Nucleon Mass Splitting at Finite Isospin Chemical Potential

We investigate nucleon mass splitting at finite isospin chemical potential in the frame of two flavor Nambu--Jona-Lasinio model. It is analytically proved that, in the phase with explicit isospin symmetry breaking the proton mass decreases and the neutron mass increases linearly in the isospin chemical potential.Comment: 3 pages and no figure

Low-momentum Pion Enhancement Induced by Chiral Symmetry Restoration

The thermal and nonthermal pion production by sigma decay and its relation with chiral symmetry restoration in a hot and dense matter are investigated. The nonthermal decay into pions of sigma mesons which are popularly produced in chiral symmetric phase leads to a low-momentum pion enhancement as a possible signature of chiral phase transition at finite temperature and density.Comment: 3 pages, 2 figure

Exact Calculation of Ring Diagrams and the Off-shell Effect on the Equation of State

The partition function with ring diagrams at finite temperature is exactly caluclated by using contour integrals in the complex energy plane. It contains a pole part with temperature and momentum dependent mass and a phase shift part induced by off-shell effect in hot medium. The thermodynamic potentials for $\phi^4$ and $\phi^3$ interactions are calculated and compared with the quasi-particle (pole) approximation. It is found that the off-shell effect on the equation of state is remarkable.Comment: 7 pages, 11 figures, refereces added, final version to appear in PR

Non-Abelian Medium Effects in Quark-Gluon Plasma

Based on the kinetic theory, the non-Abelian medium property of hot Quark-Gluon Plasma is investigated. The nonlinearity of the plasma comes from two aspects: The nonlinear wave-wave interaction and self-interaction of color field. The non-Abelian color permittivity is obtained by expanding the kinetic equations to third order. As an application, the nonlinear Landau damping rate and the nonlinear eigenfrequency shift are calculated in the longwave length limit.Comment: 12 pages(Revtex), no figure

Hadronization Approach for a Quark-Gluon Plasma Formed in Relativistic Heavy Ion Collisions

A transport model is developed to describe hadron emission from a strongly coupled quark-gluon plasma formed in relativistic heavy ion collisions. The quark-gluon plasma is controlled by ideal hydrodynamics, and the hadron motion is characterized by a transport equation with loss and gain terms. The two sets of equations are coupled to each other, and the hadronization hypersurface is determined by both the hydrodynamic evolution and the hadron emission. The model is applied to calculate the transverse momentum distributions of mesons and baryons, and most of the results agree well with the experimental data at RHIC.Comment: 16 pages, 24 figures. Version accepted by PR

Density Effect on Hadronization of a Quark Plasma

The hadronization cross section in a quark plasma at finite temperature and density is calculated in the framework of Nambu--Jona-lasinio model with explicit chiral symmetry breaking. In apposition to the familiar temperature effect, the quark plasma at high density begins to hadronize suddenly. It leads to a sudden and strong increase of final state pions in relativistic heavy ion collisions which may be considered as a clear signature of chiral symmetry restoration.Comment: Latex2e, 11 pages, 7 Postscript figures, submitted to Phys. Rev.

An advanced meshless method for time fractional diffusion equation

Recently, because of the new developments in sustainable engineering and renewable energy, which are usually governed by a series of fractional partial differential equations (FPDEs), the numerical modelling and simulation for fractional calculus are attracting more and more attention from researchers. The current dominant numerical method for modeling FPDE is Finite Difference Method (FDM), which is based on a pre-defined grid leading to inherited issues or shortcomings including difficulty in simulation of problems with the complex problem domain and in using irregularly distributed nodes. Because of its distinguished advantages, the meshless method has good potential in simulation of FPDEs. This paper aims to develop an implicit meshless collocation technique for FPDE. The discrete system of FPDEs is obtained by using the meshless shape functions and the meshless collocation formulation. The stability and convergence of this meshless approach are investigated theoretically and numerically. The numerical examples with regular and irregular nodal distributions are used to validate and investigate accuracy and efficiency of the newly developed meshless formulation. It is concluded that the present meshless formulation is very effective for the modeling and simulation of fractional partial differential equations

Hierarchical recurrent neural encoder for video representation with application to captioning

© 2016 IEEE. Recently, deep learning approach, especially deep Convolutional Neural Networks (ConvNets), have achieved overwhelming accuracy with fast processing speed for image classification. Incorporating temporal structure with deep ConvNets for video representation becomes a fundamental problem for video content analysis. In this paper, we propose a new approach, namely Hierarchical Recurrent Neural Encoder (HRNE), to exploit temporal information of videos. Compared to recent video representation inference approaches, this paper makes the following three contributions. First, our HRNE is able to efficiently exploit video temporal structure in a longer range by reducing the length of input information flow, and compositing multiple consecutive inputs at a higher level. Second, computation operations are significantly lessened while attaining more non-linearity. Third, HRNE is able to uncover temporal tran-sitions between frame chunks with different granularities, i.e. it can model the temporal transitions between frames as well as the transitions between segments. We apply the new method to video captioning where temporal information plays a crucial role. Experiments demonstrate that our method outperforms the state-of-the-art on video captioning benchmarks

An Embeddable Optical Strain Gauge based on a Buckled Beam

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time

Meson Screening Mass in a Strongly Coupled Pion Superfluid

We calculate the meson screening mass in a pion superfluid in the framework of Nambu--Jona-Lasinio model. The minimum of the attractive quark potential is always located at the phase boundary of pion superfluid. Different from the temperature and baryon density effect, the potential at finite isospin density can not be efficiently suppressed and the matter is always in a strongly coupled phase due to the Goldstone mode in the pion superfluid.Comment: 8 pages, 7 figures(Accepted by European Physical Journal C