118 research outputs found
Spontaneous Symmetry Breaking at Infinite Momentum without P+ Zero-Modes
The nonrelativistic interpretation of quantum field theory achieved by
quantization in an infinite momentum frame is spoiled by the inclusion of a
mode of the field carrying p+=0. We therefore explore the viability of doing
without such a mode in the context of spontaneous symmetry breaking (SSB),
where its presence would seem to be most needed. We show that the physics of
SSB in scalar quantum field theory in 1+1 space-time dimensions is accurately
described without a zero-mode.Comment: LaTeX, 8 pages, 3 eps figure
Monte Carlo Simulation Calculation of Critical Coupling Constant for Continuum \phi^4_2
We perform a Monte Carlo simulation calculation of the critical coupling
constant for the continuum {\lambda \over 4} \phi^4_2 theory. The critical
coupling constant we obtain is [{\lambda \over \mu^2}]_crit=10.24(3).Comment: 11 pages, 4 figures, LaTe
The NuTeV Anomaly, Lepton Universality, and Non-Universal Neutrino-Gauge Couplings
In previous studies we found that models with flavor-universal suppression of
the neutrino-gauge couplings are compatible with NuTeV and Z-pole data. In this
paper we expand our analysis to obtain constraints on flavor-dependent coupling
suppression by including lepton universality data from W, tau, pi and K decays
in fits to model parameters. We find that the data are consistent with a
variety of patterns of coupling suppression. In particular, in scenarios in
which the suppression arises from the mixing of light neutrinos with heavy
gauge singlet states (neutrissimos), we find patterns of flavor-dependent
coupling suppression which are also consistent with constraints from mu -> e
gamma.Comment: REVTeX4, 25 pages, 10 postscript figures. Updated fits using the new
top mass. Updated figures. Extended discussion on the status of the
determination of B(tau->pi nu
Critical dimensions of the diffusion equation
We study the evolution of a random initial field under pure diffusion in
various space dimensions. From numerical calculations we find that the
persistence properties of the system show sharp transitions at critical
dimensions d1 ~ 26 and d2 ~ 46. We also give refined measurements of the
persistence exponents for low dimensions.Comment: 4 pages, 5 figure
Coherent states of P{\"o}schl-Teller potential and their revival dynamics
A recently developed algebraic approach for constructing coherent states for
solvable potentials is used to obtain the displacement operator coherent state
of the P\"{o}schl-Teller potential. We establish the connection between this
and the annihilation operator coherent state and compare their properties. We
study the details of the revival structure arising from different time scales
underlying the quadratic energy spectrum of this system.Comment: 13 pages, 6 figure
The NuTeV Anomaly, Neutrino Mixing, and a Heavy Higgs Boson
Recent results from the NuTeV experiment at Fermilab and the deviation of the
Z invisible width, measured at LEP/SLC, from its Standard Model (SM) prediction
suggest the suppression of neutrino-Z couplings. Such suppressions occur
naturally in models which mix the neutrinos with heavy gauge singlet states. We
postulate a universal suppression of the Z-nu-nu couplings by a factor of
(1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon
and the oblique correction parameters S and T. Compared to a fit with S and T
only, inclusion of epsilon leads to a dramatic improvement in the quality of
the fit. The values of S and T preferred by the fit can be obtained within the
SM by a simple increase in the Higgs boson mass. However, if the W mass is also
included in the fit, a non-zero U parameter becomes necessary which cannot be
supplied within the SM. The preferred value of epsilon suggests that the seesaw
mechanism may not be the reason why neutrinos are so light.Comment: 19 pages, REVTeX4, 8 postscript figures. Updated references. Typos
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Topcolor-Assisted Supersymmetry
It has been known that the supersymmetric flavor changing neutral current
problem can be avoided if the squarks take the following mass pattern, namely
the first two generations with the same chirality are degenerate with masses
around the weak scale, while the third generation is very heavy. We realize
this scenario through the supersymmetric extension of a topcolor model with
gauge mediated supersymmetry breaking.Comment: 12 pages, latex, no figure
Detecting a light Higgs boson at the Fermilab Tevatron through enhanced decays to photon pairs
We analyze the prospects of the Tevatron for finding a Higgs boson in the two
photon decay mode. We conclude that the Standard Model (SM) Higgs boson will
likely not be discovered in this mode. However, we motivate several theories
beyond the SM, including the MSSM, that predict a Higgs boson with enhanced
branching fractions into photons, and calculate the luminosity needed to
discover a general Higgs boson at the Tevatron by a two-photon invariant mass
peak at large transverse momentum. We find that a high luminosity Tevatron will
play a significant role in discovering or constraining these theories.Comment: 20 pages, latex, 5 figure
Pseudo-Goldstone Boson Effects in Top-Antitop Productions at High Energy Hadron Colliders and Testing Technicolor Models
We study the top quark pair production process p+p(anti-p)-->top+antitop in
various kinds of technicolor (TC) models at the Fermilab Tevatron Run II and
the CERN LHC. The s-channel neutral pseudo-Goldstone bosons (PGB's) contribute
dominately to the production amplitudes from its coupling to the gluons through
the triangle loops of techniquarks and the top quark. Cross sections in
different TC models with s-channel PGB contributions are calculated. It is
shown that the PGB effects can be experimentally tested and different TC models
under consideration can be distinguished at the LHC. Therefore, the
p+p-->top+antitop process at the LHC provides feasible tests of the TC models.Comment: 10 pages in RevTex and 4 PS-files for the figures. Paramemter range
is changed, and some references are added. Version for publication in Phys.
Rev.
Production and decay of the neutral top-pion in high energy colliders
We study the production and decay of the neutral top-pion
predicted by topcolor-assisted technicolor(TC2) theory. Our results show that,
except the dominant decay modes , and , the
can also decay into and modes. It can
be significantly produced at high energy collider(LC) experiments
via the processes and . We further calculate the production cross sections of the
processes and . We find that the signatures of the neutral top-pion
can be detected via these processes.Comment: Latex file, 13 Pages, 6 eps figures. to be published in Phys.Rev.
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