26,386 research outputs found
Tensor and scalar interactions of neutrinos may lead to observable neutrino magnetic moments
Recently more generalized four-fermion interactions of neutrinos such as
tensor and scalar interactions (TSIs) have been extensively studied in response
to forthcoming precision measurements of neutrino interactions. In this letter,
we show that due to the chirality-flipping nature, at the 1-loop level TSIs
typically generate much larger () neutrino magnetic moments
(MMs) than the vector case. For some cases, the large MMs generated
by TSIs may reach or exceed the known bounds, which implies potentially
important interplay between probing TSIs and searching for MMs in current
and future neutrino experiments.Comment: Comments on effective magnetic moment add; matches the journal
versio
Why Is The Neutrino Oscillation Formula Expanded In Still Accurate Near The Solar Resonance In Matter?
The conventional approximate formula for neutrino oscillation in matter which
is obtained from the expansion in terms of the ratio of mass square differences
, first proposed by
Cervera, et al and Freund, turns out to be an accurate formula for accelerator
neutrino experiments. Originally it required the neutrino energy to be well
above the solar resonance to validate the expansion but it is found to be still
very accurate when the formula is extrapolated to the resonance, which is
practically important for the T2K experiment. This paper shows that the
accuracy is guaranteed by cancellations of branch cut singularities and also,
for the first time, analytically computes the actual error of the formula. The
actual error implies that the original requirement can be safely removed in
current experiments.Comment: 22 pages,7 figures. Some materials are removed for simplicity.
Accepted by JHE
Tree-level vacuum stability of two-Higgs-doublet models and new constraints on the scalar potential
The scalar potential of the two-Higgs-doublet model (2HDM) may have more than
one local minimum and the usually considered vacuum could be located at one of
them that could decay to another. This paper studies the condition that the
usually considered vacuum is the global minimum which, combined with the
bounded-from-below condition, will stabilize the vacuum at tree-level. We
further apply these conditions to a specific 2HDM and obtain new constraints
which could be important in phenomenological studies.Comment: 12 pages, references adde
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