1,082 research outputs found
Exploring the QCD phase diagram through relativistic heavy ion collisions
We present a review of the studies related to establishing the QCD phase
diagram through high energy nucleus-nucleus collisions. We particularly focus
on the experimental results related to the formation of a quark-gluon phase,
crossover transition and search for a critical point in the QCD phase diagram.Comment: 8 pages, based on invited talk at International Nuclear Physics
Conference (INPC 2013), Firenze, Ital
Estimation of attractive and repulsive interactions from the fluctuation observables at RHIC using van der Waals hadron resonance gas Model
Experimental data on the moments of net-proton distribution in central Au-Au
collisions for various center of mass energies ()
measured by the STAR collaboration at the Relativistic Heavy-Ion Collider
(RHIC) are compared to the corresponding results from a van der Waals type
interacting hadron resonance gas (VDWHRG) model. The parameters representing
the attractive and repulsive interactions in the VDWHRG model have been
extracted by fitting the /, and
, where is the mean, is the standard deviation,
is the skewness and the kurtosis of the net-proton
distribution. Considering all the three moment products we observe that the
strength of the repulsive interactions increases with decrease in
= 200 to 19.6 GeV while the strength of the
attractive interaction is of the similar magnitude. For = 11.5 and 7.7 GeV there is drop in the strength of both attractive
and repulsive interactions relative to = 19.6 GeV. On
the other hand, if we consider only the higher order moment products,
and , which are more sensitive to critical
point physics, a segregation with respect to the strength of the attractive
parameter is observed. The data for = 19.6 and 27 GeV
supports a larger attractive strength compared to other energies. For this
latter case, the repulsive interaction values are of similar order for most of
the beam energies studied, except for 7.7 GeV where the parameter value is not
well constrained due to large uncertainties
The width of the rapidity distribution in heavy ion collisions
We have studied the widths of the rapidity distributions of particles
produced in nucleus-nucleus collisions at various center of mass energies and
as a function of centrality at SPS energies. We show that the width of the
rapidity distribution is sensitive to longitudinal flow, velocity of sound in
the medium, and rescattering of particles. We explore the possibility of
distinguishing the initial hard scattering regime from final state effects by
studying the variation in the width of the rapidity distribution of the
particles with centrality for various pT values.Comment: 4 pages, 6 figures, to appear in Physical Review
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