein Phenomenology of Higgs Bosons 19.5. students Daniel Wiesler LHC phenomenology of Leptoquarks in a SUSY GUT 2.6. students Evelyn Schmidt Tuning possibilities of ATLFAST II with single photons and J/Psi→ee events Felix Braam E6SSM from orbifold compactification 16.6. Ulrich Landgraf Latest developments for gas detectors 7.7. Fabio Maltoni Top: The importance of being single tba 14.7. Andreas Vogt (Liverpool) Higher-order calculations in QCD and their applications in phenomenology and theory tba 28.7. students Matthias Werner egamma performance of Atlfast II with the new FastCaloSim parametrization Sascha Thoma Studies of the process bb A/H → τ τ → lep had at sqrt(S) = 7 TeV

WS 2009/2010

 Date Speaker Topic Talk 16.9. S.Weinzierl (Mainz) Event shapes and jet rates in electron-positron annihilation 14.10. students Sascha Thoma Soft electron identification and b-tagging with neural nets Oliver Fischer Scalar Dark Matter Sebastian Schmidt Analytic parton showers for WHIZARD 21.10. students Jochen Hartert Beyhan Pulice 17.11. Sebastian Stern (MPI München) Background estimation from data for neutral MSSM Higgs searches in the channel A → μμ 18.11. Giacinto Piacquadio Searching for a low mass Higgs boson with ATLAS: revisiting H → bb using jet substructure 25.11. Achim Stahl Neutrino oscillations: Status and Perspectives 9.12. 16:15 Frank Siegert Photon production processes and ME+PS merging 9.12., 17:15 Valerio Consorti (Univ. Roma La Sapienza) ATLAS MDT data quality monitoring at the Rome calibration center 16.12. Fabio Maltoni +++ postponed +++ information coming soon +++ 13.1. Oliver Brein +++ postponed +++ information coming soon +++ 20.1. Klaus Desch (Bonn) Measuring the Parameters of Supersymmetry 21.1., 13:30h Jana Kraus (Bonn) Special Seminar: Measurement of electron production from cosmic rays in the ATLAS detector 3.2. Kai Zuber Status and perspectives of the COBRA double beta decay experiment tba 10.2. Robert Harlander (Wuppertal) Higgs production in gluon fusion for finite top quark mass tba 3.3. Thomas Reiter Tools for One-Loop Calculations abstract

SS 2009

 Date Speaker Topic Talk 8.4. Steffen Schumann QCD Matrix Elements and Truncated Showers abstract, pdf 22.4. Karl Jakobs Summary of the Moriond-QCD 2009 results 20.5. Kristin Lohwasser Proton Structure at the LHC Using inclusive W and W+jets measurements 5.6. Hartmut Sadrozinski Development of Proton Computer Tomography 10.6. Emmanuel Turlay (LAL Orsay) Electron reconstruction and identification and SUSY with decoupled scalars in ATLAS 24.6. Matthias Grosse Perdekamp Proton Spin Structure and Spin-Dependent Effects in Quark Fragmentation abstract 1.7. students: Björn Penning H→WW→ℓℓ at DØ Stephan Horner Absorbing systematic effects in control selections to obtain a better background model 2.7. Martin Flechl Prospects for Charged Higgs Boson Searches with ATLAS 3.7. Anurag Tripathi Photon pair production at NLO in the ADD model at the LHC 15.7. Michael Rauch SFitter: Parameter Determination at the LHC 27.7. Christian Speckner s Channel Production of Heavy Vector Bosons in the Three-Site Higgsless Model --- 16:00, Hörsaal I, Physikhochhaus (Sonderseminar) --- abstract 29.7. Luca Panizzi One-Loop Electroweak Analysis of (S)Top Production Processes at LHC --- 10:00, Hörsaal I, Physikhochhaus (Sonderseminar) --- abstract 29.7. Giovanni Balossini Combining electroweak and QCD corrections to single W production at hadron colliders --- 16:00, Seminar Room, Gustav-Mie-Haus (Sonderseminar) --- abstract 29.7. students: cancelled!

WS 2008/09

 Date Speaker Topic Talk 15.10. students: Jochen Hartert RADMON abstract, pdf Björn Penning H->WW searches at DØ (Tevatron) pdf 29.10. Helmut Burkhardt (CERN) The LHC Machine abstract, pdf 12.11. Daniel Froidevaux Expected performances of ATLAS and CMS experiments at the LHC abstract, pdf, ppt 26.11. Per Grafstrom Luminosity Measurements in ATLAS abstract, pdf, ppt 10.12. students: Song Xie Gas monitoring for MuonDriftTubes in ATLAS protected Henrik Nilsen Z+Jet Measurements at DØ, Tevatron; Comparing Data with Event Generators protected ~~~ Christmas Break ~~~ 11.2. students: Asen Christov ele/tau separation in first data 25.2. Philipp Biallass (Aachen) Model-dependent and model-independent SUSY searches at CMS

Talks from previous semesters can be found here.

