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Jet production in higher orders of perturbation theory

English title Jet production in higher orders of perturbation theory
Applicant Gehrmann Thomas
Number 149517
Funding scheme Project funding
Research institution Institut für Theoretische Physik Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Particle Physics
Start/End 01.10.2013 - 30.09.2015
Approved amount 530'000.00
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Keywords (4)

Quantum field theory; Perturbation theory; Elementary particles; Collider physics

Lay Summary (German)

Lead
Die Produktion hochenergetischer Teilchenjets gehoert zu den wichtigsten Beobachtungsgroessen in der Elementarteilchenphysik. Diese Messungen erlauben die Bestimmung fundamentaler Parameter der Teilchenphysik. Unser Projekt zielt auf die Entwicklung theoretischer Methoden fuer eine praezise Beschreibung von Jet-Observablen, und deren Anwendung auf experimentell wichtige Prozesse.
Lay summary

Die theoretische Beschreibung von Jet-Observablen war bis vor kurzem nur in der naechstfuehrenden Ordnung der Stoerungstheorie moeglich; die daraus resultierende theoretische Unsicherheit war nicht ausreichend um Praezisionsdaten zuverlaessig interpretieren zu koennen. Dieses Projekt wird neue Methoden zur Berechnung von Jet-Observablen entwickeln und anwenden. Die Berechnung hoeherer Ordnungen in der Stoerungstheorie erfolgt ueber die Bestimmung aller feldtheoretischen Beitraege, die zu einer vorgegebenen Observablen beitragen. Nach geeigneter Bearbeitung koennen diese Beitraege in ein flexibles numerisches Programm, einen sogenannten Parton-Level Event Generator, implementiert werden. In diesem Projekt bearbeiten wir folgende Fragestellungen: (a) Entwicklung von Parton-Level Event Generator Programmen fuer Jet-Produktion und Higgs-plus-Jet Produktion am CERN LHC; (b) Berechnung von Massenkorrekturen zur Higgs-plus-Jet Produktion; (c) vorbereitende Studien zur Berechnung von Zwei-Schleifen-Korrekturen zu 2->3 Prozessen; (d) Entwicklung moderner Programme zur Event-Simuation und Verbesserungen der zugrundeliegenden Formalismen. 

 

Direct link to Lay Summary Last update: 03.10.2013

Lay Summary (English)

Lead
Jet cross sections and multi-particle production are among the most important observables studied at current and future experiments in high energy physics. Their measurement enables the determination of fundamental parameters of the theory of strong interactions. This project aims to develop the theoretical tools for a precise description of jet observables, and to apply these to several processes of high relevance to experimental studies.
Lay summary

The theoretical description of jet observables was up to very recently restricted to the next-to-leading order in perturbation theory; the resulting theoretical uncertainty is by now insufficient to match the current experimental precision. The proposed project aims to develop new methods for the calculation of jet and multi-particle cross sections in higher orders of perturbation theory, and to apply these methods in actual computations. The computation of higher orders in perturbation theory goes through the evaluation of all field theoretic subprocesses contributing to the observable under consideration. After suitable rearrangement, it is possible to add together different subprocesses in order to obtain predictions for experimentally measured jet observables, which is made using a flexible numerical programme, a so-called parton level event generator. The project proposed here aims to contribute to the following aspects of precision physics at high energy particle colliders: (a) development of NNLO parton-level event generator programs for jet production and for Higgs-boson-plus-jet production in hadron-hadron collisions; (b) computation of mass corrections in Higgs-boson-plus-jet production to NLO; (c) preparatory studies towards two-loop QCD corrections to 2 -> 3 scattering processes; (d) development of modern event simulation programs for multi-particle final states and improvements to the parton shower formalism.

