33 research outputs found
Some constraints on the Yukawa parameters in the neutrino modification of the Standard Model (nuMSM) and CP-violation
The equations connecting elements of the Yukawa matrix to elements of the
active neutrino mass matrix in the \nu MSM theory (an extension of the Standard
Model by a singlet of three right-handed neutrinos) was analyzed, and explicit
relations for the ratio of the Yukawa matrix elements through elements of the
active neutrino mass matrix were obtained. This relation can be used for
getting more accurate constraints on the model parameters. Particularly, with
the help of the obtained results we investigated CP-violating phase in the \nu
MSM theory. We demonstrate that even in the case when elements of the active
neutrino mass matrix are real the baryon asymmetry can be generated also.Comment: 14 pages, 2 figures, many clarifications and references adde
Scaling Of Chiral Lagrangians And Landau Fermi Liquid Theory For Dense Hadronic Matter
We discuss the Fermi-liquid properties of hadronic matter derived from a
chiral Lagrangian field theory in which Brown-Rho (BR) scaling is incorporated.
We identify the BR scaling as a contribution to Landau's Fermi liquid
fixed-point quasiparticle parameter from "heavy" isoscalar meson degrees of
freedom that are integrated out from a low-energy effective Lagrangian. We show
that for the vector (convection) current, the result obtained in the chiral
Lagrangian approach agrees precisely with that obtained in the
semi-phenomenological Landau-Migdal approach. This precise agreement allows one
to determine the Landau parameter that enters in the effective nucleon mass in
terms of the constant that characterizes BR scaling. When applied to the weak
axial current, however, these two approaches differ in a subtle way. While the
difference is small numerically, the chiral Lagrangian approach implements
current algebra and low-energy theorems associated with the axial response that
the Landau method misses and hence is expected to be more predictive.Comment: 39 pages, latex with 4 eps figure, modified addresses and reference
Constraint on the heavy sterile neutrino mixing angles in the SO(10) model with double see-saw mechanism
Constraints on the heavy sterile neutrino mixing angles are studied in the
framework of a minimal supersymmetric model with {\it double
see-saw mechanism}. A new singlet matter in addition to the right-handed
neutrinos is introduced to realize the double see-saw mechanism. The minimal
model gives an unambiguous Dirac neutrino mass matrix, which
enables us to predict the masses and the mixing angles in the enlarged neutrino mass matrix. Mixing angles between the light Majorana
neutrinos and the heavy sterile neutrinos are shown to be within the LEP
experimental bound on all ranges of the Majorana phases.Comment: 16 pages, 4 figures; the version to be published in Eur. Phys. J.
Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System
A simple model for the dynamics of the Magellanic Stream (MS), in the
framework of modified gravity models is investigated. We assume that the galaxy
is made up of baryonic matter out of context of dark matter scenario. The model
we used here is named Modified Gravity (MOG) proposed by Moffat (2005). In
order to examine the compatibility of the overall properties of the MS under
the MOG theory, the observational radial velocity profile of the MS is compared
with the numerical results using the fit method. In order to obtain
the best model parameters, a maximum likelihood analysis is performed. We also
compare the results of this model with the Cold Dark Matter (CDM) halo model
and the other alternative gravity model that proposed by Bekenstein (2004), so
called TeVeS. We show that by selecting the appropriate values for the free
parameters, the MOG theory seems to be plausible to explain the dynamics of the
MS as well as the CDM and the TeVeS models.Comment: 14 pages, 3 Figures, accepted in Int. J. Theor. Phy
Neutrino Masses, Mixing and New Physics Effects
We introduce a parametrization of the effects of radiative corrections from
new physics on the charged lepton and neutrino mass matrices, studying how
several relevant quantities describing the pattern of neutrino masses and
mixing are affected by these corrections. We find that the ratio omega = sin
theta / tan theta_atm is remarkably stable, even when relatively large
corrections are added to the original mass matrices. It is also found that if
the lightest neutrino has a mass around 0.3 eV, the pattern of masses and
mixings is considerably more stable under perturbations than for a lighter or
heavier spectrum. We explore the consequences of perturbations on some flavor
relations given in the literature. In addition, for a quasi-degenerate neutrino
spectrum it is shown that: (i) starting from a bi-maximal mixing scenario, the
corrections to the mass matrices keep tan theta_atm very close to unity while
they can lower tan theta_sol to its measured value; (ii) beginning from a
scenario with a vanishing Dirac phase, corrections can induce a Dirac phase
large enough to yield CP violation observable in neutrino oscillations.Comment: 14 pages, 21 figures. Uses RevTeX4. Added several comments and
references. Final version to appear in PR
Measurement of tau polarization in e+ e- annihilation at sqrt{s}=58 GeV
The polarization of tau leptons in the reaction e+ e- --> tau+ tau- has been
measured using a e+e- collider, TRISTAN, at the center-of-mass energy of 58
GeV. From the kinematical distributions of daughter particles in tau --> e nu
nu-bar, mu nu nu-bar, rho nu or pi(K) nu decays, the average polarization of
tau- and its forward-backward asymmetry have been evaluated to be 0.012 +-
0.058 and 0.029 +- 0.057, respectively.Comment: 18 pages, 5 figure
Thermostatistics of deformed bosons and fermions
Based on the q-deformed oscillator algebra, we study the behavior of the mean
occupation number and its analogies with intermediate statistics and we obtain
an expression in terms of an infinite continued fraction, thus clarifying
successive approximations. In this framework, we study the thermostatistics of
q-deformed bosons and fermions and show that thermodynamics can be built on the
formalism of q-calculus. The entire structure of thermodynamics is preserved if
