QCD@LHC 2018

Session

Perturbative QCD, jets and substructure

27 Aug 2018, 14:30

POT/81 (TU Dresden)

102. Analytic calculation of multi-loop Feynman integrals

Stefano Di Vita (Università degli Studi e INFN Milano (IT))

27/08/2018, 14:30

Perturbative QCD, Jets and Substructure

Multi-loop Feynman integrals represent an essential building block for the precision physics program at high-energy colliders and beyond. In my talk I will review recent developments concerning their evaluation with the method of differential equations, giving particular emphasis to the so-called canonical form and presenting some examples of phenomenological interest.

79. Differential Equations for Feynman Integrals

Ulrich Schubert (Argonne National Laboratory)

27/08/2018, 15:00

Perturbative QCD, Jets and Substructure

The calculation of Feynman Integrals is one of bottlenecks for precision calculations at Next-to-Next-to-leading order and beyond. Differential Equations have proven to be a powerful tool to relieve this bottleneck and have seen a rapid development in the last years. In this talk I will review these recent developments especially focusing on the so-called canonical form. I will present the...

71. Systematic approximation of multi-scale Feynman integrals

Mr Daniel Hulme (UZH)

27/08/2018, 15:30

Perturbative QCD, Jets and Substructure

Abstract: An algorithm for the systematic analytical approximation of multi-scale Feyn-
man integrals will be discussed. The algorithm produces algebraic expressions as functions of
the kinematical parameters and mass scales appearing in the Feynman integrals, allowing
for fast numerical evaluation. The results are valid in all kinematical regions, both above
and below thresholds, up to in...

74. Precise predictions for diboson processes

Marius Wiesemann (CERN)

27/08/2018, 16:30

Perturbative QCD, Jets and Substructure

I will review recent theory developments for diboson production at the LHC within the puclicly available code MATRIX: With the two lepton plus two neutrino channels, which mix ZZ and WW production, NNLO corrections have been completed to all experimentally relevant leptonic final states for diboson processes. NLO corrections to the loop-induced gg channel are formally of N3LO accuracy, but...

54. Tests of the Gauge Structure of the Electroweak Sector with ATLAS

Jonathan Crane (University of Manchester (GB))

27/08/2018, 17:00

Perturbative QCD, Jets and Substructure

Measurements of the cross sections of the production of two or three electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. Such studies can be complemented by measurements of vector boson fusion or vector boson scattering processes with one or two gauge...

22. Prospects for a measurement of the W boson mass in the all-jets final state at hadron colliders

Andreas Hinzmann (Hamburg University (DE))

27/08/2018, 17:30

Perturbative QCD, Jets and Substructure

Precise measurements of the mass of the W boson are important to test the overall consistency of the Standard Model of particle physics. The current best measurements of the W boson mass come from single production measurements at hadron colliders in its decay mode to a lepton (electron or muon) and a neutrino and pair production of W bosons at lepton colliders, where also the decay mode of...

9. Two-loop five-gluon helicity amplitudes in QCD via integrand reduction

Heribertus Bayu Hartanto (Durham University)

28/08/2018, 14:30

Perturbative QCD, Jets and Substructure

I will present a calculation of the leading-colour five-gluon amplitude at two loop in QCD. The calculation is performed by means of D-dimensional integrand reduction method, complemented with the finite-field reconstruction techniques and momentum twistor parameterization. Numerical results for all helicity configurations are obtained by employing both sector decomposition methods and IBP...

17. Jet(s) with the CoLoRFulNNLO framework

Adam Kardos (University of Debrecen)

28/08/2018, 15:00

Perturbative QCD, Jets and Substructure

We observe more and more advances in the technology of multiloop calculations.
Hence it is of utmost importance to develope computational frameworks which
can tackle the computational burden presented by the regularization
of up to two unresolved parton emissions coming from the matrix elements.
CoLoRFulNNLO is such a framework built around local subtractions
derived from first principles. In...

5. Differential jet cross sections at the CMS experiment

Mr Suman Chatterjee (Tata Inst. of Fundamental Research (IN))

28/08/2018, 15:30

Perturbative QCD, Jets and Substructure

We present measurements of differential jet cross sections over a wide range in transverse momenta from inclusive jets to multi-jet final states. Studies on the impact that these measurements have on the determination of the strong coupling alpha_s as well as on parton density functions are reported.

