185 research outputs found
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is . The combined inclusive and differential asymmetries are consistent with recent standard model predictions
Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments
With the discovery of non-zero value of mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. In this document we intend to highlight the importance of Near Detector facilities in LBN experiments to both constrain the systematic uncertainties affecting oscillation analyses but also to perform, thanks to their close location, measurements of broad benefit for LBN physics goals. A strong European contribution to these efforts is possible
Muon - electron final states in neutrino interactions
In an experiment carried out at the Brookhaven National Laboratory Alternating Gradient Synchrotron, we have observed eight candidates for the reaction
vu + N + -> u + e + anything
with a total background of 1.5 ± 0.6 events. The detector consisted of twenty-eight optical spark chambers interspersed with liquid and plastic scintillation counters. Events classified as muon electron final states are required to have a long noninteracting straight track in conjunction with an electromagnetic shower characteristic of that produced by an electron. Background processes are discussed and the total muon -electron background calculated.
The ratio of the number. of muon electron candidates to all charged currrnt events, corrected for the percentage of the neutrino beam above threshold, is
[equation]U of I OnlyThesi
Dark Sector Studies with Neutrino Beams
An array of powerful neutrino-beam experiments will study the fundamental properties of neutrinos with unprecedented precision in the coming years. Along with their primary neutrino-physics motivations, there has been growing recognition that these experiments can carry out a rich program of searches for new, light, weakly-coupled particles that are part of a dark sector. In this white paper, we review the diverse theoretical motivations for dark sectors and the capabilities of neutrino beam experiments to probe a wide range of models and signatures. We also examine the potential obstacles that could limit these prospects and identify concrete steps needed to realize an impactful dark sector search program in this and coming decades
Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments
With the discovery of non-zero value of mixing angle, the next
generation of long-baseline neutrino (LBN) experiments offers the possibility
of obtaining statistically significant samples of muon and electron neutrinos
and anti-neutrinos with large oscillation effects. In this document we intend
to highlight the importance of Near Detector facilities in LBN experiments to
both constrain the systematic uncertainties affecting oscillation analyses but
also to perform, thanks to their close location, measurements of broad benefit
for LBN physics goals. A strong European contribution to these efforts is
possible
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