3,924 research outputs found
Predictions from the Fritzsch-Type Lepton Mass Matrices
We revisit the Fritzsch-type lepton mass matrix models confronted with new
experiments for neutrino mixings. It is shown that the model is viable and
leads to a rather narrow range of free parameters. Using empirical mixing
information between and , and between and
, it is predicted that the mixing angle between and
is in the range , consistent with the CHOOZ experiment and
the lightest neutrino mass is eV. The range of the
effective mass measured in double beta decay is eV.Comment: Latex file with 13 pages, 6 eps file
Volume dependence of light hadron masses in full lattice QCD
The aim of the GRAL project is to simulate full QCD with standard Wilson
fermions at light quark masses on small to medium-sized lattices and to obtain
infinite-volume results by extrapolation. In order to establish the functional
form of the volume dependence we study systematically the finite-size effects
in the light hadron spectrum. We give an update on the status of the GRAL
project and show that our simulation data for the light hadron masses depend
exponentially on the lattice size.Comment: 3 pages, 1 figure, Lattice2003(spectrum
How natural is a small but nonzero cosmological constant?
Based on our previous attempt, we propose a better way to understand a small
but nonzero cosmological constant, as indicated by a number of recent
observational studies. We re-examine the assumptions of our model of two scalar
fields, trying to explain the basic mechanism resulting in a series of
mini-inflations occuring nearly periodically with respect to with
the cosmic time. We also discuss how likely the solution of this type would be,
depending on the choice of the parameters.Comment: 12 pages, latex, 5 figures as epsf files included, compressed
uuencode
Matter Distribution around Galaxies
We explore the mass distribution of material associated with galaxies from
the observation of gravitational weak lensing for the galaxy mass correlation
function with the aid of -body simulations of dark matter. The latter is
employed to unfold various contributions that contribute to the integrated line
of sight mass density. We conclude that galaxies have no definite edges of the
matter distribution, extending to the middle to neighbouring galaxies with the
density profile roughly beyond the virial radius. The mass
distributed beyond the virial radius (gravitationally bound radius) explains
the gap seen in the mass density estimates, the global value and typically from the luminosity density
multiplied by the mass to light ratio. We suggest to use a physical method of
gravitational lensing to characterise galaxy samples rather than characterise
them with photometric means.Comment: 16 pages, 5 figures. ApJ accepte
- …