Proton Shell Gaps in N=28 Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator.

The first complete measurement of the ß-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the ß-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the ß-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.

Strong Evidence for

The boundaries of the chart of nuclides contain exotic isotopes that possess extreme proton-to-neutron asymmetries. Here we report on strong evidence of ^{9}N, one of the most exotic proton-rich isotopes where more than one half of its constitute nucleons are unbound. With seven protons and two neutrons, this extremely proton-rich system would represent the first-known example of a ground-state five-proton emitter. The invariant-mass spectrum of its decay products can be fit with two peaks whose energies are consistent with the theoretical predictions of an open-quantum-system approach; however, we cannot rule out the possibility that only a single resonancelike peak is present in the spectrum.

The SπRIT time projection chamber.

The Superconducting Analyzer for MUlti-particles from RAdioIsotope (SAMURAI) Pion-Reconstruction and Ion-Tracker Time Projection Chamber (SπRIT TPC) was designed to enable measurements of heavy ion collisions with the SAMURAI spectrometer at the RIKEN radioactive isotope beam factory and provides constraints on the equation of state of neutron-rich nuclear matter. The SπRIT TPC has a 50.5 cm drift length and an 86.4 × 134.4 cm2 pad plane with 12 096 pads that are equipped with the generic electronics for TPCs. The SπRIT TPC allows for an excellent reconstruction of particles and provides isotopic resolution for pions and other light charged particles across a wide range of energy losses and momenta. The details of the SπRIT TPC are presented, along with discussion of the TPC performance based on cosmic rays and charged particles emitted in heavy ion collisions.

Probing the Symmetry Energy with the Spectral Pion Ratio.

Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42

Observation of the Exotic Isotope

A ^{13}F resonance was observed following a charge-exchange reaction between a fast ^{13}O beam and a ^{9}Be target. The resonance was found in the invariant-mass distribution of 3p+^{10}C events and probably corresponds to a 5/2^{+} excited state. The ground state was also expected to be populated, but was not resolved from the background. The observed level decays via initial proton emissions to both the ground and first 2^{+} state of ^{12}O, which subsequently undergo 2p decay. In addition, there may also be a significant proton decay branch to the second 2^{+} level in ^{12}O. The wave function associated with the observed level may be collectivized due to coupling to the continuum as is it located just above the threshold for proton decay to the 2_{2}^{+} state of ^{12}O.

Publisher's Note: Direct Lifetime Measurements of the Excited States in

This corrects the article DOI: 10.1103/PhysRevLett.116.122502.

First Observation of Unbound

The structure of the extremely proton-rich nucleus _{8}^{11}O_{3}, the mirror of the two-neutron halo nucleus _{3}^{11}Li_{8}, has been studied experimentally for the first time. Following two-neutron knockout reactions with a ^{13}O beam, the ^{11}O decay products were detected after two-proton emission and used to construct an invariant-mass spectrum. A broad peak of width ∼3.4 MeV was observed. Within the Gamow coupled-channel approach, it was concluded that this peak is a multiplet with contributions from the four lowest ^{11}O resonant states: J^{π}=3/2_{1}^{-}, 3/2_{2}^{-}, 5/2_{1}^{+}, and 5/2_{2}^{+}. The widths and configurations of these states show strong, nonmonotonic dependencies on the depth of the p-^{9}C potential. This unusual behavior is due to the presence of a broad threshold resonant state in ^{10}N, which is an analog of the virtual state in ^{10}Li in the presence of the Coulomb potential. After optimizing the model to the data, only a moderate isospin asymmetry between ground states of ^{11}O and ^{11}Li was found.

Prevalence of Polysubstance Abuse and Dual Diagnosis in Patients Admitted to Alcohol Rehabilitation Units for Alcohol-Related Problems in Italy: Changes in 15 Years.

