S.R. Mishra

K/π production ratios from 450 GeV/c protons on beryllium

Abstract This paper reports on the charged K / π production ratios and on the shape of the p T distributions of π fluxes measured by the SPY/NA56 experiment for 450 GeV/c proton interactions on beryllium targets. The present data cover a secondary momentum range from 7 GeV/c to 135 GeV/c in the forward direction and with p T values up to 600 MeV/c. An experimental accuracy of about 3% has been achieved. These results will reduce the uncertainty on the estimation of the ν e component of neutrino beams.

Physics sensitivity studies of Fine-Grained Tracker

The reference design of the near detector for the LBNE experiment is a high-resolution Fine-Grained Tracker (FGT). We performed sensitivity studies – critical to constraining the systematics in oscillation searches – of measurements of (1) the absolute neutrino flux, (2) neutrino-nucleon quasi-elastic (QE) and (3) resonance (Res) interactions. In QE and Res emphasis is laid in identifying in situ measurables that help constrain nuclear effects such as initial state pair wise correlations and final state interactions.

Fine-Grained Tracker as a Near Detector for LBNE

The reference design of the near detector for the LBNE experiment is a high-resolution FineGrained Tracker (FGT) capable of precisely measuring all four species of neutrinos: nm , ne, ¯ nm and ¯ ne. The FGT is composed of a Straw-Tube Tracker (STT) with transition-radiation capability surrounded by a high resolution electromagnetic calorimeter (ECAL) and embedded in a dipole magnet. Muon-ID detectors instrument the iron-yoke of the magnet and the downstream and upstream stations outside the magnet. The STT is instrumented with Ar and other nuclear targets. The goals of the FGT is to constrain the systematic errors, below the corresponding statistical error in the far detector, for all oscillation studies; and to conduct a panoply of precision measurements and searches in Neutrino physics. We present sensitivity studies ‐ critical to constraining the systematics in oscillation searches ‐ of measurements of (1) the absolute neutrino flux, (2) neutrino-nucleon quasi-elastic (QE) and (3) resonance (Res) interactions. In QE and Res emphasis is laid in identifying in situ measurables that help constrain nuclear effects such as initial state pair wise correlations and final state interactions.

Experimental Particle Physics

The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PIs), and C. Rosenfeld (PI), engaged in studies in Experimental Particle Physics. The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the flavor of a neutrino is not immutable. A neutrino of flavor e, mu, or tau, as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they oscillate. The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a morexa0» substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a low energy window on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the BaBar experiment, which collected data at SLAC until 2008. They continued to analyze the voluminous BaBar data with an emphasis on precision tests of Quantum Chromodynamics and on properties of the eta_B, a bottom quark paired in a meson with a strange quark. The ATLAS experiment became the principal research focus for Purohit. One of the worlds largest pieces of scientific equipment, ATLAS observes particle collisions at the highest-energy particle accelerator ever built, the Large Hadron Collider (LHC) at CERN. Our efforts on ATLAS included participation in the commissioning, calibration, and installation of components called CSCs. The unprecedented energy of 14 TeV enabled the ATLAS and CMS collaborations to declare discovery of the famous Higgs particle in 2012. «xa0less