scholarly journals On the transverse size of hadrons at asymptotically high energies

2020 ◽  
Vol 35 (38) ◽  
pp. 2050314
Author(s):  
M. L. Nekrasov
Keyword(s):  
Transverse Momentum ◽  
Impact Parameter ◽  
Momentum Space ◽  
Parameter Plane ◽  
Square Root ◽  
Transverse Size ◽  
High Energies ◽  
The Impact ◽  
Logarithmic Growth

We show that Gribov diffusion of the partons in the impact parameter plane, which leads to the square-root-of-logarithmic growth of the transverse size of the hadrons, can occur only simultaneously with a similar diffusion in the transverse-momentum space. At the same time, a restriction of the partons in the transverse momenta entails an increase in their propagation in the impact parameter plane. Ultimately this leads to a logarithmic growth of the transverse size of hadrons at asymptotically high energies.

On the Calculation of Pair Creation by Fast Charged Particles and the Effect of Screening

1935 ◽  
Vol 31 (3) ◽  
pp. 394-406 ◽  
Author(s):  
H. J. Bhabha
Keyword(s):  
Impact Parameter ◽  
Momentum Space ◽  
Minimum Distance ◽  
Rest Mass ◽  
Charged Particles ◽  
The Other ◽  
Initial State ◽  
Special Cases ◽  
The Creation ◽  
The Impact

In a recent paper I developed a method for calculating the probability of the creation of an electron pair in the collision of two charged particles moving with a relative velocity very near that of light. I showed there that under certain conditions it is legitimate to treat one of the colliding particles, say the heavier one of charge Z2 and rest mass M2, which we shall call the particle 2, as fixed at the origin of coordinates, and the other, of charge Z1 and rest mass M1, which we shall call the particle 1, as moving classically along a straight line with uniform velocity V in the direction of the z-axis, passing the other particle 2 at a minimum distance of approach (impact parameter) b. I developed expressions (given by (18) to (22) of A) giving the probability of the transition of an electron from an initial state of negative energy E0 and momentum p0 lying in an element of momentum space dp0 to a final state of energy E and momentum p lying in an element of momentum space dp, under the combined perturbing influence of the two colliding particles when they pass at a minimum distance b. The initial state of the electron, left vacant after the transition, appears as a positron of momentum p+ = − p0. To get the differential effective cross-section for the creation of the above pair, we must integrate this probability over all values of the impact parameter b, and this integration can be performed easily as shown in A. The final result can be written as a sum of a finite number of doubly infinite integrals (A, (24)). The purpose of this paper is to carry through the evaluation of these integrals for certain special cases, and to consider the effects of screening. The results have already been communicated in A.

MULTIPARTICLE PRODUCTION FROM THE COHERENT SUPERPOSITION OF STRING-LIKE ENTITIES OVER THE IMPACT-PARAMETER PLANE

1987 ◽  
Vol 02 (09) ◽  
pp. 693-697 ◽  
Author(s):  
SAUL BARSHAY
Keyword(s):  
Impact Parameter ◽  
Particle Production ◽  
Multiplicity Distribution ◽  
Parameter Plane ◽  
Minimum Length ◽  
Natural Feature ◽  
Large Numbers ◽  
New Interpretation ◽  
Energy Dependent ◽  
The Impact

We construct a coherent-model amplitude for n-particle production, which gives rise to the multiplicity distribution <n>Pn = KK/Γ(K)(n/<n>K−1e−K(n/<n>). A natural feature is a new interpretation of the parameter K in terms of an energy-dependent minimum length for a multitude of string-like entities which are stretched forward and backward along the collision direction, over the entire impact-parameter plane. The continuous decrease of K with increasing [Formula: see text] corresponds to the appearance of strings of decreasing length, which leads directly to a continuous broadening of the multiplicity distribution through the emission, with significant probability, of large numbers of, presumably soft, particles.

