Lifetime and mass of rho meson in correlation with magnetic-dimensional reduction

It is simply anticipated that in a strong magnetic configuration, the Landau quantization ceases the neutral rho meson to decay to the charged pion pair, so the neutral rho meson will be long-lived. To closely access this naive observation, we explicitly compute the charged pion-loop in the magnetic field at the one-loop level, to evaluate the magnetic dependence of the lifetime for the neutral rho meson as well as its mass.Due to the dimensional reduction induced by the magnetic field (violation of the Lorentz invariance), the polarization (spin $s_z=-1,0,+1$) modes of the rho meson, as well as the corresponding pole mass and width, are decomposed in a nontrivial manner compared to the vacuum case. To see the significance of the reduction effect, we simply take the lowest-Landau level approximation to analyze the spin-dependent rho masses and widths. We find that the "fate" of the rho meson may be more complicated because of the magnetic-dimensional reduction: as the magnetic field increases, the rho width for the spin $s_z=0$ starts to develop, reach a peak, to be vanishing at the critical magnetic field to which the folklore refers. On the other side, the decay rates of the other rhos for $s_z=-1,+1$ monotonically increase as the magnetic field develops. The correlation between the polarization dependence and the Landau-level truncation is also addressed.Comment: 10 pages, 2 figures, typos correcte

Taking Judicial Notice of Genocide? The Problematic Law and Policy of the Karemera Decision

On June 16, 2006, the Appeals Chamber of the International Criminal Tribunal for Rwanda issued a decision in Prosecutor v. Karemera taking judicial notice of the fact that genocide occurred in Rwanda in 1994. This decision startled many court observers. While no internationally respected commentator would today question whether the Rwanda genocide took place, should such an event be judicially noticed without evidence? This paper examines that question, arguing that the ICTR Appeals Chamber’s expansive use of judicial notice in Karemera was both illogical and unwise. Genocide, whether as an historical fact or legal charge, fails to meet the “common knowledge” standard of judicial notice. Further, taking such notice hinders the creation of an historical record and risks violating the rights of defendants. This paper proposes a solution: acknowledging genocide as a “previously adjudicated fact” under Rule 94(B). This article—the first to critique Karemera—reviews the jurisprudence of judicial notice in the tribunals, examines the modern concept of genocide, critiques the ICTR’s reasoning and proposes a practical solution that may be relevant to future international courts. This paper is particularly relevant to scholars and practitioners of international criminal law, and may be of interest to scholars of genocide and conflict studies

IR Horava-Lifshitz gravity coupled to Lorentz violating matter: A spectral action approach

We continue our study of Horava-Lifshitz type theories using the methods of the spectral geometry. In this work we construct the infrared action of gravity and matter coupled to gravity in the most general way respecting the foliation preserving diffeomorphisms. This is done with the help of the spectral action principle based on some generalized Dirac operator. The gravity part reproduces the infrared limit of the Horava-Lifshitz gravity, while the matter part gives the generalization of the earlier suggested models. Due to the fact that the same Dirac operator is used in the construction of both sectors, the parameters of the gravity and matter parts are related. We expect that this potentially could naturally exclude fine tunings needed to get some desired properties as well as open new possibilities for the experimental tests of the model.Comment: 21 page