115699498
A study of nucleon-nucleon spin-orbit force in quark model
Abstract Spin-orbit interactions between two quarks due to the one-gluon exchange, confinement potential, σ-exchange of the chiral field and two-gluon exchange are considered in our calculation. As a consequence, the spin-orbit energy splitting of the 1P state in the baryon spectrum and the 3 P 2 phase shifts of NN scattering can unifiedly be explained.
121548156
BARYON–BARYON INTERACTION IN THE EXTENDED CHIRAL SU(3) QUARK MODEL
The hyperon-nucleon scattering processes and some dibaryon states are studied both in the chiral SU(3) quark model and in the extended chiral SU(3) quark model by solving the resonating group method (RGM) equation. We find that the short-range interaction could be described either by the one-gluon exchange or by the vector meson exchange for baryon-baryon system.
181353095
Color screening effect in b anti-b system
122341351
Color screening effect in the quark potential model
By using the color confinement potential which includes the color screening effect, we studied the baryon spectra and the nucleon-nucleon interaction. The results show that the color screening effect not only improves the baryon spectrum calculation, but also can solve the long-tail problem of the color Van der Waals force. A part of the medium attraction of the nuclear force can be obtained from the color Van der Waals force.
116985474
Color screening effect and nucleon-nucleon interaction
120491051
Hyperon-Meson Vertices and Hyperon-Nucleon Interactions on Quark Model
In this paper, we introduce two parts of work: the hyperon-meson vertex structure from the one-gluon-exchange quark-antiquark pair creation model and the hyperon-nucleon interactions on a modified quark potential model. For both parts some significant results have been obtained.
119289155
HIGH-ENERGY GAMMA-RAY AFTERGLOWS FROM LOW-LUMINOSITY GAMMA-RAY BURSTS
The observations of gamma-ray bursts (GRBs) such as 980425, 031203 and 060218, with luminosities much lower than those of other classic bursts, lead to the definition of a new class of GRBs—LL-GRBs. The nature of the outflow responsible for them is not yet clear. Two scenarios have been suggested: one is the conventional relativistic outflow with initial Lorentz factor of order of Γ0 10 and the other is a trans-relativistic outflow with Γ0 1-2. Here, we compare the high-energy gamma-ray afterglow emission from these two different models, taking into account both synchrotron self-inverse Compton (SSC) scattering and the external inverse Compton scattering due to photons from the cooling supernova or hypernova envelope (SNIC). We find that the conventional relativistic outflow model predicts a relatively high gamma-ray flux from SSC at early times (<104 s for typical parameters) with a rapidly decaying light curve, while in the trans-relativistic outflow model, one would expect a much flatter light curve of high-energy gamma-ray emission at early times, which could be dominated by both the SSC emission and the SNIC emission, depending on the properties of the underlying supernova and the shock parameter e and B . The Fermi Gamma-ray Space Telescope should be able to distinguish between the two models in the future.
25190674
A Supramassive Magnetar Central Engine for GRB 130603B
We show that the peculiar early optical emission and, in particular, the X-ray after glow emission of the short-duration burst GRB 130603B can be explained by continuous energy injection into the blastwave from a supramassive magnetar central engine. The observed energetics and temporal/spectral properties of the late infrared bump (i.e., the "kilonova") are also found to be consistent with emission from the ejecta launched during a neutron star (NS)-NS merger and powered by a magnetar central engine. The isotropic-equivalent kinetic energies of both the gamma-ray burst (GRB) blastwave and the kilonova are approximately E-k similar to 10(51) erg, consistent with being powered by a near-isotropic magnetar wind. However, this relatively small value requires that most of the initial rotational energy of the magnetar (similar to a few x 10(52) erg) is carried away by gravitational wave radiation. Our results suggest that (1) the progenitor of GRB 130603B was a NS-NS binary system, the merger product of which would have been a supramassive NS that lasted for about similar to 1000 s; (2) the equation of state of the nuclear matter should be stiff enough to allow the survival of a long-lived supramassive NS; thus this suggested that the detection of the bright electromagnetic counterparts of gravitational wave triggers without short GRB associations is promising in the upcoming Advanced LIGO/VIRGO era.
119273299
The Newly Born Magnetars Powering Gamma-Ray Burst Internal-Plateau Emission: Are There Strange Stars?
The internal-plateau X-ray emission of gamma-ray bursts (GRBs) indicates that a newly born magnetar could be the central object of some GRBs. The observed luminosity and duration of the plateaus suggest that, for such a magnetar, a rapid spin with a sub- or millisecond period is sometimes able to last thousands of seconds. In this case, the conventional neutron star (NS) model for the magnetar may be challenged, since the rapid spin of nascent NSs would be remarkably decelerated within hundreds of seconds due to r-mode instability. In contrast, the r-modes can be effectively suppressed in nascent strange stars (SSs). In other words, to a certain extent, only SSs can keep nearly constant extremely rapid spin for a long period of time during the early ages of the stars. We thus propose that the sample of the GRB rapidly spinning magnetars can be used to test the SS hypothesis based on the distinct spin limits of NSs and SSs.
16514100
The effect of r-mode instability on the evolution of isolated strange stars
We studied the evolution of isolated strange stars (SSs) synthetically, considering the influence of r-mode instability. Our results show that the cooling of SSs with non-ultrastrong magnetic fields is delayed by heating due to r-mode damping for millions of years, while the spin-down of the stars is dominated by gravitational radiation (GR). Especially for the SSs in a possible existing colour-flavour locked (CFL) phase, the effect of r-mode instability on the evolution of stars becomes extremely important because the viscosity, neutrino emissivity and specific heat involving pairing quarks are blocked. It leads to the cooling of these colour superconducting stars being very slow and the stars can remain at high temperature for millions of years, which differs completely from previous understanding. In this case, an SS in CFL phase can be located at the bottom of its r-mode instability window for a long time, but does not spin-down to a very low frequency for hours.
120879129
Effect of a strong magnetic field on the surface electric field of strange stars
We made a detailed study of the properties of the electron layer near the quark surface of strange stars with strong (${\sim}10^{14}{-}10^{17}$ G) magnetic fields. The electrostatic potential and the electric field at the quark surface were calculated as functions of the magnetic field intensity of bare strange stars. Using an ultrastrong ($B\geq 2.5\times10^{16}$ G) magnetic field, we found that the distribution of electrons becomes an exponential function of radial distance, which is quite different in a magnetic field-free case. We also calculated the variation in gap width between the strange core and the normal nuclear crust for strange stars, which is due to magnetic field effect.