Study of the γd→K+K−np\gamma d\to K^{+}K^{-}np reaction and an alternative explanation for the "Θ+(1540)\Theta^{+}(1540) pentaquark" peak

We present a calculation of the $\gamma d \to K^+ K^- n p$ reaction with the aim of seeing if the experimental peak observed in the $K^+ n$ invariant mass around 1526 MeV, from where evidence for the existence of the $\Theta^+$ has been claimed, can be obtained without this resonance as a consequence of the particular dynamics of the process and the cuts applied in the experimental set up. We find that a combination of facts leads indeed to a peak around 1530 MeV for the invariant mass of $K^+ n$ without the need to invoke any new resonance around this energy. This, together with statistical fluctuations that we prove to be large with the statistics of the experiment, is likely to produce the narrower peak observed there.Comment: published versio

Random matrix study for a three-terminal chaotic device

We perform a study based on a random-matrix theory simulation for a three-terminal device, consisting of chaotic cavities on each terminal. We analyze the voltage drop along one wire with two chaotic mesoscopic cavities, connected by a perfect conductor, or waveguide, with one open mode. This is done by means of a probe, which also consists of a chaotic cavity that measure the voltage in different configurations. Our results show significant differences with respect to the disordered case, previously considered in the literature.Comment: Proccedings of the V Leopoldo Garcia-Colin Mexican Meeting on Mathematical and Experimental Physic

Linearization of nonlinear connections on vector and affine bundles, and some applications

A linear connection is associated to a nonlinear connection on a vector bundle by a linearization procedure. Our definition is intrinsic in terms of vector fields on the bundle. For a connection on an affine bundle our procedure can be applied after homogenization and restriction. Several applications in Classical Mechanics are provided