UPDATE E923 - SEARCH FOR T VIOLATING MUON POLARIZATION IN K+ YIELDS M+P0VM DECAY.

This is an update to the E923 proposal for a new search for the time reversal violating polarization of the muon normal to the decay plane of the K{sup +} {r_arrow} {mu}{sup +}{pi}{sup 0}{nu} decay. The value of such polarization in the Standard Model is zero. However, it is now accepted that the baryon asymmetry of the universe requires a source of CP violation stronger than that embodied in the quark mixing matrix. Models of non-standard CP violation that produce the baryon asymmetry could also produce effects observable in the transverse polarization. The very high sensitivity of the experiment makes this search interesting and timely. In this update we discuss the possibility of additional kaon decay measurements with the same apparatus as well as the detector development over the last year. In particular, we show that we will be able to measure the T-violating muon polarization in K{sup +} {r_arrow} {mu}{sup +}{nu}{gamma} decays. Such a measurement is complimentary to the main goal of this experiment. We also show that we will obtain a large sample of K{sup +} {r_arrow} {pi}{sup +}{pi}{sup 0}{gamma} events that can be used to understand kaon structure and test the detailed predictions from Chiral Perturbation Theory