共查询到20条相似文献,搜索用时 159 毫秒
1.
R. Adhikari A. Sil A. Raychaudhuri 《The European Physical Journal C - Particles and Fields》2002,25(1):125-130
We present a solution of the solar neutrino deficit using three flavors of neutrinos and R-parity non-conserving supersymmetry. In this model, in vacuum, the is massless and unmixed, mass and mixing being restricted to the - sector only, which we choose in consistency with the requirements of the atmospheric neutrino anomaly. The flavor changing
and flavor diagonal neutral currents present in the model and the three-flavor picture together produce an energy dependent
resonance-induced - mixing in the sun. This mixing plays a key role in the new solution to the solar neutrino problem. The best fit to the solar
neutrino rates and spectrum (1258-day SK and 241-day SNO data) requires a mass square difference of eV2 in vacuum between the two lightest neutrinos. This solution cannot accommodate a significant day-night effect for solar neutrinos
nor CP violation in terrestrial neutrino experiments.
Received: 26 December 2001 / Revised version: 16 February 2002 / Published online: 26 July 2002 相似文献
2.
M.M. Guzzo P.C. de Holanda N. Reggiani 《The European Physical Journal C - Particles and Fields》2002,25(3):459-464
We analyze here how future solar neutrino experiments could detect neutrino flux fluctuations due to magnetohydrodynamics
(MHD) perturbations on the solar plasma. We state that if such time fluctuations are detected, this would provide a unique
signature of the resonant spin-flavor precession (RSFP) mechanism as a solution to the solar neutrino problem.
Received: 2 July 2001 / Revised version: 4 April 2002 / Published online: 20 August 2002 相似文献
3.
P.H. Chankowski P. Wąsowicz 《The European Physical Journal C - Particles and Fields》2002,23(2):249-258
We compute the low energy threshold corrections to neutrino masses and mixing in the standard model (SM) and its minimal
supersymmetric version, using the effective theory technique. We demonstrate that they stabilize the results for neutrino
masses and mixing with respect to the choice of the scale to which the renormalization group (RG) equation is integrated.
(This confirms the correctness of the recent re-derivation of the RGE for the SM in hep-ph/0108005.) Since, as is known, those
corrections are potentially very important for phenomenology we derive for them the explicit formulae that can be applied
to specific models of neutrino masses and mixing.
Received: 24 October 2001 / Revised version: 19 November 2001 / Published online: 25 January 2002 相似文献
4.
D. V. Ahluwalia-Khalilova 《General Relativity and Gravitation》2004,36(9):2183-2187
In a 1996 JRO Fellowship Research Proposal (Los Alamos), the author suggested that neutrino oscillations may provide a powerful indirect energy transport mechanism to supernovae explosions. The principal aim of this addendum is to present the relevant unedited text of Section 1 of that proposal. We then briefly remind, (a) of an early suggestion of Mazurek on vacuum neutrino oscillations and their relevance to supernovae explosion, and (b) Wolfenstein's result on suppression of the effect by matter effects. We conclude that whether or not neutrino oscillations play a significant role in supernovae explosions shall depend if there are shells/regions of space in stellar collapse where matter effects play no essential role. Should such regions exist in actual astrophysical situations, the final outcome of neutrino oscillations on supernovae explosions shall depend, in part, on whether or not the LNSD signal is confirmed. Importantly, the reader is reminded that neutrino oscillations form a set of flavor-oscillation clocks and these clock suffer gravitational redshift which can be as large as 20 percent. This effect must be incorporated fully into any calculation of supernova explosion. 相似文献
5.
We study radiative spontaneous electroweak symmetry breaking in the non-supersymmetric extra dimension scenarios of the standard
model extension proposed by Antoniadis et al., Dienes et al. and Pomarol et al. In the framework of the multi-scale effective
theory, by using the renormalization group method with an up-to-down viewpoint, we find that the effects of Kaluza-Klein excitations
of bosons of the standard model can change the sign of the Higgs mass term of the standard model from positive to negative
and break the electroweak symmetry. The critical scale for the electroweak phase transition to occur depends on the compactification
scale (say 1.6 (2.0) TeV if the compactification scale is assumed to be 0.8 (1.5) TeV or so), and is insensitive to the mass
of the Higgs particle. This radiative spontaneous symmetry breaking mechanism can work naturally in the extra dimension scenarios,
and neither new particle contents beyond the standard model from the supersymmetry nor technicolor are necessary.
Received: 7 January 2002 / Revised version: 2 March 2002 / Published online: 7 June 2002 相似文献
6.
The forthcoming experiments on neutrino mass measurement using beta decay, open a new window to explore the large extra dimension model. The Kaluza–Klein tower of neutrinos in large extra dimension contributes to the Kurie function of beta decay that can be tested kinematically. In addition to providing an alternative approach using just the kinematical properties, we show that KATRIN can probe the compactification radius of extra dimensions down to 0.2 μm which is better, at least by a factor of two, than the upper limits from neutrino oscillation experiments. 相似文献
7.
