Search results for "detector"
showing 10 items of 3491 documents
Neutrino masses: from fantasy to facts
2000
Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in addition to the three active ones. Out of the four neutrinos, two are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. These schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments. I discuss the simplest theoretical scenarios, where the lightness of the sterile …
Improved search for heavy neutrinos in the decay π→eν
2018
A search for massive neutrinos has been made in the decay π+→e+ν. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (π→e+νh). Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60–135 MeV/c2 were set and are an order of magnitude improvement over previous results.
ATLAS search for a heavy gauge boson decaying to a charged lepton and a neutrino in pp collisions at root s=7 TeV
2012
The ATLAS detector at the LHC is used to search for high-mass states, such as heavy charged gauge bosons (W'), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.7 fb(-1). No excess beyond Standard Model expectations is observed. A W' with Sequential Standard Model couplings is excluded at the 95 % credibility level for masses up to 2.55 TeV. Excited chiral bosons (W*) with equivalent coupling strength are excluded for masses up to 2.42 TeV.
Search for high-mass states with one lepton plus missing transverse momentum in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
2011
The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W'. W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb(-1). No excess beyond standard model expectations is observed. A W' with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.
"Table 2" of "Measurement of the production cross section for W-bosons in association with jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS de…
2011
The measured cross section times branching ratio for W+jets in the muon channel as a function of corrected jet multiplicity.
"Table 4" of "Measurement of the production cross section for W-bosons in association with jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS de…
2011
The measured cross section ratio for W+jets in the muon channel as a function of corrected jet multiplicity.
Unified atmospheric neutrino passing fractions for large-scale neutrino telescopes
2018
The atmospheric neutrino passing fraction, or self-veto, is defined as the probability for an atmospheric neutrino not to be accompanied by a detectable muon from the same cosmic-ray air shower. Building upon previous work, we propose a redefinition of the passing fractions by unifying the treatment for muon and electron neutrinos. Several approximations have also been removed. This enables performing detailed estimations of the uncertainties in the passing fractions from several inputs: muon losses, cosmic-ray spectrum, hadronic-interaction models and atmosphere-density profiles. We also study the passing fractions under variations of the detector configuration: depth, surrounding medium a…
Characterization of a new plastic scintillation material and comparison with liquid BC-501A scintillator
2015
In this work the capability of various scintillation materials to discriminate gamma rays and neutrons were studied. Also such basic properties of scintillators as light emission spectrum and light output were determined. The studied materials were BC-501A liquid scintillator and a plastic scintillator provided by CEA. An experimental setup consisting of detector shielding, analog and digital electronics and data acquisition system was built to study the neutron-gamma discrimination properties of the scintillation materials. Pulse shape discrimination (PSD) technique was utilized. A computer code with a PSD algorithm was written. This code integrates the scintillation pulse waveforms over s…
"Table 20" of "Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisio…
2016
Effective mass in the muon plus four jets W+jets control region.
"Table 30" of "Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisio…
2016
Effective mass in the 4-jet tight signal region (muon channel).