Decay of neutron-richPr152andCe

Abstract

The previously unreported decay of " Pr to levels in " Nd has been studied from massseparated activity produced in the thermal neutron fission of ' 'U. The '"Pr half-life was measured to be 3.24+0. 19 s, and its decay scheme was constructed based on y singles and coincidence measurements.Excited states in " Nd at 72.6 (2+) and 236.6 (4+) were established and the E(4+)/E(2+) ratio of 3.26 is close to the rigid rotor value of 3.33. The implications of the above ratio for the systematics of deformation in this region are discussed.A y transition observed at 285.0 keV probably results from the P decay of '"Ce with a half-life of 3. 1+0.3 s, but that conclusion is tentative. The most likely J for the "Pr ground state is 3.

High energy neutrinos from superheavy dark matter annihilation

“…The quarks and gluons then fragment into high multiplicity jets of hadrons and secondary decay products. Defining x = E/E jet = E/m X , one can take the fragmentation function for the total number of hadrons to be [18] dN…”

Indirect search for dark matter: Prospects for GLAST

“…We assume that hadronization and subsequent γ-ray emission is similar to the decay of QCD jets and that the annihilation of two neutralinos results in two jets, each of energy ∼ m χ . Using the fragmentation function of jets into photons, neutrinos and baryons, which is known to a good approximation up to a few TeV [45,47], the number of photons per annihilation and per jet produced in the energy interval x, x + dx is…”

First identification of high-spin states in the odd-odd neutron-rich nucleus152Pr

“…This is reasonable because levels in 152 Pr populated in the beta-decay of the even-even 152 Ce nucleus cannot have spins larger than three when the ground sate spin of 152 Pr is either 3 or 4 [7][8][9][10]. The levels observed in the spontaneous fission of 252 Cf have usually high spins.…”

“…Previously, fourteen low-lying excited levels in 152 Pr were identified in the beta-decay of 152 Ce [6] where an isomer at 114.8(2) keV was found with a half-life of 4.1(1) µs. The configurations of the ground state of 152 Pr were discussed in the reports of the beta-decay of 152 Pr to 152 Nd [7][8][9][10] with different assignments. However, no high-spin level has been observed in 152 Pr before the present work.…”