Slavnov-Taylor identity for nonequilibrium quark-gluon plasma

Within the closed-time-path formalism of nonequilibrium QCD, we derive a Slavnov-Taylor (ST) identity for the gluon polarization tensor. The ST identity takes the same form both in Coulomb and covariant gauges. Application to quasi-uniform quark-gluon plasma (QGP) near equilibrium or nonequilibrium quasistationary QGP is made.Comment: 10page

A Slavnov-Taylor identity and equality of damping rates for static transverse and longitudinal gluons in hot QCD

A Slavnov-Taylor identity is derived for the gluon polarization tensor in hot QCD. We evaluate its implications for damping of gluonic modes in the plasma. Applying the identity to next to the leading order in hard-thermal-loop resummed perturbation theory, we derive the expected equality of damping rates for static transverse and longitudinal (soft) gluons. This is of interest also in view of deviating recent reports of $\gamma_t(p=0)\neq\gamma_l(p=0)$ based on a direct calculation of $\gamma_l(p=0)$.Comment: 13 pages, 1 figure, LaTe

Dynamic SU(2) Lattice Gauge Theory at Finite Temperature

The dynamic relaxation process for the (2+1)--dimensional SU(2) lattice gauge theory at critical temperature is investigated with Monte Carlo methods. The critical initial increase of the Polyakov loop is observed. The dynamic exponents $\theta$ and $z$ as well as the static critical exponent $\beta/\nu$ are determined from the power law behaviour of the Polyakov loop, the auto-correlation and the second moment at the early stage of the time evolution. The results are well consistent and universal short-time scaling behaviour of the dynamic system is confirmed. The values of the exponents show that the dynamic SU(2) lattice gauge theory is in the same dynamic universality class as the dynamic Ising model.Comment: 10 pages with 2 figure

On the Segregation Phenomenon in Complex Langevin Simulation

In the numerical simulation of certain field theoretical models, the complex Langevin simulation has been believed to fail due to the violation of ergodicity. We give a detailed analysis of this problem based on a toy model with one degree of freedom ($S=-\beta\cos\theta$). We find that the failure is not due to the defect of complex Langevin simulation itself, but rather to the way how one treats the singularity appearing in the drift force. An effective algorithm is proposed by which one can simulate the ${1/\beta}$ behaviour of the expectation value $$ in the small $\beta$ limit.Comment: (20 pages + 8 figures on request). Siegen Si-93-8, Tokuyama TKYM-93-

A new approach to dynamic finite-size scaling

In this work we have considered the Taylor series expansion of the dynamic scaling relation of the magnetization with respect to small initial magnetization values in order to study the dynamic scaling behaviour of 2- and 3-dimensional Ising models. We have used the literature values of the critical exponents and of the new dynamic exponent $x_0$ to observe the dynamic finite-size scaling behaviour of the time evolution of the magnetization during early stages of the Monte Carlo simulation. For 3-dimensional Ising Model we have also presented that this method opens the possibility of calculating $z$ and $x_0$ separately. Our results show good agreement with the literature values. Measurements done on lattices with different sizes seem to give very good scaling.Comment: Latex file with six figures. Accepted for publication in IJM

ALKALI-RICH FRAGMENTS IN LL-CHONDRITIC BRECCIAS.

第2回極域科学シンポジウム/第34回南極隕石シンポジウム 11月17日（木） 国立国語研究所 2階講

Universality and Scaling in Short-time Critical Dynamics

Numerically we simulate the short-time behaviour of the critical dynamics for the two dimensional Ising model and Potts model with an initial state of very high temperature and small magnetization. Critical initial increase of the magnetization is observed. The new dynamic critical exponent $\theta$ as well as the exponents $z$ and $2\beta/\nu$ are determined from the power law behaviour of the magnetization, auto-correlation and the second moment. Furthermore the calculation has been carried out with both Heat-bath and Metropolis algorithms. All the results are consistent and therefore universality and scaling are confirmed.Comment: 14 pages, 14 figure

Observation of an energetic radiation burst from mountain-top thunderclouds

During thunderstorms on 2008 September 20, a simultaneous detection of gamma rays and electrons was made at a mountain observatory in Japan located 2770 m above sea level. Both emissions, lasting 90 seconds, were associated with thunderclouds rather than lightning. The photon spectrum, extending to 10 MeV, can be interpreted as consisting of bremsstrahlung gamma rays arriving from a source which is 60 - 130 m in distance at 90% confidence level. The observed electrons are likely to be dominated by a primary population escaping from an acceleration region in the clouds.Comment: 12 pages, 3 figures, accepted for publication in Physical Review Letter