Dynamical chiral symmetry breaking in QED3_{3} at finite density and impurity potential

We study the effects of finite chemical potential and impurity scattering on dynamical fermion mass generation in (2+1)-dimensional quantum electrodynamics. In any realistic systems, these effects usually can not be neglected. The longitudinal component of gauge field develops a finite static length produced by chemical potential and impurity scattering, while the transverse component remains long-ranged because of the gauge invariance. Another important consequence of impurity scattering is that the fermions have a finite damping rate, which reduces their lifetime staying in a definite quantum state. By solving the Dyson-Schwinger equation for fermion mass function, it is found that these effects lead to strong suppression of the critical fermion flavor $N_c$ and the dynamical fermion mass in the symmetry broken phase.Comment: 8 pages, 4 figure

Interaction and excitonic insulating transition in graphene

The strong long-range Coulomb interaction between massless Dirac fermions in graphene can drive a semimetal-insulator transition. We show that this transition is strongly suppressed when the Coulomb interaction is screened by such effects as disorder, thermal fluctuation, doping, and finite volume. It is completely suppressed once the screening factor $\mu$ is beyond a threshold $\mu_{c}$ even for infinitely strong coupling. However, such transition is still possible if there is an additional strong contact four-fermion interaction. The differences between screened and contact interactions are also discussed.Comment: 7 pages, 4 figures, to appear in Phys. Rev.

Photon scattering by an atomic ensemble coupled to a one-dimensional nanophotonic waveguide

We theoretically investigate the quantum scattering of a single-photon pulse interacting with an ensemble of $\Lambda$-type three-level atoms coupled to a one-dimensional waveguide. With an effective non-Hermitian Hamiltonian, we study the collective interaction between the atoms mediated by the waveguide mode. In our scheme, the atoms are randomly placed in the lattice along the axis of the one-dimensional waveguide, which closely corresponds to the practical condition that the atomic positions can not be controlled precisely in experiment. Many interesting optical properties occur in our waveguide-atom system, such as electromagnetically induced transparency (EIT) and optical depth. Moreover, we observe that strong photon-photon correlation with quantum beats can be generated in the off-resonant case, which provides an effective candidate for producing non-classical light in experiment. With remarkable progress in waveguide-emitter system, our scheme may be feasible in the near future.Comment: 10 pages,7 figure

xFx_F Dependence of Drell-Yan Transverse Moemtum Broadening

We analyze $x_F$ dependence of Drell-Yan transverse momentum broadening in hadron-nucleus collisions. In terms of generalized factorization theorem, we show that the $x_F$ dependence of transverse momentum broadening, $\Delta < q_T^2 > (x_F)$, can be calculated in perturbative QCD. We demonstrate that $\Delta (x_F)$ is a good observable for studying the effects of initial-state multiple scattering and extracting quark-gluon correlation functions.Comment: 10 pages, 3 figure

(E)-3-Dimethyl­amino-1-(4-pyrid­yl)prop-2-en-1-one

The title compound, C10H12N2O, is approximately planar, the r.m.s. deviation of the non-H atoms from the mean plane being 0.099 Å

Advantages of the multinucleon transfer reactions based on 238U target for producing neutron-rich isotopes around N = 126

The mechanism of multinucleon transfer (MNT) reactions for producing neutron-rich heavy nuclei around N = 126 is investigated within two different theoretical frameworks: dinuclear system (DNS) model and isospin-dependent quantum molecular dynamics (IQMD) model. The effects of mass asymmetry relaxation, N=Z equilibration, and shell closures on production cross sections of neutron-rich heavy nuclei are investigated. For the first time, the advantages for producing neutron-rich heavy nuclei around N = 126 is found in MNT reactions based on 238U target. We propose the reactions with 238U target for producing unknown neutron-rich heavy nuclei around N = 126 in the future.Comment: 6 pages, 6 figure

A Whole Process Prediction Method for Temperature Field of Fire Smoke in Large Spaces

AbstractBased on the fire development model for the whole process of localized fires in large-space buildings and assisted by the technology of FDS large eddy simulation, the temperature fields of fire smoke of localized fires in large spaces were investigated with different building heights, building areas and fire powers. It has been found that for large-space buildings with a height greater than 6 m and a building area more than 1500 m2, factors like building height and building area can slightly affect the curve trend of fire smoke, while such factor like fire power has more significant influence on the curve trend of fire smoke. Through the analysis of temperature rise curves of fire smoke in various fire scenarios, the paper proposed a whole-process prediction model for the temperature fields of fire smoke of localized fires in large-space buildings. As long as the model uses the appropriate shape coefficient, the prediction model can accurately predict the temperature fields of fire smoke of localized fires in large-space buildings