We review recent progress in calculations of one-loop QCD amplitudes. By imposing the consistency requirements of unitarity and correct behavior as the momenta of two legs become collinear, we construct ansätze for one-loop amplitudes with an arbitrary number of external legs. For supersymmetric amplitudes, which can be thought of as components of QCD amplitudes, the cuts uniquely specify the a...

In the OSp invariant closed string field theory, we construct the states corresponding to parallel D-branes that are located at different points in the space-time. Using these states, we evaluate annulus amplitudes. We show that the results coincide with those of first quantized string theory. e-mail: [email protected] e-mail: [email protected] e-mail: [email protected]

Cerebral Palsy (CP) leads to various clinical signs mainly induced by spasticity. Among these ones impaired balance and posture are very common. Traditional physical therapy exercise programs are focusing on this aspect but it is difficult to motivate patients to regularly perform these exercises. Specially developed serious games (SG) could therefore be an interesting option to motivate childr...

We evaluate the contribution of second order terms to the pionnucleus s-wave optical potential of pionic atoms generated by short range nuclear correlations. The corrections are sizeable because they involve the isoscalar s-wave πN amplitude for half off-shell situations where the amplitude is considerably larger than the on-shell one. In addition, the s-wave optical potential is reanalyzed by ...

By manipulating the discrete optical levels inside an optical resonator, we obtain a classical realization of a twisted Landau ± Zener model. We experimentally demonstrate the geometric amplitude factor in the transition amplitude that arises for this model. We consider in particular the region of parameter space addressed in the original study of the geometric amplitude factor by M. V. Berry [7].

We discuss a number of old and new methods for computing K → ππ amplitudes on the lattice. They all involve a non-perturbative determination of matching coefficients. We show how problems related to operator mixing can be greatly reduced by using point-split hadronic currents.

We show that a modified form of the semiclassical coupled wave theory gives a reliable description of wave propagation in a 1D photonic crystal with complex refractive index. The key idea of the theory remains the same: to include both variable amplitudes and variable (geometric-optics) phases in the counterpropagating coupled waves within the photonic crystal. Here, however, the phases become ...

Abstract. The explicit procedures are described for reconstruction of the full set of helicity amplitudes in proton-proton and proton-antiproton elastic scattering. The procedures are based on the derivative relations for the helicity amplitudes in s-channel, on the explicit parametrization of the leading spin non flip amplitudes and crossing symmetry relations. Asymptotic theorems are used for...

In this paper, two suboptimum detectors are proposed for coherent radar signal detection in K-distributed clutter. Assuming certain values for several initial moments of clutter amplitude, the characteristic function of the clutter amplitude is approximated by a limited series. Using the Pade approximation, it is then converted to a rational fraction. Thus, the pdf of the clutter amplitude is o...

The present investigation is concerned with the reflection of plane waves from a free surface of a micropolar thermoelastic diffusion half space in the context of coupled theory of thermoelastic diffusion. The amplitude ratios of various reflected waves are obtained in a closed form. The dependence of these amplitude ratios with an angle of propagation as well as other material parameter are sh...