Conveners
Hard QCD: Jets and Photons
- Evelin Meoni (Tufts University (US))
- Joao Pires (Milano Bicocca)
Hard QCD: Higgs - Session I
- Evelin Meoni (Tufts University (US))
- Marcella Bona (Queen Mary University of London (UK))
- Joao Pires (Milano Bicocca)
Hard QCD: Higgs - Session II
- Marcella Bona (Queen Mary University of London (UK))
- Evelin Meoni (Tufts University (US))
- Joao Pires (Milano Bicocca)
Hard QCD: W/Z +jets
- Evelin Meoni (Tufts University (US))
- Joao Pires (Milano Bicocca)
Hard QCD: W/Z Theory Session
- Joao Pires (Milano Bicocca)
- Evelin Meoni (Tufts University (US))
Hard QCD: Electroweak
- Evelin Meoni (Tufts University (US))
- Joao Pires (Milano Bicocca)
Hector De La Torre
(Universidad Autonoma de Madrid-Unknown-Unknown),
Hector De La Torre Perez
(Universidad Autonoma de Madrid (ES))
9/1/15, 4:30 PM
Hard QCD
Cross sections for jet and isolated photon production in pp collisions have been measured by the ATLAS collaboration at 7 and 8 TeV. Double-differential cross sections for inclusive, di, and tri-jet final states are measured and compared to expectations based on next-to-leading order QCD calculations as well as to next-to-leading order Monte Carlo simulations. First LHC Run2 results...
ALESSANDRA LUCA'
(INFN - National Institute for Nuclear Physics),
Alessandra Luca
9/1/15, 5:00 PM
Hard QCD
The production of photons with large transverse energy in hadronic collisions is an important testing ground for perturbative Quantum Chromodynamics (pQCD), enabling to probe parton distribution functions (PDFs) and the parton-to-photon fragmentation functions (FFs). In addition, high-ET photons can also constitute an irreducible background for important searches such as H→γγ, or SUSY and...
Gudrun Heinrich
(Max Planck Institute for Physics)
9/1/15, 5:30 PM
Hard QCD
New features of the program SecDec will be presented,
which allow the numerical calculation of multi-scale loop integrals
in a highly efficient way.
Results for two-loop integrals with several mass scales will be
shown to illustrate some applications of the program.
Nicola Adriano Lo Presti
(University of Zurich)
9/1/15, 5:50 PM
Hard QCD
I present recent progress in the calculation of the master integrals for the five-point amplitude at two loops in QCD, which is a crucial contribution to computation of the the next-to-next-to-leading order cross section for three-jet production at the LHC.
After a brief review of the differenential-equation method for evaluating Feynman integrals,
I will discuss its application to compute...
Alexander Ochirov
(University of Edinburgh)
9/1/15, 6:10 PM
Hard QCD
We work out a new color decomposition for tree amplitudes in quantum chromodynamics with flavored quarks in a reduced basis of primitive amplitudes. These primitives, with k quark-antiquark pairs and (n-2k) gluons, are taken in the (n-2)!/k! Melia basis, and are independent under the color-algebra Kleiss-Kuijf relations. This generalizes the color decomposition of Del Duca, Dixon, and Maltoni...
Amina Zghiche
(CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR)),
Amina Zghiche
(LAPP-CNRS-France)
9/2/15, 4:30 PM
Bo Liu
(Academia Sinica (TW)/Shandong University(CN)),
Bo Liu,
Bo.Bo Liu
(Tsinghua University (CN))
9/2/15, 5:00 PM
Walter Giele
9/2/15, 5:30 PM
Hard QCD
The calculation and phenomenology of PP->H+1 jet and PP->V+1 jet at NNLO
will be presented. The calculations use the so-called jettiness subtraction
which makes it easy to combine the 2-loop virtual corrections into MCFM by
using the already build-in NLO PP->H+2 parton and PP->V+2 parton processes.
Markus Christian Schulze
(CERN)
9/2/15, 5:50 PM
I will present new results for the fully differential Higgs plus jet cross section at NNLO in perturbative
QCD which include decays of the Higgs boson to electroweak vector bosons. I will review some technical details of the computation, present kinematic distributions for a realistic final state, and compare our findings with the experimental measurements.
Marco Bonvini
(University of Oxford)
9/2/15, 6:10 PM
Hard QCD
I will describe how approximate higher order results can be obtained from known asymptotic regimes, in turn determined by all-order resummed expressions. Specifically, threshold (large-x) resummation combined with high-energy (small-x) resummation can lead to reliable determinations of inclusive N3LO cross sections such as those of Higgs, $t\bar t$ or Drell-Yan productions. The method is...
Dr
Alexander Hasselhuhn
(Karlsruhe Institute of Technology)
9/2/15, 6:30 PM
Hard QCD
The total production cross section from gluon fusion is an important ingredient in further studies of the discovered Higgs boson. I will present the analytic computation of the NNNLO QCD corrections to its total production cross section in the qq'-channel. The computation is performed using differential equations for canonical bases of master integrals, and the results are exact in the Higgs...
