23,608 research outputs found
Phase Transitions in the NMSSM
We study phase transitions in the Next-to-Minimal Supersymmetric Standard
Model (NMSSM) with the weak scale vacuum expectation values of the singlet
scalar, constrained by Higgs spectrum and vacuum stability. We find four
different types of phase transitions, three of which have two-stage nature. In
particular, one of the two-stage transitions admits strongly first order
electroweak phase transition, even with heavy squarks. We introduce a
tree-level explicit CP violation in the Higgs sector, which does not affect the
neutron electric dipole moment. In contrast to the MSSM with the CP violation
in the squark sector, a strongly first order phase transition is not so
weakened by this CP violation.Comment: 21 pages, 8 figure
CP Violation in the Higgs Sector and Phase Transition in the MSSM
We investigate the electroweak phase transition in the presence of a large CP
violation in the squark sector of the MSSM. When the CP violation is large,
scalar-pseudoscalar mixing of the Higgs bosons occurs and a large CP violation
in the Higgs sector is induced. It, however, weakens first-order phase
transition before the mixing reaches the maximal. Even when the CP violation in
the squark sector is not so large that the phase transition is strongly first
order, the phase difference between the broken and symmetric phase regions
grows to O(1), which leads to successful baryogenesis, when the charged Higgs
bosons is light.Comment: 18 pages, 6 figures, LaTeX2
Kinetics of viral self-assembly: the role of ss RNA antenna
A big class of viruses self-assemble from a large number of identical capsid
proteins with long flexible N-terminal tails and ss RNA. We study the role of
the strong Coulomb interaction of positive N-terminal tails with ss RNA in the
kinetics of the in vitro virus self-assembly. Capsid proteins stick to
unassembled chain of ss RNA (which we call "antenna") and slide on it towards
the assembly site. We show that at excess of capsid proteins such
one-dimensional diffusion accelerates self-assembly more than ten times. On the
other hand at excess of ss RNA, antenna slows self-assembly down. Several
experiments are proposed to verify the role of ss RNA antenna.Comment: 4 pages, 3 figures, several experiments are proposed, a new idea of
experiment is adde
X(1835): A Natural Candidate of 's Second Radial Excitation
Recently BES collaboration observed one interesting resonance X(1835). We
point out that its mass, total width, production rate and decay pattern favor
its assignment as the second radial excitation of meson very
naturally
The ensemble of random Markov matrices
The ensemble of random Markov matrices is introduced as a set of Markov or
stochastic matrices with the maximal Shannon entropy. The statistical
properties of the stationary distribution pi, the average entropy growth rate
and the second largest eigenvalue nu across the ensemble are studied. It is
shown and heuristically proven that the entropy growth-rate and second largest
eigenvalue of Markov matrices scale in average with dimension of matrices d as
h ~ log(O(d)) and nu ~ d^(-1/2), respectively, yielding the asymptotic relation
h tau_c ~ 1/2 between entropy h and correlation decay time tau_c = -1/log|nu| .
Additionally, the correlation between h and and tau_c is analysed and is
decreasing with increasing dimension d.Comment: 12 pages, 6 figur
To travel or not to travel: âWeatherâ is the question. Modelling the effect of local weather conditions on bus ridership
© 2017 The Authors While the influence of weather on public transport performance and ridership has been the topic for some research, the real-time response of transit usage to variations in weather conditions is yet to be fully understood. This paper redresses this gap by modelling the effect that local weather conditions exert on hourly bus ridership in sub-tropical Brisbane, Australia. Drawing on a transit smart card data set and detailed weather measurements, a suite of time-series regression models are computed to capture the concurrent and lagged effects that weather conditions exert on bus ridership. Our findings highlight that changes in particularly temperature and rainfall were found to induce significant hour-to-hour changes in bus ridership, with such effects varying markedly across both a 24 h period and the transit network. These results are important for public transport service operations in their capacity to inform timely responses to real-time changes in passengersâ travel demand induced by the onset of particular weather conditions
Information processing and signal integration in bacterial quorum sensing
Bacteria communicate using secreted chemical signaling molecules called
autoinducers in a process known as quorum sensing. The quorum-sensing network
of the marine bacterium {\it Vibrio harveyi} employs three autoinducers, each
known to encode distinct ecological information. Yet how cells integrate and
interpret the information contained within the three autoinducer signals
remains a mystery. Here, we develop a new framework for analyzing signal
integration based on Information Theory and use it to analyze quorum sensing in
{\it V. harveyi}. We quantify how much the cells can learn about individual
autoinducers and explain the experimentally observed input-output relation of
the {\it V. harveyi} quorum-sensing circuit. Our results suggest that the need
to limit interference between input signals places strong constraints on the
architecture of bacterial signal-integration networks, and that bacteria likely
have evolved active strategies for minimizing this interference. Here we
analyze two such strategies: manipulation of autoinducer production and
feedback on receptor number ratios.Comment: Supporting information is in appendi
Topology of Knotted Optical Vortices
Optical vortices as topological objects exist ubiquitously in nature. In this
paper, by making use of the -mapping topological current theory, we
investigate the topology in the closed and knotted optical vortices. The
topological inner structure of the optical vortices are obtained, and the
linking of the knotted optical vortices is also given.Comment: 11 pages, no figures, accepted by Commun. Theor. Phys. (Beijing, P.
R. China
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