A STUDY OF RESONANCES OF THE Z-7r SYSTEM

Recently a T = 1 resonance in the {Lambda}-{pi} system called Y{sub 1} has been observed with a mass of 1385 MeV. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the {Lambda}-{pi} and {Sigma}-{pi} systems predicted by global symmetry, corresponding to the (3,2/ 3/2) resonance of the {pi}-N system, (2) a spin-1/2 Y-{pi} resonance resulting from a bound state in the {bar K}-N system. The position and the width of the observed Y{sub 1} resonance agree with both theories, but since the spin and parity have not yet been determined, they cannot distinguish between the two theoretical interpretations

Observation of prompt single muons and of missing energy associated with μ+μ−\mu^{+}\mu^{-} pairs produced in hadronic interactions

In a study of interactions of 400 GeV protons in a totally absorbing iron calorimeter the authors report two observations indicating the hadronic production of heavy short-lived weakly decaying particles. First they have observed a prompt muon signal in the region .8<p/sub t /<2.5 GeV/c. The rate is comparable in magnitude to the prompt 2 mu rate in the same kinematic region. In addition to detecting mu /sup +/ mu /sup -/ events arising from electromagnetic sources (e.g. rho to mu /sup +/ mu /sup -/, psi to mu /sup +/ mu /sup -/ etc.) they have observed mu /sup +/ mu /sup -/ pairs associated with a significant amount of missing energy indicative of final state neutrinos. Interpreting these data as production of DD pairs followed by single or double muonic decays leads to a model dependent estimate of total production cross-section of order 15 mu b. (14 refs)

A Compact Beam Stop for a Rare Kaon Decay Experiment

We describe the development and testing of a novel beam stop for use in a rare kaon decay experiment at the Brookhaven AGS. The beam stop is located inside a dipole spectrometer magnet in close proximity to straw drift chambers and intercepts a high-intensity neutral hadron beam. The design process, involving both Monte Carlo simulations and beam tests of alternative beam-stop shielding arrangements, had the goal of minimizing the leakage of particles from the beam stop and the resulting hit rates in detectors, while preserving maximum acceptance for events of interest. The beam tests consisted of measurements of rates in drift chambers, scintilation counter hodoscopes, a gas threshold Cherenkov counter, and a lead glass array. Measurements were also made with a set of specialized detectors which were sensitive to low-energy neutrons, photons, and charged particles. Comparisons are made between these measurements and a detailed Monte Carlo simulation.Comment: 39 pages, 14 figures, submitted to Nuclear Instruments and Method

A straw drift chamber spectrometer for studies of rare kaon decays

We describe the design, construction, readout, tests, and performance of planar drift chambers, based on 5 mm diameter copperized Mylar and Kapton straws, used in an experimental search for rare kaon decays. The experiment took place in the high-intensity neutral beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, using a neutral beam stop, two analyzing dipoles, and redundant particle identification to remove backgrounds

Neutrino oscillation parameters from MINOS, ICARUS and OPERA combined

We perform a detailed analysis of the capabilities of the MINOS, ICARUS and OPERA experiments to measure neutrino oscillation parameters at the atmospheric scale with their data taken separately and in combination. MINOS will determine $\Delta m^2_{32}$ and $\sin^2 2\theta_{23}$ to within 10% at the 99% C.L. with 10 kton-years of data. While no one experiment will determine $\sin^2 2\theta_{13}$ with much precision, if its value lies in the combined sensitivity region of the three experiments, it will be possible to place a lower bound of O(0.01) at the 95% C.L. on this parameter by combining the data from the three experiments. The same bound can be placed with a combination of MINOS and ICARUS data alone.Comment: Version to appear in PR

Extrinsic CPT Violation in Neutrino Oscillations in Matter

We investigate matter-induced (or extrinsic) CPT violation effects in neutrino oscillations in matter. Especially, we present approximate analytical formulas for the CPT-violating probability differences for three flavor neutrino oscillations in matter with an arbitrary matter density profile. Note that we assume that the CPT invariance theorem holds, which means that the CPT violation effects arise entirely because of the presence of matter. As special cases of matter density profiles, we consider constant and step-function matter density profiles, which are relevant for neutrino oscillation physics in accelerator and reactor long baseline experiments as well as neutrino factories. Finally, the implications of extrinsic CPT violation on neutrino oscillations in matter for several past, present, and future long baseline experiments are estimated.Comment: 47 pages, 7 figures, RevTeX4. Final version to be published in Phys. Rev.

Supernova neutrino detection in NOvA

The NOvA long-baseline neutrino experiment uses a pair of large, segmented, liquid-scintillator calorimeters to study neutrino oscillations, using GeV-scale neutrinos from the Fermilab NuMI beam. These detectors are also sensitive to the flux of neutrinos which are emitted during a core-collapse supernova through inverse beta decay interactions on carbon at energies of O(10 MeV). This signature provides a means to study the dominant mode of energy release for a core-collapse supernova occurring in our galaxy. We describe the data-driven software trigger system developed and employed by the NOvA experiment to identify and record neutrino data from nearby galactic supernovae. This technique has been used by NOvA to self-trigger on potential core-collapse supernovae in our galaxy, with an estimated sensitivity reaching out to 10 kpc distance while achieving a detection efficiency of 23% to 49% for supernovae from progenitor stars with masses of 9.6 M☉ to 27 M☉, respectively