Asymmetric lepton-flavor violating Higgs boson decays

14.01.2015

Lepton Flavour Violation (LFV) is known to exist in nature. The observation of neutrino oscillations indicates that lepton flavor is not an exact symmetry, and calls for physics beyond the SM that participates in flavor changing dynamics. With the recently discovered Higgs boson, new channels in which such dynamics may be observed become experimentally available and serve as a motivation for this work. After a brief description of models that give rise to LFV Higgs boson decays, I will present our new method to search for the lepton-flavor violating Higgs boson decays H to tau mu and H to tau e in the leptonic tau decay channel. In particular, I'll show that using this method, the Standard Model background can be estimated in a fully data driven way. The method exploits the asymmetry between electrons and muons in the final state of signal events and is sensitive to differences in the rates of the two decays. We show that the small e/mu asymmetry expected in Standard Model processes and asymmetries induced by the experiment itself can be estimated directly from the data, thus suppressing systematic uncertainties associated with the use of Monte Carlo simulation as well as uncertainties associated with theoretical calculations of the production cross section of the different Standard Model processes.

Overview on Top and Single Top production

02.07.2014

In this talk I will give an overview on top and single top production in hadron colliders. I will also review the status of the theory predictions for these processes.

Scattering amplitudes and hidden symmetries in supersymmetric gauge theory and a duality to strings

28.05.2014

An introduction to the fundamental role of symmetries in quantum field theory will be given. We shall discuss conformal symmetry, supersymmetry and a holographic description of quantum gauge fields in terms of a higher dimensional string theory known as the AdS/CFT correspondence. Finally, we focus on recent results for scattering amplitudes in supersymmetric gauge theory employing on-shell methods, their string dual description and surprising hidden symmetries pointing towards an integrable structure.

NLO QCD corrections for the LHC and Higgs physics

05.02.2014

The talk will review recent calculations of NLO QCD corrections to a vaiety of scattering cross sections at the LHCand their implementation in the VBFNLO Monte Carlo program. Deviations from SM predictions in electroweak physics are implemented in the program via anomalous couplings which are based on an effective Lagrangian approach. They affect Higgs couplings and trilinear and quartic gauge couplings.

Direct search for dark matter

29.01.2014

There is strong evidence from astrophysics and cosmological data that there is a factor 5 more exotic matter than normal baryonic matter in the universe. From the particle physics point of view so-called WIMPs (weakly interacting massive particles) are very attractive since they would have been created in the early universe with about the correct abundance to explain the missing dark matter. Theoretically a supersymmetric extension of the Standard Model could explain the WIMP as the lightest supersymmetric particle.
In the direct dark matter search very sensitive and ultra-low background detectors in underground laboratories are used. They look for the recoil of a WIMP from the dark matter halo around our milkyway on a nucleus. The main detector techniques for these types of rare event searches are cryogenic bolometers or liquid noble gas detectors. By using two observables background events can be separated from nuclear recoil events.
In this lecture the astrophysical evidence for dark matter and the experimental direct search for WIMPs are presented.

Exploring the Hidden Sector @ Low Energies

15.01.2014

Over the years we have accumulated a large number of indications for physics beyond the standard model. This new physics is often sought-after at high masses and energies. Here collider experiments can bring decisive insights. However, over recent years it has become increasingly clear that new physics can also appear at low energy, but extremely weak coupling. Experiments and observations at this `low energy frontier' therefore provide a powerful tool to gain insight into fundamental physics, which is complementary to accelerators.

Search for Exotics Physics at the LHC

21.01.2014

Last year's discovery of the Higgs particle by the ATLAS and CMS collaborations provided an experimental confirmation of the last untested area of the Standard Model of particle physics. This moves the focus of the High Energy community to the search for Physics beyond the Standard Model. There are various extensions to the Standard Model aiming at explaining its deficiencies, such as the missing explanation of the large difference between the Planck scale and the electroweak scale, known as the hierarchy problem, the source for dark matter in the universe, the nature of neutrino oscillations and others. We will review the searches for Physics Beyond the Standard Model based on the data collected by the ATLAS experiment during the 7 and 8 TeV runs of the LHC, and if time allows discuss the prospect for the runs at the new energy regime of 13-14 TeV expected for next year.

Measuring Higgs properties using jet substructure

27.11.2013

The discovery of a Higgs boson by both multipurpose experiments, ATLAS and CMS, constitutes a paradigm shift in our understanding of electroweak symmetry breaking. This discovery raises the questions if the observed Higgs boson is the long-ago predicted Higgs boson of the Standard model or if it is part of a non-minimal realization of a spontaneous-symmetry-breaking mechanism. Detailed measurements of its properties and couplings are necessary to answer this question. After a brief introduction of subjet techniques I will argue that studying hadronic decays of the Higgs boson is of utmost importance to measure some of the most important Higgs couplings, e.g Hbb, Htt or HHH. I will present methods which can maximize the experiments' sensitivity in measuring Higgs properties in the forthcoming LHC runs.

The Planck satellite results: A Universe so big, but so simple?

