1,229 research outputs found
Effects of physics beyond the standard model on the neutrino charge radius: an effective Lagrangian approach
In this work, we look for possible new physics effects on the electromagnetic
charge and anapole form factors, and , for a massless
Dirac neutrino, when these quantities are calculated in the context of an
effective electroweak Yang-Mills theory, which induces the most general
--invariant Lorentz tensor structure of nonrenormalizable type for the
vertex. It is found that in this context, besides the standard model
contribution, the additional contribution to and
( and , respectively) are gauge independent
and finite functions of after adopting a renormalization scheme. These
form factors, and , get contribution at
the one loop level only from the proper neutrino electromagnetic vertex.
Besides, the relation
(,
) is still fulfilled and
hence the relation (, )is gotten, just as in the SM. Using the experimental
constraint on the anomalous vertex, a value for the additional
contribution to the charge radius of |^{O_W}| \lsim 10^{-34}
cm^2 is obtained, which is one order of magnitude lower than the SM value.Comment: 9 pages, 3 figure
T-violation in decay in a general two-Higgs doublet model
We calculate the transverse muon polarization in the process
arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs
doublet model where spontaneous violation of CP is presentComment: 6 pages, latex, accepted for publication in Phys. Rev.
Possibility between earthquake and explosion seismogram differentiation by discrete stochastic non-Markov processes and local Hurst exponent analysis
The basic purpose of the paper is to draw the attention of researchers to new
possibilities of differentiation of similar signals having different nature.
One of examples of such kind of signals is presented by seismograms containing
recordings of earthquakes (EQ's) and technogenic explosions (TE's). We propose
here a discrete stochastic model for possible solution of a problem of strong
EQ's forecasting and differentiation of TE's from the weak EQ's. Theoretical
analysis is performed by two independent methods: with the use of statistical
theory of discrete non-Markov stochastic processes (Phys. Rev. E62,6178 (2000))
and the local Hurst exponent. Time recordings of seismic signals of the first
four dynamic orthogonal collective variables, six various plane of phase
portrait of four dimensional phase space of orthogonal variables and the local
Hurst exponent have been calculated for the dynamic analysis of the earth
states. The approaches, permitting to obtain an algorithm of strong EQ's
forecasting and to differentiate TE's from weak EQ's, have been developed.Comment: REVTEX +12 ps and jpg figures. Accepted for publication in Phys. Rev.
E, December 200
DMTPC: A dark matter detector with directional sensitivity
By correlating nuclear recoil directions with the Earth's direction of motion
through the Galaxy, a directional dark matter detector can unambiguously detect
Weakly Interacting Massive Particles (WIMPs), even in the presence of
backgrounds. Here, we describe the Dark Matter Time-Projection Chamber (DMTPC)
detector, a TPC filled with CF4 gas at low pressure (0.1 atm). Using this
detector, we have measured the vector direction (head-tail) of nuclear recoils
down to energies of 100 keV with an angular resolution of <15 degrees. To study
our detector backgrounds, we have operated in a basement laboratory on the MIT
campus for several months. We are currently building a new, high-radiopurity
detector for deployment underground at the Waste Isolation Pilot Plant facility
in New Mexico.Comment: 4 pages, 2 figures, proceedings for the CIPANP 2009 conference, May
26-31, 200
Self-interacting Elko dark matter with an axis of locality
This communication is a natural and nontrivial continuation of the 2005 work
of Ahluwalia and Grumiller on Elko. Here we report that Elko breaks Lorentz
symmetry in a rather subtle and unexpected way by containing a `hidden'
preferred direction. Along this preferred direction, a quantum field based on
Elko enjoys locality. In the form reported here, Elko offers a mass dimension
one fermionic dark matter with a quartic self-interaction and a preferred axis
of locality. The locality result crucially depends on a judicious choice of
phases.Comment: 14 pages (RevTex
Bound - states for truncated Coulomb potentials
The pseudoperturbative shifted - expansion technique PSLET is generalized
for states with arbitrary number of nodal zeros. Bound- states energy
eigenvalues for two truncated coulombic potentials are calculated using PSLET.
In contrast with shifted large-N expansion technique, PSLET results compare
excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge
On the Dalitz Plot Approach in Non-leptonic Charm Meson Decays
We claim that the non-resonant contribution to non-leptonic charm meson
decays may not be constant in the phase space of the reaction. We argue that
this can be relevant for any weak reaction. We discuss in detail the decay .Comment: Version accepted for publication in Physical Review Letters. 9 pages,
Latex, including 2 figure
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