14,788 research outputs found
Two and three electrons in a quantum dot: 1/|J| - expansion
We consider systems of two and three electrons in a two-dimensional parabolic
quantum dot. A magnetic field is applied perpendicularly to the electron plane
of motion. We show that the energy levels corresponding to states with high
angular momentum, J, and a low number of vibrational quanta may be
systematically computed as power series in 1/|J|. These states are relevant in
the high-B limit.Comment: LaTeX, 15 pages,6 postscript figure
Neutrino Discovery Limit of Dark Matter Direct Detection Experiments in the Presence of Non-Standard Interactions
The detection of coherent neutrino-nucleus scattering by the COHERENT
collaboration has set on quantitative grounds the existence of an irreducible
neutrino background in direct detection searches of Weakly Interacting Massive
Dark Matter candidates. This background leads to an ultimate discovery limit
for these experiments: a minimum Dark Matter interaction cross section below
which events produced by the coherent neutrino scattering will mimic the Dark
Matter signal, the so-called \emph{neutrino floor}. In this work we study the
modification of such neutrino floor induced by non-standard neutrino
interactions within their presently allowed values by the global analysis of
oscillation and COHERENT data. By using the full likelihood information of such
global analysis we consistently account for the correlated effects of
non-standard neutrino interactions both in the neutrino propagation in matter
and in its interaction in the detector. We quantify their impact on the
neutrino floor for five future experiments: DARWIN (Xe), ARGO (Ar), Super-CDMS
HV (Ge and Si) and CRESST phase III (CaWO). Quantitatively, we find that
non-standard neutrino interactions allowed at the level can result in
an increase of the neutrino floor of up to a factor with respect to
the Standard Model expectations and impact the expected sensitivities of the
ARGO, CRESST phase III and DARWIN experiments.Comment: 21 pages, 4 figures. Matches version published in the JHEP. Corrected
exposure and results for CRESST phase II
Identifying spin properties of evaporating black holes through asymmetric neutrino and photon emission
Kerr black holes radiate neutrinos in an asymmetric pattern, preferentially in the lower hemisphere relative to the black hole’s rotation axis, while antineutrinos are predominantly produced in the upper hemisphere. Leveraging this asymmetric emission, we explore the potential of high energy, Eν ≳ 1 TeV, neutrino, and antineutrino detection to reveal crucial characteristics of an evaporating primordial black hole at the time of its burst when observed near Earth. We improve upon previous calculations by carefully accounting for the nonisotropic particle emission, as Earth occupies a privileged angle relative to the black hole’s rotation axis. Additionally, we investigate the angular dependence of primary and secondary photonspectra and assess the evaporating black hole’s time evolution during the final explosive stages of its lifetime. Since photon events outnumber neutrinos by about three orders of magnitude, we find that a neutrino measurement can aid in identifying the initial angular momentum and the black hole hemisphere facing Earth only for evaporating black holes within our solar system, at distances ≲10−4 pc, and observed during the final 100 s of their lifetime
Impact of Beyond the Standard Model Physics in the Detection of the Cosmic Neutrino Background
We discuss the effect of Beyond the Standard Model charged current
interactions on the detection of the Cosmic Neutrino Background by neutrino
capture on tritium in a PTOLEMY-like detector. We show that the total capture
rate can be substantially modified for Dirac neutrinos if scalar or tensor
right-chiral currents, with strength consistent with current experimental
bounds, are at play. We find that the total capture rate for Dirac neutrinos,
, can be between 0.3 to 2.2 of what is expected for
Dirac neutrinos in the Standard Model, , so that it
can be made as large as the rate expected for Majorana neutrinos with only
Standard Model interactions. A non-negligible primordial abundance of
right-handed neutrinos can only worsen the situation, increasing by 30 to 90\%. On the other hand, if a much lower total rate is
measured than what is expected for , it may be a sign
of new physics.Comment: Version published in JHEP. Some comments and references adde
A possible cosmological application of some thermodynamic properties of the black body radiation in dimensional Euclidean spaces
In this work we present the generalization of some thermodynamic properties
of the black body radiation (BBR) towards an dimensional Euclidean space.
For this case the Planck function and the Stefan-Boltzmann law have already
been given by Landsberg and de Vos and some adjustments by Menon and Agrawal.
However, since then no much more has been done on this subject and we believe
there are some relevant aspects yet to explore. In addition to the results
previously found we calculate the thermodynamic potentials, the efficiency of
the Carnot engine, the law for adiabatic processes and the heat capacity at
constant volume. There is a region at which an interesting behavior of the
thermodynamic potentials arise, maxima and minima appear for the BBR
system at very high temperatures and low dimensionality, suggesting a possible
application to cosmology. Finally we propose that an optimality criterion in a
thermodynamic framework could have to do with the nature of the universe.Comment: 9 pages, 8 figure
Gluino zero-modes for non-trivial holonomy calorons
We couple fermion fields in the adjoint representation (gluinos) to the SU(2)
gauge field of unit charge calorons defined on R^3 x S_1. We compute
corresponding zero-modes of the Dirac equation. These are relevant in
semiclassical studies of N=1 Super-symmetric Yang-Mills theory. Our formulas,
show that, up to a term proportional to the vector potential, the modes can be
constructed by different linear combinations of two contributions adding up to
the total caloron field strength.Comment: 17 pages, 3 Postscript figures, late
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