Measurement of the neutrino velocity with the OPERA detector in the CNGS beam using the 2012 dedicated data

Abstract

In spring 2012 CERN provided two weeks of a short bunch proton beam dedicated to the neutrino velocity measurement over a distance of 730 km. The OPERA neutrino experiment at the underground Gran Sasso Laboratory used an upgraded setup compared to the 2011 measurements, improving the measurement time accuracy. An independent timing system based on the Resistive Plate Chambers was exploited providing a time accuracy of ∼1 ns. Neutrino and anti-neutrino contributions were separated using the information provided by the OPERA magnetic spectrometers. The new analysis profited from the precision geodesy measurements of the neutrino baseline and of the CNGS/LNGS clock synchronization. The neutrino arrival time with respect to the one computed assuming the speed of light in vacuum is found to be δt ν ≡ T OF c − T OF ν = (0.6±0.4 (stat.)±3.0 (syst.)) ns and δtν ≡ T OF c −T OFν = (1.7±1.4 (stat.)±3.1 (syst.)) ns for ν µ andν µ , respectively. This corresponds to a limit on the muon neutrino velocity with respect to the speed of light of −1.8 × 10 −6 < (v ν − c)/c < 2.3 × 10 −6 at 90% C.L. This new measurement confirms with higher accuracy the revised OPERA result.

Theoretical particle limiting velocity from the bicubic equation: Neutrino example

“…Along the same lines, one notices that c 1 is unphysical in the OPERA [2] experiments.The same is true for other neutrino velocity experiments [1] and [3]. Furthermore, because the muon neutrino mass being negligible, one finds out that in fact c 3 ≃ c. To verify this perturbative result, one performs the calculation also with exact non-perturbative expression for c 3 .…”

“…Both mistakes were found and the OPERA collaborators made proper corrections and after a precise measurment of the neutrino velocity in agreement with c, the velocity of light, published the result in [1] (version 3). OPERA collaborators also published the results from a measurement of a special bunched neutrino beam [2] (version 2) giving the precision measurement of the muon neutrino and muon anti-neutrino velocities, in good agreement with c, the velocity of light. Other, so called Gran Sasso laboratory repeated the measurements and obtained c, the velocity of light, for the neutrino velocity [3] (version 2).…”

“…There have been the whole series of neutrino velocity experiments such as the OPERA collaborations with the detector in the CNGS beam [1] (versions 1, 2 and 3), the OPERA detector the CNGS beam using the 2012 dedicated data [2] (versions 1 and 2) as well as the ICARUS detector in the CNGS beam [3] (versions 1 and 2).…”

“…In Section 3, after deducing the three flavor neutrino masses, one finds out that the physical parameter structure of the OPERA [2] muon neutrino velocity experiment is such that the Taylor series expansion, in terms of (mv 2 /E), strongly suggests c 3 as the luminal solution. Along the same lines, one notices that c 1 is unphysical in the OPERA [2] experiments.The same is true for other neutrino velocity experiments [1] and [3].…”

Extraordinary claims: the 0.000029% solution

“…The effect spurred lively debates, got enormous media coverage, and triggered independent measurements by the neighbor ICARUS experiment; dedicated beam runs were performed to collect data less affected by jitter effects in the timing structure of the beam. After several months of investigations the effect was finally understood to be due to a single large source of systematic uncertainty, which had not been accounted for: the delay was produced by a loose signal cable [16]. In the same year the CDF collaboration showed a large, 4σ signal at 145 GeV in the mass distribution of jet pairs produced in association with leptonic W boson decays in the Tevatron 1.96 TeV proton-antiproton collisions [17].…”