Related papers: Sommerfeld effect in heavy quark chemical equilibr…
We compute the color coherence effects for soft gluon radiation off antennas containing heavy quarks in the presence of a QCD medium - in color singlet, triplet or octet global states. This work completes the studies of antenna radiation…
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $\gamma\gamma$ collisions. The results are relevant to heavy quark…
The magnitude of the strong interaction is characterized by $\alpha_s$, the coupling parameter in Quantum Chromodynamics (QCD), a parameter with an unexplained value in the Standard Model. In this paper, a candidate explanation for…
We calculate the heavy quarkonium energy levels and decay widths in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> T >> m alpha_s^2 >> m_D (m being the heavy-quark mass), at order m…
Within first-order phase transitions, we investigate the pre-transitional effects due to the nonperturbative, large-amplitude thermal fluctuations which can promote phase mixing before the critical temperature is reached from above. In…
The relativistic Fokker Planck equation has been used to study the evolution of the quark distribution in the quark gluon phase expected to be formed in ultra-relativistic heavy ion collisions. The effect of thermal masses for quarks and…
Heavy-ion experiments have recently revealed that azimuthal momentum anisotropy -- elliptic flow -- of direct photons from a QCD medium is a few times larger than hydrodynamic predictions. I present a possible explanation for the…
We present an introductory review of the early time dynamics of high-energy heavy-ion collisions and the kinetics of high temperature QCD. The equilibration mechanisms in the quark-gluon plasma uniquely reflect the non-abelian and…
Charm- and bottom-quark rescattering in a Quark-Gluon Plasma (QGP) is investigated with the objective of assessing the approach towards thermalization. Employing a Fokker-Planck equation to approximate the collision integral of the…
Hadronic annihilation rate of $1^{+-}$ heavy quarkonium is given to next-to-leading order in $\alpha_s$ and leading order in $v^2$ using a recently developed factorization formalism which is based on NRQCD. The result includes both the…
We extend the analysis of asymmetric Dark Matter relic density with Sommerfeld enhancement to the case where the mediator is massive. In asymmetric Dark Matter models, the asymmetric Dark Matter is assumed to couple to light scalar or…
In this paper, we suggest a method of a complete calculation of the Sommerfeld effect in both the s-wave and p-wave annihilation situations. The basic idea is to uniformly consider the equal-time Beth-Salpeter wave functions of both the…
It is shown that the correction to the vertex for fermion pair annihilation and production in the low-energy region is equal to the value of the wave function for the two-body system at the origin. The procedure also shows directly that the…
The onset of thermalization in heavy ion collisions in the weak coupling framework can be viewed as a transition from the initial state Color Glass Condensate dynamics, characterized by the energy density scaling like $\epsilon \sim 1/\tau$…
The vacuum parton creation in quickly varying external fields is studied at the time scale of order 1 fm/$c$ typical for the quark-gluon plasma formation and thermalization. To describe the pre-equilibrium evolution of the system the…
Quarkonium suppression in heavy ion collisions is a potential signature of the formation of the quark-gluon plasma. After a very brief review of the J/psi result at CERN, we restrict our discussion to the effects of the high-energy multiple…
We compute the imaginary part of the heavy quark contribution to the photon polarization tensor, i.e. the quarkonium spectral function in the vector channel, at next-to-leading order in thermal QCD. Matching our result, which is valid…
We study the impact of the Sommerfeld enhancement on the thermal relic density of the lightest neutralino in the case of large co-annihilation effects with a scalar particle. The proper way of including the Sommerfeld effect in this case is…
The recent experimental results on the flow of $J/\psi$ at LHC show that ample amount of charm quarks is present in the quark gluon plasma and probably they are thermalized. In the current study we investigate the effect of thermalized…
We follow Quark-gluon transport theory and analyse singularities of the ultra-relativistic and spherical expanding quark-gluon plasma. Within the linearized QCD oscillations and instabilities of the ultra-relativistic and spherical…