9,080 research outputs found
Novel Non-equilibrium Phase Transition Caused by Non-linear Hadronic-quark Phase Structure
We consider how the occurrence of first-order phase transitions in
non-constant pressure differs from those at constant pressure. The former has
shown the non-linear phase structure of mixed matter, which implies a particle
number dependence of the binding energies of the two species. If the mixed
matter is mixed hadron-quark phase, nucleon outgoing from hadronic phase and
ingoing to quark phase probably reduces the system to a non-equilibrium state,
in other words, there exists the imbalance of the two phases when deconfinement
takes place. This novel non-equilibrium process is very analogous to the
nuclear reactions that nuclei emit neutrons and absorb them under appropriate
conditions. We present self-consistent thermodynamics in description for the
processes and identify the microphysics responsible for the processes. The
microphysics is an inevitable consequence of non-linear phase structure instead
of the effect of an additional dissipation force. When applying our findings to
the neutron star containing mixed hadron-quark matter, it is found that the
newly discovered energy release might strongly change the thermal evolution
behavior of the star.Comment: 18pages,3figures;to be accepted for publication in Physics Letters
Non-classical properties and algebraic characteristics of negative binomial states in quantized radiation fields
We study the nonclassical properties and algebraic characteristics of the
negative binomial states introduced by Barnett recently. The ladder operator
formalism and displacement operator formalism of the negative binomial states
are found and the algebra involved turns out to be the SU(1,1) Lie algebra via
the generalized Holstein-Primarkoff realization. These states are essentially
Peremolov's SU(1,1) coherent states. We reveal their connection with the
geometric states and find that they are excited geometric states. As
intermediate states, they interpolate between the number states and geometric
states. We also point out that they can be recognized as the nonlinear coherent
states. Their nonclassical properties, such as sub-Poissonian distribution and
squeezing effect are discussed. The quasiprobability distributions in phase
space, namely the Q and Wigner functions, are studied in detail. We also
propose two methods of generation of the negative binomial states.Comment: 17 pages, 5 figures, Accepted in EPJ
Leptophilic dark matter in gauged model in light of DAMPE cosmic ray excess
Motivated by the very recent cosmic-ray electron+positron excess observed by
DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the
gauged model. DM interacts with the electron and muon via the
gauge boson . The model can explain the DAMPE data well.
Although a non-zero DM-nucleon cross section is only generated at one loop
level and there is a partial cancellation between and
couplings, we find that a large portion of mass is ruled out from
direct DM detection limit leaving the allowed mass to be close to two
times of the DM mass. Implications for and , and muon anomaly are also studied.Comment: Discussions added, version accepted by EPJ
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