Spectroscopy of medium-heavy Lambda hypernuclei via the (pi(+),K+) reaction - art. no. 044302

Excitation energy spectra of Y-89(Lambda), V-51(Lambda), and C-12(Lambda) h ave been measured via the (pi (+),K+) reaction by using the SKS spectromete r at the K6 beam line in the KEK 12-GeV Proton Synchrotron. In the Y-89(Lam bda) spectrum, obtained with an energy resolution of 1.65 MeV (FWHM) and in the highest statistics so far, we have succeeded in clearly observing a ch aracteristic fine structure in heavy Lambda hypernuclear systems and precis ely obtaining a series of Lambda single-particle energies in the very wide excitation energy range of more than 20 MeV, for the first time. Also in th e V-51(Lambda) spectrum, a similar structure to that of Y-89(Lambda) was ob served. In the C-12(Lambda) spectrum, new core-excited states were clearly resolved thanks to the best energy resolution of 1.45 MeV so far achieved b y using the SKS spectrometer.