13.11.2013

The first cosmological data released from the Planck satellite have provided several new and independent precision tests of the standard cosmological model and are playing a role similar to LEP for the standard model of particle physics. I will review the implications of these Planck data for cosmology and particle physics and discuss the status of possible indications for new physics. After two decades of observations of anisotropies in the cosmic microwave background, it seems that mankind understands the large-scale universe well beyond the expectations of the most optimistic physicists of the mid-XXth century.

10.07.2013

Calculations to next-to-leading order (NLO) in QCD of Standard-Model processes are required for quantitatively reliable predictions. They are a prerequisite for comparisons to experimental data. I review the on-shell methods developed in recent years to calculate the one-loop amplitudes needed. I also present results obtained using these methods by the BlackHat collaboration at the high-multiplicity frontier at NLO. I present the next-to-leading predictions for W and Z production in association with three and four jets at the LHC; preliminary results for W production in association with five jets; and results for pure four-jet production. I also discuss briefly applications to various LHC searches.

Non-minimal Higgs Inflation

26.06.2013

We analyze whether the recently discovered Standard Model Higgs boson and the cosmological inflation, responsible for the accelerated expansion of the early universe, can be described by one and the same scalar field -- the Higgs-inflaton. An essential assumption of this model is a large non-minimal coupling of the Higgs-inflation to gravity. By calculating the renormalization group flow from the electroweak vacuum of the Standard Model up to the high energies during inflation, we can connect particle physics and cosmology within one unified model. While the numerical predictions of the model come close to the latest experimental data of the LHC and PLANCK, there still remain some conceptional problems. One of these problems is associated with the choice of the cosmological frame. While the classical theory is independent of this choice, we find by an explicit calculation that already the first quantum corrections induce a frame dependence. We give a geometrical explanation of this frame dependence by embedding it into a more general field theoretical context.

Latest results in B physics

06.11.2013

Over the last decade, the electron-positron B-factory experiments Belle and BaBar have recorded huge samples of B mesons, which have enabled precision studies of the quark flavor sector of the Standard Model. Since the start of the Large Hadron Collider also the LHCb experiment at CERN has delivered impressive B-physics results. In this talk, I will explain some of the key measurements in B physics and present a selection of recent interesting results in CP violation, CKM measurements and rare B decays from LHCb, Belle and BaBar.

CP Violation in cosmology and baryogenesis

17.04.2013

We will present the cosmological evidence for the baryon asymmetry of the Universe, discuss the Sakharov conditions to generate it dynamically and review the most popular baryogenesis mechanisms.

An introduction to Bayesian reasoning in high-energy physics

15.05.2013

I will give an introduction to Bayesian reasoning in high-energy physics. Starting from Bayes' Theorem, the estimation of parameters and intervals (uncertainties, limits) will be discussed and typical examples will be given. These include limits on production cross-sections and masses of new particles as well as multi-dimensional fits in the interpretation of rare b-decays. The numerical issues encountered in the calculation of marginal distributions will be convered, and algorithms and tools to solve these will be introduced.

Towards the ILC: Physics and Detectors

12.06.2013

The discovery of a light Higgs boson by ATLAS and CMS has triggered renewed interest in a e+e- linear collider. Detector concepts for the International Linear Collider use the particle flow concept in order to meet the challenges imposed by the need to precisely reconstruct fully hadronic final states. In the talk I will introduce precision Higgs physics and other challenging linear collider measurements in order to motivate the need for such a dedicated detector concept. I will discuss how particle flow is implemented and how it is expected to perform based on detailed simulations. Finally some of the ongoing detector R&D work with focus on charged particle tracking will be discussed.

NLO accuracy in modern Monte-Carlo event generators

08.05.2013

Different approaches to achieve QCD NLO accuracy in full hadron-level Monte Carlo event generators are reviewed. Due to the double counting between real emission parts in a NLO calculation and parton shower emissions on top of Born-like events a matching prescription (NLO+PS) has to be implemented. Schemes like the original MC@NLO method, and POWHEG as a variant of it, are introduced. More recently, it has become possible to merge multiple such NLO+PS samples for different jet multiplicities, to achieve NLO accuracy in different jet multiplicities simultaneously without double counting. Examples of the improvements achieved with these methods are given, with a focus on the agreement with experimental data and reduction of perturbative uncertainties.

High-energy γ-ray astronomy. An exciting window into the universe.

13.02.2013

High-energy γ-ray astronomy - only a few decades old - is one of the fastest growing fields in modern astronomy. Current satellite and ground based instruments cover seven orders of magnitude in energy between 20 MeV and 100 TeV. I will introduce the current generation of instruments and highlight several recent breakthroughs in the studies of Pulsars, the origin and propagation of cosmic rays, and the properties of extragalactic γ-ray sources.

