We calculate the O(a) improvement coefficient for the axial-vector current using the nonperturbative method proposed by the LANL group. Results for the coefficient in the range β = 5.93 to 6.2 are presented. We find cA is close to the 1-loop tadpole-improved perturbative value. In addition, scaling of the pseudoscalar decay constant and renormalised quark mass is improved compared to that obtai...

We discuss the radiation problem of total reflection for a time-harmonic generalized Maxwell system in a nonsmooth exterior domain Ω ⊂ RN , N ≥ 3 , with nonsmooth inhomogeneous, anisotropic coefficients converging near infinity with a rate r−τ , τ > 1 , towards the identity. By means of the limiting absorption principle a Fredholm alternative holds true and the eigensolutions decay polynomially...

We give a review and present a comprehensive calculation for the leptonic constant fBc of the low-lying pseudoscalar and vector states of Bc-meson in the framework of static and QCD-motivated nonrelativistic potential models taking into account the one-loop and two-loop QCD corrections in the short distance coefficient that governs the leptonic constant of Bc quarkonium system. Further, we use ...

The linear super-Burnett coefficient gives corrections to the diffusion equation in the form of higher derivatives of the density. Like the diffusion coefficient, it can be expressed in terms of integrals of correlation functions, but involving four different times. The power law decay of correlations in real gases (with many moving particles) and the random Lorentz gas (with one moving particl...

Abstract. In this paper, we consider anisotropic diffusion with decay, which takes the form α(x)c(x) − div[D(x)grad[c(x)]] = f(x) with decay coefficient α(x) ≥ 0, and diffusivity coefficient D(x) to be a second-order symmetric and positive definite tensor. It is well-known that this particular equation is a second-order elliptic equation, and satisfies a maximum principle under certain regulari...

The QCD radiative corrections to the leptonic decay rate of the B c meson are calculated using the formalism of nonrelativistic QCD (NRQCD) to separate short-distance and long-distance effects. The B c decay constant is factored into a sum of NRQCD matrix elements each multiplied by a short-distance coefficient. The short-distance coefficient for the leading matrix element is calculated to orde...

Ultrasonic backscattering measurements by means of spatial averaging technique were carried out in steel to determine the ultrasonic attenuation coefficient. The attenuation coefficients were evaluated from the exponential decay of the backscattering signal. The results were compared with those obtained by evaluating the amplitude decay of the main pulse. Good agreement is observed provided the...