15,101 research outputs found
Reconstruction of the spontaneously broken gauge theory in non-commutative geometry
The scheme previously proposed by the present authors is modified to
incorporate the strong interaction by affording the direct product internal
symmetry. We do not need to prepare the extra discrete space for the color
gauge group responsible for the strong interaction to reconstruct the standard
model and the left-right symmetric gauge model(LRSM). The approach based on
non-commutative geometry leads us to presents many attractive points such as
the unified picture of the gauge and Higgs field as the generalized connection
on the discrete space; Minkowski space multipied by N-points discrete space.
This approach leads us to unified picture of gauge and Higgs fields as the
generalized connection. The standard model needs N=2 discrete space for
reconstruction in this formalism. \lr is still alive as a model with the
intermediate symmetry of the spontaneously broken SO(10) grand unified
theory(GUT). N=3 discrete space is needed for the reconstruction of LRSM to
include two Higgs bosons and which are as usual transformed as
(2,2*,0)$ and (1,3,-2) under left-handed SU(2)x right-handed SU(2)x U(1),
respectively. xi is responsible to make the right handed-neutrino Majorana
fermion and so well explains the seesaw mechanism. Up and down quarks have the
different masses through the vacuum expectation value of phi.Comment: 21 page
Elastic scattering signals of solar neutrinos with enhanced baryonic currents
The coupling of the baryonic current to new neutrino states \nu_b with
strength in excess of the weak interactions is a viable extension of the
Standard Model. We analyze the signature of \nu_b appearance in the solar
neutrino flux that gives rise to an elastic scattering signal in dark matter
direct detection and in solar neutrino experiments. This paper lays out an
in-depth study of \nu_b detection prospects for current and future underground
rare event searches. We scrutinize the model as a possible explanation for the
reported anomalies from DAMA, CoGeNT, and CRESST-II and confront it with
constraints from other null experiments.Comment: 30 pages, 9 figures; code-correction to Xenon ionization (S2)
analyses; Xenon10 constraint in Fig.6 is weakened and Xenon100 projection in
Fig.7 is revise
Critical behavior of charmonia across the phase transition: A QCD sum rule approach
We investigate medium-induced change of mass and width of J/psi and eta_c
across the phase transition in hot gluonic matter using QCD sum rules. In the
QCD sum rule approach, the medium effect on heavy quarkonia is induced by the
change of both scalar and twist-2 gluon condensates, whose temperature
dependences are extracted from the lattice calculations of energy density and
pressure. Although the stability of the operator product expansion side seems
to break down at T > 1.06Tc for the vector channel and T>1.04Tc for the
pseudoscalar channel, we find a sudden change of the spectral property across
the critical temperature Tc, which originates from an equally rapid change of
the scalar gluon condensate characterized by e-3p. By parameterizing the ground
state of the spectral density by the Breit-Wigner form, we find that for both
J/psi and eta_c, the masses suddenly decrease maximally by a few hundreds of
MeV and the widths broaden to ~100 MeV slightly above Tc. Implications for
recent and future heavy ion experiments are discussed.
We also carry out a similar analysis for charmonia in nuclear matter, which
could serve as a testing ground for observing the precursor phenomena of the
QCD phase transition. We finally discuss the possibility of observing the mass
shift at nuclear matter at the FAIR project at GSI.Comment: 18 pages, 21 figures, 2 figures are added and discussion on effect of
dynamical quarks is extended. version to appear in Phys.Rev.
Quaternion Octonion Reformulation of Quantum Chromodynamics
We have made an attempt to develop the quaternionic formulation of Yang -
Mill's field equations and octonion reformulation of quantum chromo dynamics
(QCD). Starting with the Lagrangian density, we have discussed the field
equations of SU(2) and SU(3) gauge fields for both cases of global and local
gauge symmetries. It has been shown that the three quaternion units explain the
structure of Yang- Mill's field while the seven octonion units provide the
consistent structure of SU(3)_{C} gauge symmetry of quantum chromo dynamics
A new realistic many-body approach for the description of high-energy scattering processes off complex nuclei
A linked cluster expansion for the calculation of ground state observables of
nuclei with realistic interactions has been developed. Using the V8' potential
the ground state energy, density and momentum distribution of complex nuclei
have been calculated and found to be in good agreement with the results
obtained within the Fermi Hyper Netted Chain, and Variational Monte Carlo
approaches. Using the same cluster expansion, with wave function and
correlations parameters fixed from the calculation of the ground-state
observables, various high energy scattering processes off complex nuclei have
been calculated taking final state interaction effects into account by means of
the Glauber multiple scattering series.Comment: 7 pages, 4 figures, presented by M. Alvioli at the "13th
International Conference on Recent Progress in Many-Body Theories", Buenos
Aires - Argentina, 5-9 December 200
Realistic calculations of correlations and final state interaction effects in the A(e,e'p)X process off complex nuclei
A linked cluster expansion for the calculation of ground state observables of
complex nuclei with realistic interactions has been used to calculate the
ground state energy, density and momentum distribution of 16O and 40Ca. Using
the same cluster expansion and the wave function and correlation parameters
obtained from the energy calculation, we have evaluated the semi inclusive
reaction A(e,e'p)X taking final state interaction (FSI) into account by a
Glauber type approach; the comparison between the distorted and undistorted
momentum distributions provides an estimate of the transparency of the nuclear
medium to the propagation of the hit proton. The effect of color transparency
is also included by considering the Finite Formation Time (FFT) that the hit
hadron needs to reach its asymptotic physical state.Comment: 8 pages, Latex, 8 figures, presented at the "2nd International
Conference on Nuclear and Particle Physics with CEBAF at JLab
Critical Behavior of J/psi across the Phase Transition from QCD sum rules
We study behavior of J/psi in hot gluonic matter using
QCD sum rules. Taking into account temperature dependences of the gluon
condensates extracted from lattice thermodynamics for the pure SU(3) system, we
find that the mass and width of J/psi exhibit rapid change across the critical
temperature.Comment: 5 pages, 3 figures. Poster contribution for Quark Matter 2008. To be
published in the proceeding
Cluster Variation Approach to the Random-Anisotropy Blume-Emery-Griffiths Model
The random--anisotropy Blume--Emery--Griffiths model, which has been proposed
to describe the critical behavior of He--He mixtures in a porous
medium, is studied in the pair approximation of the cluster variation method
extended to disordered systems. Several new features, with respect to mean
field theory, are found, including a rich ground state, a nonzero percolation
threshold, a reentrant coexistence curve and a miscibility gap on the high
He concentration side down to zero temperature. Furthermore, nearest
neighbor correlations are introduced in the random distribution of the
anisotropy, which are shown to be responsible for the raising of the critical
temperature with respect to the pure and uncorrelated random cases and
contribute to the detachment of the coexistence curve from the line.Comment: 14 pages (plain TeX) + 12 figures (PostScript, appended), Preprint
POLFIS-TH.02/9
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