Measurement of Θ₁₃ in Neutrino Oscillation Experiments

31.01.2013

Neutrino oscillations are described by a mixing matrix connecting the weak and the mass eigenstates of the three neutrino flavours. It contains three mixing angles, Θ₁₂, Θ₂₃, Θ₁₃, from which Θ₁₃ has only recently been determined by oscillation experiments both at reactors and accelerators. The talk presents these experiments, shows latest results and explains their implications on our understanding of neutrino oscillation. Emphasis is placed on the reactor experiment DoubleChooz and the accelerator experiment T2K.

QCD and the spin structure of the nucleon

16.01.2013

The current experimental status will reviewed of our understanding of nucleon in terms of quarks and gluons with emphasis on the spin structure. The nucleon is a powerful QCD laboratory in which we can test theoretical predictions and ideas. The experimental focus will be on the COMPASS experiment at CERN. In an outlook the next steps will be sketched.

The 126 GeV Discovery: Implications for the SM and MSSM

18.12.2012

Some facts on the discovery of a new state with a mass around 126 GeV are briefly reviewd. This discovery is discussed in the frameworks of the Standard Model and Supersymmetry (especially in view of possible deviations from Standard Model predictions). The implications in the Minimal Supersymmetric Standard Model as well as for future high-energy experiments are discussed.

Sterile Neutrinos as Dark Matter

23.01.2013

I will review the status of sterile neutrino dark matter and discuss astrophysical and cosmological bounds on its properties as well as future prospects for its experimental searches. I will argue that if sterile neutrinos are the dominant fraction of dark matter, detecting an astrophysical signal from their decay may be the only way to identify these particles experimentally. However, it may be possible to check the dark matter origin of the observed signal unambiguously using its characteristic properties and/or using synergy with accelerator experiments, searching for other sterile neutrinos, responsible for neutrino flavour oscillations. I will also argue that to fully explore this possibility a dedicated cosmic mission -- an X-ray spectrometer -- is needed.

Neutrinoastronomy from MeV to PeV Energies

21.11.2012

The IceCube neutrino telescope instruments the Antarctic ice at the South Pole with a grid of optical sensors. Fully completed in 2011, it is the first cubic kilometer-scale neutrino telescope collecting data. One of the main goals of IceCube is to detect astrophysical sources of high-energy neutrinos and to eventually identify the sources of the high-energy cosmic radiation. IceCube also provides tests of particle physics, e.g. by indirect searches for dark matter and studying neutrino oscillations. Neutrinos from galactic supernovae could shed light on the neutrino hierarchy. This is also the driving physics theme for envisaged low energy extensions both at the South Pole and the Mediterranean. The smaller Antares detector complements the search; a technical design report for the mediterranean Km3Net detector, envisaged to be substantially larger than IceCube, was completed in 2011.

Recent Results in Spin Physics at STAR and Belle

20.11.2012

Quantum Chromodynamics, the theory of the strong interaction, is firmly established in the perturbative regime, However there is no consistent description of hadronic physics and new experimental results will have to drive progress in this field. The Relativistic Heavy Ion Collider (RHIC) at BNL uses polarized proton collisions at energies up to sqrt(s)=500 GeV to access the proton structure and unravel the mechanisms behind the unexplained phenomena in transverse spin physics. In these efforts, we increasingly use correlations in final state hadrons that are sensitive to the inital quark spin and non-perturbative QCD effects. To use our results in global analysis, the strength of these correlations have to be known and we measure them in q\bar{q} prodution in e+e- annihilation at Belle. This talk will highlight recent results in transverse and longitudinal spin physics from the STAR experiment at RHIC and the measurement of light quark fragmentation functions at Belle. I will give an outlook on our planned physics program at STAR, Belle and its successor Belle II.

Implications of LHC measurements on parton distribution functions

31.10.2012

The first results from the LHC pp collider provided a wealth of information on details of particle interactions at the highest energies. So far the data are consistent with the Standard Model. However the LHC data can be used not only to challenge the Standard Model but also study and constrain its parameters. In particular, measurements of the W,Z bosons, high energy jets and top production provide interesting and sometime unexpected constraints on the proton structure. Implications of these results for the physics at the LHC is discussed.

Considerations on the Standard Model and the Higgs Sector

24.10.2012

I will give a somewhat personal interpretation of the recent results at the LHC, focusing mostly on the Higgs sector, in particular discussing what possibilities are still there without having to impose fine tunings in many parameters.

Grand Unified Theories and Beyond

18.07.2012

The motivation of Grand Unification and the most important details of SU(5) and supersymmetric SU(5) models will be presented. In addition will be presented the idea of "reduction of couplings" with an application in the Finite SU(5) Unified Theory which becomes a very predictive theory. The most important predictions of current interest are
(i) the Higgs-boson mass in the range 121 - 126 GeV and
(ii) the relatively heavy spectrum with coloured supersymmetric particles above 1.5 TeV.

