5,457 research outputs found
Lepton flavor violating and conversion in unparticle physics
We have studied lepton flavor violation processes and
conversion in nuclei induced by unparticle. Both and conversion rate strongly
depend on the scale dimension and the unparticle coupling
(K=V, A, S, P). Present experimental upper bounds on
, and put stringent constraints on the parameters of unaprticle physics. The
scale dimensions around 2 are favored for the unparticle scale
of and the unparticle coupling of
. is proportional to
for the pure vector and scalar couplings between
unparticle and SM fermions, this peculiar atomatic number dependence can be
used to distinguish unparticle from other theoretical models.Comment: 16 pages, 5 figure
Quantum Statistical Entropy and Minimal Length of 5D Ricci-flat Black String with Generalized Uncertainty Principle
In this paper, we study the quantum statistical entropy in a 5D Ricci-flat
black string solution, which contains a 4D Schwarzschild-de Sitter black hole
on the brane, by using the improved thin-layer method with the generalized
uncertainty principle. The entropy is the linear sum of the areas of the event
horizon and the cosmological horizon without any cut-off and any constraint on
the bulk's configuration rather than the usual uncertainty principle. The
system's density of state and free energy are convergent in the neighborhood of
horizon. The small-mass approximation is determined by the asymptotic behavior
of metric function near horizons. Meanwhile, we obtain the minimal length of
the position which is restrained by the surface gravities and the
thickness of layer near horizons.Comment: 11pages and this work is dedicated to the memory of Professor Hongya
Li
Spectroscopy of -States in Quark Model and Baryon-Antibaryon Enhancements
We study the mass spectrum of the mesons both from
the quark model with triquark correlations and from common quark model with
colormagnetic interactions and with relative S-waves between quarks. Two
cluster configurations and
are considered. In the spectrum
we find rather stable states which have the same quantum number with particle
resonances which are corresponding to the enhancement,
enhancement and enhancement with
spin- or . This imply these enhancements are NOT
experimental artifacts. The color-spin-flavor structures of ,
, and enhancements are revealed. The
existence of spin-
enhancements is predicted.Comment: 45 pages, 5 figure
Quantum mechanical path integrals and thermal radiation in static curved spacetimes
The propagator of a spinless particle is calculated from the quantum
mechanical path integral formalism in static curved spacetimes endowed with
event-horizons. A toy model, the Gui spacetime, and the 2D and 4D Schwarzschild
black holes are considered. The role of the topology of the coordinates
configuration space is emphasised in this framework. To cover entirely the
above spacetimes with a single set of coordinates, tortoise coordinates are
extended to complex values. It is shown that the homotopic properties of the
complex tortoise configuration space imply the thermal behaviour of the
propagator in these spacetimes. The propagator is calculated when end points
are located in identical or distinct spacetime regions separated by one or
several event-horizons. Quantum evolution through the event-horizons is shown
to be unitary in the fifth variable.Comment: 22 pages, 10 figure
Universal critical properties of the Eulerian bond-cubic model
We investigate the Eulerian bond-cubic model on the square lattice by means
of Monte Carlo simulations, using an efficient cluster algorithm and a
finite-size scaling analysis. The critical points and four critical exponents
of the model are determined for several values of . Two of the exponents are
fractal dimensions, which are obtained numerically for the first time. Our
results are consistent with the Coulomb gas predictions for the critical O()
branch for and the results obtained by previous transfer matrix
calculations. For , we find that the thermal exponent, the magnetic
exponent and the fractal dimension of the largest critical Eulerian bond
component are different from those of the critical O(2) loop model. These
results confirm that the cubic anisotropy is marginal at but irrelevant
for
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