Quantum field theory; Elementary particles; Collider physics; Perturbation theory
Currie James, Gehrmann-De Ridder Aude, Gehrmann Thomas, Glover E. W. N., Huss Alexander, Pires Joao (2017), Precise predictions for dijet production at the LHC, in
Phys. Rev. Lett., (15), 152001.
Andreev V., others (2017), Determination of the strong coupling constant $α_s(M_Z)$ in next-to-next-to-leading order QCD using H1 jet cross section measurements, in
Eur.Phys.J. C, 77, 791.
de Florian Daniel et al. (376 authors), Gehrmann Thomas, Karlberg Alexander (2017),
Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector, CERN, Geneva.
Gehrmann Thomas, Glover Nigel, Huss Alexander, Niehues Jan, Zhang Hantian (2017), NNLO QCD corrections to event orientation in e+e- annihilation, in
Phys. Lett. B, 775, 185.
Currie James, Gehrmann Thomas, Huss Alexander, Niehues Jan (2017), NNLO QCD corrections to jet production in deep inelastic scattering, in
JHEP, 018-018.
Gauld R., Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Huss A. (2017), Precise predictions for the angular coefficients in Z-boson production at the LHC, in
JHEP, 11, 003.
Gehrmann Thomas, Luisoni Gionata, Monni Pier Francesco (2017), Resummation of jet rates and event-shape distributions in $e^+ e^−$, in
Proceedings, Parton Radiation and Fragmentation from LHC to FCC-ee: CERN, Geneva, Switzerland, Novem, 97-102, CERN, Geneva97-102.
Currie James, Glover E. W. N., Gehrmann Thomas, Gehrmann-De Ridder Aude, Huss Alexander, Pires Joao (2017), Single Jet Inclusive Production for the Individual Jet $p_{\rm T}$ Scale Choice at the LHC, in
Proceedings, 23rd Cracow Epiphany Conference on Particle Theory Meets the First Data from LHC Run 2:, 955-967, Acta Physica Polonica, Cracow955-967.
Mangano M. et al (76 authors), Cieri Leandro, Karlberg Alexander (2017), Standard Model processes, in Mangano M. (ed.), CERN, Geneva, 1.
Bernreuther Werner, Chen Long, Dekkers Oliver, Gehrmann Thomas, Heisler Dennis (2017), The forward-backward asymmetry for massive bottom quarks at the $Z$ peak at next-to-next-to-leading order QCD, in
JHEP, 053-053.
Cieri Leandro, Coradeschi Francesco, de Florian Daniel, Fidanza Nerina (2017), Transverse-momentum resummation for the signal-background interference in the H→γγ channel at the LHC, in
Phys. Rev., (5), 054003-054003.
Gehrmann T., Henn J. M., Lo Presti N. A. (2016), Erratum: Analytic Form of the Two-Loop Planar Five-Gluon All-Plus-Helicity Amplitude in QCD [Phys. Rev. Lett. 116 , 062001 (2016)], in
Physical Review Letters, 116(18), 189903-189903.
Gehrmann Thomas (2016), Advances in QCD predictions, in
Proceedings, 24th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2016, 003-003, PoS, Trieste003-003.
Gehrmann T., Henn J. M., Lo Presti N. A. (2016), Analytic form of the two-loop planar five-gluon all-plus-helicity amplitude in QCD, in
Phys. Rev. Lett., (6), 062001-062001.
Anastasiou Charalampos, Duhr Claude, Dulat Falko, Furlan Elisabetta, Gehrmann Thomas, Herzog Franz, Lazopoulos Achilleas, Mistlberger Bernhard (2016), CP-even scalar boson production via gluon fusion at the LHC, in
JHEP, 037-037.
Almasy A. A., Lo Presti N. A., Vogt A. (2016), Generalized threshold resummation in inclusive DIS and semi-inclusive electron-positron annihilation, in
JHEP, 028-028.
Chen Xuan, Gehrmann Thomas, Glover Nigel, Jaquier Matthieu (2016), Higgs plus one jet production at NNLO, in
Proceedings, 12th International Symposium on Radiative Corrections (Radcor 2015) and LoopFest XIV (R, 056-056, PoS, Trieste056-056.