Light dark stuff in cosmology: Warm dark matter, hot dark matter and dark radiation

06.06.2012

It is now well-established that a large part of the Universe's energy budget consists of "invisible" dark matter. In the cosmological concordance model, it is assumed that the dark matter is cold, i.e., its velocity dispersion is negligible. However, if the dark matter is entirely or partially made up of light (m < O(10) keV) particle species, this assumption may no longer hold, and the formation of cosmic structures can be affected in potentially observable ways. Depending on their masses and momentum distributions, these light particle species can be labelled warm dark matter, hot dark matter, or dark radiation. I will review the impact of hot/warm dark matter and dark radiation on structure formation, discuss the status given current data, and present an outlook on upcoming observational probes.

ATLAS and LHC plans for the medium and long-term future

25.07.2012

With the Large Hadron Collider (LHC) evolving with time towards its nominal design value and even beyond, the ATLAS detector has to be ready to exploit in optimal conditions the delivered beam luminosity. Today's plans are to run the LHC with a repetitive pattern of typically 3 years followed by major shutdowns, to allow accelerator and detectors to face the new challenges in the best conditions. Three major shutdowns are already scheduled in 2013 (LS1), 2018 (LS2) and 2022 (LS3). After 2022 the LHC will evolve into a high-luminosity machine, capable of delivering a target integrated Luminosity of about 3000 fb-1 at 14 TeV center-of-mass energy. The ATLAS plans on how to follow these evolutions and optimize the detector performance at an optimum for new physics at all stages will be discussed.

Medical applications of particle accelerators

25.04.2012

Out of the almost 20,000 particle accelerators in operation worldwide, about half of them are used in the medical field. The seminar will review the two major applications in this domain: radionuclide production and cancer radiation therapy with electron, photons and hadron beams. The pros and cons of reactor versus cyclotron production of medical radionuclides will be illustrated, along with the possibility of accelerator production (using either electrons or protons) of the radionuclide most widely used in medical imaging, the 99^Mo/99^mTc generator, presently made at nuclear reactors. Cancer radiation therapy largely relies on electron linacs operating in the energy range 6-25 MeV: some of the most advanced treatment modalities of these "conventional" devices will be described. The state-of the-art is represented by radiation therapy with protons and carbon ions, which require cyclotrons or synchrotrons with energy up to 250 MeV and 400 MeV/u, respectively, and complex transport and irradiation systems. The lecture will close with a hint to future accelerator developments in this domain.

Exploring the Quark-Gluon Plasma with ALICE at the LHC

27.06.2012

A Large Ion Collider Experiment (ALICE) is the dedicated detector setup to study all aspects of heavy ion collisions at the LHC at CERN. It is assumed that in nucleus-nucleus collisions at high energies a high density de-confined state of strongly interacting matter, known as Quark-Gluon-Plasma (QGP), is created. ALICE is designed to measure a large set of observables in order to study the properties of this QGP, the form of matter believed to have existed in our Universe during the first microsecond after the Big Bang. The QGP is predicted by the fundamental theory of strong interactions (Quantum-Chromodynamics, QCD) and is characterized by an equilibrated system of liberated quarks and gluons that are the constituents of atomic nuclei. This talk will focus on a few selected results obtained with the ALICE experiment during the two long heavy ion runs at sqrt(s_NN) = 2.76 TeV, which took place at the end of 2010 and 2011.

Precision Cosmology

08.02.2012

I will give a brief introduction to the standard cosmological model, and discuss how precision measurements of the cosmic microwave background anisotropies and the large-scale structure distribution can be used to constrain fundamental physics.

Tomography of the Proton using Deeply Virtual Compton scattering to measure Generalized Parton Distributions at COMPASS-II at CERN

11.01.2012

One of the main open questions in the theory of strong interactions is to understand how the nucleon is built from quarks and gluons, the fundamental degrees of freedom in QCD. An essential tool to investigate the nucleon structure is the study of deep inelastic scattering processes where individual quarks and gluons are resolved. Parton density Functions (PDF) can be extracted from inclusive deep inelastic scattering. PDF describe the distribution of longitudinal momentum, where longitudinal refers to the direction of the fast moving nucleon in the centre of mass of the virtual photon - nucleon collision. Nevertheless they do not carry any information about the distribution of partons in the transverse plane. In this sense inclusive deep inelastic scattering provides us with a 1-dimensional image of the nucleon. In recent years it has become clear that much more detailed information, encoded in generalized parton distribution (GPD), can be obtained from hard exclusive processes such as deeply virtual Compton scattering (DVCS) and hard exclusive meson production (HEMP). GPD can be considered as momentum dissected form factors which provide information on the transverse localization of a parton as a function of the fraction it carries of the nucleon's longitudinal momentum. Obtaining such a '3 dimensional picture' of the nucleon is also referred to as 'nucleon tomography'. A lot of attention to these GPD arises due to their connection to the orbital angular momentum. This is a major part of the future COMPASS-II program using the high energy muon beams available at CERN which will be described.

