No abstract available

No abstract available

No abstract available

No abstract available

No abstract available

[en] Experiments of ²³Al and ²²Mg radioactive beams bombarding a ¹²C target at an energy of 60 ~70 A MeV have been performed at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton emission from ²³Al and ²²Mg excited states, respectively. The trajectories of the decay products, namely ²¹Na + p + p from ²³Al and ²⁰Ne + p + p from ²²Mg, are clean identified. The relative momentum and opening angle between two protons in the rest frame of three body decay channels are obtained by relativistic-kinematics reconstruction. The results demonstrate that there are some di-proton emission components from ²He cluster for the excited ²³Al and ²²Mg. (author)

[en] Short communication

[en] The EOS Collaboration, consisting of groups from GSI, Kent State University, Lawrence Berkeley Laboratory, INFN Catania, Purdue University, Texas A ampersand M, and U.C. Davis, has been interested in flow and multifragmentation for over ten years. The Purdue High Energy Nuclear Physics Group studies of proton-nucleus collisions using an internal gas jet target of heavy noble gases allowed them to accurately measure target fragment yields over a wide range of fragment mass, charge, and incident energies. A high statistics study of the fragment yield in the limiting fragmentation regime provided evidence that heavy fragments come from the simultaneous disassembly of a system somewhat lighter than the original target nucleus and nearly at rest in the laboratory. Complementary studies indicated that the missing nucleons were knocked out in a prompt first stage, leaving the excited target remnant to decay. With the development of time projection chambers (TPCs) it has become possible to reconstruct all of the charged fragments. The author reports here some preliminary results from the EOS Collaboration experiment in which they used reverse kinematics to study projectile fragmentation of 1 GeV/nucleon gold nuclei incident on a carbon target

[en] The violation of the Ellis-Jaffe Sum Rule observed by the EMC has raised significant issues on the role of strange quarks in the nucleon and the total spin projection. The neutral weak axial vector form factor of the nucleon is directly sensitive to isosinglet contributions to the nucleon spin. This form factor is measurable in neutrino-nucleon elastic scattering. It does not require the use of the SU(3) symmetry to extract the isosinglet contribution nor is any extrapolation to x = 0 required. The authors show that the ratio of the yield of (ν,p) to (ν,n) from an isoscalar target yields an accurate value for the isosinglet axial vector form factor that is rather insensitive to the neutrino flux. The authors have reanalyzed the experimental results of E-734 AGS and find that there are appreciable uncertainties that can be remedied in a future experiment. The data do, however, allow a strong constraint on the sum of the strange vector form factors |F₁^s(Q²) + F₂^s(Q²)| in the range .5 < Q² < 1.0 GeV²

[en] Some highlights of the physics sessions of the Kaon Factory Workshop held in connection with the 8th International Conference on High-Energy Physics and Nuclear Structure in British Columbia in 1979 are presented. Particular emphasis is placed on the different investigations that can be carried out with kaons and antiprotons as opposed to pions and protons. Some data on K + ¹²C elastic scattering are shown. 3 figures