113,886 research outputs found
New Lepton Family Symmetry and Neutrino Tribimaximal Mixing
The newly proposed finite symmetry Sigma(81) is applied to the problem of
neutrino tribimaximal mixing. The result is more satisfactory than those of
previous models based on A_4 in that the use of auxiliary symmetries (or
mechanisms) may be avoided. Deviations from the tribimaximal pattern are
expected, but because of its basic structure, only tan^2 (theta_12) may differ
significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close
to one, and theta_13 very nearly zero.Comment: 8 pages, no figur
Centers and Cocenters of -Hecke algebras
In this paper, we give explicit descriptions of the centers and cocenters of
-Hecke algebras associated to finite Coxeter groups.Comment: 13 pages, a mistake in 4.2 is correcte
Many-server queues with customer abandonment: numerical analysis of their diffusion models
We use multidimensional diffusion processes to approximate the dynamics of a
queue served by many parallel servers. The queue is served in the
first-in-first-out (FIFO) order and the customers waiting in queue may abandon
the system without service. Two diffusion models are proposed in this paper.
They differ in how the patience time distribution is built into them. The first
diffusion model uses the patience time density at zero and the second one uses
the entire patience time distribution. To analyze these diffusion models, we
develop a numerical algorithm for computing the stationary distribution of such
a diffusion process. A crucial part of the algorithm is to choose an
appropriate reference density. Using a conjecture on the tail behavior of a
limit queue length process, we propose a systematic approach to constructing a
reference density. With the proposed reference density, the algorithm is shown
to converge quickly in numerical experiments. These experiments also show that
the diffusion models are good approximations for many-server queues, sometimes
for queues with as few as twenty servers
Flavor changing Z' couplings at the LHC
Models with a non-universal Z' exhibit in general flavor changing neutral
currents (FCNC) at tree-level. When the Z' couplings favor the third
generation, flavor changing transitions of the form Z'tc and Z'tu could be
large enough to be observable at the LHC. In this paper we explore this
possibility using the associated production of a single top-quark with the Z'
and find that integrated luminosities of a few hundred fb are necessary
to probe the interesting region of parameter space.Comment: 12 LaTeX Pages, 10 EPS Figure
CP Violation in Fermion Pair Decays of Neutral Boson Particles
We study CP violation in fermion pair decays of neutral boson particles with
spin 0 or 1. We study a new asymmetry to measure CP violation in decays and discuss the possibility of measuring it
experimentally. For the spin-1 particles case, we study CP violation in the
decays of to octet baryon pairs. We show that these decays can
be used to put stringent constraints on the electric dipole moments of
, and .Comment: 14p, OZ-93/22, UM-93/89, OITS 51
Consequences of R-Parity violating interactions for anomalies in and
We investigate the possibility of explaining the enhancement in semileptonic
decays of , the anomalies induced by in and violation of lepton
universality in
within the framework of R-parity violating (RPV) MSSM. Exchange of down type
right-handed squark coupled to quarks and leptons yield interactions which are
similar to leptoquark induced interactions that have been proposed to explain
the by tree level interactions and anomalies by loop induced interactions, simultaneously. However,
the Yukawa couplings in such theories have severe constraints from other rare
processes in and decays. Although this interaction can provide a viable
solution to anomaly, we show that with the severe constraint from
, it is impossible to solve the anomalies in process simultaneously.Comment: RevTex, 13 pages, three figures. In our earlier version, we had
neglected a contribution to C^{NP}_9 and obtained erroneous conclusions which
we have corrected them in this versio
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