scholarly journals Resummed inclusive cross-section in ADD model at N3LL

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Goutam Das ◽  
M. C. Kumar ◽  
Kajal Samanta
Keyword(s):  
Invariant Mass ◽  
Cross Section ◽  
Invariant Mass Distribution ◽  
Large Extra Dimensions ◽  
Hadron Collider ◽  
Form Factors ◽  
Standard Technique ◽  
Inclusive Cross Section ◽  
Mass Region ◽  
Matching Procedure

Abstract We present three loop soft-plus-virtual (SV) corrections to the spin-2 production at the Large Hadron Collider (LHC). For this calculation, we make use of the recently computed quark and gluon three loop form factors for the spin-2 production, the universal soft-collinear coefficients as well as the mass factorization kernels. The SV coefficients are presented up to next-to-next-to-next-to leading order (N3LOsv). We also use these coefficients at three loops to compute the resummed prediction for inclusive cross-section to next-to-next-to-next-to leading logarithmic accuracy (N3LL) matched to N3LOsv. We use the standard technique to derive the Mellin N-dependent coefficients and also the N-independent coefficients to achieve the resummation using the minimal prescription matching procedure. Considering the spin-2 propagator in the large extra dimensional (ADD) model, we also study the numerical impact of these three-loop SV corrections as well as the resummed predictions on the di-lepton invariant mass distribution at the 13 TeV LHC. We find that the conventional scale uncertainties in the N3LOsv +N3LL resummed results substantially get reduced to as low as 2% in the high invariant mass region. We also estimate the PDF uncertainties in our predictions that will be useful in the experimental searches for large extra dimensions.

Cross section and invariant mass distribution of the reaction at 4.7 ⩽ Eγ ⩽ 6.6 GeV

1983 ◽  
Vol 133 (3-4) ◽  
pp. 275-278 ◽  
Author(s):  
J. Bodenkamp ◽  
D.C. Fries ◽  
A. Markou ◽  
E. Seitz ◽  
H.J. Behrend ◽  
...  
Keyword(s):  
Invariant Mass ◽  
Mass Distribution ◽  
Cross Section ◽  
Invariant Mass Distribution

scholarly journals Diffractive Production of Quarkonium in p-A Collisions at LHC

2017 ◽  
Vol 45 ◽  
pp. 1760063
Author(s):  
Érison S. Rocha ◽  
Magno V. T. Machado
Keyword(s):  
Cross Section ◽  
Hadron Collider ◽  
Meson Production ◽  
Inclusive Cross Section ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Psi Meson ◽  
Diffractive Cross Section ◽  
Diffractive Production ◽  
Order Of Magnitude

In the present work, we investigated the exclusive diffractive production of charmonium in pronton-nucleus collisions at the Large Hadron Collider (LHC) energies. Such exclusive production reactions possess a cleaner experimental signal than inclusive production once it is characterized by low multiplicity of particles between final produced state and the incident protons of collider beam. The considered theoretical framework was the perturbative model of Quantum Cromodynamics (QCD) for the Pomeron exchange. In particular, we have used the resolved Pomeron model which depends on the Pomeron flux and Pomeron parton distribution functions. The main goal is to provide predictions for the single diffractive cross section for the J/Psi meson production at the energies of 5.02 TeV and 8.8 TeV. We have shown that a measurement is feasible as the order of magnitude is 400 microbarns even absorption corrections. Furthermore, we analyze the ratio of the diffractive to inclusive cross section which allows theoretical uncertainties to be canceled, mostly those associated to approximations performed in inclusive case.

scholarly journals ON A POSSIBLE MANIFESTATION OF THE FOUR-COLOR SYMMETRY Z' BOSON IN μ+μ- EVENTS AT THE LHC

2009 ◽  
Vol 24 (15) ◽  
pp. 1199-1207
Author(s):  
A. D. SMIRNOV ◽  
YU. S. ZAITSEV
Keyword(s):  
Mass Spectrum ◽  
Pair Production ◽  
Invariant Mass ◽  
Cross Section ◽  
Z Boson ◽  
Invariant Mass Spectrum ◽  
Mass Region ◽  
Pp Collisions ◽  
Color Symmetry ◽  
The Cross

The cross section of the μ+μ- pair production in pp-collisions at the LHC is calculated with account of the Z' boson induced by the minimal four-color quark–lepton symmetry (MQLS). The μ+μ- invariant mass spectrum with account of the MQLS Z' boson is analyzed in dependence on the Z' mass. The mass region for the MQLS Z' boson observable at the LHC is found in dependence on the significance and on the integrated luminosity.

scholarly journals The role of the threshold variable in soft-gluon resummation of the $$ t\overline{t}h $$ production process

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Melissa van Beekveld ◽  
Wim Beenakker
Keyword(s):  
Cross Section ◽  
Top Quark ◽  
Mellin Transform ◽  
Invariant Mass Distribution ◽  
Hadron Collider ◽  
Soft Gluon ◽  
Deformation Method ◽  
Final State ◽  
Scale Uncertainty

Abstract We study the role of the scale of the threshold variable in soft-gluon threshold resummation. We focus on the computation of the resummed total cross section, the final-state invariant-mass distribution, and transverse-momentum distribution of the Higgs boson when produced in association with a top-anti-top quark pair for the Large Hadron Collider operating at 13 TeV. We show that different choices for the scale of the threshold variable result in differences at next-to-leading power, i.e. contributions that are down by one power of the threshold variable. These contributions are noticeable numerically, although their effect on the resummed observables lies within the scale uncertainty of those observables. The average central results, obtained after combining several central- scale choices, agree remarkably well for different choices of the threshold variable. However, different threshold choices do affect the resulting scale uncertainty. To compute our results, we introduce a novel numerical method that we call the deformation method, which aids the stabilization of the inverse Mellin transform in cases where the analytical Mellin transform of the partonic cross section is unknown. We show that this method leads to a factor of 10 less function evaluations, while gaining a factor of 4 − 5 in numerical precision when compared to the standard method.

