Spectroscopic factors of six low-lying neutron hole states in 207 Pb were measured with a (p,d) reaction at 65 MeV. The results are compared with previous ( p,d) reaction data as well as recent escape width ones of isobaric analog states in 208 Bi into the neutron hole states in 207 Pb. The spectroscopic factor for the 2 f 7/2 hole state shows a strong quenching ͑about 50% of the sum-rule limit͒, which suggests the existence of considerable strengths in higher excitation energy region. The appearance of the fragmentation or quenching in neutron hole strength distribution observed in the 2p-1 f and 3p-2 f shell regions is discussed. ͓S0556-2813͑97͒00406-8͔PACS number͑s͒: 21.10. Jx, 25.40.Hs, 27.80.ϩw It has been known that the distribution of some singlehole states shows an explosive fragmentation in several MeV excitation energy region ͓1-4͔. For example, the 1 f 7/2 hole state in 59 Ni and 61 Ni observed with high-resolution (p,d) reactions at 65 MeV splits to over 20 levels in the excitation energy region of 1-6 MeV, while the low-lying 2p 1/2 , 1 f 5/2 , and 2p 3/2 hole states to 2-4 levels ͓3,4͔. A similar level sequence in the p-f shell nuclei is found in lead isotopes. For the 207 Pb nucleus, the ground 1/2 Ϫ , 0.570 MeV 5/2 Ϫ , 0.900 MeV 3/2 Ϫ , and 2.340 MeV 7/2 Ϫ states are strongly excited with one neutron transfer reactions ͓5-10͔, and are assigned to be the 3 p 1/2 , 2 f 5/2 , 3p 3/2 , and 2 f 7/2 hole states, respectively. There is no fragmentation around the principal peaks of these hole states. Van der Werf et al. compiled escape width data of isobaric analog states in 208 Bi into these hole states in 207 Pb and evaluated carefully one-neutron-transfer spectroscopic factors for these four-hole states ͓11͔. They have concluded that three low-lying 3p 1/2 , 2f 5/2 , and 3p 3/2 hole states consume almost full strengths ͑ϳ90%͒ for the shell-model sum-rule limit, but the 2 f 7/2 hole state consumes a half ͑ϳ50%͒. They have also shown that the geometrical parameters of the Woods-Saxon well to calculate the single-particle bound-state wave function in the escape width analysis affect more weakly on the final results than in a one-nucleon-transfer reaction analysis. And average values of the parameters determined in the analysis of (e,eЈp) reaction data were adopted. Recently, Majumdar analyzed the 207 Pb hole states with a particlevibration coupling model which considered the giant quadrupole and octupole resonances and showed a strong quenching of the principal 2 f 7/2 hole state ͓12͔. The strength of the low-lying 2 f 7/2 hole state of 50% for the sum-rule limit is interpreted in terms of core polarization accompanying many residual strengths located in 4-18 MeV excitation energy region.To confirm the above interesting fact, it is desired to compare spectroscopic factors with those from one-nucleontransfer reactions because there is a great number of data with these reactions for target nuclei over the Periodic Table. It is also suggestive to analyze the data using the parameters for calculating t...

The 62 Ni(p,d) 61 Ni reaction has been studied with 65 MeV polarized protons. Angular distributions of the differential cross section and analyzing power have been measured for neutron hole states in 61 Ni up to an excitation energy of 7 MeV. The data analysis with a standard distorted-wave Born approximation theory provides transferred angular momenta l and j and spectroscopic factors for several strongly excited states. The 1 f 7/2 hole state spreads largely in the excitation energy region of 2-6 MeV, while the 1 f 5/2 , 2p 3/2 , and 2p 1/2 hole states into only 2-4 levels. The strength function of the 1 f 7/2 hole state is analyzed with an asymmetrical Lorentzian function. The damping mechanism of the single hole states is discussed.