Jefferson Lab Hall A High Luminosity Spectator Tagged Physics program*

Jefferson Lab Hall A spectator tagged physics program will allow precision measurements of high luminosity electron scattering off effectively free pion, kaon and neutron targets. This will make possible the measurement of some of the most sought after quantities in particle physics such as a direct, precision measurement of the elusive meson content of the nucleon, structure functions of pions and kaons, and Deeply Virtual Compton Scattering (DVCS) on the neutron. This program is centered around a multi-Time Projection Chamber (mTPC) optimized to detect low-momentum particle tracks in extreme high background rate conditions. The upcoming Tagged Deep Inelastic Scattering (TDIS) experiment will measure semi-inclusive eN → e'N'X reactions in the deep inelastic regime through the spectator tagging technique, or the Sullivan process. The experiment will invoke the Sullivan process by tagging low-momentum recoiling and spectator protons with the mTPC device in conjunction with the scattered electron detected by the Super Bigbite Spectrometer (SBS). The data would provide access to pion and kaon structure functions in a new kinematical domain, allowing a probe of the mesonic structure of the nucleon. In this talk, I will present the current status of the TDIS experiment and prospects of the spectator tagged physics program.