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 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 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.

scholarly journals Pseudorapidity Distribution of Charged Particles and Square Speed of Sound Parameter inp-porp-p-Collisions over an Energy Range from 0.053 to 7 TeV

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ya-Qin Gao ◽  
Tian Tian ◽  
Li-Na Gao ◽  
Fu-Hu Liu
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Speed Of Sound ◽  
Hydrodynamic Model ◽  
Charged Particles ◽  
Pseudorapidity Distribution ◽  
Proton Antiproton ◽  
Proton Proton ◽  
High Energies ◽  
Related Energy

Pseudorapidity distributions of charged particles produced in proton-proton (p-p) or proton-antiproton (p-p-) collisions over an energy range from 0.053 to 7 TeV are studied by using the four-component Landau hydrodynamic model. The results calculated by the model are in agreement with the experimental data of the UA5, PHOBOS, UA1, P238, CDF, ALICE, and CMS Collaborations which present orderly from low to high energies. According to the distribution widths of different components, the values and some features of square speed of sound parametercs2for “participant” and “spectator” quark components are obtained. It is shown that the speed of sound for “participant” quark components agrees approximately with that for “spectator” quark components in the error ranges. The present work is useful for studying nucleus-nucleus collisions in the related energy range.

Energy density in small systems equal to the one in heavy-ion collisions

2016 ◽  
Vol 25 (07) ◽  
pp. 1642009 ◽  
Author(s):  
G. Paić ◽  
E. Cuautle
Keyword(s):  
Experimental Data ◽  
Energy Density ◽  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Collective Effects ◽  
Small Systems ◽  
Ion Collisions ◽  
Recent Developments ◽  
The One

The recent developments in the study of quark–gluon matter at high densities have shown that there are many similarities between the behavior of the observables in light and heavy systems, especially when the light systems are observed at high multiplicities. Contrary to what was previously thought, the small systems do exhibit collective effects that could indicate that small droplets of strongly interacting quark–gluon plasma are possible. The results infer that the energy densities can be computed in light systems in the same way as in heavy systems and hence, the energy density should be considered when comparing systems with different sizes. We review some of the aspects as well as the existing main models and the way to disentangle them using experimental data.

scholarly journals Computational Modelling of Glucose Uptake in the Enterocyte

Physiome ◽  
2022 ◽  
Author(s):  
Nima Afshar ◽  
Soroush Safaei ◽  
David Nickerson ◽  
Peter J. Hunter ◽  
Vinod Suresh
Keyword(s):  
Experimental Data ◽  
Glucose Transporter ◽  
Computational Modelling ◽  
Glucose Absorption ◽  
Composite Model ◽  
The Other ◽  
Sodium Glucose Cotransporter ◽  
Protein Models

We describe an implemented model of glucose absorption in the enterocyte, as previously published by Afshar et al. (2019), The model used mechanistic descriptions of all the responsible transporters and was built in the CellML framework. It was validated against published experimental data and implemented in a modular structure which allows each individual transporter to be edited independently from the other transport protein models. The composite model was then used to study the role of the sodium-glucose cotransporter (SGLT1) and the glucose transporter type 2 (GLUT2), along with the requirement for the existence of the apical Glut2 transporter, especially in the presence of high luminal glucose loads, in order to enhance the absorption. Here we demonstrate the reproduction of the figures in the original paper by using the associated model. EDITOR'S NOTE (v3): Instructions within the manuscript changed, in order to properly execute the model files. Spelling of author's name corrected in filenames. (v4): Abstract fixes.

scholarly journals Computational Modelling of Glucose Uptake in the Enterocyte

2020 ◽  
Author(s):  
Nima Afshar ◽  
Soroush Safaei ◽  
David Nickerson ◽  
Peter J. Hunter ◽  
Vinod Suresh
Keyword(s):  
Experimental Data ◽  
Glucose Transporter ◽  
Computational Modelling ◽  
Glucose Absorption ◽  
Composite Model ◽  
The Other ◽  
Sodium Glucose Cotransporter ◽  
Protein Models

We describe an implemented model of glucose absorption in the enterocyte, as previously published by Afshar et al. Afshar et al. (2019), The model used mechanistic descriptions of all the responsible transporters and was built in the CellML framework. It was validated against published experimental data and implemented in a modular structure which allows each individual transporter to be edited independently from the other transport protein models. The composite model was then used to study the role of the sodium-glucose cotransporter (SGLT1) and the glucose transporter type 2 (GLUT2), along with the requirement for the existence of the apical Glut2 transporter, especially in the presence of high luminal glucose loads, in order to enhance the absorption. Here we demonstrate the reproduction of the figures in the original paper by using the associated model.

scholarly journals Role of glueballs in non-perturbative quark–gluon plasma

2007 ◽  
Vol 650 (4) ◽  
pp. 239-243 ◽  
Author(s):  
Nikolai Kochelev ◽  
Dong-Pil Min
Keyword(s):  
Quark Gluon Plasma ◽  
Gluon Plasma

scholarly journals FROM COMPLEX TO STOCHASTIC POTENTIAL: HEAVY QUARKONIA IN THE QUARK–GLUON PLASMA

2013 ◽  
Vol 28 (08) ◽  
pp. 1330005 ◽  
Author(s):  
ALEXANDER ROTHKOPF
Keyword(s):  
Quark Gluon Plasma ◽  
First Principles ◽  
Bound States ◽  
Recent Progress ◽  
Open Quantum Systems ◽  
Gluon Plasma ◽  
Quantum Systems ◽  
Heavy Quarkonium ◽  
General Complex

The in-medium physics of heavy quarkonium is an ideal proving ground for our ability to connect knowledge about the fundamental laws of physics to phenomenological predictions. One possible route to take is to attempt a description of heavy quark bound states at finite temperature through a Schrödinger equation with an instantaneous potential. Here we review recent progress in devising a comprehensive approach to define such a potential from first principles QCD and extract its, in general complex, values from non-perturbative lattice QCD simulations. Based on the theory of open quantum systems we will show how to interpret the role of the imaginary part in terms of spatial decoherence by introducing the concept of a stochastic potential. Shortcomings as well as possible paths for improvement are discussed.

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