249 research outputs found
The origins of cosmic rays and quantum effects on gravity
The energy spectrum of primary cosmic rays is explained by particles emitted during a thermal expansion of explosive objects inside and near the galaxy, remnants of which may be supernova and/or active talaxies, or even stars or galaxies that disappeared from our sight after the explosion. A power law energy spectrum for cosmic rays, E to the (-alpha -1, is obtained from an expansion rate T is proportional to R to the alpha. Using the solution of the Einstein equation, we obtain a spectrum which agrees very well with experimental data. The implication of an inflationary early universe on the cosmic ray spectrum is also discussed. It is also suggested that the conflict between this model and the singularity theorem in classical general relativity may be eliminated by quantum effects
High energy cosmic rays, gamma rays and neutrinos from AGN
The author reviews a model for the emission of high energy cosmic rays,
gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed
since 1985. Further discussion of the knee energy phenomenon of the cosmic ray
energy spectrum requires the existence of a heavy particle with mass in the
knee energy range. A possible method of detecting such a particle in the Pierre
Auger Project is suggested. Also presented is a relation between the spectra of
neutrinos and gamma-rays emitted from AGN. This relation can be tested by high
energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and
possibly by the Pierre Auger Project.Comment: 4 pages, no figure
Exotic hadrons in s-wave chiral dynamics
We study s-wave scattering of a hadron and a Nambu-Goldstone boson induced by
the model-independent low energy interaction in the flavor SU(3) symmetric
limit. Establishing the general structure of the low energy interaction based
on group theoretical arguments, we find that the interaction in the exotic
channels are in most cases repulsive, and that for possible attractive channels
the interaction strengths are weak and uniquely given independent of channel.
Solving the scattering problem with this interaction, we show that the
attraction in the exotic channels is not strong enough to generate a bound
state from the physically known target hadrons. We also find that there are no
attractive interaction in the exotic channels in large Nc limit.Comment: RevTeX4, 4 pages, 1 figure, 2 tables, typos correcte
Low lying axial-vector mesons as dynamically generated resonances
We make a theoretical study of the s-wave interaction of the nonet of vector
mesons with the octet of pseudoscalar mesons starting from a chiral invariant
Lagrangian and implementing unitarity in coupled channels. By looking for poles
in the unphysical Riemann sheets of the unitarized scattering amplitudes, we
get two octets and one singlet of axial-vector dynamically generated
resonances. The poles found can be associated to most of the low lying
axial-vector resonances quoted in the Particle Data Book: ,
, , , and two poles to the
resonance. We evaluate the couplings of the resonances to the
states and the partial decay widths in order to reinforce the arguments in the
discussion.Comment: 31 pages, 12 figures, Accepted for publication in Phys.Rev.
Study of exotic hadrons in S-wave scatterings induced by chiral interaction in the flavor symmetric limit
We study s-wave bound states of a hadron and a light pseudoscalar meson
induced by the Weinberg-Tomozawa (WT) interaction in the flavor SU(3) symmetric
limit. The WT interaction is a driving force to generate quasibound states
dynamically in the chiral unitary approaches. The strength and sign of the WT
interaction are determined only by the group theoretical structure of the
target hadrons, and we present a general expression of the strengths for the
flavor SU(3) case. We show that, for the channels which are more exotic than
the target, the interaction is repulsive in most cases, and the strength of the
attractive interaction is universal for any possible target states. We
demonstrate that the attractive coupling is not strong enough to generate an
exotic state from the physically known masses of target hadrons. In addition,
we also find a nontrivial Nc dependence of the coupling strengths. We show that
the channels which are attractive at Nc=3 changes into repulsive ones for large
Nc, and, therefore, no attractive interaction exists in exotic channels in the
large-Nc limit.Comment: RevTeX4, 16 pages, 5 figure, 6 tables, This manuscript is a full
paper of Phys. Rev. Lett. 97, 192002 (hep-ph/0609014), typos corrected, final
versio
Evaluation of the Axial Vector Commutator Sum Rule for Pion-Pion Scattering
We consider the sum rule proposed by one of us (SLA), obtained by taking the
expectation value of an axial vector commutator in a state with one pion. The
sum rule relates the pion decay constant to integrals of pion-pion cross
sections, with one pion off the mass shell. We remark that recent data on
pion-pion scattering allow a precise evaluation of the sum rule. We also
discuss the related Adler--Weisberger sum rule (obtained by taking the
expectation value of the same commutator in a state with one nucleon),
especially in connection with the problem of extrapolation of the pion momentum
off its mass shell. We find, with current data, that both the pion-pion and
pion-nucleon sum rules are satisfied to better than six percent, and we give
detailed estimates of the experimental and extrapolation errors in the closure
discrepancies.Comment: Plain TeX file;minor changes; version to be published in Pys. Rev. D;
corrected refs.12,1
Two components of dark matter in the DAMA data
It is shown that the DAMA data indicate two dark matter components, one that
circulates around the galactic center (GC) and another that is emitted from the
GC. From the location of the maximum yearly variation, one can compute the
ratio of the two components.Comment: 4 pages, no figur
Interplay of the Chiral and Large N_c Limits in pi N Scattering
Light-quark hadronic physics admits two useful systematic expansions, the
chiral and 1/N_c expansions. Their respective limits do not commute, making
such cases where both expansions may be considered to be especially
interesting. We first study pi N scattering lengths, showing that (as expected
for such soft-pion quantities) the chiral expansion converges more rapidly than
the 1/N_c expansion, although the latter nevertheless continues to hold. We
also study the Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules of pi N
scattering, finding that both fail if the large N_c limit is taken prior to the
chiral limit.Comment: 10 pages, ReVTe
Residual interaction effects on deeply bound pionic states in Sn and Pb isotopes
We have studied the residual interaction effects theoretically on the deeply
bound pionic states in Pb and Sn isotopes. We need to evaluate the residual
interaction effects carefully in order to deduce the nuclear medium effects for
pion properties, which are believed to provide valuable information on nuclear
chiral dynamics. The s- and p-wave interactions are used for the
pion-nucleon residual interactions. We show that the complex energy shifts are
around [(10-20)+i(2-7)]keV for 1s states in Sn, which should be taken into
account in the analyses of the high precision data of deeply bound pionic
states in Sn isotopes.Comment: REVTEX4, 6 pages, 5 tables, Submitted to Phys. Rev. C, Some
explanations are added in Version
Supersymmetry and parastatistics
An analysis is made of the supersymmetry of parafields in Wess-Zumino-type models with two cases in which parabosons and parafermions form a supermultiplet. In case one the symmetry is realized by either the normal superalgebra or an infinite Lie algebra as in ordinary supersymmetry. In case two the infinite Lie algebra is intrinsic to the supersymmetry. With appropriate symmetry breaking, formulations of these types may be used to explain the generation problem by postulating unobserved parabosons as supersymmetric partners. The relevance to these models of an infinite Lie algebra constructed from supersymmetry is mentioned.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25130/1/0000563.pd
- âŠ