8,094 research outputs found
Fermion Families from Two Layer Warped Extra Dimensions
In extra dimensions, the quark and lepton mass hierarchy can be reproduced
from the same order bulk mass parameters, and standard model fermion families
can be generated from one generation in the high dimensional space. We try to
explain the origin of the same order bulk mass parameters and address the
family replication puzzle simultaneously. We show that they correlate with each
other. We construct models that families are generated from extra dimensional
space, and in the meantime the bulk mass parameters of same order emerge
naturally. The interesting point is that the bulk mass parameters, which are in
same order, correspond to the eigenvalues of a Schr\"{o}dinger-like equation.
We also discuss the problem existing in this approach.Comment: 21 latex pages, final version to appear in JHE
Second and third orders asymptotic expansions for the distribution of particles in a branching random walk with a random environment in time
Consider a branching random walk in which the offspring distribution and the
moving law both depend on an independent and identically distributed random
environment indexed by the time.For the normalised counting measure of the
number of particles of generation in a given region, we give the second and
third orders asymptotic expansions of the central limit theorem under rather
weak assumptions on the moments of the underlying branching and moving laws.
The obtained results and the developed approaches shed light on higher order
expansions. In the proofs, the Edgeworth expansion of central limit theorems
for sums of independent random variables, truncating arguments and martingale
approximation play key roles. In particular, we introduce a new martingale,
show its rate of convergence, as well as the rates of convergence of some known
martingales, which are of independent interest.Comment: Accepted by Bernoull
Baryon spectrum in a finite-temperature AdS/QCD model
We propose a model for baryons at finite temperature using AdS/QCD
correspondence. In this model, we modify the AdS spacetime into the
AdS-Schwarzchild spacetime and consider a couple of bulk spinors in this
background. Solving this model, we get an eigenvalue equation for the baryon
masses. We then investigate the effects of temperature on the baryon masses
numerically, and find an interesting temperature dependence. Our result is
consistent with the results from lattice QCD and other phenomenological models.Comment: 6 Latex pages, 2 figures. Final version to appear in PR
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