Influence of two different representations of the G-matrix to the in-medium nucleon-nucleon cross sections

We calculate the in-medium nucleon-nucleon scattering cross sections from the G-matrix using the Dirac-Brueckner-Hartree-Fock (DBHF) approach. And we investigate the influence of the different representations of the G-matrix to the cross sections, the difference of which is mainly from the different effective masses.

BRST quantization and canonical Ward identity of the supersymmetric electromagnetic interaction system

According to the method of path integral quantization for the canonical constrained system in Becchi-Rouet-Stora-Tyutin scheme, the supersymmetric electromagnetic interaction system was quantized. Both the Hamiltonian of the supersymmetric electromagnetic interaction system in phase space and the quantization procedure were simplified. The BRST generator was constructed, and the BRST transformations of supersymmetric fields were gotten; the effective action was calculated, and the generating functional for the Green function was achieved; also, the gauge generator was constructed, and the gauge transformation of the system was obtained. Finally, the Ward-Takahashi identities based on the canonical Noether theorem were calculated, and two relations between proper vertices and propagators were obtained.

Observation of negative-parity high spin states of Cs-126

The nucleus Cs-126 was investigated by means of in-beam gamma-ray spectroscopy techniques using the Nordball detector system at the Niels Bohr Institute. Excited states of Cs-126 were populated via the Cd-116(N-14, 4n)Cs-126 reaction at a beam energy of 65 MeV. The Cs-126 level scheme was considerably extended, especially at negative parity and about 40 new levels and 70 new transitions were added into the level scheme. The previously reported negative-parity rotational bands, built on pi g(7/2)circle times nu h(11/2),pi d(5/2)circle times nu h(11/2),pi h(11/2)circle times nu g(7/2), and pi h(11/2)circle times nu d(5/2) configurations, have been extended and evolve into bands involving rotationally aligned (pi h(11/2))(2) and (nu h(11/2))(2) quasiparticles. Two new rotational bands have been tentatively assigned the pi h(11/2)circle times nu s(1/2) and pi g(9/2)circle times nu h(11/2) configurations, respectively

Shell effect on stabilization processes following multi-electron transfer in slow Arq+-Ar (g=6-9, 11) collisions

We experimentally investigate the shell effect on the stabilization processes following the multi-electron transfer in slow collisions of Arq+-Ar (q = 6-9, It) The relative cross-section ratios of multi-electron transfer and of the subsequent stabilization with respect to single-electron capture are measured meanwhile compared with the theoretical results predicted by the classical over-barrier model. Our result indicates that the multi-electron transfer is dominant when the projectile charge is large and the subsequent stabilization shows a dramatic variation if the projectile L-shell configuration becomes open. It shows that the subsequent stabilization processes of multiply excited scattering ions have a strong dependence on the projectile shell. (C) 2010 Elsevier BV All rights reserved.

A mixing scheme for the structure of f(0)(600) and f(0)(1370)

Within the framework of a nonlinear chiral Lagrangian we explore the nontrivial nature of f(0)(600) and f(0)(1370) in terms of quarkonium, tetraquark and gluonium components. The mass constraints are obtained and the strong and radiative partial widths are calculated to demonstrate and discriminate these components. The static properties of f(0)(1500) and glueball are also studied. Our results are confronted with the experimental and theoretical data available as well as the upcoming measurements. (C) 2010 Elsevier B.V. All rights reserved.

4KG-M制冷机做冷源的自循环氦液化装置研制；Development of helium liquefaction self-circulation system with 4 K G-M cryocoolers

采用5台1.5W/4.2KG-M制冷机(日本住友RDK415D)并联研制出了1台方便实验室使用的小型氦液化装置,并为其建立了性能测量实验台。实验结果表明:液氦温度为4.17K(饱和压力为96kPa)时,氦液化率为74L/d;液氦温度为4.42K(饱和压力为121kPa)时,液化率为116L/d,经拟合,在4.2K(饱和压力为100kPa)时液化率为83L/d,并且通过100小时以上的连续运行,说明该氦液化装置自循环性能良好。通过实验发现:实测氦液化率远大于制冷机冷头制冷量对应的计算氦液化率。分析认为:G-M制冷机气缸壁对氦气预冷是提高实际氦液化率的主要因素。