Nonleptonic two-body B-decays including axial-vector mesons in the final state

We present a systematic study of exclusive charmless nonleptonic two-body B decays including axial-vector mesons in the final state. We calculate branching ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a vector and a pseudoscalar meson, respectively. We assume naive factorization hypothesis and use the improved version of the nonrelativistic ISGW quark model for form factors in B\to A transitions. We include contributions that arise from the effective \Delta B=1 weak Hamiltonian H_{eff}. The respective factorized amplitude of these decays are explicitly showed and their penguin contributions are classified. We find that decays B^-to a_1^0\pi^-,\barB^0\to a_1^{\pm}\pi^{\mp}, B^-\to a_1^-\bar K^0, \bar B^0\to a_1^+K^-, \bar B^0\to f_1\bar K^0, B^-\to f_1K^-, B^-\to K_1^-(1400)\etap, B^-\to b_1^-\bar K^{0}, and \bar B^0\to b_1^+\pi^-(K^-) have branching ratios of the order of 10^{-5}. We also study the dependence of branching ratios for B \to K_1P(V,A) decays (K_1=K_1(1270),K_1(1400)) with respect to the mixing angle between K_A and K_B.Comment: 28 pages, 2 tables and one reference added, notation changed in appendices, some numerical results and abstract correcte

Growers' Perspective on Attracting Migrant Labor and Migrants' Workplace Choice in Michigan

This study was conducted to analyze Michigan's migrant farm labor situation. Data were collected from growers and migrants. Growers reported wages, housing, and perquisites as tools they use to attract migrants. Migrants reported housing, wages, grower honesty, and respectful treatment of workers to be key factors in choosing a workplace.Labor and Human Capital,

The use of colloquial words in advanced French interlanguage

This article addresses the issue of underrepresentation or avoidance of colloquial words in a cross-sectional corpus of advanced French interlanguage (IL) of 29 Dutch L1 speakers and in a longitudinal corpus of 6 Hiberno-Irish English L1 speakers compared with a control of 6 native speakers of French. The main independent variable analysed in the latter corpus is the effect of spending a year in a francophone environment. This analysis is supplemented by a separate study of sociobiographical and psychological factors that affect the use of colloquial vocabulary in the cross-sectional corpus. Colloquial words are not exceptionally complex morphologically and present no specific grammatical difficulties, yet they are very rare in our data. Multivariate regression analyses suggest that only active authentic communication in the target language (TL) predicts the use of colloquial lexemes in the cross-sectional corpus. This result was confirmed in the longitudinal corpus where a t-test showed that the proportion of colloquial lexemes increased significantly after a year abroad

First order perturbations of the Einstein-Straus and Oppenheimer-Snyder models

We derive the linearly perturbed matching conditions between a Schwarzschild spacetime region with stationary and axially symmetric perturbations and a FLRW spacetime with arbitrary perturbations. The matching hypersurface is also perturbed arbitrarily and, in all cases, the perturbations are decomposed into scalars using the Hodge operator on the sphere. This allows us to write down the matching conditions in a compact way. In particular, we find that the existence of a perturbed (rotating, stationary and vacuum) Schwarzschild cavity in a perturbed FLRW universe forces the cosmological perturbations to satisfy constraints that link rotational and gravitational wave perturbations. We also prove that if the perturbation on the FLRW side vanishes identically, then the vacuole must be perturbatively static and hence Schwarzschild. By the dual nature of the problem, the first result translates into links between rotational and gravitational wave perturbations on a perturbed Oppenheimer-Snyder model, where the perturbed FLRW dust collapses in a perturbed Schwarzschild environment which rotates in equilibrium. The second result implies in particular that no region described by FLRW can be a source of the Kerr metric.Comment: LaTeX; 29 page