Mirror matter admixtures in K_S to gamma gamma

The latest measurement of the K_S to gamma gamma branching ratio clearly shows an enhancement over the current theoretical prediction. As in other K and B meson decays, this invites to consider the possibility of the contribution of new physics. We study a particular form of the latter, which may be referred to as manifest mirror symmetry. The experimental data are described using previously determined values for the mixing angles of the admixtures of mirror matter in ordinary hadrons and by assuming that for pi^0, eta, eta', the mirror decay amplitudes have the same magnitudes as their ordinary counterparts

Constraining the False Positive Rate for Kepler Planet Candidates with Multi-Color Photometry from the GTC

Using the OSIRIS instrument installed on the 10.4-m Gran Telescopio Canarias (GTC) we acquired multi-color transit photometry of four small (Rp < 5 R_Earth) short-period (P < 6 days) planet candidates recently identified by the Kepler space mission. These observations are part of a program to constrain the false positive rate for small, short-period Kepler planet candidates. Since planetary transits should be largely achromatic when observed at different wavelengths (excluding the small color changes due to stellar limb darkening), we use the observed transit color to identify candidates as either false positives (e.g., a blend with a stellar eclipsing binary either in the background/foreground or bound to the target star) or validated planets. Our results include the identification of KOI 225.01 and KOI 1187.01 as false positives and the tentative validation of KOI 420.01 and KOI 526.01 as planets. The probability of identifying two false positives out of a sample of four targets is less than 1%, assuming an overall false positive rate for Kepler planet candidates of 10% (as estimated by Morton & Johnson 2011). Therefore, these results suggest a higher false positive rate for the small, short-period Kepler planet candidates than has been theoretically predicted by other studies which consider the Kepler planet candidate sample as a whole. Furthermore, our results are consistent with a recent Doppler study of short-period giant Kepler planet candidates (Santerne et al. 2012). We also investigate how the false positive rate for our sample varies with different planetary and stellar properties. Our results suggest that the false positive rate varies significantly with orbital period and is largest at the shortest orbital periods (P < 3 days), where there is a corresponding rise in the number of detached eclipsing binary stars... (truncated)Comment: 13 pages, 12 figures, 3 tables; revised for MNRA

La figura de Quetzalcóatl: Santo Tomás apóstol en el sermón de Fray Servando Teresa de Mier

1 archivo PDF (8 páginas). fhundequadragintaUna de las figuras independentistas más controversiales, sin duda, ha sido y será la del Doctor Servando Teresa de Mier y Noriega Guerra, quien pasaría a la historia, entre otras cosas, por su sermón promulgado el 12 de septiembre de 1794. El presente trabajo se enfoca en estudiar una de las cuatro propuestas expuestas en el sermón, aquella referida a la llegada del apóstol Santo Tomás a tierras mexicanas, mismo que la gente llamó Quetzalcóatl

Bryophytes of Mona Island Natural Reserve, Puerto Rico

This checklist provides in addition to a list of mosses and hepatics, a key to the species. We report 17 moss species of which 9 are new to Mona Island and 3 are new records for Puerto Rico (Fissidens minutus, Plaubelia sprengelii and Brymela callicostelloides). This report represents a 35% increase to the moss flora of Mona Island. Thirteen hepatics are reported of which 8 are new records, representing an increase of 31%. Two new synonyms (Bryum microdecurrens = Bryum coronatum, Riccia brittonii = Riccia elliottii) are included. No hornworts are known for the island.Este listado en adición a la lista de musgos y hepáticas provee una clave para las especies. Reportamos 17 especies de musgos de los cuales 9 son nuevos para Isla de Mona y 3 son registros nuevos para Puerto Rico (Fissidens minutus, Plaubelia sprengelii y Brymela callicostelloides). Este reporte representa un aumento de un 35% en la flora muscinal de Isla de Mona. Trece hepáticas son reportadas de las cuales 8 son registros nuevos, representando un aumento de 31%. Dos nuevos sinónimos (Bryum microdecurrens = Bryum coronatum, Riccia brittonii = Riccia elliottii) se incluyen. No se conocen registros de antocerotes para la isla

Presencia de patos pijije, alablanca (Dendrocygna autumnalis) y canelo (Dendrocygna bicolor), en Toluca, Estado de México

Se reporta por primera ocasión la presencia veraniega de patos pijije, alablanca (Dendrocygna autumnalis) y canelo (Dendrocygna bicolor), en un cuerpo de agua artificial localizado en el municipio de Toluca, Estado de México. Los registros fueron hechos del 27 de junio al 1° de septiembre del 200

A theoretical study of transition probabilities and lifetimes for the Sn III: core polarization effects

Data on atomic properties are not only relevant to spectroscopy, but these values are of interest in a variety of other fields in physics and technology. In this work we present a completer study of Sn III transition probabilities and lifetimes of spectral lines arising from 4d105sns (n=6-9) and 4d105snp (n=5-6) configurations These values were obtained in intermediate coupling (IC) and using relativistic Hartree-Fock calculations including core-polarization effects following the suggestions of Migdalek et al. [1]. We use for the IC calculations the standard method of least square fitting from experimental energy levels by means of Cowan [2] computer code. For the calculations we used all the experimental levels present in the Moore table. Transition probabilities and lifetimes are generally in good agreement with the experimental data [3, 4, 5]. In the next Table we present some values as example