scholarly journals Possible effects of the large extra dimensions on ZZW production at the LHC

2014 ◽  
Vol 29 (31) ◽  
pp. 1450153 ◽  
Author(s):  
Chong Chen ◽  
Lei Guo ◽  
Wen-Gan Ma ◽  
Ren-You Zhang ◽  
Xiao-Zhou Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Extra Dimensions ◽  
Selection Criteria ◽  
Large Extra Dimensions ◽  
Hadron Collider ◽  
Leading Order ◽  
Event Selection ◽  
The Standard Model ◽  
Kaluza Klein

We investigate the possible large extra dimensions (LED) effects induced by the Kaluza–Klein (KK) gravitons up to the QCD next-to-leading order (NLO) on ZZW production at the large hadron collider (LHC). The integrated cross-sections and some kinematic distributions are presented in both the Standard Model (SM) and the LED model. The numerical results demonstrate that the NLO QCD corrections are sizeable and remarkably reduce the leading order (LO) LED effect depending strongly on the phase space. The NLO LED relative discrepancies of the total cross-section could become sizable for the ZZW production, if we apply proper event selection criteria. We find that the LO result overestimates the LED effect and is insufficient to provide a believable theoretical prediction.

scholarly journals Nucleon form factors at threshold

2019 ◽  
Vol 218 ◽  
pp. 04003
Author(s):  
Alexandr Milstein
Keyword(s):  
Invariant Mass ◽  
Cross Section ◽  
Cross Sections ◽  
Mass Spectra ◽  
Form Factors ◽  
Invariant Mass Spectrum ◽  
Nucleon Form Factors ◽  
The Cross ◽  
Good Agreement ◽  
Invariant Mass Spectra

The pp¯invariant mass spectra in the processes e+e−→ pp¯, e+e−→ nn¯, J/ψ → pp¯ω, J/ψ → pp¯ρ, and J/ψ → pp¯γ close to the pp¯is discussed. The optical potentials for NN¯pair in the superposition of S and D waves (due to tensor forces) at spin unity of the pair, as well as for NN¯pair in the S wave at spin zero of the pair, are proposed. The parameters of the potentials are obtained by fitting the cross sections of NN¯scattering together with the pp¯invariant mass spectra in e+e−→ pp¯annihilation and J/ψ decays. Good agreement with the available experimental data is achieved. Using our potential and the Green’s function approach we also describe the cross section of e+ e−→ 6π and the η’π+ π− invariant mass spectrum in the decay J/ψ → γη’π+π− in the energy region near the NN¯threshold.

scholarly journals Measurements of the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson at $$\sqrt{s} = 13$$ TeV with the ATLAS detector

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
◽  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Production Cross ◽  
Hadron Collider ◽  
Inclusive Cross Section ◽  
Atlas Detector ◽  
Proton Collision ◽  
Proton Proton ◽  
Theoretical Predictions

AbstractMeasurements of both the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson ($$t{\bar{t}}Z$$ t t ¯ Z ) are presented. The measurements are performed by targeting final states with three or four isolated leptons (electrons or muons) and are based on $$\sqrt{s} = 13$$ s = 13  TeV proton–proton collision data with an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 , recorded from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. The inclusive cross section is measured to be $$\sigma _{t{\bar{t}}Z} = 0.99 \pm 0.05$$ σ t t ¯ Z = 0.99 ± 0.05  (stat.) $$\pm \, 0.08$$ ± 0.08  (syst.) pb, in agreement with the most precise theoretical predictions. The differential measurements are presented as a function of a number of kinematic variables which probe the kinematics of the $$t{\bar{t}}Z$$ t t ¯ Z system. Both absolute and normalised differential cross-section measurements are performed at particle and parton levels for specific fiducial volumes and are compared with theoretical predictions at different levels of precision, based on a $$\chi ^{2}/$$ χ 2 / ndf and p value computation. Overall, good agreement is observed between the unfolded data and the predictions.

scholarly journals Measurement of the inclusive cross-section for the production of jets in association with a Z boson in proton–proton collisions at 8 TeV using the ATLAS detector

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  
Keyword(s):  
Cross Section ◽  
Radiation Effects ◽  
Hadron Collider ◽  
Inclusive Cross Section ◽  
Atlas Detector ◽  
Proton Collision ◽  
Leading Order ◽  
Final State ◽  
Proton Proton ◽  
Model Calculations

Abstract The inclusive cross-section for jet production in association with a Z boson decaying into an electron–positron pair is measured as a function of the transverse momentum and the absolute rapidity of jets using 19.9 fb$$^{-1}$$-1 of $$\sqrt{s}=8$$s=8 TeV proton–proton collision data collected with the ATLAS detector at the Large Hadron Collider. The measured $$Z\text { + jets}$$Z+ jets cross-section is unfolded to the particle level. The cross-section is compared with state-of-the-art Standard Model calculations, including the next-to-leading-order and next-to-next-to-leading-order perturbative QCD calculations, corrected for non-perturbative and QED radiation effects. The results of the measurements cover final-state jets with transverse momenta up to 1 TeV, and show good agreement with fixed-order calculations.

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