Anup Kumar Sikdar

This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.

This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.

The India-based Neutrino Observatory (INO) is a project aimed at building a large underground laboratory to explore the Earth's mater effects on the atmospheric neutrinos in multi-GeV range. INO will host a 50 kton magnetized iron calorimeter detector (ICAL) in which Resistive Plate Chambers(RPCs) will be the active detector elements. In ICAL, 28,800 glass RPCs of 2 m × 2 m size will be operated in the avalanche mode. A small variation in the compositions of ionizing gaseous medium in the RPC affects its performance. Study of the charge distribution of the RPC at different gas compositions is necessary to optimize the gas mixture. An RPC made with glass plates of dimension 30 cm × 30 cm was operated in avalanche mode with a gas mixture of C2H2F4/iC4H10/SF6. We have studied the performance of these RPCs at the same ambient conditions. The percentages of the iC4H10 or SF6 were varied and its effect on the performance of RPC were studied. The study of the charge distribution and time resolution of the RPC signals at different gas compositions is presented in this paper.

India-based Neutrino Observatory (INO) isSikdar, Anup Kumar proposed to detect atmospheric neutrinos and measure the earth’s matter effect to address the mass hierarchy problem in neutrino physics. INO is going to hostBehera, Prafulla Kumar the world’s largest 50 kton iron calorimeter (ICAL) using 28,800 Resistive Plate Chambers (RPC) as an active element. These glass RPCs are very efficient for the energy of coming muons on the GeV scale. The performance of the RPC depends on how we are separating the signal from the background. We are studying the performance of a glass RPC of dimension $$30 \times 30$$ cm $$^{2}$$ by measuring the efficiency of RPC and calculating charge and timing of signal with varying charge threshold at flow rate 10 standard cubic centimeters per minute (SCCM) of gas mixture $$C_2H_2F_4$$ / $$iC_4H_{10}$$ / $$SF_6$$ at 10.4 kV and 21 $$^{\circ }$$ C with relative humidity (RH) $$\sim $$ 53%.