5,944 research outputs found
Fractional spin through quatum (super)Virasoro algebras
The splitting of a -deformed boson, in the Q\to q=e^{\frac{\QTR{rm}{2\pi
i}}{\QTR{rm}{k}}} limit, is discussed. The equivalence between a -fermion
and an ordinary one is established. The properties of the quantum
(super)Virasoro algebras when their deformation parameter goes to a root of
unity, are investigated. These properties are shown to be related to fractional
supersymmetry and -fermionic spin
Dissociation of Quarkonium in hot and Dense Media in an Anisotropic Plasma in the Non-Relativistic Quark Model
In this paper, quarkonium dissociation is investigated in an anisotropic
plasma in the hot and dense media. For that purpose, the multidimensional
Schrodinger equation is solved analytically by Nikiforov-Uvarov (NU) method for
the real part of the potential in an anisotropic medium. The binding energy and
dissociation temperature are calculated. In comparison with an isotropic
medium, the binding energy of quarkonium is enhanced in the presence of an
anisotropic medium. The present results show that the dissociation temperature
increases with increasing anisotropic parameter for 1S state of the charmonium
and bottomonium. We observe that the lower baryonic chemical potential has
small effect in both isotropic and anisotropic media. A comparison is presented
with other pervious theoretical works.Comment: 11 pages, 10 figures, 1 table
Dissipative Processes in the Early Universe: Bulk Viscosity
In this talk, we discuss one of the dissipative processes which likely take
place in the Early Universe. We assume that the matter filling the isotropic
and homogeneous background is to be described by a relativistic viscous fluid
characterized by an ultra-relativistic equation of state and finite bulk
viscosity deduced from recent lattice QCD calculations and heavy-ion collisions
experiments. We concentrate our treatment to bulk viscosity as one of the
essential dissipative processes in the rapidly expanding Early Universe and
deduce the dependence of the scale factor and Hubble parameter on the comoving
time . We find that both scale factor and Hubble parameter are finite at
, revering to absence of singularity. We also find that their evolution
apparently differs from the one resulting in when assuming that the background
matter is an ideal and non-viscous fluid.Comment: 8 pages, 2 eps figure, Invited talk given at the 7th international
conference on "Modern Problems of Nuclear Physics", 22-25 September 2009,
Tashkent-Uzbekista
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