13,738 research outputs found
Charged coherent states related to su_{q}(2) covariance
A new kind of q-deformed charged coherent states is constructed in Fock space
of two-mode q-boson system with su_{q}(2) covariance and a resolution of unity
for these states is derived. We also present a simple way to obtain these
coherent states using state projection method.Comment: 7 pages. To appear in Modern Phyics Letter:
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Development of stochastic models of window state changes in educational buildings
How people would like to interact with surrounding environment will subsequently influence indoor thermal conditions and further impact building energy performance. In order to understand occupants' adaptive behaviours in terms of environmental control utilization from the point of view of quantification, an investigation on windows operation was carried out in non-air-conditioned educational buildings in the UK during summer time considering the effects of occupant type (active and passive) and the time of a day. Outdoor air temperature was a better predictor or window operation than indoor air temperature. Window operation was found to be time-evolving event. The purpose or criteria of adjusting window states were different at different occupancy stages. Active occupants were more willing to change windows states in response to outdoor air temperature variations. Sub-models predicting transition probabilities of window state for different occupant type and occupancy stages were developed. The results derived from this field study are helpful with improving building simulation accuracy by integrating sub-models into simulation software and further providing guideline on building energy reduction without sacrificing indoor thermal comfort
Semiquantum key distribution using entangled states
Recently, Boyer et al. presented a novel semiquantum key distribution
protocol [M. Boyer, D. Kenigsberg, and T. Mor, Phys. Rev. Lett. 99, 140501
(2007)], by using four quantum states, each of which is randomly prepared by Z
basis or X basis. Here we present a semiquantum key distribution protocol by
using entangled states in which quantum Alice shares a secret key with
classical Bob. We also show the protocol is secure against eavesdropping.Comment: 6 page
Potential HPAI Shocks and Welfare Implications of Market Power in the U.S. Broiler Industry
Recent outbreaks of highly pathogenic avian influenza (HPAI) in Asia, Europe, and Africa have caused severe impacts on the broiler sector through production losses, trade restrictions and negative shocks to demand. This study develops a multimarket econometric model that is the basis of simulations to assess the spread and market implications of a potential HPAI outbreak in U.S. broiler industry. It takes into account market power that might exist within the livestock and meat sectors and endogenizes the optimal production condition on the model system. The results imply that the HPAI shocks affect prices at different marketing levels unequally and change the price margins along the supply chain with the existence of market power. The change in the price margin, although statistically significant, is quite small in absolute value.animal disease, broilers, HPAI, market power, meat market price margins, Agricultural and Food Policy,
Influence of Fermion Velocity Renormalization on Dynamical Mass Generation in QED
We study dynamical fermion mass generation in (2+1)-dimensional quantum
electrodynamics with a gauge field coupling to massless Dirac fermions and
non-relativistic scalar bosons. We calculate the fermion velocity
renormalization and then examine its influence on dynamical mass generation by
using the Dyson-Schwinger equation. It is found that dynamical mass generation
takes place even after including the scalar bosons as long as the bosonic
compressibility parameter is sufficiently small. In addition, the fermion
velocity renormalization enhances the dynamically generated mass.Comment: 6 pages, 3 figures, Chinese Physics Letter, Vol 29, page 057401(2012
Technipion Limits from LHC Higgs Searches
LHC searches for the standard model Higgs Boson in di-photon or di-tau decay
modes place strong constraints on the light top-pion state predicted in
technicolor models that include colored technifermions. Compared with the
standard Higgs Boson, the top-pions have an enhanced production rate (largely
because the technipion decay constant is smaller than the weak scale) and also
enhanced branching ratios into di-photon and di-tau final states (largely due
to the suppression of WW decays of the technipions). These factors combine to
make the technipions more visible in both channels than a standard model Higgs
would be. Hence, the recent ATLAS and CMS searches for Higgs bosons exclude the
presence of technipions with masses from 110 GeV to nearly twice the top-quark
mass in technicolor models that (a) include colored technifermions (b) feature
topcolor dynamics and (c) have technicolor groups with three or more
technicolors. For certain models, the limits also apply out to higher
technipion masses or down to the minimum number of technicolors. The limits may
be softened somewhat in models where extended technicolor plays a significant
role in producing the top quark's mass. Additional LHC data on di-tau and
di-photon final states will be extremely valuable in further exploring
technicolor parameter space.Comment: 15 pages, 5 figures, PDF-LaTe
Electromagnetic manipulation for anti-Zeno effect in an engineered quantum tunneling process
We investigate the quantum Zeno and anti-Zeno effects for the irreversible
quantum tunneling from a quantum dot to a ring array of quantum dots. By
modeling the total system with the Anderson-Fano-Lee model, it is found that
the transition from the quantum Zeno effect to quantum anti-Zeno effect can
happen as the magnetic flux and the gate voltage were adjusted.Comment: 6 pages, 5 figure
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