Tests of constituent-quark generation methods which maintain both the nucleon center of mass and the desired radial distribution in Monte Carlo Glauber models

Mitchell, J. T.; Perepelitsa, D. V.; Tannenbaum, M. J.; Stankus, P. W.

doi:10.1103/physrevc.93.054910

Cited by 37 publications

(33 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wounded quark scaling also works for the SPS energy range [15]. More recent studies were reported in [16][17][18][19].Our results for particle production at midrapidity are shown in Fig. 1.…”

supporting

confidence: 62%

See 1 more Smart Citation

On wounded constituents in nuclear collisions

Božek¹,

Broniowski²,

Rybczyński³

2017

EPJ Web Conf.

View full text Add to dashboard Cite

Abstract. In this talk we summarize the main results of our recent paper [1], where we explore predictions of the wounded quark model for particle production and the properties of the initial state formed in ultra-relativistic collisions of atomic nuclei.Particle-particle interactions at high energies usually lead to copious production of new particles whose number rises as a function of the collision energy. The charged particle multiplicity (N ch ) and its pseudorapidity density (dN ch /dη) are fundamental measurable quantities which serve as important characteristics of the global properties of the system. The data on production of particles in relativistic collisions of atomic nuclei collected during the operation of RHIC [2,3] and the LHC [4] accelerators indicate that the standard wounded nucleon model [5] (according to the definition, a wounded nucleon is the one which underwent at least one inelastic collision) does not describe the observed centrality dependence of particle multiplicities in the A+A collisions, unless a component proportional to the binary collisions [6] is added.We are interested in the impact of subnucleonic components of matter on the dynamics of the of the early stage of the collisions, and explore th wounded quark model [10][11][12][13]. One of the interesting results of [1] is that taking into account subnucleonic degrees of freedom in the description of the early phase of the collision one obtains the linear dependence of production of particles as a function of the number of wounded constituents, namelywhere Q W is the number of wounded constituents involved in the collision. Such scaling has been suggested in [14] for the RHIC data. The wounded quark scaling also works for the SPS energy range [15]. More recent studies were reported in [16][17][18][19].Our results for particle production at midrapidity are shown in Fig. 1. We note an approximately flat centrality dependence of dN ch /dη/Q W in qualitative agreement with the earlier studies [8,14,15,20]. In contrast, the flatness is not the case in the wounded nucleon model, where, as is well known, the ratio dN ch /dη/N W substantially increases with the number of wounded nucleons, N W . The value of dN ch /dη/Q W (i.e., the average number of charged hadrons per unit of rapidity coming from a single Presented by M. Rybczyński a

show abstract

supporting

confidence: 62%

“…The wounded quark scaling also works for the SPS energy range [15]. More recent studies were reported in [16][17][18][19].…”

mentioning

confidence: 99%

On wounded constituents in nuclear collisions

Božek¹,

Broniowski²,

Rybczyński³

2017

EPJ Web Conf.

View full text Add to dashboard Cite

show abstract

“…Shifting the nucleons by the average displacement, however, introduces a distortion of the radial profile, which increases with decreasing degrees of freedom. This effect has been recently discussed in Glauber approaches accounting for subnucleonic degrees of freedom, where the distortion is particularly large when only three partons (quarks) are distributed inside a proton [64]. For a 208 Pb nucleus, the width of the center-of-mass shift is about 0.2 fm in each direction, and the effect of the associated distortions have so far been ignored.…”

Section: Recenteringmentioning

confidence: 99%

Improved Monte Carlo Glauber predictions at present and future nuclear colliders

2018

View full text Add to dashboard Cite

We present the results of an improved Monte Carlo Glauber (MCG) model of relevance for collisions involving nuclei at center-of-mass energies of BNL RHIC ( √ s NN = 0.2 TeV), CERN LHC ( √ s NN = 2.76-8.8 TeV), and proposed future hadron colliders ( √ s NN ≈ 10-63 TeV). The inelastic pp cross sections as a function of √ s NN are obtained from a precise data-driven parametrization that exploits the many available measurements at LHC collision energies. We describe the nuclear density of a lead nucleus with two separated 2-parameter Fermi distributions for protons and neutrons to account for their different densities close to the nuclear periphery. Furthermore, we model the nucleon degrees of freedom inside the nucleus through a lattice with a minimum nodal separation, combined with a "recentering and reweighting" procedure, that overcomes some limitations of previous MCG approaches. The nuclear overlap function, number of participant nucleons and binary nucleonnucleon collisions, participant eccentricity and triangularity, overlap area and average path length are presented in intervals of percentile centrality for lead-lead (PbPb) and proton-lead (pPb) collisions at all collision energies. We demonstrate for collisions at √ s NN = 5.02 TeV that the central values of the Glauber quantities change by up to 7% in a few bins of reaction centrality, due to the improvements implemented, though typically remain within the previously assigned systematic uncertainties, while their new associated uncertainties are generally smaller (mostly below 5%) at all centralities than for earlier calculations. Tables for all quantities versus centrality at present and foreseen collision energies involving Pb nuclei, as well as for collisions of XeXe at √ s NN = 5.44 TeV, and AuAu and CuCu at √ s NN = 0.2 TeV, are provided. The source code for the improved Monte Carlo Glauber model is made publicly available.

show abstract

“…Without resort to non-perturbative physics, it is difficult to justify this model, since particle production is thought to be perturbative in the regime where partons are good degrees of freedom, and perturbative dynamics does not scale with participants. But phenomenologically a wounded quark model appears to work [22][23][24][25] well enough that fusing this with the geometrical deep inelastic scattering warrants a try.…”

Section: Partonic Nuclear Dynamics and Limiting Fragmentationmentioning

confidence: 99%

“…We then argue that a currently popular model capable of bringing the applicability of limiting fragmentation to LHC energies and varying system sizes, provided it is indeed confirmed experimentally, is a "wounded parton model", with Glauber wounded partons [22][23][24][25][26] smeared in rapidity space according to Bjorken scaling. We conclude with some experimental considerations regarding this observable.…”

Section: Introductionmentioning

confidence: 99%

Limiting fragmentation as an initial-state probe in heavy ion collisions

et al. 2019

View full text Add to dashboard Cite

We discuss limiting fragmentation within a few currently popular phenomenological models. We show that popular Glauber-inspired models of particle production in heavy ion collisions, such as the two-component model, generally fail to reproduce limiting fragmentation when all energies and system sizes experimentally available are considered. This is due to the energy-dependence of number of participants and number of collisions. We quantify this violation in terms of the model parameters. We also make the same calculation within a Color Glass Condensate scenario and show that the dependence of the saturation scale on the number of participants generally leads to violation of limiting fragmentation. We further argue that wounded parton models, provided the nucleon size and parton density vary predominantly with Bjorken x, could in principle reproduce both multiplicity dependence with energy and limiting fragmentation. We suggest, therefore, that an experimental measurement of deviation from limiting fragmentation in heavy ion collisions, for different system sizes and including the experimentally available range of energies, is a powerful test of initial state models.

show abstract

Tests of constituent-quark generation methods which maintain both the nucleon center of mass and the desired radial distribution in Monte Carlo Glauber models

Cited by 37 publications

References 31 publications

On wounded constituents in nuclear collisions

On wounded constituents in nuclear collisions

Improved Monte Carlo Glauber predictions at present and future nuclear colliders

Limiting fragmentation as an initial-state probe in heavy ion collisions

Contact Info

Product

Resources

About