41288355
Spectroscopy of the odd-odd fp-shell nucleus Sc-52 from secondary fragmentation
The odd-odd fp-shell nucleus {sup 52}Sc was investigated using in-beam {gamma}-ray spectroscopy following secondary fragmentation of a {sup 55}V and {sup 57}Cr cocktail beam. Aside from the known {gamma}-ray transition at 674(5) keV, a new decay at E{sub {gamma}}=212(3) keV was observed. It is attributed to the depopulation of a low-lying excited level. This new state is discussed in the framework of shell-model calculations with the GXPF1, GXPF1A, and KB3G effective interactions. These calculations are found to be fairly robust for the low-lying level scheme of {sup 52}Sc irrespective of the choice of the effective interaction. In addition, the frequency of spin values predicted by the shell model is successfully modeled by a spin distribution formulated in a statistical approach with an empirical, energy-independent spin-cutoff parameter.
121267185
Properties of excited states in Ge77
The nucleus $^{77}\mathrm{Ge}$ was studied through the $^{76}\mathrm{Ge}(^{13}\mathrm{C},^{12}\mathrm{C})^{77}\mathrm{Ge}$ reaction at a sub-Coulomb energy. The angular distributions of $\ensuremath{\gamma}$ rays depopulating excited states in $^{77}\mathrm{Ge}$ were measured in order to constrain spin and parity assignments. Some of these assignments are of use in connection with neutrinoless double beta decay, where the population of states near the Fermi surface of $^{76}\mathrm{Ge}$ was recently explored using transfer reactions.
119706030
Cross-shell excitations near the "island of inversion": Structure of Mg-30
Excited states in {sup 30}Mg have been populated to {approx}6{h_bar} and 5 MeV excitation energy with the {sup 14}C({sup 18}O,2p) reaction. Firm spin assignments for states with J>2{h_bar} have been made in this nucleus. The level scheme is compared to shell-model calculations using the Universal sd effective interaction and the Monte Carlo shell model method. Calculations employing a full sd model space fail to reproduce the observed levels. The results indicate that excitations across the N=20 gap are required at relatively low excitation energy to achieve a description of the data. The incorporation of the f{sub 7/2} and p{sub 3/2} orbitals into the model space gives improved results but indicate the need for further refinement of the models to reproduce the observed spectra.
118976996
One-neutron knockout in the vicinity of the N=32 sub-shell closure: Be-9(Cr-57,Cr-56+gamma)X
Gade, A. Janssens, R. V. F. Bazin, D. Brown, B. A. Campbell, C. M. Carpenter, M. P. Cook, J. M. Deacon, A. N. Dinca, D. -C. Freeman, S. J. Glasmacher, T. Horoi, M. Kay, B. P. Mantica, P. F. Mueller, W. F. Terry, J. R. Tostevin, J. A. Zhu, S.
328610
High-j single-particle neutron states outside the N=82 core
Abstract The behaviour of the i 13 / 2 and h 9 / 2 single-neutron strength was studied with the ( α , He 3 ) reaction on 138Ba, 140Ce, 142Nd and 144Sm targets at a beam energy of 51 MeV. The separation between the single-neutron states i 13 / 2 and h 9 / 2 was measured in N = 83 nuclei with changing proton number. To this end spectroscopic factors for states populated in high-l transfer were extracted from the data. Some mixing of l = 5 and 6 strength was observed with states that are formed by coupling the f 7 / 2 state to the 2 + and 3 − vibrational states and the mixing matrix elements were found to be remarkably constant. The centroids of the strength indicate a systematic change in the energies of the i 13 / 2 and h 9 / 2 single-neutron states with increasing proton number that is in quantitative agreement with the effects expected from the tensor interaction.
122045264
The double-wedge algebra for quantum fields on Schwarzschild and Minkowski spacetimes
We consider the Klein-Gordon equation (m≧0) on the double Schwarzschild wedge of the Kruskal spacetime, and construct the Hartle-Hawking stateωH as a thermal state relative to the Boulware quantization. We prove that, on the double wedge,ωH is a pure state, and in the corresponding representation, the left- and right-wedgeC* algebras each have the Reeh-Schlieder property, while the corresponding von-Neumann algebras are typeIII1 factors which are dual to (i.e. commutants of) each other. We discuss the extent to which these properties may generalize to non-quasi-free field theories.Pursuing the Rindler-Fulling-Unruh analogy with the Klein-Gordon equation (m>0) in (d-dimensional) flat spacetime, we establish an explicit formula for the Minkowski vacuum on a spacelike double wedge as a thermal state relative to the Fulling quantization. We also treat the cased=2,m=0 of this formula since this is essential input for a paper with Dimock on scattering theory for the quantum Klein-Gordon equation on the Schwarzschild metric.
5060903
Monotonicity with volume of entropy and of mean entropy for translationally invariant systems as consequences of strong subadditivity
We consider some questions concerning the monotonicity properties of entropy and of mean entropy for translationally invariant states on translationally invariant systems (classical lattice, quantum lattice and quantum continuous). By taking the property of strong subadditivity, which for quantum systems was proven rather late in the historical development, as one of four primary axioms (the other three being simply positivity, subadditivity and translational invariance), we are able to obtain results, some new, some proved in a new way, which appear to complement in an interesting way results proved around 30 years ago on limiting mean entropy and related questions. In particular, we prove that as the sizes of boxes in Z ν or R ν increase in the sense of set inclusion, (1) their mean entropy decreases monotonically and (2) their entropy increases monotonically. We include a proof of (2) based on the notion of mpoint correlation entropies, which we introduce and which generalize the notion of index of correlation (see e.g. Horodecki R 1994 Phys. Lett. A 187 145). We mention a number of further results and questions concerning monotonicity of entropy and of mean entropy for more general shapes than boxes and for more general translationally invariant (/homogeneous) lattices and spaces than Z ν or R ν . We also obtain some further results on monotonicity of entropy in these more general situations by adjoining a fifth axiom, which embodies yet another general property of entropy (which we call the ‘strong triangle inequality’).