9,227 research outputs found
Elliptic flow splitting as a probe of the QCD phase structure at finite baryon chemical potential
Using a partonic transport model based on the 3-flavor Nambu-Jona-Lasinio
model and a relativistic hadronic transport model to describe, respectively,
the evolution of the initial partonic and the final hadronic phase of heavy-ion
collisions at energies carried out in the Beam-Energy Scan program of the
Relativistic Heavy Ion Collider, we have studied the effects of both the
partonic and hadronic mean-field potentials on the elliptic flow of particles
relative to that of their antiparticles. We find that to reproduce the measured
relative elliptic flow differences between nucleons and antinucleons as well as
between kaons and antikaons requires a vector coupling constant as large as 0.5
to 1.1 times the scalar coupling constant in the Nambu-Jona-Lasinio model.
Implications of our results in understanding the QCD phase structure at finite
baryon chemical potential are discussed.Comment: 5 pages, 4 figures, discussions added, version accepted by Phys. Rev.
Let
Prompt Ultraviolet-to-Soft-X-Ray Emission of Gamma-Ray Bursts: Application to GRB 031203?
We discuss the prompt emission of GRBs, allowing for pair
production and synchrotron self-absorption. The observed hard spectra suggest
heavy pair-loading in GRBs. The re-emission of the generated pairs results in
the energy transmission from high-energy gamma-rays to long-wavelength
radiation. Due to strong self-absorption, the synchrotron radiation by pairs is
in optically thick regime, showing a thermal-like spectral bump in the
extreme-ultraviolet/soft X-ray band, other than the peak from the main burst.
Recently, the prompt soft X-ray emission of GRB 031203 was detected thanks to
the discovery of a delayed dust echo, and it seems to be consistent with the
model prediction of a double-peak structure. The confirmation of the
thermal-like feature and the double-peak structure by observation would
indicate that the dominant radiation mechanism in GRBs is synchrotron rather
than inverse-Compton radiation.Comment: ApJL accepted, shortened to match the 4 page limit, aastex styl
The Application of Bifurcation Method to Klein-Gordon-Zakharov Equations
Bifurcation method of dynamical systems is employed to study the Klein-Gordon-Zakharov equations. Under some parameter conditions, some explicit expressions of solutions for the equation are obtained. These solutions contain solitary wave solutions, blow-up solutions, periodic solutions, periodic blow-up solutions and kink-shaped solutions. Key Words: Klein-Gordon-Zakharov equations; Exact solutions; Bifurcation metho
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