1,021 research outputs found
The sign of dm2_{31} and the muon-charge asymmetry for atmospheric neutrinos
We discuss the possibility to measure the sign of dm2_{31} from
matter-induced charge asymmetries in atmospheric neutrino oscillations. The
main conclusion is that an impact on the nu_mu survival probability requires
the action of the MSW resonance, which becomes visible for baselines above
\~7000 km.Comment: 6 pp, 1 fig. Talk given at the 7th International Workshop on Topics
in Astroparticles and Underground Physics (TAUP2001), Laboratori Nazionali
del Gran Sasso, Italy, September 8-12, 200
Observable Medium Effects For Atmospheric Neutrinos
We discuss the possibility to observe matter effects in atmospheric neutrino
oscillations. The main conclusion is that an impact on the nu_mu survival
probability requires the action of the MSW resonance, which becomes visible for
baselines above ~7000 km. The associated muon charge asymmetry carries
information on theta_{13} and the sign of Dm^2_{31}.Comment: 7 pp, 2 fig. Talk given at the EPS-Conference on HEPP, Budapest
(Hungary), July 2001, to be published in the Proceeding
The Earth Mantle-Core Effect in Matter-Induced Asymmetries for Atmospheric Neutrino Oscillations
Earth medium effects in the three-neutrino oscillations of atmospheric
neutrinos are observable under appropriate conditions. This paper generalizes
the study of the medium effects and the possibility of their observation in the
atmospheric neutrino oscillations from the case of neutrinos traversing only
the Earth mantle, where the density is essentially constant, to the case of
atmospheric neutrinos crossing also the Earth core. In the latter case new
resonance-like effects become apparent. We calculate the CPT-odd asymmetry for
the survival probability of muon neutrinos and the observable muon-charge
asymmetry, taking into account the different atmospheric neutrino fluxes, and
show the dependence of these asymmetries on the sign of
and on the magnitude of the mixing angle . A magnetized detector
with a sufficiently good neutrino momentum resolution is required for the
observation of the muon-charge asymmetry generated by the Earth mantle-core
effect.Comment: 14 pages, 5 figure
Whole-Genome Sequence of a European Clone II and OXA-72-Producing Acinetobacter baumannii Strain from Serbia.
We report here the draft genome sequence of a carbapenem-resistant Acinetobacter baumannii strain isolated from a patient, a strain which previously stayed in Serbia. This isolate possessed the blaOXA-72 carbapenemase gene. The draft genome sequence consists of a total length of 3.91 Mbp, with an average G+C content of 38.8%
Probing CPT in transitions with entangled neutral kaons
In this paper we present a novel CPT symmetry test in the neutral kaon system based, for the first time, on the direct comparison of the probabilities of a transition and its CPT reverse. The required interchange of in out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a phi-factory. The observable quantities have been constructed by selecting the two semileptonic decays for flavour tag, the pi and 3 pi(0) decays for CP tag and the time orderings of the decay pairs. The interpretation in terms of the standard Weisskopf-Wigner approach to this system, directly connects CPT violation in these observables to the violating R delta parameter in the mass matrix of K-0 (K) over bar (0), a genuine CPT violating effect independent of Delta Gamma and not requiring the decay as an essential ingredient. Possible spurious effects induced by CP violation in the decay and/or a violation of the Delta S = Delta Q rule have been shown to be well under control. The proposed test is thus fully robust, and might shed light on possible new CPT violating mechanisms, or further improve the precision of the present experimental limits. It could be implemented at the DA Phi NE facility in Frascati, where the KLOE-2 experiment might reach a statistical sensitivity of O (10(-3)) on the newly proposed observable quantities
Searching For Anomalous Couplings
The capability of current and future measurements at low and high energy
colliders to probe for the existence of anomalous, CP conserving,
dipole moment-type couplings is examined. At present, constraints
on the universality of the tau charged and neutral current interactions as well
as the shape of the energy spectrum provide the strongest
bounds on such anomalous couplings. The presence of these dipole moments are
shown to influence, e.g., the extraction of from
decays and can lead to apparent violations of CVC expectations.Comment: 24 pages, 9 figure
QCD Accurately Predicts the Induced Pseudoscalar Coupling Constant
Using chiral Ward identities of QCD, we derive a relation for the induced
pseudoscalar coupling constant which is accurate within a few percent, .Comment: 5pp, LaTeX, CRN-94/1
Neutrino reactions via neutral and charged current by Quasi-particle Random Phase Approximation(QRPA)
We developed the quasi-particle random phase approximation (QRPA) for the
neutrino scattering off even-even nuclei via neutral current (NC) and charged
cur- rent (CC). The QRPA has been successfully applied for the \beta and
\beta\beta decay of relevant nuclei. To describe neutrino scattering, general
multipole transitions by weak interactions with a finite momentum transfer are
calculated for NC and CC reaction with detailed formalism. Since we consider
neutron-proton (np) pairing as well as neutron-neutron (nn) and proton-proton
(pp) pairing correlations, the nn + pp QRPA and np QRPA are combined in a
framework, which enables to describe both NC and CC reactions in a consistent
way. Numerical results for \nu-^{12}C, -^{56}Fe and -^{56}Ni reactions are
shown to comply with other theoretical calculations and reproduce well
available experimental data
On a Neutrino Electroweak Radius
We study a combination of amplitudes for neutrino scattering that can isolate
a (gauge-invariant) difference of chirality-preserving neutrino electroweak
radii for and . This involves both photon and
exchange contributions. It is shown that the construction singles out the
contributions of the hypercharge gauge field in the standard model.
We comment on how gauge-dependent terms from the charge radii cancel with other
terms in the relative electroweak radii defined.Comment: 16 pages, revtex with embedded figure
Gravitational Waves in a Spatially Closed deSitter Spacetime
Perturbation of gravitational fields may be decomposed into scalar,vector and
tensor components.In this paper we concern with the evolution of tensor mode
perturbations in a spatially closed deSitter background of RW form. It may be
thought as gravitional waves in a classical description. The chosen background
has the advantage of to be maximally extended and symmetric. The spatially flat
models commonly emerge from inflationary scenarios are not completely
extended.We first derive the general weak field equations.Then the form of the
field equations in two special cases, planar and spherical waves are obtained
and their solutions are presented. We conclued with discussing the significance
of the results and their implications.Comment: 16 pages,no figure
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