Search results for "Degenerate energy levels"
showing 10 items of 221 documents
Discontinuous solutions of linear, degenerate elliptic equations
2008
Abstract We give examples of discontinuous solutions of linear, degenerate elliptic equations with divergence structure. These solve positively conjectures of De Giorgi.
Control of essential supremum of solutions of quasilinear degenerate parabolic equations
2001
Sufficient conditions are obtained so that a weak subsolution of a class of quasilinear degenerate parabolic equations, bounded from above on theparabolic boundary of the cylinder Q, turns out to be bounded from above in Q.
Statistical sensitivity of the nEDM apparatus at PSI to n − n′ oscillations
2018
The neutron and its hypothetical mirror counterpart, a sterile state degenerate in mass, could spontaneously mix in a process much faster than the neutron β-decay. Two groups have performed a series of experiments in search of neutron – mirror-neutron (n − n′) oscillations. They reported no evidence, thereby setting stringent limits on the oscillation time τnn′. Later, these data sets have been further analyzed by Berezhiani et al.(2009–2017), and signals, compatible with n − n′ oscillations in the presence of mirror magnetic fields, have been reported. The Neutron Electric Dipole Moment Collaboration based at the Paul Scherrer Institute performed a new series of experiments to further test…
Global existence for a degenerate nonlinear diffusion problem with nonlinear gradient term and source
1999
Dynamically generated resonances from the vector octet-baryon octet interaction
2010
We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled-channels unitary approach. We examine the scattering amplitudes and their poles, which can be associated to known J(P) = 1/2(-), 3/2(-) baryon resonances, in some cases, or give predictions in other ones. The formalism employed produces doublets of degenerate J(P) = 1/2(-), 3/2(-) states, a pattern which is observed experimentally in several cases. The findings of this work should also be useful to guide present experimental programs searching for new resonances, in particular in the strange sector where the current information is very poor.
Search for charginos nearly mass degenerate with the lightest neutralino in e+e− collisions at centre-of-mass energies up to 209 GeV
2002
A search for charginos nearly mass degenerate with the lightest neutralino is performed with the data collected by the ALEPH detector at LEP, at centre-of-mass energies between 189 and 209 GeV, corresponding to an integrated luminosity of 628 pb-1. The analysis is based on the detection of isolated and energetic initial state radiation photons, produced in association with chargino pairs whose decay products have little visible energy. The number of candidate events observed is in agreement with that expected from Standard Model background sources. These results are combined with those of other direct searches for charginos, and a lower limit of 88 GeV/c2 at 95 % confidence level is derived…
Resolving the octant of theta(23) with T2K and NOvA
2013
Preliminary results of MINOS experiment indicate that theta(23) is not maximal. Global fits to world neutrino data suggest two nearly degenerate solutions for theta(23): one in the lower octant (LO: theta(23) 45 degrees). v(mu) -> v(e) oscillations in superbeam experiments are sensitive to the octant and are capable of resolving this degeneracy. We study the prospects of this resolution by the current T2K and upcoming NOvA experiments. Because of the hierarchy-delta(CP) degeneracy and the octant delta(CP) degeneracy, the impact of hierarchy on octant resolution has to be taken into account. As in the case of hierarchy determination, there exist favorable (unfavorable) values of delta(CP) fo…
Collective effects inνν¯synchrotron radiation from neutron stars
1999
We have considered the collective effects in $\ensuremath{\nu}\overline{\ensuremath{\nu}}$ synchrotron radiation from an ultrarelativistic degenerate electron gas in neutron stars with strong magnetic fields. For this problem we apply a calculation method which explicitly makes use of the fact that the radiating electron moves semiclassically, but takes into account the interaction among particles in a quantum way. First we apply this method to calculate $\ensuremath{\nu}\overline{\ensuremath{\nu}}$ synchrotron radiation by an ultrarelativistic electron in vacuum and we compare this result with that obtained previously by other techniques. When a degenerate plasma is considered, we show tha…
The local boundedness of solutions for a class of degenerate nonlinear elliptic higher-order equations withL1-data
2008
We prove local boundedness of solutions for a class of degenerate nonlinear elliptic higher-order equations with L(1)-data.
On the implementation of weno schemes for a class of polydisperse sedimentation models
2011
The sedimentation of a polydisperse suspension of small rigid spheres of the same density, but which belong to a finite number of species (size classes), can be described by a spatially one-dimensional system of first-order, nonlinear, strongly coupled conservation laws. The unknowns are the volume fractions (concentrations) of each species as functions of depth and time. Typical solutions, e.g. for batch settling in a column, include discontinuities (kinematic shocks) separating areas of different composition. The accurate numerical approximation of these solutions is a challenge since closed-form eigenvalues and eigenvectors of the flux Jacobian are usually not available, and the characte…