Universal Transition Curve in Pseudo-Rapidity Distribution

We show that an unambiguous way of determining the universal limiting fragmentation region is to consider the derivative ($d^2n/d\eta^2$) of the pseudo-rapidity distribution per participant pair. In addition, we find that the transition region between the fragmentation and the central plateau regions exhibits a second kind of universal behavior that is only apparent in $d^2n/d\eta^2$. The \sqrts dependence of the height of the central plateau $(dn/d\eta)_{\eta=0}$ and the total charged particle multiplicity $n_{\rm total}$ critically depend on the behavior of this universal transition curve. Analyzing available RHIC data, we show that $(dn/d\eta)_{\eta=0}$ can be bounded by $\ln^2 s$ and $n_{\rm total}$ can be bounded by $\ln^3 s$. We also show that the deuteron-gold data from RHIC has the exactly same features as the gold-gold data indicating that these universal behaviors are a feature of the initial state parton-nucleus interactions and not a consequence of final state interactions. Predictions for LHC energy are also given.Comment: Published version. dA data also shown to follow the same trend. 29 pages in revtex4. Includes 19 figures in ep

Statistical and Dynamic Models of Charge Balance Functions

Charge balance functions, which identify balancing particle-antiparticle pairs on a statistical basis, have been shown to be sensitive to whether hadronization is delayed by several fm/c in relativistic heavy ion collisions. Results from two classes of models are presented here, microscopic hadronic models and thermal models. The microscopic models give results which are contrary to recently published pi+pi- balance functions from the STAR collaboration, whereas the thermal model roughly reproduce the experimental results. This suggests that charge conservation is local at breakup, which is in line with expectations for a delayed hadronization. Predictions are also presented for balance functions binned as a function of Q_inv.Comment: 12 pages 6 figure

Predictions for p+Pbp+Pb Collisions at sNN=5TeV\sqrt s_NN = 5 TeV

Albacete JL, Armesto N, Baier R, et al. Predictions for $p+Pb$ Collisions at $\sqrt s_NN = 5 TeV$. International Journal of Modern Physics E. 2013;22(04): 1330007.Predictions for charged hadron, identified light hadron, quarkonium, photon, jet and gauge bosons in p + Pb collisions at root s(NN) = 5 TeV are compiled and compared. When test run data are available, they are compared to the model predictions