CENTRALITY, TRANSVERSE MOMENTUM AND PSEUDORAPIDITY DEPENDENCES OF “MACH-LIKE” CORRELATIONS IN A PARTONIC TRANSPORT MODEL

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2029-2034
Author(s):  
SONG ZHANG ◽  
G. L. MA ◽  
Y. G. MA ◽  
X. Z. CAI ◽  
J. H. CHEN
Keyword(s):  
Transverse Momentum ◽  
Impact Parameter ◽  
Transport Model ◽  
Hadronic Interactions ◽  
Azimuthal Correlations ◽  
Central Collisions ◽  
Splitting Parameter ◽  
Multi Phase ◽  
The Impact ◽  
Phase Transport

It has been observed a “Mach-like” structure of di-hadron azimuthal correlations in Au + Au central collisions at [Formula: see text] in the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions. In this paper, we will show centrality, transverse momentum (pT) and pseudorapidity (η) dependences of “Mach-like” structure. The splitting parameter D, i.e. half distance between two splitting peaks on away side, decreases with the impact parameter b (corresponding to centrality) and slightly increases with transverse momentum of associated hadrons [Formula: see text], which from string melting AMPT version is consistent with experimental results. And the splitting parameter D is flat in mid-pseudorapidity region and rapidly decreases with the increasing of high-|η assoc |.

scholarly journals Effects of the reflective scattering in hadron production at high energies

2014 ◽  
Vol 29 (26) ◽  
pp. 1450151 ◽  
Author(s):  
S. M. Troshin ◽  
N. E. Tyurin
Keyword(s):  
Impact Parameter ◽  
Cross Sections ◽  
Hadron Production ◽  
Multiparticle Production ◽  
Gradual Transition ◽  
High Energies ◽  
Production Processes ◽  
Parameter Values ◽  
The Impact ◽  
Production Dynamics

A gradual transition to the reflecting scattering mode developing already at the LHC energies is affecting multiparticle production dynamics, in particular, relation of the centrality with the impact parameter values of pp-collisions. We discuss the issues in the framework of the geometrical picture for the multiparticle production processes proposed by Chou and Yang. We consider effects of reflective scattering mode presence for the inclusive cross-sections.

scholarly journals The cos 2ϕ azimuthal asymmetry in ρ0 meson production in ultraperipheral heavy ion collisions

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Hongxi Xing ◽  
Cheng Zhang ◽  
Jian Zhou ◽  
Ya-Jin Zhou
Keyword(s):  
Transverse Momentum ◽  
Vector Meson ◽  
Cross Section ◽  
Impact Parameter ◽  
Heavy Ion Collisions ◽  
Decay Product ◽  
Heavy Ion ◽  
Azimuthal Asymmetry ◽  
Ion Collisions ◽  
The Impact

Abstract We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We compute the unpolarized cross section and cos 2ϕ azimuthal angular correlation for ρ0 photoproduction with ϕ defined as the angle between the ρ0’s transverse momentum and its decay product pion meson’s transverse momentum. Our result on unpolarized coherent differential cross section gives excellent description to the STAR experimental data. A first compari- son between theoretical calculation and experimental measurement on the cos 2ϕ azimuthal asymmetry, which results from the linearly polarized photons, is performed and reasonable agreement is reached. We find out the characteristic diffractive patterns at both RHIC and LHC energies and predict the impact parameter dependent cos 2ϕ azimuthal asymmetries for ρ0 photoproduction by considering UPCs and peripheral collisions. The future experimental measurements at RHIC and LHC relevant to our calculations will provide a tool to rigorously investigate the coherent and incoherent production of vector meson in UPCs, as well as to probe the nuclear structure in heavy ion collisions.

Poles in the impact parameter plane

1969 ◽  
Vol 62 (2) ◽  
pp. 604-614 ◽  
Author(s):  
N. W. Dean
Keyword(s):  
Impact Parameter ◽  
Parameter Plane ◽  
The Impact

Regge-like poles in the impact parameter plane

1967 ◽  
Vol 52 (4) ◽  
pp. 1129-1151 ◽  
Author(s):  
N. W. Dean
Keyword(s):  
Impact Parameter ◽  
Parameter Plane ◽  
The Impact
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