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.
In Fig. 3 and its inset the vertical scales should be reduced by a factor of 4. This plotting error affects only the figure. All relevant quantities in the text and in the table are correct as published. We regret the oversight.The corrected version of Fig. 3 is reproduced here. This correction does not affect any results or conclusions of the published paper.FIG. 3. Inclusive ÿ ; K spectrum on Si at K 6 2 . The curves are the calculated spectra for the repulsive (solid) and shallow (dashed) -nucleus potentials, fitted to the measured spectrum. A value of the scaling factor and 2 per degree of freedom are shown for each fitting.
Brown dwarfs are classified as objects which are not massive enough to sustain nuclear fusion of hydrogen, and are distinguished from planets by their ability to burn deuterium. 1 Old (>10 Myr) brown dwarfs are expected to possess short-lived magnetic fields 2 and, since they no longer generate energy from collapse and accretion, weak radio and X-ray emitting coronae. Several efforts have been undertaken in the past to detect chromospheric activity from the brown dwarf LP944−20 at X-ray 1,3 and optical 4,5,6,7 wavelengths, but only recently an X-ray flare from this object was detected. 3 Here we report on the discovery of quiescent and flaring radio emission from this source, which represents the first detection of persistent radio emission from a brown dwarf, with luminosities that are several orders of magnitude larger than predicted from an empirical relation 8,9 between the X-ray and radio luminosities of many stellar types. We show in the context of synchrotron emission, that LP944−20 possesses an unusually weak magnetic field in comparison to active dwarf M stars, 10,11 which might explain the null results from previous optical and X-ray observations of this source, and the deviation from the empirical relations. This paper has been submitted to Nature. You are free to use the results here for the purpose of
The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.