Anastasiou Charalampos, Duhr Claude, Dulat Falko, Furlan Elisabetta, Gehrmann Thomas, Herzog Franz, Lazopoulos Achilleas, Mistlberger Bernhard (2016), High precision determination of the gluon fusion Higgs boson cross-section at the LHC, in
JHEP, 058-058.
Niehues Jan, Currie James, Gehrmann Thomas (2016), NNLO dijet production in DIS with the antenna subtraction method, in
Proceedings, 13th DESY Workshop on Elementary Particle Physics: Loops and Legs in Quantum Field Theo, 055-055, PoS, Trieste055-055.
Gehrmann-De Ridder Aude, Gehrmann Thomas, Glover Nigel, Huss Alexander, Morgan Thomas A. (2016), NNLO QCD corrections for $Z$ boson plus jet production, in
Proceedings, 12th International Symposium on Radiative Corrections (Radcor 2015) and LoopFest XIV (R, 075-075, PoS, Trieste075-075.
Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Huss A., Morgan T. A. (2016), NNLO QCD corrections for Drell-Yan $p_T^Z$ and $ϕ^*$ observables at the LHC, in
JHEP, 094-094.
Chen X., Cruz-Martinez J., Gehrmann T., Glover E. W. N., Jaquier M. (2016), NNLO QCD corrections to Higgs boson production at large transverse momentum, in
JHEP, 066-066.
Currie James, Gehrmann Thomas, Niehues Jan (2016), Precise QCD predictions for the production of dijet final states in deep inelastic scattering, in
Phys. Rev. Lett., (4), 042001-042001.
Gehrmann-De Ridder Aude, Gehrmann T., Glover E. W. N., Huss A., Morgan T. A. (2016), The NNLO QCD corrections to Z boson production at large transverse momentum, in
JHEP, 133-133.
Lo Presti Nicola Adriano, Gehrmann Thomas, Henn Johannes (2016), Two-loop five-point integrals in massless QCD, in
Proceedings, 13th DESY Workshop on Elementary Particle Physics: Loops and Legs in Quantum Field Theo, 051-051, PoS, Trieste051-051.
Tancredi Lorenzo, Gehrmann Thomas, von Manteuffel Andreas (2016), Two-loop QCD corrections to vector boson pair production at the LHC, in
Proceedings, 12th International Symposium on Radiative Corrections (Radcor 2015) and LoopFest XIV (R, 025-025, PoS, Trieste025-025.
Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Huss Alexander, Morgan T. A. (2016), Z+jet production at NNLO, in
Proceedings, 38th International Conference on High Energy Physics (ICHEP 2016): Chicago, IL, USA, Au, 594-594, PoS, Trieste594-594.
Gehrmann-De Ridder A., Gehrmann T., Glover E. W. N., Huss A., Morgan T. A. (2016), Z+jet production at NNLO, in
Proceedings, 13th DESY Workshop on Elementary Particle Physics: Loops and Legs in Quantum Field Theo, 056-056, PoS, Trieste056-056.
Ahmed Taushif, Gehrmann Thomas, Mathews Prakash, Rana Narayan, Ravindran V. (2015), Pseudo-scalar Form Factors at Three Loops in QCD, in
JHEP, 169-169.
Kara Dominik (2015), The rare decay $H \rightarrow Z gamma$ in perturbative QCD, in
Proceedings, 12th International Symposium on Radiative Corrections (Radcor 2015) and LoopFest XIV (R, 010-010, PoS, Trieste010-010.
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 Standard Model theory of particle physics. The theoretical description of these observables is usually 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 and automate 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 devises 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 various jet observables at hadron colliders have been performed recently. The project proposed here aims to contribute to the following aspects of precision physics at high energy particle colliders: (a) development of a framework for the automated generation of code components for NNLO parton-level event generator programs; (b) application of these tools to the calculation of NNLO corrections to jet production in hadron-hadron collisions and di-jet production in deep inelastic scattering; (c) computation of mass corrections in Higgs-boson-plus-jet production to NLO; (d) computation of the two-loop QCD corrections to 2->3 massless parton scattering processes; (e) development of a new method for the calculation of multi-loop multi-scale integrals.