15,805 research outputs found

    Two and three electrons in a quantum dot: 1/|J| - expansion

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    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

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    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 (CaWO4_4). Quantitatively, we find that non-standard neutrino interactions allowed at the 3σ3\sigma level can result in an increase of the neutrino floor of up to a factor ∼5\sim 5 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

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    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

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    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, ΓDBSM\Gamma_{\rm D}^{\rm BSM}, can be between 0.3 to 2.2 of what is expected for Dirac neutrinos in the Standard Model, ΓDSM\Gamma_{\rm D}^{\rm SM}, 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 ΓDBSM\Gamma_{\rm D}^{\rm BSM} by 30 to 90\%. On the other hand, if a much lower total rate is measured than what is expected for ΓDSM\Gamma_{\rm D}^{\rm SM}, 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 n−n-dimensional Euclidean spaces

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    In this work we present the generalization of some thermodynamic properties of the black body radiation (BBR) towards an n−n-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 n−dn-d 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 3−d3-d nature of the universe.Comment: 9 pages, 8 figure

    Gluino zero-modes for non-trivial holonomy calorons

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    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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