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تسجيل مستخدم جديدOPERA, SN1987a and energy dependence of superluminal neutrino velocity
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N. D. Hari Dass
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This is a brief note discussing the energy dependence of superluminal neutrino velocities recently claimed by OPERA [1,2]. The analysis is based on the data provided there on this issue, as well as on consistency with neutrino data from SN1987a as recorded by the Kamioka detector [3]. It is seen that it is quite difficult to reconcile OPERA with SN1987a. The so called Coleman- Glashow dispersion relations do not do that well, if applied at all neutrino energies. The so called quantum gravity inspired dispersion relations perform far worse. Near OPERA energies both an energy-independent velocity, as well as a linear energy dependence with an offset that is comparable in value to the observed {delta}v by OPERA at 28.1 GeV works very well. Our analysis shows that precision arrival time data from SN1987a still allow for superluminal behaviour for supernova neutrinos. A smooth interpolation is given that reconciles OPERA and SN1987a quite well. It suggests a fourth power energy dependence for {delta}v of supernova neutrinos. This behaviour is insensitive to whether the velocities are energy-independent, or linearly dependent on energy, near OPERA scale of energies. Suggestions are made for experimental checks for these relations.
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In this work we consider a possible conceptual similarity between recent, amazing OPERA experiment of the superluminal propagation of neutrino and experiment of the gain-assisted superluminal light propagation realized about ten years ago. Last exper
iment refers on the propagation of the light, precisely laser pulse through a medium, precisely caesium atomic gas, with characteristic anomalous dispersion and corresponding negative group-velocity index with very large amplitude between two closely spaced gain lines (that is in some way similar to quantum theory of the ferromagnetism). It implies superluminal propagation of the light through this medium. Nevertheless all this, at it has been pointed out by authors, is not at odds with causality or special relativity, since it simply represents a direct consequence of the classical interference between ... different frequency components. We suggest that OPERA experiment can be in some way conceptually similar to the gain-assisted superluminal light propagation experiment. For this reason we suppose too that OPERA experiment can be simply explained in full agreement with causality and special relativity if there is some medium, precisely a scalar field (e.g. dark matter field, Higgs field or similar) through which neutrino propagates. We prove that, according to OPERA experiment data, supposed medium must be non-dispersive while its refractive index must be positive, smaller but relatively close to 1 (that is in some way similar to quantum theory of the diamagnetism). If it is true OPERA experiment results do not mean that special theory of relativity is broken, but they mean detection of suggested medium, i.e. a scalar field (e.g. dark matter field, Higgs field or similar).
Generally speaking, the existence of a superluminal neutrino can be attributed either to re-entrant Lorentz violation at ultralow energy from intrinsic Lorentz violation at ultrahigh energy or to spontaneous breaking of fundamental Lorentz invariance
(possibly by the formation of a fermionic condensate). Re-entrant Lorentz violation in the neutrino sector has been discussed elsewhere. Here, the focus is on mechanisms of spontaneous symmetry breaking.
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km. The measurement is based on data taken by OPERA in the years 2009, 2010 and 2011. D
edicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (6.5 +/- 7.4(stat.)((+8.3)(-8.0)sys.))ns was measured corresponding to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c =(2.7 +/-3.1(stat.)((+3.4)(-3.3)(sys.))x10^(-6). The above result, obtained by comparing the time distributions of neutrino interactions and of protons hitting the CNGS target in 10.5 microseconds long extractions, was confirmed by a test performed at the end of 2011 using a short bunch beam allowing to measure the neutrino time of flight at the single interaction level.
From the data release of OPERA - CNGS experiment, and publicly announced on 23 September 2011, we cast a phenomenological model based on a Majorana neutrino state carrying a fictitious imaginary mass term, already discussed by Majorana in 1932. This
mass term can be induced by the interaction with the matter of the Earths crust during the 735 Km travel. Within the experimental errors, we prove that the model fits with OPERA, MINOS and supernova SN1987a data. Possible violations to Lorentz invariance due to quantum gravity effects have been considered.
OPERA is a long-baseline experiment at the Gran Sasso laboratory (LNGS) designed to search for $ u_mu rightarrow u_tau$ oscillations in appearance mode. OPERA took data from 2008 to 2012 with the CNGS neutrino beam from CERN. The data analysis is on
going, with the goal of establishing $ u_tau$ appearance with high significance and improving the sensitivity to the sterile neutrino search in the $ u_mu$ $rightarrow$ $ u_e$ appearance channel. Current results will be presented and perspectives discussed.
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