36,235 research outputs found
Proton decay suppression in a supersymmetric SO(10) model
We propose a mechanism for sufficient suppression of dimension-5 operators
for proton decay in a supersymmetric SO(10) model. This mechanism is analogue
to the double seesaw mechanism in studying neutrino masses. Only an
intermediate VEV instead of an intermediate scale is required so that gauge
coupling unification is maintained. The VEV is generated by introducing an
anomalous U(1) symmetry whose breaking is at higher scale. The proton decay
amplitudes are suppressed by this VEV over the GUT scale. We use
in breaking GUT symmetry. is included so that
fermion sector is fully realistic. Assuming a minimal fine-tuning in the Higgs
doublet sector, of order one is predicted.Comment: Several small corrections, 13 pages, no figur
Optimal Quantization in Energy-Constrained Sensor Networks under Imperfect Transmission
This paper addresses the optimization of quantization at local sensors under strict energy constraint and imperfect transmission to improve the reconstruction performance at the fusion center in the wireless sensor networks (WSNs). We present optimized quantization scheme including the optimal quantization bit rate and the optimal transmission power allocation among quantization bits for BPSK signal and binary orthogonal signal with envelope detection, respectively. The optimization of the quantization is formulated as a convex problem and the optimal solution is derived analytically in both cases. Simulation results demonstrate the effectiveness of our proposed quantization schemes
Proton decay in a supersymmetric SO(10) model with missing partner mechanism
The extended supersymmetric SO(10) model with missing partner mechanism is
studied. An intermediate vacuum expectation value is incorporated which
corresponds to the see-saw scale. Gauge coupling unification is not broken
explicitly. Proton decay is found to satisfy the present experimental limits at
the cost of fine-tuning some parameters.Comment: 14 pages; Several improvements, References adde
Fermions on Thick Branes in the Background of Sine-Gordon Kinks
A class of thick branes in the background of sine-Gordon kinks with a scalar
potential was constructed by R. Koley and S.
Kar [Classical Quantum Gravity \textbf{22}, 753 (2005)]. In this paper, in the
background of the warped geometry, we investigate the issue of localization of
spin half fermions on these branes in the presence of two types of
scalar-fermion couplings: and . By presenting the mass-independent potentials in the corresponding
Schr\"{o}dinger equations, we obtain the lowest Kaluza--Klein (KK) modes and a
continuous gapless spectrum of KK states with for both types of
couplings. For the Yukawa coupling , the effective
potential of the right chiral fermions for positive and is always
positive, hence only the effective potential of the left chiral fermions could
trap the corresponding zero mode. This is a well-known conclusion which had
been discussed extensively in the literature. However, for the coupling
, the effective potential of the right chiral
fermions for positive and is no longer always positive. Although the
value of the potential at the location of the brane is still positive, it has a
series of wells and barriers on each side, which ensures that the right chiral
fermion zero mode could be trapped. Thus we may draw the remarkable conclusion:
for positive and , the potentials of both the left and right chiral
fermions could trap the corresponding zero modes under certain restrictions.Comment: 22 pages, 21 figures, published version to appear in Phys. Rev.
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