Monte Carlo Glauber wounded nucleon model with meson cloud

Abstract

We study the effect of the nucleon meson cloud on predictions of the Monte Carlo Glauber wounded nucleon model for AA, pA, and pp collisions. From the analysis of the data on the charged multiplicity density in AA collisions we find that the meson-baryon Fock component reduces the required fraction of binary collisions by a factor of ∼ 2 for Au+Au collisions at √ s = 0.2 TeV and ∼ 1.5 for Pb+Pb collisions at √ s = 2.76 TeV. For central AA collisions the meson cloud can increase the multiplicity density by ∼ 16 − 18%. We give predictions for the midrapidity charged multiplicity density in Pb+Pb collisions at √ s = 5.02 TeV for the future LHC run 2. We find that the meson cloud has a weak effect on the centrality dependence of the ellipticity ǫ2 in AA collisions. For collisions of the deformed uranium nuclei at √ s = 0.2 TeV we find that the meson cloud may improve somewhat agreement with the data on the dependence of the elliptic flow on the charged multiplicity for very small centralities defined via the ZDCs signals. We find that the meson cloud may lead to a noticeable reduction of ǫ2 and the size of the fireball in pA and pp collisions.

Forward-backward multiplicity fluctuations in ultrarelativistic nuclear collisions with wounded quarks and fluctuating strings

“…Whereas the wounded nucleon scaling [5], when applied to the highest BNL Relativistic Heavy-Ion Collider (RHIC) or the CERN Large Hadron Collider (LHC) energies, requires a sizable admixture of binary collisions [6,7], the scaling based on wounded quarks [8][9][10][11] works remarkably well [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Another successful approach [29,30] amends the wounded nucleons with a meson-cloud component.…”

Updated analysis of jet quenching at RHIC and LHC within the light cone path integral approach

“…We determine the total entropy in the overlap region using the charged hadron multiplicity pseudorapidity density dN ch /dη calculated in the Glauber wounded nucleon model [48]. We use the parameters of the model as in our Monte-Carlo Glauber analyses [49,50], which describe very well data on the midrapidity dN ch /dη in 0.2 TeV Au + Au [51], 2.76 [52] and 5.02 TeV [53] Pb + Pb, and 5.44 TeV Xe + Xe [54] collisions. For the ideal gas model the entropy density reads s(T ) = aT 3 with a = 4π 2 15 8/3 + 7N f /4 (a ≈ 18.53, if one takes N f = 2.5).…”

“…This choice gives 2 that vanishes as centrality tends to zero. In the second variant we use the rms 2 (it is often denoted 2 {2}) obtained in our previous Monte-Carlo Glauber model simulations [49,50] of AA-collisions. In this case, due to the density fluctuations, the eccentricity does not vanishes at zero centrality.…”

Jet quenching from heavy to light ion collisions

“…where S f is the area of the overlap region of two colliding nuclei, and C = dS/dy dN ch (AA)/dη ≈ 7.67 [57] is the entropy/multiplicity ratio. We calculate dN ch (AA)/dη in the Glauber wounded nucleon model [58] with parameters of the model as in our Monte-Carlo Glauber analyses [59,60], which describe very well data on the midrapidity dN ch /dη in 0.…”

“…We perform calculations of v 2 for two choices of the fireball eccentricity 2 . For the first variant, we calculate 2 in the optical Glauber wounded nucleon model, and for the second variant we use 2 obtained in the Monte-Carlo Glauber model of [59,60]. The Monte-Carlo version gives 2 , which, contrary to the optical model one, does not vanish for central collisions (due to density fluctuations).…”