3,589 research outputs found
Model dependence of the bremsstrahlung effects from the superluminal neutrino at OPERA
We revisit the bremsstrahlung process of a superluminal neutrino motivated by
OPERA results. From a careful analysis of the plane wave solutions of the
superluminal neutrino, we find that the squared matrix elements contain
additional terms from Lorentz violation due to the modified spin sum for the
neutrino. We point out that the coefficients of the decay rate and the energy
loss rate significantly depend on the details of the model, although the
results are parametrically similar to the ones obtained by Cohen and Glashow
[1]. We illustrate this from the modified neutral current interaction of
neutrino with Lorentz violation of the same order as in the modified dispersion
relation.Comment: 10 pages, no figures, version to appear as a Rapid Communication in
Phys. Rev.
On the robustness of the primordial power spectrum in renormalized Higgs inflation
We study the cosmological consequences of higher-dimensional operators
respecting the asymptotic symmetries of the tree-level Higgs inflation action.
The main contribution of these operators to the renormalization group enhanced
potential is localized in a compact field range, whose upper limit is close to
the end of inflation. The spectrum of primordial fluctuations in the so-called
universal regime turns out to be almost insensitive to radiative corrections
and in excellent agreement with the present cosmological data. However,
higher-dimensional operators can play an important role in critical Higgs
inflation scenarios containing a quasi-inflection point along the inflationary
trajectory. The interplay of radiative corrections with this quasi-inflection
point may translate into a sizable modification of the inflationary
observables.Comment: 12 pages, 8 figures - matches the published versio
The Planck and LHC results and particle physics
I will discuss the recent LHC and Planck results, which are completely
compatible with the Standard Model of particle physics, and the standard
cosmological model (CDM), respectively. It turns out that the
extension of the Standard Model is, of course, required, but can be very
minimal. I will discuss also what future measurements may be important to test
this approach.Comment: 7 pages, talk on the EPS-HEP 2013 prepared for conference proceeding
Dynamics of Unitarization by Classicalization
We study dynamics of the classicalization phenomenon suggested in
arXiv:1010.1415, according to which a class of non-renormalizable theories
self-unitarizes at high-energies via creation of classical configurations
(classicalons). We study this phenomenon in an explicit model of
derivatively-self-coupled scalar that serves as a prototype for a
Nambu-Goldstone-St\"uckelberg field. We prepare the initial state in form of a
collapsing wave-packet of a small occupation number but of very high energy,
and observe that the classical configuration indeed develops. Our results
confirm the previous estimates, showing that because of self-sourcing the
wave-packet forms a classicalon configuration with radius that increases with
center of mass energy. Thanks to self-sourcing by energy, unlike solitons, the
production of classicalons dominates the high-energy scattering. In order to
confront classicalizing and non-classicalizing theories, we use a language in
which the scattering cross section can be universally understood as a geometric
cross section set by a classical radius down to which waves can propagate
freely. The difference is, that in non-classicalizing examples this radius
shrinks with increasing energy, whereas in classicalizing theories expands and
becomes macroscopic. We study analogous scattering in a Galileon system and
discover that classicalization is less efficient there. We thus observe, that
classicalization is source-sensitive and that Goldstones pass the first test.Comment: 20 page
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