8.
Supernova (SN) neutrinos detected on the Earth are subject to the shock wave effects, the Mikheyev- Smirnov-Wolfenstein (MSW) effects, the neutrino collective effects and the Earth matter effects. Considering the recent experimental result about the large mixing angle 013 (-8.8°) provided by the Daya Bay Collaboration and applying the available knowledge for the neutrino conversion probability in the high resonance region of SN, PH , which is in the form of hypergeometric function in the case of large 813, we deduce the expression of PH taking into account the shock wave effects. It is found that PH is not zero in a certain range of time due to the shock wave effects. After considering all the four physical effects and scanning relevant parameters, we calculate the event numbers of SN neutrinos for the "Garehing" distribution of neutrino energy spectrum. From the numerical results, it is found that the behaviors of neutrino event numbers detected on the Earth depend on the neutrino mass hierarchy and neutrino spectrum parameters including the dimensionless pinching parameter βa (where a refers to neutrino flavor), the average energy 〈Ea〉, and the SN neutrino luminosities La. Finally, we give the ranges of SN neutrino event numbers that will be detected at the Daya Bay experiment. 相似文献
9.
Bipin Singh Koranga 《International Journal of Theoretical Physics》2017,56(8):2445-2449
We have studied neutrino mixing at extreme high energy considering two flavour framework with matter effects. We analyze the atmospheric neutrino data within the simplest scheme of two neutrino oscillation. We consider as special case of matter density profile, which are relevant for neutrino oscillations. In particular, we compute to constrain a specific from of neutrino mass square difference and mixing in extreme high energy in matter. The dispersion relation for the neutrino mixing in neutrino oscillation in matter are discussed. 相似文献
10.
Francis Halzen 《Brazilian Journal of Physics》2013,43(5-6):308-313
With IceCube and its low-energy extension DeepCore, a neutrino detector with an energy reach from tens of gigaelectronvolt to exaelectronvolt has been commissioned. It measures the atmospheric neutrino spectrum from the lower energies where neutrinos oscillate to energies as large as 100 TeV with a statistic of more than 100,000 events per year. The initial results suggest that IceCube can measure the oscillation parameters in an energy range that exceeds existing observations by 1 order of magnitude, thus opening a new window on neutrino physics. We emphasize the search for sterile neutrinos particularly relevant to cosmology. We also discuss the first observation of (PEV) petaelectronvolt-Energy events that cannot be accommodated by the flux anticipated by extrapolation of the present atmospheric neutrino measurements. 相似文献
11.
Y. Kamo Y. Higasida J.-I. Ichihara S.-I. Kubota S. Tokuo S. Yajima 《The European Physical Journal C - Particles and Fields》2003,28(2):211-221
We analytically derive the transition probabilities for four-neutrino oscillations in matter. The time-evolution operator
giving the neutrino oscillations is expressed by a finite sum of terms up to the third power of the Hamiltonian in a matrix
form, using the Cayley-Hamilton theorem. The result of the computation for the probabilities in some mass patterns tells us
that it is actually difficult to observe the resonance between one of the three active neutrinos and the fourth (sterile)
neutrino near the earth, even if the fourth neutrino exists.
Received: 9 October 2002 / Revised version: 27 December 2002 / Published online: 14 March 2003
RID="a"
ID="a" e-mail: kamo@sci.kumamoto-u.ac.jp 相似文献
12.
13.
Manasse R. Mbonye 《General Relativity and Gravitation》2002,34(11):1865-1875
We explore the dynamics of neutrinos in a vacuum dominated cosmology. First we show that such a geometry will induce a phase change in the eigenstates of a massive neutrino and we calculate the phase change. We also calculate the delay in the neutrino flight times in this geometry. Applying our results to the presently observed background vacuum energy density, we find that for neutrino sources further than 1.5 Gpc away both effects become non-trivial, being of the order of the standard relativistic corrections. Such sources are within the observable Hubble Deep Field. The results which are theoretically interesting are also potentially useful, in the future, as detection techniques improve. For example such effects on neutrinos from distant sources like supernovae could be used, in an independent method alternative to standard candles, to constrain the dark energy density and the deceleration parameter. The discussion is extended to investigate Caianiello's inertial or maximal acceleration (MA) effects of such a vacuum dominated spacetime on neutrino oscillations. Assuming that the MA phenomenon exists, we find that its form as generated by the presently observed vacuum energy density would still have little or no measurable effect on neutrino phase evolution, for neutrinos in the energy range of a few eV. 相似文献
14.
Barwick SW Beatty JJ Besson DZ Binns WR Cai B Clem JM Connolly A Cowen DF Dowkontt PF Duvernois MA Evenson PA Goldstein D Gorham PW Hebert CL Israel MH Learned JG Liewer KM Link JT Matsuno S Miocinović P Nam J Naudet CJ Nichol R Palladino K Rosen M Saltzberg D Seckel D Silvestri A Stokes BT Varner GS Wu F 《Physical review letters》2006,96(17):171101
We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing -burst model. 相似文献
15.
