Eightfold - Way Assignments for Y , * ( 1660 ) and Other

out the whole region will provide a final answer to the spin question and information on the parity. In particular, the energy dependence of the Z w+ differential cross sections must be established carefully, because we cannot rule out the possibility that the large value of A, (Z ~+) at 760 MeV/c is due mainly to nonresonant terms. If this is the case, the value of x& would be much smaller, and this, in turn, would decrease our confidence in the spin assignment. Finally, let us say a few words about the threebody final states. If Av+m is formed predominantly through the chain K P —Z (1660)Z (1385) +m —Av+m, one could hope to say something about the spin and parity of Z(1660), taking Z(1385) to be '; .' However, the observed cross section for K P Am+v at 760 MeV/c is 4. 3 mb, and Z(1660) can contribute only -0.4 mb to that value since the normalized channel width for Z(1660) —Am+ais approximately 0. 10. Therefore, Y,*(1660) cannot affect the Av+m distributions significantly. Similar negative conclusions are drawn about the Zn v channels. We wish to thank Professor Luis W. Alvarez, Donald H. Miller, Arthur H. Rosenfeld, Robert D. Tripp, and Dr. Massimiliano Ferro-Luzzi and Dr. Joseph J. Murray for advice and encouragement.