Measurements of top-quark properties: Tevatron legacy and first LHC results

30.11.2011

The top-quark is by far the heaviest elementary particle and plays therefore a special role in the world of particle physics. Due to its high mass the top quark decays before hadrons can be formed, giving unique access to polarization and spin correlation effects. Loops involving top quarks lead to large higher order corrections, providing a strong link between the masses of the top-quark, the W boson and the yet "unknown" Higgs boson. The large Yukawa coupling may suggest that the top quark might play a special role in electroweak symmetry breaking. After the discovery of the top-quark at the Tevatron in 1995 an extended program to measure top-quark properties was launched during Tevatron Run II that lasted from 2002 to 2011. Now LHC experiments have taken over and have presented a first round of results on top-quark physics. The talk will start with a broad introduction on top-quark physics and proceed with a summary on the status of top-quark measurements at the Tevatron and the LHC. This includes production properties like top-antitop-pair cross section, single top cross sections, spin correlations, forward-backward asymmetry, as well as intrinsic and decay properties such as mass, width, branching ratio, and W polarization in top-quark decay.

Multi parton interactions in QCd

04.07.2012

Multiparton interactions in proton proton collisions can have important consequences on the hadronic final state at the LHC. Their description is currently based on simple intuitive models, whereas a rigorous formulation in QCD remains an outstanding task. In the seminar, I will present both the simplified picture and recent theoretical progress towards a rigorous description of multiparton interactions in QCD.

Search for new, exotic physics at the LHC

14.12.2011

After 20 years of construction, the Large Hadron Collider and its detectors started operating in 2010 and about 5 fb-1 of data have been recorded in 2011. Its main purpose is to study the structure of matter through collisions of protons with an unprecedented energy of 7 TeV, which is about 3.5 times higher than what has previously been achieved. In these highly energetic collision new particles and phenomena are predicted by a wealth of new theories and being searched for with two multipurpose detectors - ATLAS and CMS. Many theories have been suggested to extend the existing, successful Standard Model and need to be verified experimentally. Searches for new phenomena are performed in many different channels, with leptons, jets or photons in the final states to address their predictions. Can we find new particles? Maybe a forth family? Do elementary particles have a substructure and actually are not elementary? Do we see black holes or other signs of extra dimensions? In this talk I will be describing some selected results obtained so far.

Prospects for NNLO measurements using jets at the LHC

16.11.2011

In this talk I will discuss the need for higher order QCD calculations for multiparticle processes at the LHC. I review recent progress in computing the NLO and NNLO corrections to processes involving jets, and describe the sorts of measurements that can (and need to) be made in order to fully exploit the potential of the LHC.

Phenomenology of the minimal B-L extension of the SM

06.07.2011

In this talk I will review the results we obtained for the so-called B-L model, a minimal U(1) extension of the SM related to the Baryon minus Lepton charge. Three RH-neutrinos are required for the anomaly cancellation, thereby naturally providing neutrino masses through a dynamical implementation of the see-saw mechanism. This minimal extension also includes one new vector state (Z') and an additional Higgs boson. I will hence present the results of our investigation of the phenomenology of the new states, discussing in detail each sector and its consequences for collider searches. New interesting signatures arise: for instance, multilepton decays of the Z' boson and of the Higgs boson(s) as well as distinctive displaced vertices. The allowed parameter space and the present experimental constraints will also be discussed.

Exploring the Nature of Dark Matter with Direct Searches - A XENON Perspective

29.06.2011

Some 85% of all matter in the universe consists of non-baryonic cold Dark Matter. We observe its gravitational influence in large astrophysical systems ranging from galaxies to galaxy clusters to the universe as a whole. Dark Matter is the driving force for structure formation and dominated the evolution of the universe over most of its history. Dark Matter, together with Dark Energy, is our most solid evidence for physics beyond the Standard Model. Weakly Interacting Massive Particles (WIMPs), a thermal relic of the hot Big Bang, make up a generic class of well-motivated Dark Matter candidates. Direct searches seek to detect WIMPs through their interactions with atomic nuclei. This talk will provide an overview of the field, present recent results from XENON100 and other experiments, and discuss future prospects of experiments at the ton scale.

Unveiling the Mystery of Mass

13.04.2011

One of the prime reasons the Large Hadron Collider (LHC) was build is to resolve the question how particles acquire their mass. While it is very simple to measure particle masses and we have a model -- the Standard Model of Particle Physics -- which explains quite accurately all presently available measurements the seemingly trivial mechanism of how particle acquire their mass remains a mystery. The Standard Model invokes a new field the Higgs field to resolve this mystery but we have so far not been able to find experimental evidence for its existence. The LHC will soon resolve this mystery or.... we have to seriously reconsider the Standard Model. I will review what the available data and the Standard Model itself tell us about the Higgs boson and show the present status of the Tevatron searches. In the second part I will present the new first results from the CMS experiment and discuss the prospects of the Tevatron and the latest projections from the LHC.

CMS Analysis Results from 7 TeV proton-proton Collisions

17.11.2010

In 2010 the Large Hadron Collider (LHC) delivered proton-proton collisions at √s=7TeV for the first time, and several inverse picobarn of integrated luminosity were recorded and analyzed with the Compact Muon Solenoid (CMS) experiment. After a brief introduction to the CMS detector design, a selection of the most relevant reconstruction and performance topics are discussed. Finally, some important analysis results are reviewed, e.g. regarding the production of W and Z bosons which decay into leptons, and the first observation of top quark pairs.

