A positive-weight next-to-leading-order Monte Carlo forZpair hadroproduction

During the first years of the LHC operation a large amount of jet data was recorded by the ATLAS and CMS experiments. In this review several measurements of jet-related observables are presented, such as multi-jet rates and cross sections, ratios of jet cross sections, jet shapes and event shape observables. All results presented here are based on jet data collected at a centre-of-mass energy of 7 TeV. Data are compared to various Monte Carlo generators, as well as to theoretical next-to-leading-order calculations allowing a test of perturbative Quantum Chromodynamics in a previously unexplored energy region.

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Inclusion of the QCD next-to-leading order corrections in the quark-gluon Monte Carlo shower

Physical Review D ◽

10.1103/physrevd.87.034029 ◽

2013 ◽

Vol 87 (3) ◽

Cited By ~ 9

Author(s):

S. Jadach ◽

A. Kusina ◽

W. Płaczek ◽

M. Skrzypek ◽

M. Slawinska

Keyword(s):

Monte Carlo ◽

Leading Order

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A positive-weight next-to-leading order simulation of weak boson pair production

Journal of High Energy Physics ◽

10.1007/jhep01(2011)009 ◽

2011 ◽

Vol 2011 (1) ◽

Cited By ~ 29

Author(s):

Keith Hamilton

Keyword(s):

Pair Production ◽

Leading Order ◽

Boson Pair ◽

Weak Boson ◽

Positive Weight ◽

Boson Pair Production

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THE IMPACT OF LO, NLO AND NNLO FOR THE HIGGS SEARCHING AT $\sqrt{s} = 7$ TeV OF LHC

Modern Physics Letters A ◽

10.1142/s0217732310034146 ◽

2010 ◽

Vol 25 (36) ◽

pp. 3027-3031

Author(s):

JIAN WANG ◽

GUOMING CHEN ◽

WEIMIN WU

Keyword(s):

Monte Carlo ◽

Cross Section ◽

Higgs Mass ◽

Monte Carlo Generator ◽

Final States ◽

Leading Order ◽

Analysis Process ◽

Signal Rate ◽

Monte Carlo Studies ◽

The Impact

Most of current Monte Carlo studies on the Higgs searching are based on LO, or NLO calculation. However, in recent years, the next-to-next-to-leading order (NNLO) corrections have been computed for some physics process, and found that the cross section increases the kinematics changes. As the results, the analysis results could be impacted by these high order QCD corrections. We use standard Monte Carlo generator for LO, as well as MC@NLO for NLO and ResBos for NNLO at 7 TeV of LHC to evaluate this impact for physics channel of the Higgs, mass at 165 GeV, to WW, then W decay to lepton and neutrino as the final states. We found the signal rate could be effected by ratio of 1:2.6:3.4 for LO, NLO and NNLO using the same standard H→WW→lνlν searching analysis process.6

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Multiplicative-accumulative matching of NLO calculations with parton showers

Journal of High Energy Physics ◽

10.1007/jhep01(2022)067 ◽

2022 ◽

Vol 2022 (1) ◽

Author(s):

Paolo Nason ◽

Gavin P. Salam

Keyword(s):

Phase Space ◽

Matrix Element ◽

Parton Shower ◽

Leading Order ◽

Positive Weight ◽

New Approach ◽

The Matrix ◽

Core Features

Abstract We propose a new approach for combining next-to-leading order (NLO) and parton shower (PS) calculations so as to obtain three core features: (a) applicability to general showers, as with the MC@NLO and POWHEG methods; (b) positive-weight events, as with the KrkNLO and POWHEG methods; and (c) all showering attributed to the parton shower code, as with the MC@NLO and KrkNLO methods. This is achieved by using multiplicative matching in phase space regions where the shower overestimates the matrix element and accumulative (additive) matching in regions where the shower underestimates the matrix element, an approach that can be viewed as a combination of the MC@NLO and KrkNLO methods.

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