Direct link to Lay Summary Last update: 03.10.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Precise QCD predictions for the production of a Z boson in association with a hadronic jet
Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Huss A., Morgan T. A. (2016), Precise QCD predictions for the production of a Z boson in association with a hadronic jet, in Phys. Rev. Lett., 117(2), 022001-022001.
Higgs boson gluon-fusion production beyond threshold in N$^{3}$LO QCD
Anastasiou Charalampos, Duhr Claude, Dulat Falko, Furlan Elisabetta, Gehrmann Thomas, Herzog Franz, Mistlberger Bernhard (2015), Higgs boson gluon-fusion production beyond threshold in N$^{3}$LO QCD, in JHEP, 03, 091-091.
Higgs production in association with bottom quarks
Wiesemann M., Frederix R., Frixione S., Hirschi V., Maltoni F., Torrielli P. (2015), Higgs production in association with bottom quarks, in JHEP, 02, 132-132.
Precise QCD predictions for the production of Higgs + jet final states
Chen X., Gehrmann T., Glover E. W. N., Jaquier M. (2015), Precise QCD predictions for the production of Higgs + jet final states, in Phys. Lett., B740, 147-150.
The rare decay $H\to Zγ$ in perturbative QCD
Gehrmann Thomas, Guns Sam, Kara Dominik (2015), The rare decay $H\to Zγ$ in perturbative QCD, in JHEP, 09, 038-038.
The two-loop helicity amplitudes for $ qøverlineq^{\prime}\to V_1V_2\to 4 $ leptons
Gehrmann Thomas, von Manteuffel Andreas, Tancredi Lorenzo (2015), The two-loop helicity amplitudes for $ qøverlineq^{\prime}\to V_1V_2\to 4 $ leptons, in JHEP, 09, 128-128.
Two-loop splitting amplitudes and the single-real contribution to inclusive Higgs production at N$^3$LO
Duhr Claude, Gehrmann Thomas, Jaquier Matthieu (2015), Two-loop splitting amplitudes and the single-real contribution to inclusive Higgs production at N$^3$LO, in JHEP, 02, 077-077.
$W^+W^-$ Production at Hadron Colliders in Next to Next to Leading Order QCD
Gehrmann T., Grazzini M., Kallweit S., Maierhöfer P., von Manteuffel A., Pozzorini S., Rathlev D., Tancredi L. (2014), $W^+W^-$ Production at Hadron Colliders in Next to Next to Leading Order QCD, in Phys. Rev. Lett., 113(21), 212001-212001.
BLM Scale Fixing in Event Shape Distributions
Gehrmann Thomas, Häfliger Niklaus, Monni Pier Francesco (2014), BLM Scale Fixing in Event Shape Distributions, in Eur. Phys. J., C74(6), 2896-2896.
EERAD3: Event shapes and jet rates in electron-positron annihilation at order $α_s^3$
Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Heinrich G. (2014), EERAD3: Event shapes and jet rates in electron-positron annihilation at order $α_s^3$, in Comput. Phys. Commun., 185, 3331-3331.
Higgs boson gluon–fusion production at threshold in N$^3$LO QCD
Anastasiou Charalampos, Duhr Claude, Dulat Falko, Furlan Elisabetta, Gehrmann Thomas, Herzog Franz, Mistlberger Bernhard (2014), Higgs boson gluon–fusion production at threshold in N$^3$LO QCD, in Phys. Lett., B737, 325-328.
Higgs Boson pair production merged to one jet
Maierhöfer Philipp, Papaefstathiou Andreas (2014), Higgs Boson pair production merged to one jet, in JHEP, 03, 126-126.
Higgs boson to di-tau channel in Chargino-Neutralino searches at the LHC
Papaefstathiou Andreas, Sakurai Kazuki, Takeuchi Michihisa (2014), Higgs boson to di-tau channel in Chargino-Neutralino searches at the LHC, in JHEP, 08, 176-176.
Higgs pair production at the LHC with NLO and parton-shower effects
Frederix R., Frixione S., Hirschi V., Maltoni F., Mattelaer O., Torrielli P., Vryonidou E., Zaro M. (2014), Higgs pair production at the LHC with NLO and parton-shower effects, in Phys. Lett., B732, 142-149.
QCD and High Energy Interactions: Moriond 2014 Theory Summary
Auge Etienne (ed.) (2014), QCD and High Energy Interactions: Moriond 2014 Theory Summary, Editions Arisf, Merignac.
Second order QCD corrections to gluonic jet production at hadron colliders
Currie James, Gehrmann-De Ridder Aude, Gehrmann Thomas, Glover Nigel, Pires Joao, Wells Steven (2014), Second order QCD corrections to gluonic jet production at hadron colliders, in PoS, LL2014, 001-001.
Standard model Higgs boson pair production in the ( $ bøverlineb $ )( $ bøverlineb $ ) final state
Ferreira de Lima Danilo Enoque, Papaefstathiou Andreas, Spannowsky Michael (2014), Standard model Higgs boson pair production in the ( $ bøverlineb $ )( $ bøverlineb $ ) final state, in JHEP, 08, 030-030.
The $Hb\barb$ form factor to three loops in QCD
Gehrmann Thomas, Kara Dominik (2014), The $Hb\barb$ form factor to three loops in QCD, in JHEP, 09, 174-174.
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
Alwall J., Frederix R., Frixione S., Hirschi V., Maltoni F., Mattelaer O., Shao H. -S., Stelzer T., Torrielli P., Zaro M. (2014), The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations, in JHEP, 07, 079-079.
The two-loop master integrals for $qøverlineq \to VV$
Gehrmann Thomas, von Manteuffel Andreas, Tancredi Lorenzo, Weihs Erich (2014), The two-loop master integrals for $qøverlineq \to VV$, in JHEP, 06, 032-032.
ZZ production at hadron colliders in NNLO QCD
Cascioli F., Gehrmann T., Grazzini M., Kallweit S., Maierhöfer P., von Manteuffel A., Pozzorini S., Rathlev D., Tancredi L., Weihs E. (2014), ZZ production at hadron colliders in NNLO QCD, in Phys. Lett., B735, 311-313.

