CP VIOLATION WITH BEAUTIFUL BARYONS

CP violation can be studied in modes of charmed or bottom baryons when a decay process is compared with its charge-conjugated partner. It can show up as a rate asymmetry and in a study of other decay parameters. Neither tagging nor time-dependences are required to observe CP violation with modes of baryons, in contrast to the conventional B0 modes. Numerous modes of bottom baryons have the potential to show large CP-violating effects within the Standard Model. Those effects can bc substantial for modes with a D0, which is seen in a final state that can also be fed from a D0BAR. For instance, a comparison of the LAMBDA(b)-->LAMBDAD(CP)0 with the LAMBDA(b)BAR-->LAMBDAD(CP)0 process can show sizeable CP violation. Here D(CP)0 denotes CP eigenstates of D0, which occur at a few percent. Six related processes, such as LAMBDA(b)-->LAMBDAD0, LAMBDA(b)-->LAMBDAD0BAR, LAMBDA(b)-->LAMBDAD(CP)0, and their charge-conjugated counterparts, can extract phi, which is the most problematic angle of the unitarity triangle and which is conventionally probed with the B(s)-->rho0 K(S) asymmetry. Here D0 and D0BAR are identified by their charged kaon or lepton. We predict B(LAMBDA(b)-->LAMBDAD0) approximately 10(-5), thus B(LAMBDA(b)-->LAMBDAD(CP)0) approximately 10(-7). Under favourable circumstances, CP violation can occur at the few tens of percent level. Thus 10(2)-10(3) LAMBDA(b)-->LAMBDAD(CP)0 decays start probing phi. Tables list many additional modes with typical branching ratios at the 10(-5)-10(-6) level, with large detection efficiencies (in contrast to the D(CP)0), and with potentially large CP-violating effects, such as XI(b)0-->LAMBDAPSI, LAMBDAphi, LAMBDArho0; LAMBDA(b)-->LAMBDAK(S), LAMBDAK*0; XI(b)--->LAMBDAK(*)-, XI-K(S), XI-K*0; OMEGA(b)--->XI-phi, XI-rho0, LAMBDAK(*)-, OMEGA-K(S), OMEGA-K*0.