Strong longitudinal color-field effects inppcollisions at energies available at the CERN Large Hadron Collider

Abstract

We study the effect of strong longitudinal color fields (SCF) in p+p reactions up to Large Hadron Collider energies in the framework of the HIJING/BB v2.0 model that combines (collinear factorized) pQCD multiple minijet production with soft longitudinal string excitation and hadronization.The default vacuum string tension, κ 0 = 1 GeV/fm, is replaced by an effective energy dependent string tension, κ(s) = κ 0 (s/s 0 ) 0.06 that increases monotonically with center-of-mass energy. The exponent λ = 0.06 is found sufficient to reproduce well the energy dependence of multiparticle observables in RHIC, Tevatron, as well as recent LHC data. This exponent is half of that predicted by the Color Glass Saturation (CGC) model, λ CGC = 0.115, where gluon fusion multiparticle production mechanisms are assumed. In HIJING/BB v2.0, the rapid growth of dN ch /dη with energy is due to the interplay of copious minijet production with increasing of strong color field (SCF) contributions. The large (strange)baryon-to-meson ratios measured at Tevatron energies are well described. A significant enhancement of these ratios is predicted up to the highest LHC energy (14 TeV). The effect of JJ loops and SCF on baryon-anti-baryon asymmetry, and its relation to baryon number transport, is also discussed.PACS numbers: 12.38. Mh, 24.85.+p, 25.40Ve, 1

Strange particle production in pp collisions at $ \sqrt {s} = 0.9 $ and 7 TeV

“…As the strange quark is heavier than up and down quarks, production of strange hadrons is generally suppressed relative to hadrons containing only up and down quarks. The amount of strangeness suppression is an important component in Monte Carlo (MC) models such as Pythia [5] and hijing/bb [6]. Because the threshold for strange quark production in a quark-gluon plasma is much smaller than in a hadron gas, an enhancement in strange particle production has frequently been suggested as an indication of quark-gluon plasma formation [7].…”

Multiplicity-dependent pT distributions of identified particles in pp collisions at 7 TeV within the HIJING/ BB¯Pop1, Petrovici2 2018Phys. Rev. CSelf Cite1000View full textAdd to dashboardCite

“…The HIJING 1.0 model has been discussed in detail in our previous papers [59,60,63]. Here, we briefly summarize the main assumptions and parameters determined as in Ref.…”

“…Heavy ion jet interacting (HIJING)-type models [32,33], HIJING2.0 [53,54], and HIJING/BB v2.0 [55][56][57][58][59][60][61][62][63][64][65] were developed in order to explain the hadron production in pp, p-A, and A-A collisions. These approaches are based on a two-component geometrical model of minijet production and soft interaction and incorporate nuclear effects such as shadowing and jet quenching, via final-state jet medium interaction.…”

“…These approaches are based on a two-component geometrical model of minijet production and soft interaction and incorporate nuclear effects such as shadowing and jet quenching, via final-state jet medium interaction. The HIJING/BB v2.0 model [57,59] includes new dynamical effects associated with long-range coherent fields (i.e., strong longitudinal color fields, SLCF), via baryon junctions and loops [56,66]. At RHIC, it was shown [55][56][57] that the dynamics of strangeness production deviates from calculations based on Schwinger-like estimates for homogeneous and constant color fields [16], pointing to a possible contribution of fluctuations of transient SLCF.…”

“…The typical field strength of SLCF at ultrarelativistic energies, in a scenario with QGP phase transition, was estimated to be about 5-12 GeV/fm [67]. Global observables and identified particle (ID) data, including (multi)strange particles production in pp [59,60,63] p-Pb [62,64,65], and Pb-Pb collisions [61] at the LHC energies were successfully described by the HIJING/BB v2.0 model. However, correlations among different measurable quantities in multiparticle production offer a better way to constrain the models.…”