537 research outputs found
The electromagnetic effects in isospin symmetry breakings of q{\bar q} systems
The isospin symmetry breakings of q{\bar q} are investigated in the QCD sum
rule method. The electromagnetic effects are evaluated following the procedure
requiring that the electromagnetic effects for charged meson be gauge
invariant. We find that the electromagnetic effects are also dominant in the
isospin violations of rho meson, which have been shown to be the case in the
mass splittings of pions. The numerical results for the difference of pion
decay constants and the masses of rho mesons are presented, which are
consistent with the data.Comment: To appear in Phys. Rev. D (1997
A basis of cranking operators for the pairing-plus-quadrupole model
We investigate the RPA normal-mode coordinates in the pairing-plus-quadrupole
model, with an eye on simplifying the application of large amplitude collective
motion techniques. At the Hartree-Bogoliubov minimum, the RPA modes are exactly
the cranking operators of the collective coordinate approach. We examine the
possibility of representing the self-consistent cranking operator by linear
combinations of a limited number of one-body operators. We study the Sm nuclei
as an example, and find that such representations exist in terms of operators
that are state-dependent in a characteristic manner.Comment: 6 pages, 1 figure, using IOP journal style files, to be published in
J. Phys.
Sterile Neutrinos and Pulsar Velocities Revisited,
We calculate the momentum given to a proto neutron star during the first 10
seconds after temperature equilibrium is reached, using recent evidence of
sterile neutrinos and a measurement of the mixing angle. This is a continuation
of an earlier estimate with a wide range of possible mixing angles. Using the
new mixing angle we find that sterile neutrinos can account for the observed
pulsar velocities.Comment: 3 pages, 2 figure
Quark propagator, instantons and gluon propagator
The Schwinger-Dyson formalism is used to check the consistency of instanton
model solutions for the quark propagator with recent models of confining gluon
propagators. We find that the models are not consistent. A major discrepancy is
the absence of a vector condensate in the instanton model that is present in
the solutions with nonperturbative confining gluons.Comment: Latex file, no figure
Glueball enhancements in p(gamma,VV)p through vector meson dominance
Double vector meson photoproduction, p(gamma, G -> VV)p, mediated by a scalar
glueball G is investigated. Using vector meson dominance (VMD) and
Regge/pomeron phenomenology, a measureable glueball enhancement is predicted in
the invariant VV = rho rho and omega omega mass spectra. The scalar glueball is
assumed to be the lightest physical state on the daughter pomeron trajectory
governing diffractive vector meson photoproduction. In addition to cross
sections, calculations for hadronic and electromagnetic glueball decays, G -> V
V' (V,V'= rho, omega, phi, gamma), and gamma_v V -> G transition form factors
are presented based upon flavor universality, VMD and phenomenological
couplings from phi photoproduction analyses. The predicted glueball decay
widths are similar to an independent theoretical study. A novel signature for
glueball detection is also discussed
The as a Hybrid
Using the QCD Sum Rule Method, we estimate the mass of the lowest strange
hybrid baryon with . We find the mass is approximately that of
the , whose nature has been a puzzle for many decades. Possible
tests of this result are discussed.Comment: fourteen pages seven figure
The finite-width Laplace sum rules for scalar glueball in instanton liquid model
In the framework of a semi-classical expansion for quantum chromodynamics in
the instanton liquid background, the correlation function of the
scalar glueball current is given. Besides the pure classical and quantum
contributions, the contributions arising from the interactions between the
classical instanton fields and quantum gluons are taken into account as well.
Instead of the usual zero-width approximation for the resonance, the
Brite-Wigner form for the spectral function of the finite-width resonance is
adopted. The family of the Laplace sum rules for the scalar glueball in quantum
chromodynamics with and without light quarks are studed. A consistency between
the subtracted and unsubtracted sum rules are very well justified, and the
values of the mass, decay width, and the coupling to the corresponding current
for the resonance in which the glueball fraction is dominant, are
obtained.Comment: 6 figure
Service oriented architecture for scientific analysis at W7-X. An example of a field line tracer
A model for the distribution of aftershock waiting times
In this work the distribution of inter-occurrence times between earthquakes
in aftershock sequences is analyzed and a model based on a non-homogeneous
Poisson (NHP) process is proposed to quantify the observed scaling. In this
model the generalized Omori's law for the decay of aftershocks is used as a
time-dependent rate in the NHP process. The analytically derived distribution
of inter-occurrence times is applied to several major aftershock sequences in
California to confirm the validity of the proposed hypothesis.Comment: 4 pages, 3 figure
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