scholarly journals Short- and long-range rapidity correlations in the model with a lattice in transverse plane

2018 ◽  
Vol 191 ◽  
pp. 04011 ◽  
Author(s):  
Vladimir Vechernin
Keyword(s):  
Long Range ◽  
Impact Parameter ◽  
String Model ◽  
High Energy ◽  
Transverse Plane ◽  
Observation Window ◽  
Hadronic Interactions ◽  
Fundamental String ◽  
Different Types ◽  
The Impact

In the framework of the quark-gluon string model we consider the various fluctuation and correlation observables used in the analysis of the multiparticle production in hadronic interactions at high energy. We express these observables through the fundamental string characteristics and analyze their resulting properties: the dependence on the width of observation window(s), the range of the correlation in rapidity, the intensive or strongly intensive behavior. To take into account the influence of a string fusion processes on the string characteristics and on the behavior of the observables. we use the version of string model with a lattice (grid) in the impact parameter plane. In particular we show that the observable between multiplicities in two acceptance windows separated in rapidity, which is a strongly intensive in the case with independent identical strings, loses this property, when we take into account the string fusion and the formation of strings of a few different types takes place in a collision.

SOME CHARACTERISTICS OF THE COMPOUND MULTIPLICITY IN HIGH-ENERGY NUCLEUS–NUCLEUS INTERACTIONS

2011 ◽  
Vol 20 (08) ◽  
pp. 1735-1754 ◽  
Author(s):  
M. MOHERY ◽  
M. ARAFA
Keyword(s):  
Experimental Data ◽  
Impact Parameter ◽  
Mass Number ◽  
Multiplicity Distribution ◽  
High Energy ◽  
Projectile Nucleus ◽  
Target Mass ◽  
Compound Multiplicity ◽  
Multiplicity Distributions ◽  
The Impact

The present paper deals with the interactions of 22 Ne and 28 Si nuclei at (4.1–4.5)A GeV /c with emulsion. Some characteristics of the compound multiplicity nc given by the sum of the number of shower particles ns and grey particles ng have been investigated. The present experimental data are compared with the corresponding ones calculated according to modified cascade evaporation model (MCEM). The results reveal that the compound multiplicity distributions for these two reactions are consistent with the corresponding ones of MCEM data. It can also be seen that the peak of these distributions shifts towards a higher value of nc with increasing projectile mass. It may further be seen that the compound multiplicity distributions becomes broader with increasing target size and its width increases with the size of the projectile nucleus. In addition, it has been found that the MCEM can describe the compound multiplicity characteristics of the different projectile, target and the correlation between different emitted particles. The values of average compound multiplicity increase with increasing mass of the projectile. Furthermore, it is observed that while the value of 〈nc〉 depends on the mass number of the projectile Ap and the target mass number At, the value of the ratio 〈nc〉/D(nc) seems to be independent of Ap and At. The impact parameter is found to affect the shape of the compound multiplicity distribution. Finally, the dependence of the average compound multiplicity on the numbers of grey and black particles, and the sum of them, is obvious. The values of the slope have been found to be independent of the projectile nucleus.

scholarly journals TACHYON DYNAMICS OF THE BLACK DISC LIMIT IN THE HARD SMALL x PROCESSES IN QCD

2006 ◽  
Vol 21 (07) ◽  
pp. 549-558 ◽  
Author(s):  
B. BLOK ◽  
L. FRANKFURT
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
High Energy ◽  
Black Disk ◽  
Black Disc ◽  
Energy Behavior ◽  
Small X ◽  
The Cross ◽  
The Impact ◽  
Black Disc Limit

We investigate the effective field theory (EFT) which gives the approximate description of the scattering of two hard small dipoles in the small x processes in QCD near the black disc limit (BDL). We argue that the perturbative QCD approaches predict the existence of tachyon and visualize it in the approximation where α′P=0. We demonstrate that the high energy behavior of the cross-section depends strongly on the diffusion law in the impact parameter plane. On the other hand, almost threshold behavior of the cross section of the hard processes and multiplicities, i.e. fast increase of cross sections (color inflation), melting of ladders into color network and softening of the longitudinal distributions of hadrons are qualitatively insensitive to the value of diffusion in the impact parameter space. We evaluate α′P near the black disk limit and find significant α′P as the consequence of the probability conservation.

scholarly journals Dependence of the multiplicities of secondary particles on the impact parameter in collisions of high-energy neon and iron nuclei with photoemulsion nuclei

1993 ◽  
Vol 551 (4) ◽  
pp. 723-733 ◽  
Author(s):  
V.E. Dudkin ◽  
E.E. Kovalev ◽  
N.A. Nefedov ◽  
V.A. Antonchik ◽  
S.D. Bogdanov ◽  
...  
Keyword(s):  
Impact Parameter ◽  
High Energy ◽  
Secondary Particles ◽  
The Impact

