57,957 research outputs found
Momentum distribution and correlation of two-nucleon relative motion in He and Li
The momentum distribution of relative motion between two nucleons gives
information on the correlation in nuclei. The momentum distribution is
calculated for both He and Li which are described in a three-body
model of ++. The ground state solution for the three-body
Hamiltonian is obtained accurately using correlated basis functions. The
momentum distribution depends on the potential model for the -
interaction. With use of a realistic potential, the He momentum
distribution exhibits a dip around 2 fm characteristic of -wave
motion. In contrast to this, the Li momentum distribution is very similar
to that of the deuteron; no dip appears because it is filled with the -wave
component arising from the tensor force.Comment: 14 pages, 9 figure
Low Energy Solar Neutrino Detection by using Liquid Xenon
Possibility to use ultra pure liquid Xenon as a low energy solar neutrino
detector by means of +e scatterings is evaluated. A possible detector with
10 tons of fiducial volume will give 14 events for pp-neutrinos and
6 events for Be neutrinos with the energy threshold at 50 keV. The
detector can be built with known and established technologies. High density of
the liquid- Xe would provide self-shields against the incoming backgrounds
originating from the container and outer environments. Internal backgrounds can
be reduced by distillation and other techniques. Purification of the liquid Xe
can be done continuously throughout the experiment. The spallation backgrounds
are estimated to be small though an experimental determination is neccessary.
The liquid-Xe detector can also provide a significantly better sensitivity for
the double beta decay and a dark matter search. However the 2 double beta
decay of Xe would be most background. It could be overcome if the
2 lifetime is longer than 10yr. However, an isotope separation of
Xe is inevitable for a shorter lifetime.
The isotope separations would, intoroduce a new opportunity to definitively
identify dark matter. The interesting feature in addition to the solar neutrino
measurements will also be discussed.Comment: 16 pages, 4 figures, Talk presented at LowNu workshop, June-15-2000,
Sudbury, Canad
Ab initio approach to s-shell hypernuclei 3H_Lambda, 4H_Lambda, 4He_Lambda and 5He_Lambda with a Lambda N-Sigma N interaction
Variational calculations for s-shell hypernuclei are performed by explicitly
including degrees of freedom. Four sets of YN interactions (SC97d(S),
SC97e(S), SC97f(S) and SC89(S)) are used. The bound-state solution of
He is obtained and a large energy expectation value of the tensor
transition part is found. The internal energy of the
He subsystem is strongly affected by the presence of a particle
with the strong tensor transition potential.Comment: Phys. Rev. Lett. 89, 142504 (2002
Ammonia formation caused by the presence of water in the wet grinding of silicon nitride powder
Si3 N4 powder (amorphous, alpha-, and beta-Si3 N4) was mixed with MeOH containing 8.87 mol. % H2O and ground. The NH3 generation rapidly increased after a grinding time of 100 hours. Silicon nitride sintered material was chosen as one of the high temperature, high strength structural materials and studies of the control of the raw material powder, preparation of the sintered body (finding the right assistant, hot press, high pressure sintering, fracture toughness and oxidation at high temperature were performed
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