RESUMO
Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a ^{54}Ca beam striking on a liquid hydrogen target at â¼200 MeV/u. A significantly larger cross section to the p_{3/2} state compared to the f_{5/2} state observed in the excitation of ^{53}Ca provides direct evidence for the nature of the N=34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.
RESUMO
White Leghorn chickens treated with testosterone-propionate on the 3rd day of embryonation were immunized with a mixture of sheep red blood cells, Brucella abortus and Salmonella pullorum at various ages, and the resulting agglutinins were titrated. The production of IgM antibody against sheep red blood cells was not affected significantly by testosterone-propionate. On the contrary, immune responses against the bacterial antigens were strongly suppressed by the same treatment. Production of IgG antibodies was strongly suppressed by the same treatment. There was little correlation between the production of IgM antibody against sheep red blood cells and the presence of bursal follicles. Immune responses against bacterial antigens correlated with the presence of the follicles. Production of IgG antibodies also correlated with the maintenance of bursal lymphoid structure.