Pair production of neutralinos via photon-photon collisions

We investigated the production of neutralino pairs via photon-photon collisions in the minimal supersymmetric model(MSSM) at future linear colliders. The numerical analysis of their production rates is carried out in the mSUGRA scenario. The results show that this cross section can reach about 18 femto barn for $\tilde{\chi}^{0}_{1} \tilde{\chi}^{0}_{2}$ pair production and 9 femto barn for $\tilde{\chi}^{0}_{2}\tilde{\chi}^{0}_{2}$ pair production with our chosen input parameters.Comment: LaTex File, 3 EPS Files, 17 page

Fast Adaptive Flat-histogram Ensemble for Calculating Density of States and Enhanced Sampling in Large Systems

We presented an efficient algorithm, fast adaptive flat-histogram ensemble (FAFE), to estimate the density of states (DOS) and to enhance sampling in large systems. FAFE calculates the means of an arbitrary extensive variable $U$ in generalized ensembles to form points on the curve $\beta_{s}(U) \equiv \frac{\partial S(U)}{\partial U}$, the derivative of the logarithmic DOS. Unlike the popular Wang-Landau-like (WLL) methods, FAFE satisfies the detailed-balance condition through out the simulation and automatically generates non-uniform $(\beta_{i}, U_{i})$ data points to follow the real change rate of $\beta_{s}(U)$ in different $U$ regions and in different systems. Combined with a $U-$compression transformation, FAFE reduces the required simulation steps from $O(N^{3/2})$ in WLL to $O(N^{1/2})$, where $N$ is the system size. We demonstrate the efficiency of FAFE in Lennard-Jones liquids with several $N$ values. More importantly, we show its abilities in finding and identifying different macroscopic states including meta-stable states in phase co-existing regions.Comment: 5 pages, 4 figure

EFFECT OF SKILL LEVEL ON KNEE FLEXOR AND EXTENSOR STRENGTH IN MALE JUDO

Judo has a high requirement of the physical strength of lower limb. In this paper, the centripetal knee force of national master athletes and first-grade athletes of male Judoka was measured using the ISOMED2000 Isokinetic system. Try to discuss the differences between different grades of judoka in the area of the physical strength of lower limb. Judo-related specific knee strength indices, such as peak torque in relation to body weight, flexor torque in relation to the extensor torque and average power of knee, were compared between the two groups by statistic analysis. The results showed that the first-grade athletes did not significantly differ from the national master athletes in terms of relative power of the knee flexors, but significant difference existed in the absolute power and explosive strength of the knee extensors between the two levels of athletes