160 research outputs found
Forward and midrapidity charmonium production at RHIC
production at forward and midrapidity at the Relativistic Heavy-Ion
Collider (RHIC) is calculated within a previously constructed rate-equation
approach accounting for both direct production and regeneration from and
. The results are compared to experimental data. The observed stronger
suppression at forward rapidity can be qualitatively explained by a smaller
statistical regeneration component together with stronger cold nuclear matter
induced suppression compared to midrapidity. The over ratio
and over ratio are also calculated.Comment: 8 pages, 19 figures, Proceeding for Hot Quarks 200
Nonperturbative Quantum Field Evolution
We introduce a nonperturbative, first-principles approach to time-dependent
problems in quantum field theory. In this approach, the time-evolution of
quantum field configurations is calculated in real time and at the amplitude
level. This method is particularly suitable for treating systems interacting
with a time-dependent background field. As a test problem, we apply this
approach to QED and study electron acceleration and the associated photon
emission in a time- and space-dependent electromagnetic background field.Comment: 6 pages, 3 figues, proceeding of the Lightcone 2013 conference
(Skiathos, Greece, May 20-24, 2013
Non-perturbative quantum time evolution on the light-front
This paper introduces "time-dependent basis light-front quantization", which
is a covariant, nonperturbative, and first principles numerical approach to
time-dependent problems in quantum field theory. We demonstrate this approach
by evaluating photon emission from an electron in a strong, time and space
dependent external field. We study the acceleration of the electron in
combination with the evolution of the invariant mass of the electron-photon
system, in real time and at the amplitude level. Successive excitations of the
electron-photon system are evident.Comment: 7 pages, 3 figures. To appear in Physics Letters
Charmonium in Medium: From Correlators to Experiment
We set up a framework in which in-medium charmonium properties are
constrained by thermal lattice QCD and subsequently implemented into a thermal
rate equation enabling the comparison with experimental data in heavy-ion
collisions. Specifically, we evaluate phenomenological consequences for
charmonium production originating from two different scenarios in which either
the free or the internal energy are identified with the in-medium 2-body
potential between charm and anti-charm quarks. These two scenarios represent
"melting temperatures" of approximately 1.25\, ("weak binding")
and 2\, ("strong binding"), respectively. Within current uncertainties in
dissociation rates and charm-quark momentum spectra, both scenarios can
reproduce the centrality dependence of inclusive yields in nuclear
collisions at SPS and RHIC reasonably well. However, the "strong-binding"
scenario associated the the internal energy as the potential tends to better
reproduce current data on transverse momentum spectra at both SPS and RHIC.Comment: 18 pages, 30 figure
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