Cold compression of nuclei induced by antiprotons
On the basis of a dynamical Relativistic Mean Field (RMF) model we study the response of a nucleus on an antiproton implanted in its interior. We solve the Vlasov equation for the p̄-nuclear system assuming different strengths of attractive p̄ potential and show that a compressed state is formed on a rather short time scale of about 4 ÷ 10 fm/c. The evolution of the system after p̄ annihilation is simulated using the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model. Finally, several observables sensitive to the p̄ annihilation in a compressed nuclear configuration are proposed, e.g. the nucleon kinetic energy spectra and the total invariant mass distributions of produced mesons.
Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size.
We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.
Secoiridoids from Olea europaea
Abstract Three new secoiridoids have been isolated from the leaves of Olea europaea along with the previously reported. The compounds were identified by spectral means.