AIMS: Alcohol abuse has long been known as a disease with social and economic burden to society. Given the complex nature of alcohol treatment, it is worthwhile to examine the change over time of patients admitted to residential alcohol abuse rehabilitation units. METHODS: The data were collected from two Italian projects on alcoholics performed in the mid-1990s (ASSALT) and in 2009 (CORRAL), respectively. Categorical variables were considered in terms of absolute and relative frequencies. Comparisons of relative frequencies between groups were assessed by means of Fisher's exact test. Mixed logistic regression models were fitted to CORRAL data to identify the predictors of the probability of being a polysubstance abuser or having a dual diagnosis. The association estimates were reported as adjusted odds ratios and relative 95% confidence intervals. RESULTS: Compared to the mid-1990s, in 2009 patients were older (P= 0.0003), with a higher level of education (P= 0.0204), with fewer comorbidities (liver disease except cirrhosis, P < 0.0001; polyneuropathy, P= 0.0001), more frequently polysubstance abusers (P < 0.0001), affected by dual diagnosis (P < 0.0001). In 2009, the probability of being a polysubstance abuser was higher in younger and in patients with dual psychiatric diagnosis. Female gender and polysubstance abuse were positively associated to the probability of being affected by dual psychiatric diagnosis. CONCLUSIONS: The increment of patients admitted to residential programs for alcohol dependence with polysubstance abuse and/or dual psychiatric diagnoses suggests the need to pay more attention to both psychological/psychiatric interventions and internal medicine/physical rehabilitation. SHORT SUMMARY: The results of this study suggest that further research is needed to identify the best treatment strategy that is safe and effective for the new population of alcoholics.

Direct Lifetime Measurements of the Excited States in (72)Ni.

The lifetimes of the first excited 2^{+} and 4^{+} states in ^{72}Ni were measured at the National Superconducting Cyclotron Laboratory with the recoil-distance Doppler-shift method, a model-independent probe to obtain the reduced transition probability. Excited states in ^{72}Ni were populated by the one-proton knockout reaction of an intermediate energy ^{73}Cu beam. γ-ray-recoil coincidences were detected with the γ-ray tracking array GRETINA and the S800 spectrograph. Our results provide evidence of enhanced transition probability B(E2;2^{+}→0^{+}) as compared to ^{68}Ni, but do not confirm the trend of large B(E2) values reported in the neighboring isotope ^{70}Ni obtained from Coulomb excitation measurement. The results are compared to shell model calculations. The lifetime obtained for the excited 4_{1}^{+} state is consistent with models showing decay of a seniority ν=4, 4^{+} state, which is consistent with the disappearance of the 8^{+} isomer in ^{72}Ni.

[Alcohol-addiction inpatient: characteristics of patients and rehabilitation program]. / La residenzialità alcologica ospedaliera: caratteristiche dei pazienti e dei percorsi terapeutici/riabilitativi.

AIM: The treatment of alcohol addiction in Italy has had a progressive evolution of therapeutic structures for in-and outpatients. During the last 20 years there had been a crescent presence of short residential treatment facilities (1-6 months) characterized by a high level of medical and psychotherapeutic intervention. About two years ago 12 of them jointed together in an association called CORRAL (COordinamento of Residenzialità Riabilitive Alcologiche). The aim of this study was to describe the socio-demographic medical and other characteristics of the patients coming for this type of treatment and to describe the characteristics of the residential treatment itself including referring and aftercare. METHODS: Two thousand sixty-one hospitalized patients of the 12 rehabilitative alcohol units were examined by using a questionnaire and collecting various sociodemographic variables and clinical diagnosis of the patients. Even it was asked who had referred the patients, the characteristics of the residential treatment and of the planned aftercare. RESULTS: The present residential facilities are mainly distributed in the North of Italy. The typical patient is male, with a high school instruction and with a comorbidity regarding psychiatric and liver disorders. The majority of the patients were referred by the public ambulatory services for addictions (SerT/SerD). The characteristics of the residential treatment were medical, pharmacological and psychotherapeutic interventions with a high intensity and the presence of a general-purpose staff. CONCLUSIONS: This study outlined a model of residential rehabilitation of alcohol disorders characterized by short duration and a complex, intense therapeutic intervention mainly addressed to patients with a severe clinical condition and a low level of social problems. Further research should be useful to understand better which sort of patient characteristics obtain a better clinical result and for that even economically a major effectiveness from this type of residential treatment.