We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of
s
=
13
TeV
in a configuration, where one jet is present in the central pseudorapidity region (
|
η
|
<
2.0
) ...while two other jets are in a more forward (same hemisphere) area (
|
η
|
>
2.0
). We compare various parton level predictions using: collinear factorisation,
k
T
-factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.
We provide a concise overview on transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and their theoretical ...connections with QCD resummation, evolution and factorization theorems. We illustrate the use of TMDs via examples of multi-scale problems in hadronic collisions. These include transverse momentum q_T spectra of Higgs and vector bosons for low q_T, and azimuthal correlations in the production of multiple jets associated with heavy bosons at large jet masses. We discuss computational tools for TMDs, and present an application of a new tool, TMDlib, to parton density fits and parameterizations.
Experiments in the high-luminosity runs at the Large Hadron Collider face the challenges of very large pile-up. Primary techniques to deal with this are based on precise vertex and track ...reconstruction. Outside tracker acceptances, however, lie regions of interest for many aspects of the LHC physics program. We explore complementary approaches to pile-up treatment and propose a data-driven jet-mixing method which can be used outside tracker acceptances without depending on Monte Carlo generators. The method can be applied to treat correlation observables and take into account, besides the jet transverse momentum pedestal, effects of hard jets from pile-up.
In the forthcoming high-luminosity phase of the LHC many of the most interesting measurements for precision QCD studies are hampered by large pile-up conditions, especially at not very high ...transverse momenta. However, with the recently discovered Higgs boson, which couples in the heavy top limit directly to gluons, we have access to a novel production process to probe QCD by a colour-singlet current. In this study we compare observables in Higgs boson and Drell-Yan production and investigate whether measuring ratios or subtractions can yield results that are stable in high pile-up environments, and yet sensitive to (small-pT) QCD physics in gluon fusion processes. We present results of Monte Carlo event generator calculations for a few specific examples.
We present performance studies of a full-length prototype for the CASTOR quartz-tungsten sampling calorimeter, installed in the very forward region of the CMS experiment at the LHC. The response ...linearity and energy resolution, the uniformity, as well as the showers’ spatial properties in the prototype have been studied with electrons, pions and muons of various energies. A special study was also carried out for testing the light-output with a 90-degree cut of the quartz plates of the calorimeter. The data were taken during the CASTOR test beam at CERN/SPS in 2007.
We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of Formula omitted in a configuration, where one jet is present in the central pseudorapidity region ( Formula ...omitted) while two other jets are in a more forward (same hemisphere) area ( Formula omitted). We compare various parton level predictions using: collinear factorisation, Formula omitted-factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.
Abstract
We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of
$$\sqrt{s} = 13 \mathrm{\ TeV}$$
s
=
13
TeV
in a configuration, where one jet is present in the ...central pseudorapidity region (
$$|\eta | < 2.0$$
|
η
|
<
2.0
) while two other jets are in a more forward (same hemisphere) area (
$$|\eta | > 2.0$$
|
η
|
>
2.0
). We compare various parton level predictions using: collinear factorisation,
$$k_\mathrm{T}$$
k
T
-factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.
Abstract We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of $$\sqrt{s} = 13 \mathrm{\ TeV}$$ s=13TeV in a configuration, where one jet is present in the central ...pseudorapidity region ($$|\eta | < 2.0$$ |η|<2.0 ) while two other jets are in a more forward (same hemisphere) area ($$|\eta | > 2.0$$ |η|>2.0 ). We compare various parton level predictions using: collinear factorisation, $$k_\mathrm{T}$$ kT -factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.
We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of \(\sqrt{s} = 13 {\rm\ TeV}\) in a configuration, where one jet is present in the central pseudorapidity ...region (\(|\eta| < 2.0\)) while two other jets are in a more forward (same hemisphere) area (\(|\eta| > 2.0\)). We compare various parton level predictions using: collinear factorisation, \(\KT{}\)-factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.
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