Zoltan Laszlo Trocsanyi
(University of Debrecen (HU))
9/3/15, 11:30 AM
Hard QCD
We compute the fully differential decay rate of the standard model Higgs boson to a b-quark pair at NNLO accuracy. We use a general subtraction scheme developed for computing QCD jet cross sections in perturbation theory. The double real and real-virtual contributions to the second order radiative corrections, regularized by subtractions, are finite in four space-time dimensions and their...
Frederic Alexandre Dreyer
(LPTHE & CERN)
9/3/15, 11:50 AM
Hard QCD
In this talk, we will present the fully differential NNLO corrections to vector-boson fusion (VBF) Higgs production at hadron colliders, in the limit in which there is no cross-talk between the hadronic systems associated with the two protons. This result is achieved by combining an inclusive NNLO calculation in the structure-function approach and a suitably factorised NLO VBF Higgs plus 3-jet...
Nicolas Greiner
(DESY)
9/3/15, 12:10 PM
Hard QCD
The largest contribution of the production of a Standard Model Higgs comes from the gluon fusion mechanism. The production of a Higgs in association with jets in this production mode is an important and dominant background to the VBF case. Its precise understanding is therefore mandatory for the reliable determination of the Higgs couplings and its
properties. In this talk we present a...
Huasheng Shao
(CERN)
9/3/15, 12:30 PM
Hard QCD
I will first review the status of the perturbative computations with QCD and electroweak corrections in the MadGraph5_aMC@NLO framework. Then, I will focus on its first phenomenological application to top quark pair associated production with a Higgs/Z/W boson at next-to-leading order QCD and electroweak accuracy. As a by product, I also present some preliminary results for the top quark pair...
Benjamin Tannenwald
(University of Kansas),
Benjamin Tannenwald
(Ohio State University (US))
9/4/15, 11:30 AM
Hard QCD
The inclusive production of W and Z bosons as well the off-shell Z/gamma* production are standard candles at hadron colliders. The measurement of their production cross-sections can be compared to theory calculations at NNLO QCD and have an impact on our knowledge of the parton densities of the proton. Run1 studies carried out by the ATLAS Collaboration are reviewed and first LHC Run2...
Thomas Morgan
(IPPP Durham University)
9/4/15, 12:20 PM
We will review our recent calculation of Z boson production in association with a jet up to Next-to-Next-to Leading Order (NNLO) precision in QCD, as shown in arXiv:1507.02850. This is a key process at the LHC, given its large event rate and clean signature with the Z boson decaying leptonically. We will discuss our approach using the antenna subtraction scheme and present new results of the...
German Sborlini
(IFIC-Valencia)
9/4/15, 12:40 PM
Higher-order computations require to combine real and virtual contributions in order to cancel infrared (IR) singularities. Loop-tree duality (LTD) allows to express virtual contributions in terms of phase-space integrals, which enables to add them directly to the real radiation terms. Thus, we obtain expressions that can be integrated in four dimensions and we avoid the introduction of IR...
Keith Hamilton
(UCL)
9/4/15, 3:00 PM
Hard QCD
I will discuss the matching of next-to-next-to-leading order QCD corrections with parton shower simulations for simple processes, via extension of the multi-scale improved NLO (MiNLO) framework.
Ye Li
(SLAC)
9/4/15, 3:30 PM
Hard QCD
We discuss recent developments in combining parton showers and
fixed-order calculations. We focus on the UNNLOPS method for matching
next-to-next-to-leading order computations to the parton shower, and we present
results from Sherpa for Drell-Yan lepton-pair and Higgs-boson production at the
LHC.
Alessandra Baas
(Ruprecht-Karls-Universitaet Heidelberg (DE))
9/4/15, 4:30 PM
Hard QCD
ATLAS measurements of multi-boson production processes involving combinations of W, Z and isolated photons are summarized. In processes like WW, ZZ, Zgamma or Wgamma large next-to-next-to-leading order QCD corrections were recently calculated and are confronted with integrated and differential data measurements. Furthermore a measurement of the differential cross section for the...
Massimiliano Grazzini
(Universitaet Zuerich (CH))
9/4/15, 5:00 PM
Hard QCD
We consider QCD radiative corrections to vector boson pair production in hadron collisions. We report on the computation of radiative corrections to NNLO in QCD perturbation theory. We present results for Zgamma, Wgamma and ZZ production at the LHC by using the selection cuts typically applied by the LHC experiments. Our calculation consistently includes the leptonic decay of the vector-bosons...
Lorena Rothen
(University of Bern)
9/4/15, 5:30 PM
Hard QCD
In electroweak-boson production processes with a jet veto, higher-order corrections are enhanced by logarithms of the veto scale over the invariant mass of the boson system. We resum these Sudakov logarithms
at next-to-next-to-leading logarithmic (NNLL) accuracy and match our predictions to next-to-leading order (NLO) fixed-order results. The calculation is performed in an automated way, for...