78. N3LO QCD DIS Single-jet production and NNLO QCD e^+e^- event orientation with NNLOJET

Jan Niehues

28/08/2018, 16:30

Perturbative QCD, Jets and Substructure

In this talk, recent results on the calculation of fully differential single-jet production in neutral current deep inelastic scattering at next-to-next-to-next-to leading order (N3LO) in the strong coupling are presented. The results are obtained by the combination of antenna subtraction at next-to-next-to leading order (NNLO) with the method of projection to born. Details of the combination...

73. Groomed jet substructure observables for inclusive jet production

Felix Ringer (Lawrence Berkeley National Laboratory)

28/08/2018, 17:00

Perturbative QCD, Jets and Substructure

The phenomenology of highly energetic jets and their substructure plays an important role for the physics program at the LHC. In recent years various grooming techniques have been proposed that need to be included consistently in perturbative calculations. Within Soft Collinear Effective Theory (SCET) we establish factorization theorems for jet substructure observables measured on an inclusive...

70. Jet energy scale and jet substructure performance in CMS

Robin Cameron Aggleton (Hamburg University (DE))

28/08/2018, 17:30

Perturbative QCD, Jets and Substructure

Jets are the experimental signature of energetic quarks and gluons produced in high energy processes. A detailed understanding of both the energy scale and the transverse momentum resolution of jets is of crucial importance for the analysis of perturbative QCD processes. In addition, the substructure, shape and mass of jets is an important tool to separate and study quark and gluon initiated...

72. The Lund Jet Plane

Frederic Alexandre Dreyer (MIT)

30/08/2018, 14:30

Perturbative QCD, Jets and Substructure

Lund diagrams, a representation of the phase space within jets, have long been used in discussing parton showers and resummations. I will point out that they can also serve as a powerful tool for experimentally characterising the radiation pattern within jets. I will briefly comment on some of their analytical properties and highlight their scope for constraining Monte Carlo simulations. I...

52. Tests of Perturbative QCD with Photon Final States at the ATLAS Experiment

Ana Rosario Cueto Gomez (Universidad Autonoma de Madrid (ES))

30/08/2018, 15:00

Perturbative QCD, Jets and Substructure

The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton.
The ATLAS collaboration has performed numerous cross section measurements of prompt photon production, among which are a precise measurement of the production of isolated prompt photons in association with heavy flavor...

53. New Results on Z Boson Production with the ATLAS Detector

Peter Wagner (University of Bonn (DE))

30/08/2018, 15:30

Perturbative QCD, Jets and Substructure

Precision measurements of the Drell-Yan production of Z bosons at the LHC provide a benchmark of our understanding of perturbative QCD and electroweak processes and probe the proton structure in a unique way.
ATLAS performed a measurement of the effective leptonic weak mixing angle using electron and muon pairs from Z boson decay at a center of mass energy of 8 TeV. It consists of a set of...

80. Precision determination of the Wtb coupling in single top production

Tobias Neumann (Illinois Tech / Fermi National Accelerator Laboratory)

30/08/2018, 16:30

Perturbative QCD, Jets and Substructure

We present our calculation of next-to-leading order QCD effects in single top production for a precision determination of the Wtb coupling. The calculation is performed analytically with an off-shell top quark and includes relevant operators from the Standard Model Effective Field Theory (SMEFT) that modify the Wtb coupling also at next-to-leading order in QCD. We discuss the phenomenological...

15. Renomalization of QCD at four and five loops

Peter Marquard (DESY)

30/08/2018, 17:00

Perturbative QCD, Jets and Substructure

We present an overview of the current status of calculations for the QCD renormalization constants.

23. Measurements of jet mass and other jet substructure studies at CMS

CMS Collaboration

Perturbative QCD, Jets and Substructure

This talk describes the measurement of the jets mass and other jet substructure studies at CMS

75. Next-to-next-to-leading order N-jettiness soft function for tW production at the LHC

Jian Wang

Perturbative QCD, Jets and Substructure

We calculate the N-jettiness soft function for tW production up to next-to-next-to-leading order in QCD, which is an important ingredient of the N-jettiness subtraction method for predicting the differential cross sections of massive coloured particle productions. We also compare the results with the predictions from renormalization group equations controlled by the soft anomalous dimension.