scholarly journals Chiral symmetry in the confinement phase of QCD

2021 ◽  
pp. 2150135
Author(s):  
S. D. Campos
Keyword(s):  
Experimental Data ◽  
Total Cross Section ◽  
Internal Energy ◽  
Cross Section ◽  
Spatial Separation ◽  
Gluon Plasma ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Text Model ◽  
The Difference

Based on the Pomeranchuk theorem, one constructs the [Formula: see text] parameter to measure the difference between experimental data for the particle–particle and particle–antiparticle total cross-section at same energy. The experimental data for the proton–proton and proton–antiproton total cross-section were used to show that, at the same energy, this parameter tends to zero as the collision energy grows. Furthermore, one assumes a classical description for the total cross-section, dividing it into a finite number of non-interacting disjoint cells, each one containing a quark–antiquark pair subject to the confinement potential. Near the minimum of the total cross-section, one associates [Formula: see text] with the entropy generated by these cells, analogously to the [Formula: see text]-model. Using both the Quigg–Rosner and Cornell confinement potentials and neglecting other energy contributions, one can calculate the internal energy of the hadron. One obtains that both the entropy and internal energy possess the same logarithmic dependence on the spatial separation between the pairs in the cell. The Helmholtz free energy is used to estimate the transition temperature, which is far from the temperature widely related to the Quark–Gluon Plasma.

scholarly journals QUESTIONS AND PROSPECTS IN QUARKONIUM POLARIZATION MEASUREMENTS FROM PROTON–PROTON TO NUCLEUS–NUCLEUS COLLISIONS

2012 ◽  
Vol 27 (23) ◽  
pp. 1230022 ◽  
Author(s):  
PIETRO FACCIOLI
Keyword(s):  
Experimental Data ◽  
Quark Gluon Plasma ◽  
Gluon Plasma ◽  
The Other ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Experimental Knowledge ◽  
Polarization Measurements ◽  
Systematic Effects

Polarization measurements are the best instrument to understand how quark and antiquark combine into the different quarkonium states, but no model has so far succeeded in explaining the measured J/ψ and ϒ polarizations. On the other hand, the experimental data in proton–antiproton and proton–nucleus collisions are inconsistent, incomplete and ambiguous. New analyses will have to properly address often underestimated issues: the existence of azimuthal anisotropies, the dependence on the reference frame, the influence of the experimental acceptance on the comparison with other measurements and with theory. Additionally, a recently developed frame-invariant formalism will provide an alternative and often more immediate physical viewpoint and, at the same time, will help probing systematic effects due to experimental biases. The role of feed-down decays from heavier states, a crucial missing piece in the current experimental knowledge, will have to be investigated. Ultimately, quarkonium polarization measurements will also offer new possibilities in the study of the properties of the quark–gluon plasma.

scholarly journals A study of the process e+ + e−→ e+ + e− + p + p̄ by the two-photon mechanism γγ → pp̄ at high energies

2017 ◽  
Vol 32 (18) ◽  
pp. 1750104 ◽  
Author(s):  
Azad I. Ahmadov
Keyword(s):  
Experimental Data ◽  
Total Cross Section ◽  
Cross Section ◽  
Beam Energy ◽  
Center Of Mass ◽  
Proton Antiproton ◽  
Exclusive Production ◽  
Two Photon ◽  
High Energies ◽  
Energy Formula

In this paper, we consider the exclusive production of proton–antiproton pairs in the interaction between two quasireal photons in [Formula: see text] collision. The differential and total cross-section of the process [Formula: see text] at a beam energy of photons from 2.1 GeV to 4.5 GeV in the center-of-mass and for different values of [Formula: see text] is calculated. At energy [Formula: see text] the total cross-section process of the [Formula: see text] is calculated by the two-photon mechanism. The results are in satisfactory agreement with the experimental data.

Measurements of the proton-proton total cross section and small angle elastic scattering at ISR energies

1978 ◽  
Vol 141 (1-2) ◽  
pp. 1-28 ◽  
Author(s):  
L. Baksay ◽  
L. Baum ◽  
A. Böhm ◽  
A. Derevshikov ◽  
G. de Zorzi ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Small Angle ◽  
Proton Proton

scholarly journals Measurement of proton-proton elastic scattering and total cross-section at \chem{\sqrt {s} = 7\,TeV}

2013 ◽  
Vol 101 (2) ◽  
pp. 21002 ◽  
Author(s):  
◽  
G. Antchev ◽  
P. Aspell ◽  
I. Atanassov ◽  
V. Avati ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Proton Proton ◽  
Proton Elastic Scattering

scholarly journals First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
G. Antchev ◽  
P. Aspell ◽  
I. Atanassov ◽  
V. Avati ◽  
J. Baechler ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Scattering Amplitude ◽  
Theoretical Models ◽  
Proton Proton ◽  
Slowing Down ◽  
Proton Elastic Scattering ◽  
Compound State ◽  
Elastic Scattering Amplitude

Abstract The TOTEM experiment at the LHC has performed the first measurement at $$\sqrt{s} = 13\,\mathrm{TeV}$$s=13TeV of the $$\rho $$ρ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at $$t=0$$t=0, obtaining the following results: $$\rho = 0.09 \pm 0.01$$ρ=0.09±0.01 and $$\rho = 0.10 \pm 0.01$$ρ=0.10±0.01, depending on different physics assumptions and mathematical modelling. The unprecedented precision of the $$\rho $$ρ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than $$10\,\mathrm{TeV}$$10TeV (from 2.76 to $$13\,\mathrm{TeV}$$13TeV), has implied the exclusion of all the models classified and published by COMPETE. The $$\rho $$ρ results obtained by TOTEM are compatible with the predictions, from other theoretical models both in the Regge-like framework and in the QCD framework, of a crossing-odd colourless 3-gluon compound state exchange in the t-channel of the proton–proton elastic scattering. On the contrary, if shown that the crossing-odd 3-gluon compound state t-channel exchange is not of importance for the description of elastic scattering, the $$\rho $$ρ value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-|t| reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton–proton cross-section measurement $$\sigma _{\mathrm{tot}} = (110.3 \pm 3.5)\,\mathrm{mb}$$σtot=(110.3±3.5)mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields $$\sigma _{\mathrm{tot}} = (110.5 \pm 2.4)\,\mathrm{mb}$$σtot=(110.5±2.4)mb.

scholarly journals Energy Dependence of Slope Parameter in Elastic Nucleon-Nucleon Scattering

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
V. A. Okorokov
Keyword(s):  
Experimental Data ◽  
Energy Dependence ◽  
Nucleon Nucleon ◽  
High Energy ◽  
Slope Parameter ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Elastic Proton ◽  
Energy Domain ◽  
Very High Energy

The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on all the available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slope is approximated by various analytic functions. The expanded “standard” logarithmic approximations with minimum number of free parameters allow description of the experimental slopes in all the available energy range reasonably. The estimations of asymptotic shrinkage parameterαP′are obtained for various|t|domains based on all the available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering from NICA up to future collider (FCC/VLHC) energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.

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