V. S. Berezinsky 《Nuclear Physics B》1992,380(3):478-506
We consider the neutrino flux from the decay of long-lived big-bang particles. The red-shift ztr at which the neutrino transparency of the universe sets in is calculated as a function of neutrino energy: ztr 1 × 105 for TeV neutrinos and ztr 3 × 106 for 10 MeV neutrinos. One might expect the production of detectable neutrino flux at z ztr, but, as demonstrated in this paper, the various upper limits, most notably due to nucleosynthesis and diffuse X- and gamma-rays, preclude this possibility. Unless the particle decay is strongly dominated by the pure neutrino channel, observable neutrino flux can be produced only at the current epoch, corresponding to red-shift z ≈ 0. For the thermal relics which annihilate through the gauge bosons of SU(3)×SU(2)×U(1) group, the neutrino flux can be marginally detectable at 0.1 < Ev < 10 TeV. As an example of non-thermal relics we consider gravitinos. If gravitinos are the lightest supersymmetric particles (LSP) they can produce the detectable neutrino flux in the form of a neutrino line with energy
, where MG is the gravitino mass. The flux strongly depends on the mechanisms of R-parity violation. It is shown that heavy gravitinos (MG 100 GeV) can make up the dark matter in the universe. 相似文献
16.
X.-J. Bi 《The European Physical Journal C - Particles and Fields》2003,27(3):399-404
A widely adopted theoretical scheme to account for the neutrino oscillation phenomena is the see-saw mechanism together with
the “lopsided” mass matrices, which is generally realized in the framework of supersymmetric grand unification. We will show
that this scheme leads to large lepton flavor violation at low energy if supersymmetry is broken at the GUT or Planck scale.
Especially, the branching ratio of already exceeds the present experimental limit. We then propose a phenomenological model which can account for the LMA solution
to the solar neutrino problem and at the same time predict a branching ratio of below the present limit.
Received: 18 November 2002 / Published online: 14 February 2003 相似文献
17.
Tritium decay and the hypothesis of tachyonic neutrinos 总被引:2,自引:0,他引:2
J. Ciborowski J. Rembieliński 《The European Physical Journal C - Particles and Fields》1999,8(1):157-161
Numerous recent measurements indicate an excess of counts near the endpoint of the electron energy spectrum in tritium decay.
We show that this effect is expected if the neutrino is a tachyon. Results of calculations, based on a unitary (causal) theory
of tachyons, are presented. The hypothesis of tachyonic neutrinos also offers a natural explanation of the vector-axial (V-A)
structure of the weak leptonic current in neutrino interactions.
Received: 12 October 1998 / Published online: 11 March 1999 相似文献
18.
We present an argument in which the scale approximately 0.1 eV associated with neutrino masses naturally appears in a class of (very) large volume compactifications, being tied to a supersymmetry scale of 10(3) GeV and a string scale of 10(11) GeV. The masses are of the Majorana type, and there is no right-handed neutrino within the low-energy field theory. The suppression scale 10(14) GeV is independent of the masses of the heavy states that are integrated out. These kinds of constructions appear naturally in type IIB flux compactifications. However, the arguments that lead to this result rely only on a few geometrical features of the compactification manifold and, hence, can be used independently of string theory. 相似文献
19.
《Journal of Geometry and Physics》2006,56(2):271-281
In this short note, we prove a generalized positive energy theorem for spaces with asymptotic SUSY compactification involving non-symmetric data. This work is motivated by the work of Dai [A positive mass theorem for spaces with asymptotic SUSY compactification, Comm. Math. Phys. 244 (2004) 335–345; A note on positive energy theorem for spaces with asymptotic SUSY compactification, 2004. arXiv:math-ph/0406006], Hertog–Horowitz–Maeda [Negative energy density in Calabi–Yau compactifications, JHEP 0305 (2003) 060], and Zhang [Angular momentum and positive mass theorem, Comm. Math. Phys. 206 (1999) 137–155]. 相似文献
20.
Valeri V. Dvoeglazov 《International Journal of Theoretical Physics》1995,34(12):2467-2490
The first part of this article presents an overview of the theory and phenomenology of truly neutral particles based on the papers of Majorana, Racah, Furry, McLennan, and Case. The recent development of the construct undertaken by Ahluwalia could be relevant for the explanation of the present experimental situation in neutrino physics and astrophysics. Then the new fundamental wave equations for self-/anti-self-conjugate type II spinors proposed by Ahluwalia are recast into covariant form. The connection with Foldy-Nigam-Bargmann-Wightman-Wigner (FNBWW)-type quantum field theory is found. Possible applications to the problem of neutrino oscillations are discussed.On leave of absence from Department of Theoretical and Nuclear Physics, Saratov State University, Saratov, Russia. E-mail: dvoeglazov@mainl.jinr.dubna.su. 相似文献