Collaboration

Group / person Country
Types of collaboration
Prof. S. Frixione, EPF Lausanne Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. E.W.N. Glover, Univ. Durham Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Prof. F. Maltoni, Univ. Louvain Belgium (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Prof. A. Gehrmann-De Ridder, ETH Zuerich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Dr. R. Bonciani, Univ. Roma Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
QCD@LHC 2015 Talk given at a conference Five-point two-loop master integrals in QCD 01.09.2015 London, Great Britain and Northern Ireland Lo Presti Nicola Adriano;
QCD@LHC 2015 Talk given at a conference Theory Summary 01.09.2015 London, Great Britain and Northern Ireland Gehrmann Thomas;
RADCOR 2015 Talk given at a conference Two-loop corrections to H->Z gamma 15.06.2015 Los Angeles, United States of America Kara Dominik;
RADCOR 2015 Talk given at a conference Higgs plus jet production at NNLO 15.06.2015 Los Angeles, United States of America Jaquier Matthieu;
Higgs plus jets workshop Talk given at a conference Towards H+jet at NNLO 08.12.2014 Durham, Great Britain and Northern Ireland Jaquier Matthieu;
Workshop on physics with HERA data Talk given at a conference NNLO corrections to dijet production in DIS 10.11.2014 Hamburg, Germany Gehrmann Thomas;
SFB Transregio Workshop Talk given at a conference Precision calculations for hadron collider observables 15.09.2014 Karlsruhe, Germany Gehrmann Thomas;
LHCPhenoNet Summer School Talk given at a conference Lectures on Antenna Subtraction 20.06.2014 Debrecen, Hungary Gehrmann Thomas;
Kolloquium Karlsruhe Individual talk Methods for multi-loop calculations 13.06.2014 Karlsruhe, Germany Tancredi Lorenzo;
TASI 2014 Summer School Talk given at a conference Lectures on 'Introduction to QCD' 02.06.2014 Boulder, United States of America Gehrmann Thomas;
New frontiers in theoretical physics Talk given at a conference Schouten identities and the two-loop sunrise graph 01.06.2014 Cortona, Italy Tancredi Lorenzo;
Loops and Legs 2014 Talk given at a conference Schouten identities and the two-loop sunrise graph 28.04.2014 Weimar, Germany Tancredi Lorenzo;
Moriond 2014: QCD and high energy interactions Talk given at a conference Theory Summary 24.03.2014 La Thuile, Italy Gehrmann Thomas;
Indian school on analytic computing Talk given at a conference Lectures on Methods for multi-loop calculations 05.03.2014 Bhubaneswar, India Tancredi Lorenzo;
Kolloquium U. Roma I (La Sapienza) Individual talk Precision physics with jet observables 27.01.2014 Rom, Italy Gehrmann Thomas;
Annual Theory Meeting (Rutherford Christmas Lectures) Talk given at a conference Status of QCD 15.12.2013 Durham, Great Britain and Northern Ireland Gehrmann Thomas;
ERC miniworkshop Talk given at a conference Status of parton showers at NLO 03.12.2013 CERN, Switzerland Torrielli Paolo;
NIKHEF Kolloquium Individual talk Precision physics with jet observables 17.10.2013 Amsterdam, Netherlands Gehrmann Thomas;
Kolloquium Bologna Individual talk Progress in Feynman graph computations 07.10.2013 Bologna, Italy Tancredi Lorenzo;


