34597488
Left-right asymmetry in neutrino-produced hadron jets.
In an experiment (E546) to study interactions of {l angle}{ital E}{r angle}=100 GeV and {l angle}{ital Q}{sup 2}{r angle}=17 GeV{sup 2} neutrinos in the Fermilab 15-foot bubble chamber, we have looked for a left-right asymmetry in the azimuthal angle {phi} of individual hadrons about the direction of the lepton momentum transfer ({ital q} vector). Significant asymmetry is found for forward positive hadrons; for {ital x}{sub {ital F}}{gt}0.10, we find {l angle}cos{phi}{r angle}={minus}0.029{plus minus}0.008, where {ital x}{sub {ital F}} is the Feynman {ital x} variable. Negative hadrons with {ital x}{sub {ital F}}{gt}0.10 show no asymmetry, {l angle}cos{phi}{r angle}=0.004{plus minus}0.011. A model which includes parton intrinsic transverse momentum {ital k}{sub {ital t}} reproduces the asymmetry of combined positive and negative hadrons with {ital x}{sub {ital F}}{gt}0.10, {l angle}cos{phi}{r angle}={minus}0.018{plus minus}0.0065, if {l angle}{ital k}{sub {ital t}}{sup 2}{r angle}=0.065{plus minus}0.024 GeV{sup 2}/c{sup 2}. But the model predicts almost equal asymmetries for positive and negative hadrons. The model also agrees poorly with the observed dependence on the kinematic variables {ital x} and {ital Q}{sup 2} if the {ital k}{sub {ital t}} distribution is assumed to be independent of kinematic variables.
16805647
A Detailed Monte Carlo simulation for the BELLE TOF system
We have developed a detailed Monte Carlo simulation program for the Belle time-of-flight (TOF) system. Based on GEANT simulation, it takes account of all physics processes in the TOF scintillation counters and readout electronics. The simulation reproduces very well the performance of the Belle TOF system, including the dE/dx response, the time walk effect, the time resolution, and the hit efficiency due to beam background. In this report, we will describe the Belle TOF simulation program in detail.
125143796
An Exposure of the 15 foot bubble chamber with a neon - hydrogen mixture to a wideband neutrino beam from the Tevatron
120839233
Search for high-energy tau-neutrino interactions
Kinematic selection criteria are developed for separating tau-neutrino charged-current interactions from a large background of muon- and electron-neutrino interactions. The criteria are designed to detect the three-prong decay mode of the $\ensuremath{\tau}$ lepton and rely on the three-particle combination's transverse momentum being anticorrelated with the tr\'ansverse momentum of the other visible particles and being correlated with the missing transverse momentum. The criteria are applied to a sample of events from an exposure of the Fermilab 15-ft bubble chamber to the quadrupole triplet neutrino beam. The average event energies for this beam are 90 GeV for neutrino and 60 GeV for antineutrino events. The $14 \ensuremath{\tau}$ candidates selected agree with the calculated background of 14.3\ifmmode\pm\else\textpm\fi{}1.2. An upper limit on the probability of muon neutrinos oscillating into tau neutrinos of 0.053 is obtained.
124266533
Observation of mu e Events in anti-neutrino and Neutrino Interactions in the Fermilab 15-Foot Neon-H Bubble Chamber
123029644
Observation of short-lived particles produced in high energy neutrino interactions
Abstract Examination of a sample of 89 high-energy, neutrino-induced dilepton events produced in the Fermilab 15 ft bubble chamber has resulted in the direct observation of the production and visible semi-leptonic decay of short-lived particles. One charged decay, two neutral decays, and one decay candidate of undetermined charge are found. Assuming these events and the remaining dilepton signal result from D meson decays, we obtain τ D + = 2.5 −1.5 +3.5 × 10 −13 s and τ D 0 = 3.5 −1.7 +3.5 × 10 −13 s, using a maximum likelihood analysis.
29305430
Comparison of some variational strategies used in field theory.
Recently two variational strategies have been applied to the standard and linear {delta} expansions for quantum field theories. These strategies, both of which improve the accuracy of the expansions, have the property that for {ital N} self-interacting fields at large {ital N} the lowest-order {delta} expansion improved by the variational strategy gives the exact large-{ital N} result. In this article, we study, in the context of supersymmetric quantum mechanics, the numerical accuracy of the improved {delta} expansions when calculated to large order in {delta} and compare them with the accuracy of the large-{ital N} expansion. We find that the usual {delta} expansion is the most accurate, followed by the linear {delta} expansion. The large-{ital N} expansion, analytically continued to {ital N}=1, is the least accurate method of the three.
42992493
Interpolating Lagrangians and SU(2) gauge theory on the lattice.
We apply the linear {delta} expansion to non-Abelian gauge theory on the lattice, with SU(2) as the gauge group. We establish an appropriate parametrization and evaluate the average plaquette energy {ital E}{sub {ital P}} to {ital O}({delta}). As a check on our results, we recover the large-{beta} expansion up to {ital O}(1/{beta}{sup 2}), which involves some {ital O}({delta}{sup 2}) contributions. Using these contributions we construct a variant of the 1/{beta} expansion which gives a good fit to the data down to the transition region.
29593010
Pion absorption above the Delta (1232) resonance.
Two-proton and three-proton inclusive [pi][sup +] absorption cross sections were measured for incident pion energies from 250 to 500 MeV on targets of [sup 12]C, [sup 58]Ni, [sup 90]Zr, [sup 118]Sn, and [sup 208]Pb using a large solid angle bismuth germanate detector array. Pion absorption events leading to three or more protons in the final state were observed to become more significant with increasing incident pion energy and were dominant at 500 MeV. The total absorption cross sections were inferred from analyses of the data with uncertanties of approximately 25%.
23488230
Optimization in the extended variational approach to SU(2) gauge theory on the lattice.
The linear [delta] expansion is applied to SU(2) gauge theory on the lattice, with a trial action based on single links. In contrast with previous calculations using this action, we use the principle of minimal sensitivity to determine the arbitrary parameter [ital J] which occurs in the interpolating action. We obtain a good fit to the Monte Carlo data on the weak-coupling side of the transition region: this can be combined with results using a different trial action to cover the entire range of [beta]. There is no sign that the procedure fails to converge.
36348760
delta expansion applied to strong-coupling Z(2), U(1), and SU(2) gauge theory on the lattice in four dimensions.
We generalize to four dimensions the linear {delta} expansion applied to gauge theory on the lattice, with {ital Z}(2), U(1), and SU(2) as the gauge groups and an unperturbed action appropriate to the strong-coupling regime. The calculation is carried to fourth order in {delta}, using the machinery of character expansions. The expansion is optimized in a bid to improve upon existing strong-coupling methods and our results are compared against results from these and from Monte Carlo calculations.