Lagrangians for Massive Dirac Chiral Superfields

A variant for the superspin one-half massive superparticle in $4D$, $\mathcal{N}=1$, based on Dirac superfields, is offered. As opposed to the current known models that use spinor chiral superfields, the propagating fields of the supermultiplet are those of the lowest mass dimensions possible: scalar, Dirac and vector fields. Besides the supersymmetric chiral condition, the Dirac superfields are not further constrained, allowing a very straightforward implementation of the path-integral method. The corresponding superpropagators are presented. In addition, an interaction super Yukawa potential, formed by Dirac and scalar chiral superfields, is given in terms of their component fields. The model is first presented for the case of two superspin one-half superparticles related by the charged conjugation operator, but in order to treat the case of neutral superparticles, the Majorana condition on the Dirac superfields is also studied. We compare our proposal with the known models of spinor superfields for the one-half superparticle and show that it is equivalent to them.Comment: 22 pages. Matches published versio

Radiative decays of dynamically generated charmed baryons

In this work we study the radiative decay of dynamically generated J^P=\oh^- charm baryons into the ground state J^P=\oh^+ baryons. Since different theoretical interpretations of these baryonic resonances, and in particular of the $\Lambda_c(2595)$, give different predictions, a precise experimental measurement of these decays would be an important step for understanding their nature.Comment: 10 pages, 1 figur

Wide binaries as a critical test for Gravity theories

Assuming Newton's gravity and GR to be valid at all scales leads to the dark matter hypothesis as a requirement demanded by the observed dynamics and measured baryonic content at galactic and extragalactic scales. Alternatively, modified gravity scenarios where a change of regime appears at acceleration scales $a<a_{0}$ have been proposed. This modified regime at $a<a_{0}$ will generically be characterised by equilibrium velocities which become independent of distance. Here we identify a critical test in this debate and we propose its application to samples of wide binary stars. Since for $1 M_{\odot}$ systems the acceleration drops below $a_{0}$ at scales of around 7000 AU, a statistical survey of wide binaries with relative velocities and separations reaching $10^{4}$ AU and beyond should prove useful to the above debate. We apply the proposed test to the best currently available data. Results show a constant upper limit to the relative velocities in wide binaries which is independent of separation for over three orders of magnitude, in analogy with galactic flat rotation curves in the same $a<a_{0}$ acceleration regime. Our results are suggestive of a breakdown of Kepler's third law beyond $a \approx a_{0}$ scales, in accordance with generic predictions of modified gravity theories designed not to require any dark matter at galactic scales and beyond.Comment: 4 pages 1 figure, Proceedings of the COSGRAV12 meeting, Kolkata, India, 7th - 11th February, 201

Experimental scheme for unambiguous discrimination of linearly independent symmetric states

We propose an optimal discrimination scheme for a case of four linearly independent nonorthogonal symmetric quantum states, based on linear optics only. The probability of discrimination is in agreement with the optimal probability for unambiguous discrimination among N symmetric states [Phys. Lett. A \textbf{250}, 223 (1998)]. The experimental setup can be extended for the case of discrimination among $2^M$ nonorthogonal symmetric quantum states

Dynamically generated open charmed baryons beyond the zero range approximation

The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.Comment: 7 figures, 8 table

Language of Interview and the Subjectively-Rated Health of Hispanic Mothers and their Children

Hispanics tend to be as healthy as non-Hispanic whites across a number of indicators, yet they consistently rate their health as worse than non-Hispanic whites. This incongruous finding has been tied both to levels of acculturation and Spanish-language use, questioning the validity of self-reported health for Spanish speakers in the United States. Furthermore, in the same way that Hispanic adults interviewed in Spanish have worse self-rated health, when asked in Spanish mothers rate their children’s health as worse than those mothers who answer in English. The exact reasons for this relationship, though, are unclear. Frequently this language effect has been taken as an indicator of acculturation; as such, the assumption is that as time progresses Hispanics become more acculturated and answer questions regarding their health more similarly to non-Hispanic whites. However, up until this point there has been no longitudinal research examining the relationship between rated health and language of interview. Using three waves of data on Hispanic mothers and their children from the Fragile Families and Child Well-being Study, this paper addresses the following questions: 1. Is Spanish language interview predictive of worse rated health for both mothers and children, and do these relationships change over time? 2. Does the effect of language on rated health persist after controlling for potential mediators? By employing two-level generalized linear models, we find that on average, those who were interviewed in Spanish are more likely to rate their and their children’s health as worse than those who answered in English. The effect of language of interview on reported health persists over time, even after controlling for measures of acculturation, physical and mental health, and access to health care. Contrary to what some have proposed, we see no discernable change over time in the way women rate their own health or that of their children.