Associated projects

Number Title Start Funding scheme
138206 Jet production in higher orders of perturbation theory 01.10.2011 Project funding
141847 Particle Physics with high-quality data from the CERN LHC 01.10.2012 Sinergia
162487 Jet production in higher orders of perturbation theory 01.10.2015 Project funding
160814 Particle Physics with high-quality data from the CERN LHC 01.10.2015 Sinergia
135101 Two-loop corrections to vector boson pair production at CERN LHC 01.04.2011 ProDoc

Abstract

Jet cross sections and multi-particle production are among the most important observables studied at current and future experiments in high energy physics. Their measurement enables the determination of fundamental parameters of the theory of strong interactions. The theoretical description of these observables was up to very recently restricted to the next-to-leading order in perturbation theory; the resulting theoretical uncertainty is by now insufficient to match the current experimental precision. The proposed project aims to develop new methods for the calculation of jet and multi-particle cross sections in higher orders of perturbation theory, and to apply these methods in actual computations. The computation of higher orders in perturbation theory goes through the evaluation of all field theoretic subprocesses contributing to the observable under consideration. Although the sum of all these subprocesses yields a finite result for suitably defined observables, individual subprocesses contain infinities due to the exchange of low-momentum particles (infrared singularities) or high-momentum particles (ultraviolet singularities). In general, the presence of these singularities forbids a direct numerical evaluation of higher order corrections. To compute jet observables in higher perturbative orders, one has to devise procedures to analytically extract especially the infrared singularities from each subprocess. Only after carrying out this infrared separation, it is possible to add together different subprocesses in order to obtain predictions for experimentally measured jet observables, which is made using a flexible numerical programme, a so-called parton level event generator. The current state of the art in the theoretical description of jet observables are calculations to the next-to-leading order (NLO) in perturbation theory. Calculations of jet observables at NNLO are at present available only for three-jet production in electron-positron collisions. Proof-of-principle implementations of NNLO corrections for jet observables at hadron colliders have been performed most recently. The project proposed here aims to contribute to the following aspects of precision physics at high energy particle colliders: (a) development of NNLO parton-level event generator programs for jet production and for Higgs-boson-plus-jet production in hadron-hadron collisions; (b) computation of mass corrections in Higgs-boson-plus-jet production to NLO; (c) preparatory studies towards two-loop QCD corrections to 2 -> 3 scattering processes; (d) development of modern event simulation programs for multi-particle final states and improvements to the parton shower formalism.
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