ordinary derivatives are replaced by the use of an appropriate Jackson
derivative and q-integral. Moreover, we derive the most important thermodynamic
functions and we study the q-boson and q-fermion ideal gas in the thermodynamic
limit.Comment: 14 pages, 2 figure
Soccer and homosexuality: the conflicts that lie within the affective game of the coach-adolescent athlete relationship
Discussions regarding homosexuality within a sports context are mediated by emotional nuances, especially in the world of soccer, where practitioners are required to have attributes such as strength, masculinity and aggressiveness. As a consequence, this work aimed to analyze the symbolic representation of homosexual relationships between
adolescent soccer players and their coaches; and, furthermore, to understand the intention behind homoerotic relationships that are established between members of the management team and its players. In this study, researchers used the life history methodology, with participation from three adolescent athletes, ages 14, 15 and 16, and three former athletes, ages 26, 28 and 45, who we called speakers. Based on the collection and analysis of research participantsâ testimonies, homosexual relations were found to have occurred between athletes and coaches, or between athletes and other members of the management team, as a part of a âsocial contractâ that is exclusively linked to their professional objectives. These relationships appear to be purely objective; authentic affective links are absent, due apparently to the transient nature of the athletes in these groups. Too, this context is usually marked by the athleteâs physical and emotional vulnerability, and the agreements he makes within this context are accompanied with moral dilemmas, because such adolescents idealize the coach as a paternal archetype.âFutebol e homossexualidade: Os conflitos que se encontram dentro do jogo afetivo da relação treinador-atleta
adolescente.â As discussĂ”es a respeito da homossexualidade no contexto esportivo sĂŁo mediadas por nuanças emocionais,
especialmente no mundo do futebol que exige de seus praticantes atributos de força, virilidade e agressividade. Por este
motivo este trabalho teve como objetivos diagnosticar existĂȘncia de relaçÔes homossexuais entre atletas adolescentes da
modalidade de futebol e seus técnicos e sua representação simbólica e ainda, compreender a intencionalidade das relaçÔes
homoafetivas que se estabelecem entre componentes da equipe diretiva e os jogadores. Esta pesquisa Ă© de natureza qualitativa
e a tĂ©cnica adotada foi a âhistĂłria de vidaâ e a participação de trĂȘs atletas adolescentes em atividade, com idade de
14, 15 e 16 anos e trĂȘs ex-atletas profissionais, com idades 26, 28 e 45 anos serviram de base metodolĂłgica. A partir da
anålise e tratamento dos depoimentos verificou-se que ocorreram relaçÔes homossexuais nas categorias de base envolvendo
técnico e atleta, ou com outros membros da equipe diretiva, como parte dos contratos sociais, ligados exclusivamente a
objetivos profissionais. Estas relaçÔes parecem ser puramente objetais, nĂŁo parecendo existir vĂnculos afetivos duradouros,
aparentemente, devido à natureza transitória de atletas nesses grupos. Também, nesses ambientes, muitas vezes marcados
pela vulnerabilidade fĂsica e emocional dos atletas, os acertos para as relaçÔes homossexuais sĂŁo permeadas por dilemas
morais, tendo em vista que os atletas adolescentes idealizam o treinador como o arquĂ©tipo paterno ideal.âEl fĂștbol y la homosexualidad: Los conflictos que se encuentran dentro del juego afectivo de la relaciĂłn
atleta-entrenador de los adolescentes.â Las discusiones sobre la homosexualidad en contexto deportivo estĂĄn mediadas por
matices emocionales, sobre todo en el mundo del fĂștbol que exige a sus jugadores atributos como la fuerza, la virilidad y los jugadores. En este estudio, los investigadores utilizaron la metodologĂa de la historia de vida, con la participaciĂłn de
tres atletas adolescentes, con 14, 15 y 16 años, y tres ex atletas con 26, 28 y 45 años, que llamamos âoradoresâ. Basado
en la recogida y anĂĄlisis de testimonios de participantes en la investigaciĂłn, se encontrĂł que las relaciones homosexuales
que se han producido entre los atletas y entrenadores, o entre atletas y otros miembros del equipo de gestiĂłn, son como
parte de un âcontrato socialâ que estĂĄ vinculado exclusivamente a sus objetivos profesionales. Estas relaciones parecen
ser solamente como un objeto; porque a veces no hay vĂnculos afectivos autĂ©nticos, debido aparentemente a la naturaleza
transitoria de los atletas en estos grupos. Demasiado, este contexto es generalmente marcado por la vulnerabilidad fĂsica
y emocional del deportista, y los acuerdos que hace dentro de este contexto se acompañan con dilemas morales, debido
a que tales adolescentes idealizan el entrenador como un arquetipo paterno.
la agresividad. Por lo tanto, este estudio tuvo como objetivo diagnosticar la existencia de relaciones homosexuales entre
adolescentes atletas de fĂștbol y sus entrenadores y la representaciĂłn simbĂłlica de estas relaciones. TambiĂ©n comprender
la intencionalidad de las relaciones homoafetivas que se intercambian entre algunos componentes del equipo directivo y(undefined
Towards a greater dialogue on disability between Muslims and Christians
Attitudes to disability and disabled people by Muslims â focusing on attitudes in the Middle East and North Africa - and Christians â focusing on the West (here taken to mean Europe, North America and Australasia) - were examined through a grounded theory literature search, with the study being divided into three phases of reading and analysis. The aims of study were to develop a dialogue on disability between the two cultures, to inform an understanding of the attitudes to disability in the two cultures, and to inform cultural practice in promoting support and equality in both cultures. The study finds that Islam and Christianity have much in common and are a force for good in promoting and developing disability equality in both Muslim and Christian cultures
A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers
Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10â8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers