618 research outputs found
Multiquark states as di-hadronic molecules
Multiquark systems such as tetraquarks, pentaquarks and hexaquarks states are
studied as di-hadronic molecules in a nonrelativistic model. The masses of
several di-hadronic states using a molecular interaction provided by asymptotic
expression of the confined gluon exchange potential are computed. The exotic
states such as f (0.982), f (1.565), f (1.950), X(3.87), D
(2.317, 2.460, 2.632), (4.040) etc are identified as the low lying
di-mesonic states, and (1.54) as a molecular state.Comment: 4 pages, Presented in the Fifth International Conference on
Perspectives in Hadronic Physics, ICTP, Trieste, Italy, May 200
Left ventricular geometry and function in hypartensive patients with ECG left ventricular hypertrophy: the LIFE trial
Models of Neutrino Masses: Anarchy versus Hierarchy
We present a quantitative study of the ability of models with different
levels of hierarchy to reproduce the solar neutrino solutions, in particular
the LA solution. As a flexible testing ground we consider models based on
SU(5)xU(1)_F. In this context, we have made statistical simulations of models
with different patterns from anarchy to various types of hierachy: normal
hierarchical models with and without automatic suppression of the 23
(sub)determinant and inverse hierarchy models. We find that, not only for the
LOW or VO solutions, but even in the LA case, the hierarchical models have a
significantly better success rate than those based on anarchy. The normal
hierachy and the inverse hierarchy models have comparable performances in
models with see-saw dominance, while the inverse hierarchy models are
particularly good in the no see-saw versions. As a possible distinction between
these categories of models, the inverse hierarchy models favour a maximal solar
mixing angle and their rate of success drops dramatically as the mixing angle
decreases, while normal hierarchy models are far more stable in this respect.Comment: v1: 28 pages, 12 figures; v2: 34 pages, 14 figures, updated previous
analysis with the inclusion of recent SNO result
Leptogenesis and low energy observables in left-right symmetric models
In the context of left-right symmetric models we study the connection of
leptogenesis and low energy parameters such as neutrinoless double beta decay
and leptonic CP violation. Upon imposition of a unitarity constraint, the
neutrino parameters are significantly restricted and the Majorana phases are
determined within a narrow range, depending on the kind of solar solution. One
of the Majorana phases gets determined to a good accuracy and thereby the
second phase can be probed from the results of neutrinoless double beta decay
experiments. We examine the contributions of the solar and atmospheric mass
squared differences to the asymmetry and find that in general the solar scale
dominates. In order to let the atmospheric scale dominate, some finetuning
between one of the Majorana phases and the Dirac CP phase is required. In this
case, one of the Majorana phases is determined by the amount of CP violation in
oscillation experiments.Comment: 18 pages, 6 figures. Matches version to appear in PR
Protecting the primordial baryon asymmetry in the seesaw model compatible with WMAP and KamLAND
We require that the primordial baryon asymmetry is not washed out in the
seesaw model compatible with the recent results of WMAP and the neutrino
oscillation experiments including the first results of KamLAND. We find that
only the case of the normal neutrino mass hierarchy with an approximate
-symmetry satisfies the requirement. We further derive, depending on the
signs of neutrino mass eigenvalues, three types of neutrino mass matrixes,
where the values of each element are rather precisely fixed.Comment: 21pages; added reference
Radiative Corrections to Neutrino Mixing and CP Violation in the Minimal Seesaw Model with Leptogenesis
Radiative corrections to neutrino mixing and CP violation are analyzed in the
minimal seesaw model with two heavy right-handed neutrinos. We find that
textures of the effective Majorana neutrino mass matrix are essentially stable
against renormalization effects. Taking account of the
Frampton-Glashow-Yanagida ansatz for the Dirac neutrino Yukawa coupling matrix,
we calculate the running effects of light neutrino masses, lepton flavor mixing
angles and CP-violating phases for both (normal mass hierarchy) and
(inverted mass hierarchy) cases in the standard model and in its
minimal supersymmetric extension. Very instructive predictions for the
cosmological baryon number asymmetry via thermal leptogenesis are also given
with the help of low-energy neutrino mixing quantities.Comment: 21 pages, 6 figures; more references adde
Statistical distribution of quantum entanglement for a random bipartite state
We compute analytically the statistics of the Renyi and von Neumann entropies
(standard measures of entanglement), for a random pure state in a large
bipartite quantum system. The full probability distribution is computed by
first mapping the problem to a random matrix model and then using a Coulomb gas
method. We identify three different regimes in the entropy distribution, which
correspond to two phase transitions in the associated Coulomb gas. The two
critical points correspond to sudden changes in the shape of the Coulomb charge
density: the appearance of an integrable singularity at the origin for the
first critical point, and the detachement of the rightmost charge (largest
eigenvalue) from the sea of the other charges at the second critical point.
Analytical results are verified by Monte Carlo numerical simulations. A short
account of some of these results appeared recently in Phys. Rev. Lett. {\bf
104}, 110501 (2010).Comment: 7 figure
- …