Measurement of the Velocity of Neutrinos from the CNGS Beam with the Large Volume Detector

Abstract

We report the measurement of the time of flight of ∼17 GeV ν(μ) on the CNGS baseline (732 km) with the Large Volume Detector (LVD) at the Gran Sasso Laboratory. The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a tightly bunched-beam structure to allow the velocity of neutrinos to be accurately measured on an event-by-event basis. LVD has detected 48 neutrino events, associated with the beam, with a high absolute time accuracy. These events allow us to establish the following limit on the difference between the neutrino speed and the light velocity: -3.8 × 10(-6) < (v(ν)-c)/c < 3.1 × 10(-6) (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements.

Precision measurement of the neutrino velocity with the ICARUS detector in the CNGS beam

“…The ICARUS result on 2011 data has been confirmed with improved precision by the other LNGS experiments [6,7] in the 2012 CNGS bunched beam campaign. We hereby report the experimental measurements of the neutrino velocity with the ICARUS detector, obtained combining the accurate determination of the distance and time of flight with the direct observation of either neutrino events inside the detector or neutrino associated muons from the surrounding rock.…”

Testing Lorentz and CPT Invariance with Neutrinos

“…The expression for the neutrino velocity (6) can be directly applied to this type of study in beam experiments [31][32][33][34][35][36][37]. Notice that for operators of dimension d = 3 there is no modification to the neutrino velocity, whereas for d = 4 this modification is independent of the energy E ≈ |p p p|.…”

Neutrinos as Probes of Lorentz Invariance

“…From the neutrino velocity (11), we clearly find that the mass term makes neutrinos travel slower than light, whereas the coefficients for Lorentz violation can generate subluminal or superluminal velocities depending on the sign of each coefficient. Different beam experiments have measured the time for neutrinos to travel a distance [58][59][60][61][62][63][64], which will experience a delay with respect to photons given by the following:…”