Nonstatistical fluctuations of target fragments emitted in high-energy nucleus–nucleus collisions

2002 ◽  
Vol 80 (2) ◽  
pp. 119-128
Author(s):  
N N Abd-Allah
Keyword(s):  
Excitation Energy ◽  
Impact Parameter ◽  
Target Nucleus ◽  
Incident Energy ◽  
Nuclear Emulsion ◽  
Residual Nucleus ◽  
High Energy ◽  
Critical Value ◽  
Nucleus Interaction ◽  
The Impact

Analysis of target-fragmented "black" particles in nuclear emulsion from high-energy relativistic interactions initiated by 28Si at 4.5 A GeV/c is investigated. The number of slowly emitted particles from the struck target nucleus is considered as a measure of the degree of excitation of the residual nucleus. This number shows a constant critical value, with the degree of the impact parameter or the degree of excitation. The target evaporation particles of nucleus–nucleus interaction reveal the existence of nonstatistical fluctuations in the azimuthal plane of the interaction. The asymmetry or nonstatistical fluctuations, while found to be independent of projectile mass or incident energy, are dependent on the excitation energy of the target nucleus. A multiparticle correlation is observed between created particles as well as target fragments. This assumes production of clusters. These clusters seem to be formed during the decoloring process. PACS No.: 25.70Mn

On the possibility of gluon number fluctuations in diffractive deep inelastic scattering data with impact parameter

2016 ◽  
Vol 31 (33) ◽  
pp. 1650186
Author(s):  
Z. Hu ◽  
W. Xiang ◽  
S. Cai
Keyword(s):  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Impact Parameter ◽  
Scattering Amplitude ◽  
Global Analysis ◽  
High Energy ◽  
Scattering Data ◽  
Deep Inelastic Scattering Data ◽  
Saturation Exponent ◽  
The Impact

A global analysis of the latest diffractive deep inelastic scattering (DIS) data with gluon number fluctuations and impact parameter is performed. The impact parameter is introduced into the scattering amplitude by saturation scale with a Gaussian b-dependence. The results show that the description of the diffractive DIS data is improved once the gluon number fluctuations and impact parameter are included, with [Formula: see text]/d.o.f = 0.878, [Formula: see text]/d.o.f = 0.928 and [Formula: see text]/d.o.f = 0.897 in different sets of free parameters. Moreover, we find that the impact parameter ([Formula: see text] 0.1) is possibly compressed by the gluon number fluctuations, which leads to the value of saturation exponent returning to [Formula: see text] 0.2. This outcome is compatible with the prediction that the saturation exponent is dominated by the fluctuations at sufficiently high energy, which may indicate the possibility of gluon number fluctuations in diffractive DIS data.

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 ON THE DISTRIBUTION OF PARTONS IN THE TRANSVERSE PLANE

2006 ◽  
Vol 21 (04) ◽  
pp. 938-941
Author(s):  
M. DIEHL
Keyword(s):  
Spatial Distribution ◽  
Angular Momentum ◽  
Impact Parameter ◽  
Form Factors ◽  
Transverse Plane ◽  
Recent Analysis ◽  
Longitudinal Momentum ◽  
Average Impact ◽  
Nucleon Form Factors ◽  
The Impact

Elastic nucleon form factors constrain the spatial distribution of quarks in the impact parameter plane. A recent analysis found that the average impact parameter of quarks strongly depends on their longitudinal momentum, and obtained an estimate of the orbital angular momentum carried by valence quarks in the proton.

scholarly journals Study of contributions of diffractive processes to forward neutral particle production with the ATLAS-LHCf detector

2019 ◽  
Vol 208 ◽  
pp. 05008
Author(s):  
Qi-Dong Zhou
Keyword(s):  
Particle Production ◽  
Neutral Particle ◽  
Specific Interaction ◽  
High Energy ◽  
Joint Analysis ◽  
Mass Composition ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Interaction Types ◽  
The Impact

LHCf is an experiment dedicated to verify the hadronic interaction models by measuring the forward neutral particle production at the LHC. Corresponding data are very important for understanding hadronic interactions occurring in air-shower development. According to the current LHCf results, no simulation model predicts the LHCf data perfectly. In order to provide more specific data, it is necessary to classify the LHCf observables into specific interaction types: diffraction or non-diffraction. Combining the information of ATLAS, LHCf is able to classify these specific interaction types experimentally. Especially, the ATLAS-LHCf joint experiment will have the unique sensitivity to low mass diffraction. LHCf and ATLAS have succeeded in the common data-taking in p-p collisions at √s = 13 TeV. We will report the first ATLAS-LHCf joint analysis result and discuss the impact of the corresponding joint analysis result to the determination of mass composition of ultra-high energy cosmic-rays.

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