Silicon detectors in Particle Physics

22.12.2010

Silicon Detectors have become the gold standard detector technology for precise particle tracking in High-Energy Physics experiments. All LHC experiments are built around a core of silicon tracking detectors. This talk briefly describes the functionality of semiconductor detectors and gives an overview of the historical evolution of semiconductor sensors in particle physics. It continues with describing today's state of the art detector technology, which forms the basis for the present LHC results and hopefully many discoveries to come. The talk then focusses on the latest R and D advances in radiation hardness technologies to ensure the availability of adequate silicon detectors for the LHC luminosity upgrade.

Automatic computation of 1-loop amplitudes for multiparticle production at colliders

09.02.2011

Unitarity inspired methods have been proven to be efficient techniques for the evaluation of 1-loop amplitudes for multiparticle production processes at colliders. I will mainly focus on the OPP method, and on the evaluation of the Cut-Constructible and the Rational contributions to 1-loop amplitudes. I will discuss the implementation in Monte Carlo event generators, in particular the HELAC code, and I will briefly sketch the present potentialities and limits of the HELAC-NLO system, together with possible further extensions.

SUSY predictions for the LHC

02.02.2011

We use currently available experimental data to determine the preferred Supersymmetry and Higgs boson mass scales. The data comprises electroweak precision observables such as the W boson mass and the anomalous magnetic moment of the muon, B physics observables such as BR(b → s gamma), as well as the cold dark matter density in the universe. Within two GUT based realizations of the MSSM the preferred masses for SUSY particles as well as for the MSSM Higgs bosons are derived. We find a clear preference for relatively light SUSY masses. The preferred mass values can directly be compared to the reach of the Tevatron, the LHC and the ILC.

Looping through Monte Carlo

09.02.2011

In this talk principles underlying the construction of parton shower Monte Carlo programs are reviewed. The successive improvement of their accuracy by means of exact matrix elements at leading and next-to leading order is discussed, before the connection to other parts of the simulation is made.

Tools for One-Loop Calculations

Special Seminar, 3.3.2010

The main collider experiments currently running are hadron colliders where the most dominant reactions are due to the strong interaction. Any predictions for these experiments therefore have to account for the fact that cross-sections calculated in QCD suffer from large renormalisation scale uncertainties and often it is inevitable to calculate the observables beyond leading order for processes with three and more final state particles. Part of the scattering amplitude at next-to-leading order are the virtual corrections consisting of Feynman diagrams with one loop.

I discuss tools and techniques to automatise such computations and present the GOLEM method for one-loop calculations. This method is based on Feynman diagrams and the semi-numerical reduction of one-loop tensor integrals. A general matrix element generator for one-loop amplitudes is currently being developed in this framework and has led to results which I present in the last part of this talk.

QCD Matrix Elements and Truncated Showers

Seminar, 8.4.2009

A realistic theoretical modelling of multijet final states in collider experiments is crucial for our understanding of this interesting class of experimental signatures. I will discuss the approach of combining QCD matrix elements with parton shower simulations -- used by modern Monte Carlo event generators. I will present recent theoretical achievements to reduce and systematise the uncertainties inherent in these calculations. As practical example I will discuss weak gauge boson production both in the Drell-Yan and the vector-boson-fusion channel.

s Channel Production of Heavy Vector Bosons in the Three-Site Higgsless Model

Sonderseminar, 8.4.2009

The Three-Site Higgsless model is an interesting example of higgsless BSM model building in which unitarity of scattering amplitudes is maintained by additional heavy vector bosons. The couplings between these and the standard model fermions are very small and strongly constrained by electroweak precision observables. I investigate the possibility of producing these heavy vectors in the $s$ channel at the LHC.

One-Loop Electroweak Analysis of (S)Top Production Processes at LHC

Sonderseminar, 29.7.2009

A thorough analysis of third family (s)particles will soon be performed at the LHC. Since the LHC will produce top quarks with high statistics, this particle will extensively be exploited for new physics searches. On the other hand, the supersymmetric partner of the top quark, the stop squark, is predicted to have a sufficiently low mass to be produced and detected at the LHC. Providing experimentalists with precise predictions on observables related to meaningful top and stop production processes is therefore mandatory. In this talk the one-loop electroweak corrections to two processes of production of top and stop at the LHC, namely PP→ tH- and PP→ stop chi-, will be analysed.

Combining electroweak and QCD corrections to single W production at hadron colliders

Sonderseminar, 29.7.2009

Single W production is a process of relevant physical interest at hadron colliders, since it should be used to perform precise measurements of the electroweak parameters, to constrain PDFs, for monitoring the luminosity and calibrating the detectors. Furthermore, it provides a background to new physics signals. Precision studies of this process require that electroweak and QCD higher-order contributions are simultaneously taken into account in theoretical predictions and data analysis. Therefore, a phenomenological study of both of them, as well as of their combination by means of a proper theoretical recipe, is presented, with emphasys on the relevant observables for the Tevatron and LHC physics programme.

