scholarly journals Investigation of exotic state X(3872) in pp collisions at $$\sqrt{s}=7$$, 13 TeV

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Hong-ge Xu ◽  
Zhi-Lei She ◽  
Dai-Mei Zhou ◽  
Liang Zheng ◽  
Xiao-Lin Kang ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Bound State ◽  
Molecular State ◽  
Cascade Model ◽  
Final States ◽  
Exotic State ◽  
Coalescence Model ◽  
Rapidity Distributions ◽  
Hadronic Final States ◽  
Sizable Difference

AbstractWe have used the dynamically constrained phase space coalescence model to study the production of the exotic state X(3872) based on the hadronic final states generated by the parton and hadron cascade model (PACIAE) with $$|y|<1$$ | y | < 1 and $$p_T < 15.5$$ p T < 15.5 GeV/c in pp collisions at $$\sqrt{s}=7$$ s = 7 and 13 TeV, respectively. Here the X(3872) is assumed to consist of bound state $$D\bar{D^*}$$ D D ∗ ¯ , which can form three possible structures for the tetraquark state, the nucleus-like state, and the molecular state. The yields of three different structures X(3872) were predicted. The transverse momentum distribution and the rapidity distribution of three different structures X(3872) are also presented. Sizable difference can be found in the transverse momentum and rapidity distributions for the three different X(3872) structures.

scholarly journals The study of exotic state $$Z_c^{\pm }(3900)$$ decaying to $$J/\psi \pi ^{\pm }$$ in the pp collisions at $$\sqrt{s}$$ = 1.96, 7, and 13 TeV

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Zhen Zhang ◽  
Liang Zheng ◽  
Gang Chen ◽  
Hong-Ge Xu ◽  
Dai-Mei Zhou ◽  
...  
Keyword(s):  
Phase Space ◽  
Transverse Momentum ◽  
Energy Dependence ◽  
Resonant State ◽  
Decay Chain ◽  
Bound State ◽  
Exotic State ◽  
Coalescence Model ◽  
Momentum Distributions ◽  
Rapidity Distributions

AbstractA dynamically constrained phase-space coalescence model and PACIAE model are used to predict the exotic resonant state $$Z_c^{\pm }(3900)$$ Z c ± ( 3900 ) yield in pp collisions at $$\sqrt{s} = 1.96, 7$$ s = 1.96 , 7 and 13 TeV, respectively, which are estimated to be around $$10^{-6}$$ 10 - 6 to $$10^{-5}$$ 10 - 5 based on the $$J/\psi \pi ^{\pm }$$ J / ψ π ± bound state in the decay chain of b hadrons. The energy dependence of the transverse momentum distributions and rapidity distributions with $$|y|<6$$ | y | < 6 and $$p_{T}<10$$ p T < 10 GeV/c are also calculated for $${Z_c^{+}(3900)}$$ Z c + ( 3900 ) and $${Z_c^{-}(3900)}$$ Z c - ( 3900 ) . The production of $${Z_c^{+}(3900)}$$ Z c + ( 3900 ) and its anti-particle $${Z_c^{-}(3900)}$$ Z c - ( 3900 ) are found to be quite similar to each other.

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.

scholarly journals Search for squarks and gluinos in final states with jets and missing transverse momentum using 139 fb−1 of $$ \sqrt{s} $$ = 13 TeV pp collision data with the ATLAS detector

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Simplified Model ◽  
Supersymmetric Particle ◽  
Final States ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
First And Second Generation ◽  
Proton Proton Collisions

Abstract A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. The results are interpreted in the context of various R-parity-conserving models where squarks and gluinos are produced in pairs or in association and a neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.30 TeV for a simplified model containing only a gluino and the lightest neutralino, assuming the latter is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.85 TeV are excluded if the lightest neutralino is massless. These limits extend substantially beyond the region of supersymmetric parameter space excluded previously by similar searches with the ATLAS detector.

scholarly journals Search for $$ t\overline{t} $$ resonances in fully hadronic final states in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Production Cross ◽  
Hadron Collider ◽  
Top Quarks ◽  
Atlas Detector ◽  
Proton Collision ◽  
Large Radius ◽  
Final States ◽  
Jet Substructure ◽  
High Transverse Momentum ◽  
Hadronic Final States

Abstract This paper presents a search for new heavy particles decaying into a pair of top quarks using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search is performed using events consistent with pair production of high-transverse-momentum top quarks and their subsequent decays into the fully hadronic final states. The analysis is optimized for resonances decaying into a $$ t\overline{t} $$ t t ¯ pair with mass above 1.4 TeV, exploiting a dedicated multivariate technique with jet substructure to identify hadronically decaying top quarks using large-radius jets and evaluating the background expectation from data. No significant deviation from the background prediction is observed. Limits are set on the production cross-section times branching fraction for the new Z′ boson in a topcolor-assisted-technicolor model. The Z′ boson masses below 3.9 and 4.7 TeV are excluded at 95% confidence level for the decay widths of 1% and 3%, respectively.

scholarly journals Energy-energy correlations in hadronic final states from Z0 decays

1990 ◽  
Vol 252 (1) ◽  
pp. 149-158 ◽  
Author(s):  
P. Abreu ◽  
W. Adam ◽  
F. Adami ◽  
T. Ayde ◽  
G.D. Alekseev ◽  
...  
Keyword(s):  
Final States ◽  
Hadronic Final States
Sign in / Sign up

Export Citation Format

Share Document