1,273 research outputs found
Color Superconductivity in N=2 Supersymmetric Gauge Theories
We study vacuum structure of N=2 supersymmetric (SUSY) QCD, based on the
gauge group SU(2) with N_f=2 flavors of massive hypermultiplet quarks, in the
presence of non-zero baryon chemical potential (\mu). The theory has a
classical vacuum preserving baryon number symmetry, when a mass term, which
breaks N=2 SUSY but preserves N=1 SUSY, for the adjoint gauge chiral multiplet
(m_{ad}) is introduced. By using the exact result of N=2 SUSY QCD, we analyze
low energy effective potential at the leading order of perturbation with
respect to small SUSY breaking parameters, \mu and m_{ad}. We find that the
baryon number is broken as a consequence of the SU(2) strong gauge dynamics, so
that color superconductivity dynamically takes place at the non-SUSY vacuum.Comment: 15 pages, 9 figures, a figure and discussions added in Sec. 4,
version to appear in Phys. Rev.
Parton showers as sources of energy-momentum deposition in the QGP and their implication for shockwave formation at RHIC and at the LHC
We derive the distribution of energy and momentum transmitted from a primary
fast parton and its medium-induced bremsstrahlung gluons to a thermalized
quark-gluon plasma. Our calculation takes into account the important and thus
far neglected effects of quantum interference between the resulting color
currents. We use our result to obtain the rate at which energy is absorbed by
the medium as a function of time and find that the rate is modified by the
quantum interference between the primary parton and secondary gluons. This
Landau-Pomeranchuk-Migdal type interference persists for time scales relevant
to heavy ion phenomenology. We further couple the newly derived source of
energy and momentum deposition to linearized hydrodynamics to obtain the bulk
medium response to realistic parton propagation and splitting in the
quark-gluon plasma. We find that because of the characteristic large angle
in-medium gluon emission and the multiple sources of energy deposition in a
parton shower, formation of well defined Mach cones by energetic jets in heavy
ion reactions is not likely.Comment: 8 pages, 4 figure
Late-time expansion in the semiclassical theory of the Hawking radiation
We give a detailed treatment of the back-reaction effects on the Hawking
spectrum in the late-time expansion within the semiclassical approach to the
Hawking radiation. We find that the boundary value problem defining the action
of the modes which are regular at the horizon admits in general the presence of
caustics. We show that for radii less that a certain critical value no
caustic occurs for all values of the wave number and time and we give a
rigorous lower bound on such a critical value. We solve the exact system of non
linear equations defining the motion, by an iterative procedure rigorously
convergent at late times. The first two terms of such an expansion give the
correction to the Hawking spectrum.Comment: 17 pages, 1 figure, LaTex, typos corrected, one intermediate formula
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Pure Gauge SU(2) Seiberg-Witten Theory and Modular Forms
We identify the spectral curve of pure gauge SU(2) Seiberg-Witten theory with
the Weierstrass curve \mathbbm{C}/L \ni z \mapsto (1,\wp(z),\wp(z)') and
thereby obtain explicitely a modular form from which the moduli space parameter
and lattice parameters , can be derived in terms of modular
respectively theta functions. We further discuss its relationship with the
triplet model conformal field theory.Comment: 11 + 2 pages, no figures, shortened, to be published in jm
Meson Production in Proton-Proton Collisions in the Naive Non-Abelianization Approximation and the Role of Infrared Renormalons
We calculate the "naive non-abelianization" (NNA) contributions of the
higher-twist Feynman diagrams to the large- inclusive pion production
cross section in proton-proton collisions in the case of the running coupling
and frozen coupling approaches. We compare the resummed "naive
non-abelianization" higher-twist cross sections with the ones obtained in the
framework of the frozen coupling approach and leading-twist cross section. The
structure of infrared renormalon singularities of the higher twist subprocess
cross section and it's resummed expression are found. We discuss the
phenomenological consequences of possible higher-twist contributions to the
pion production in proton-proton collisions in within NNA.Comment: 17 pages, 9 figure
Integro-differential diffusion equation for continuous time random walk
In this paper we present an integro-differential diffusion equation for
continuous time random walk that is valid for a generic waiting time
probability density function. Using this equation we also study diffusion
behaviors for a couple of specific waiting time probability density functions
such as exponential, and a combination of power law and generalized
Mittag-Leffler function. We show that for the case of the exponential waiting
time probability density function a normal diffusion is generated and the
probability density function is Gaussian distribution. In the case of the
combination of a power-law and generalized Mittag-Leffler waiting probability
density function we obtain the subdiffusive behavior for all the time regions
from small to large times, and probability density function is non-Gaussian
distribution.Comment: 12 page
New solutions of Heun general equation
We show that in four particular cases the derivative of the solution of Heun
general equation can be expressed in terms of a solution to another Heun
equation. Starting from this property, we use the Gauss hypergeometric
functions to construct series solutions to Heun equation for the mentioned
cases. Each of the hypergeometric functions involved has correct singular
behavior at only one of the singular points of the equation; the sum, however,
has correct behavior
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