Proton Spin Structure and Spin-Dependent Effects in Quark Fragmentation

Seminar, 24.06.2009

The Collins effect in hadron fragmentation describes a correlation between the transverse spin of the initial quark and the orbital angular momentum of final state hadrons. We present measurements of the Collins effect in electron-positron annihilation at KEKB using the Belle detector and show how this measurements can be used to determine the quark transversity distributions of the proton.

Seminar, 15.10.2008

In LHC experiments, a precise measurement of the radiation dose at various detector locations is crucial. In ATLAS, this task is performed by a set of radiation monitors (RADMON) which are able to record Non-Ionising Energy Loss (NIEL), the Total Ionizing Dose (TID) and measure fluences of thermal neutrons. These measurements are vital for understanding the changes in detector performance during ATLAS operation, verifying simulations and optimising the operation scenario. The RADMONs are multi-sensor boards, containing several RADFETs, diodes and DMILL transistors.

The LHC Machine

Seminar, 29.10.2008

The LHC machine was recently completed and commissioning with beams started. The large project and some of its main challenges will be reviewed. The talk will then focus on the first observations with beams in the LHC, the current status, further commissioning plans and end with a short outlook into longer term perspectives.

Expected performances of ATLAS and CMS experiments at the LHC

Seminar, 12.11.2008

After a short historical introduction to put into perspective the scope of the LHC experiment endeavour, the talk will focus on the major design choices made for the ATLAS and CMS experiments. Now that the detectors are installed and commissioned ten-fifteen years after these choices were made, it is interesting to review the performances expected in terms of reconstruction and identification of the basic physics objects of interest (tracks, electrons, photons, muons, tau- leptons, jets, ETmiss).

Luminosity Measurements in ATLAS

Seminar, 26.11.2008

Different methods to determine the luminosity for the ATLAS experiment at the LHC will be discussed. Physics processes with a potential to be used for absolute luminosity determination will be discussed. The option of using accelerator parameters to calculate the luminosity will also be addressed. ATLAS Forward Detectors to be used for absolute luminosity determination as well as a detector for relative luminosity measurement will be described. The expected precision in different methods will be evaluated.

Lectures:

SS 2011

Glen Cowan (Royal Holloway, University of London):Statistical tests for discovery and setting limits in HEP

The series of lectures will cover the statistical methods used in searches for new phenomena in a particle physics experiment. Statistical tests will be formally defined and used to quantify the level of agreement between a specified model and the observed data. Specifically, one tries to reject the Standard Model in such a test, as this will indicate the discovery of something new. Even in the absence of a discovery, we would like to say what possible signal models one may exclude by setting limits on their parameters. Several procedures for doing this will be discussed, including CLs, Power-Constrained Limits (PCL), Bayesian, and Feldman-Cousins methods. The lectures will focus on frequentist methods, but the Bayesian approach will be addressed as well. In both cases the role of systematic uncertainties will be emphasized. Computer tutorials will provide a practical exposure to the procedures covered in the lectures.

Date Lecture Exercises
27.6. 8:00-10:00 (HS II, HH Physik) in the afternoon, time t.b.a., in the CIP-POOL
28.6. 9:00-12:00 (Großer Hörsaal, Physikalisches Institut) in the afternoon, time t.b.a., in the CIP-POOL
29.6. 8:00-10:00 (HS II, HH Physik)

WS 2010/11

James Stirling: Lectures on QCD at the LHC
Herbert Dreiner: Introduction to Supersymmetry
Frank Steffen: Dark Matter

Abstract

SS 2009

Helge Voss (MPI-K, Heidelberg):Multivariate Data Analysis and Machine Learning in High Energy Physics

Multivariate classification and regression techniques are becoming increasingly important for high energy physics experiments with ever larger data samples allowing to assess events with ever smaller cross section. This lecture will explain the basic principles of machine learning and introduce the most common multivariate statistical methods. The behaviour of the individual classifiers is demonstrated using example applications. During the accompanying exercises, the TMVA program package is used in order to gain hands on experience in the proper training and evaluation of various classifiers.

To find the locations: See here

Date Lecture Exercises
11.5. 9:30-10:30 (HS6 in Hermann-Herder-Str. 6) [pdf] 15:00 -17:00 in the CIP-POOL [pdf]
12.5. 9:30-10:30 (HS6 in Hermann-Herder-Str. 6) [pdf] 16:00 -18:00 in the CIP-POOL [pdf]
13.5. 9:30-10:30 (HS6 in Hermann-Herder-Str. 6) [pdf] 15:00 -17:00 in the CIP-POOL
14.5. 9:30-10:30 (HS in the Weismann-Haus) [pdf] 16:00 -18:00 in the CIP-POOL
15.5. 9:30-10:30 (HS in the Weismann-Haus) [pdf] 14:00 -16:00 in the CIP-POOL

WS 2008/09

You should also take a look at the following links :

Lectures from previous semesters can be found here.