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. Dedicated 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.)) × 10 −6 . The above result, obtained by comparing the time distributions of neutrino interactions and of protons hitting the CNGS target in 10.5 µs 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.

review the design and construction of the detector and of its related infrastructures, and report on some technical performances of the various components. The construction of the detector started in 2003 and it was completed in Summer 2008. The experiment is presently in the data taking phase. The whole sequence of operations has proven to be successful, from triggering to brick selection, development, scanning and event analysis.

New higher precision measurements of the hyperfine Zeeman transitions in the ground state of muonium have been performed with use of the high-stopping-density surface \i + beam at the Clinton P 0 Anderson Meson Physics Facility. The results are Ay = 4 463-302.88(16) kHz (0.036 ppm) and n^/np^ 3.183 3461(11) (0.36 ppm). The current theoretical value of Ay agrees well with experiment within the 0.77-ppm error of Ay t^eor , which is due principally to inaccuracy in evaluation of the nonrecoil radiative correction term. The most precise current value of m n /m e is obtained from our value of \ij\x p ,

This is a repository copy of Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects.

A new precision measurement of the branching ratio of the rare pion decay into a positron and a neutrino Or-* ev) has been completed. A beam of positive pions was stopped in an active target of plastic scintillator surrounded by a An BGO calorimeter. 3xl0 5 rare decays and 1.2xl0 6 normal pion decays (/r-*/xv) were recorded. The branching ratio was finally calculated from 1.2 xlO 5 rare decays after various cuts in the time window from 7.5 to 200 ns after pion stop. The errors of the result (1.235 ±0.005) x 10 " 4 are 0.28% statistical and 0.29% systematical.PACS numbers: 13.20.Cz An experiment was performed to measure the branching ratio R for the rare decay /r-> ev(y) (i.e., K-+ ev including K-* evy), normalized to the normal pion decay K-* jnv(y) with high precision, testing the fie universality of the weak interaction. This rare decay has been treated theoretically many times and values for R have been published by several authors during the development of the theory of the weak interaction [1-3] and also later inthe framework of gauge theories. The most recent predictions for R are as follows: Marciano and Sirlin [4], (1.233 ±0.004) x 10 " 4 ; Goldman and Wilson [5], (1.239 ± 0.001) x 10 " 4 ; Marciano [6], (1.2345 ± 0.0010) x 10 " 4 .