scholarly journals Studies of gluon TMDs and their evolution using quarkonium-pair production at the LHC

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Florent Scarpa ◽  
Daniël Boer ◽  
Miguel G. Echevarria ◽  
Jean-Philippe Lansberg ◽  
Cristian Pisano ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Pair Production ◽  
Tree Level ◽  
Data Sets ◽  
Gluon Polarization ◽  
High Luminosity ◽  
Transverse Momentum Spectrum ◽  
Momentum Distributions ◽  
Future Data ◽  
Azimuthal Asymmetries

Abstract $$J/\psi $$J/ψ- or $$\Upsilon $$Υ-pair production at the LHC are promising processes to study the gluon transverse momentum distributions (TMDs) which remain very poorly known. In this article, we improve on previous results by including the TMD evolution in the computation of the observables such as the pair-transverse-momentum spectrum and asymmetries arising from the linear polarization of gluons inside unpolarized protons. We show that the azimuthal asymmetries generated by the gluon polarization are reduced compared to the tree level case but are still of measurable size (in the 5–10% range). Such asymmetries should be measurable in the available data sets of $$J/\psi $$J/ψ pairs and in the future data sets of the high-luminosity LHC for $$\Upsilon $$Υ pairs.

scholarly journals Search for new phenomena in final states with b-jets and missing transverse momentum in $$ \sqrt{\mathrm{s}} $$ = 13 TeV pp collisions with the ATLAS detector

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Pair Production ◽  
Atlas Detector ◽  
Final States ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
The Standard Model ◽  
Proton Data ◽  
Identification Techniques ◽  
New Phenomena

Abstract The results of a search for new phenomena in final states with b-jets and missing transverse momentum using 139 fb−1 of proton-proton data collected at a centre-of-mass energy $$ \sqrt{s} $$ s = 13 TeV by the ATLAS detector at the LHC are reported. The analysis targets final states produced by the decay of a pair-produced supersymmetric bottom squark into a bottom quark and a stable neutralino. The analysis also seeks evidence for models of pair production of dark matter particles produced through the decay of a generic scalar or pseudoscalar mediator state in association with a pair of bottom quarks, and models of pair production of scalar third-generation down-type leptoquarks. No significant excess of events over the Standard Model background expectation is observed in any of the signal regions considered by the analysis. Bottom squark masses below 1270 GeV are excluded at 95% confidence level if the neutralino is massless. In the case of nearly mass-degenerate bottom squarks and neutralinos, the use of dedicated secondary-vertex identification techniques permits the exclusion of bottom squarks with masses up to 660 GeV for mass splittings between the squark and the neutralino of 10 GeV. These limits extend substantially beyond the regions of parameter space excluded by similar ATLAS searches performed previously.

ResBos and ePump Analysis on ATLAS 8TeV Z Boson Transverse Momentum Distributions

2021 ◽  
Author(s):  
Qaynar Jandaolet ◽  
Alim Ablat ◽  
Pazilet Obul ◽  
Reyima Rashidin ◽  
Ibrahim Sitiwaldi
Keyword(s):  
Transverse Momentum ◽  
Z Boson ◽  
Momentum Distributions

scholarly journals Constraints on neutrino non-standard interactions from LHC data with large missing transverse momentum

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
DianYu Liu ◽  
ChuanLe Sun ◽  
Jun Gao
Keyword(s):  
Transverse Momentum ◽  
Neutral Current ◽  
Data Sets ◽  
Leading Order ◽  
Missing Transverse Momentum ◽  
Upper Limit ◽  
Theoretical Predictions ◽  
Parton Showering ◽  
Single Jet

Abstract The possible non-standard interactions (NSIs) of neutrinos with matter plays important role in the global determination of neutrino properties. In our study we select various data sets from LHC measurements at 13 TeV with integrated luminosities of 35 ∼ 139 fb−1, including production of a single jet, photon, W/Z boson, or charged lepton accompanied with large missing transverse momentum. We derive constraints on neutral-current NSIs with quarks imposed by different data sets in a framework of either effective operators or simplified Z′ models. We use theoretical predictions of productions induced by NSIs at next-to-leading order in QCD matched with parton showering which stabilize the theory predictions and result in more robust constraints. In a simplified Z′ model we obtain a 95% CLs upper limit on the conventional NSI strength ϵ of 0.042 and 0.0028 for a Z′ mass of 0.2 and 2 TeV respectively. We also discuss possible improvements from future runs of LHC with higher luminosities.

Longitudinal- and Transverse-Momentum Distributions forπ−Mesons in18.5−GeVc π±pInteractions

1971 ◽  
Vol 26 (25) ◽  
pp. 1589-1592 ◽  
Author(s):  
N. N. Biswas ◽  
N. M. Cason ◽  
V. P. Kenney ◽  
J. T. Powers ◽  
W. D. Shephard ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Momentum Distributions

scholarly journals EVENTS WITH ISOLATED CHARGED LEPTONS AND LARGE MISSING TRANSVERSE MOMENTUM AT HERA

2004 ◽  
Vol 19 (25) ◽  
pp. 1881-1902 ◽  
Author(s):  
TANCREDI CARLI ◽  
DOMINIK DANNHEIM ◽  
LORENZO BELLAGAMBA
Keyword(s):  
Transverse Momentum ◽  
Zeus Collaboration ◽  
Tau Leptons ◽  
High Luminosity ◽  
Final State ◽  
Missing Transverse Momentum ◽  
State Formula ◽  
Charged Leptons ◽  
Good Agreement ◽  
Event Topology

Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state [Formula: see text] were observed at the electron proton collider HERA in a data sample corresponding to an integrated luminosity of about 130 pb-1. The H1 collaboration observed 11 events with isolated electrons or muons and with [Formula: see text]. Only 3.4±0.6 events were expected from Standard Model (SM) processes. Six of these events have [Formula: see text], while 1.3±0.3 events were expected. The ZEUS collaboration observed good agreement with the SM. However, ZEUS found two events with a similar event topology, but tau leptons instead of electrons or muons in the final state. Only 0.2±0.05 events were expected from SM processes. For various hypotheses, the compatibility of the experimental results was investigated with respect to the SM and with respect to possible explanations beyond the SM. Prospects for the high-luminosity HERA-II data taking period are given.

scholarly journals Transverse momentum distributions of neutral pions from central and peripheral16O+Au collisions at 200A·GeV

1990 ◽  
Vol 47 (3) ◽  
pp. 367-375 ◽  
Author(s):  
◽  
R. Albrecht ◽  
T. C. Awes ◽  
C. Baktash ◽  
P. Beckmann ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Neutral Pions ◽  
Momentum Distributions
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