55925233
Transfer probability measurements in the superfluid 116Sn+60Ni system
We measured excitation functions for the main transfer channels in the 116 Sn+ 60 Ni reaction from above to well below the Coulomb barrier. The experiment has been performed in inverse kinematics, detecting the lighter (target-like) ions with the magnetic spectrometer PRISMA at very forward angles. The comparison between the data and microscopic calculations for the present case and for the previously measured 96 Zr+ 40 Ca system, namely superfluid and near closed shells nuclei, should significantly improve our understanding of nucleon-nucleon correlation properties in multinucleon transfer processes.
121651616
Reaction dynamics and nuclear structure studies via deep inelastic collisions with heavy-ions: spin and parity assignment in 49Ca
The population and gamma decay of neutron rich nuclei around 48Ca has been measured at Legnaro National Laboratory with the PRISMA-CLARA setup, using deep-inelastic collisions (DIC) on 64Ni, at an energy approximately twice the Coulomb barrier. The reaction properties of the main products are investigated, focusing on total cross sections and angular distributions both integrated in energy and associated to the population of specific excited states. Gamma spectroscopy studies are also performed, giving evidence, for the first time in transfer reactions with heavy ions, of a large spin alignment (~70%), perpendicular to the reaction plane. This makes possible the use of angular distributions and polarization measurements to firmly establish the spin and parity of excited states populated in nucleon transfer channels, as in the case of 49Ca, where candidates for particle-core coupling are investigated. Both reaction and gamma spectroscopy studies demonstrate the relevance of DIC with heavy ions for a detailed investigation of moderately neutron rich systems.
120912280
Measurement of isospin mixing at a finite temperature in Zr-80 via giant dipole resonance decay
A. Corsi,1,2,* O. Wieland,2 S. Barlini,3,4 A. Bracco,1,2 F. Camera,1,2 V. L. Kravchuk,5 G. Baiocco,7 L. Bardelli,4 G. Benzoni,2 M. Bini,3 N. Blasi,2 S. Brambilla,2 M. Bruno,7 G. Casini,4 M. Ciemala,8 M. Cinausero,5 F. C. L. Crespi,1,2 M. D’Agostino,7 M. Degerlier,5 A. Giaz,1,2 F. Gramegna,5 M. Kmiecik,8 S. Leoni,1,2 A. Maj,8 T. Marchi,5,6 K. Mazurek,8 W. Meczynski,8 B. Million,2 D. Montanari,6 L. Morelli,7 S. Myalski,8 A. Nannini,4 R. Nicolini,1,2 G. Pasquali,3 G. Poggi,3 V. Vandone,1,2 and G. Vannini7 1Dipartimento di Fisica, Università di Milano and INFN Sezione di Milano, Italy 2INFN, Sezione di Milano, Milano, Italy 3Dipartimento di Fisica, Università di Firenze and INFN Sezione di Firenze, Italy 4INFN Sezione di Firenze, Italy 5INFN Laboratori Nazionali di Legnaro, Padova, Italy 6Dipartimento di Fisica, Università di Padova and INFN Sezione di Padova, Italy 7Dipartimento di Fisica, Università di Bologna and INFN Sezione di Bologna, Italy 8The Henryk Niewodniczaǹski Institute of Nuclear Physics PAN, Krakow, Poland (Received 20 March 2011; published 20 October 2011)
56152487
Rotation and shape changes in 151Tb and 196Pb: Probes of nuclear structure and tunneling process in warm nuclei. I. Experimental analysis
The {gamma} decay associated with the warm rotation of the superdeformed nuclei {sup 151}Tb and {sup 196}Pb has been measured with the Euroball IV array. Several experimental quantities are presented, putting strong constraints on the decay dynamics in the superdeformed well. The data are successfully reproduced using a Monte Carlo simulation of the {gamma} decay based on microscopically calculated energy levels, E2 decay probabilities, collective mass parameters, and potential energy barriers between the wells associated with normal and super deformation. This allows one to test the basic ingredients of the physical process, such as the strength of the two-body residual interaction and the potential barriers as a function of spin and excitation energy. We also show that the data probe the E1 strength function, indicating an enhancement around 1-2 MeV {gamma} rays, which might be related to octupole vibrations.
54660865
Dynamical Dipole and Equation of State in N/Z Asymmetric Fusion Reactions
In heavy ion reactions, in the case of N/Z asymmetry between projectile and target, the process leading to complete fusion is expected to produce pre-equilibrium dipole γ -ray emission. It is generated during the charge equilibration process and it is known as Dynamical Dipole. A new measurement of the dynamical dipole emission was performed by studying 16 O + 116 Sn at 12 MeV/u. These data, together with those measured at 8.1 MeV/u and 15.6 MeV/u for the same reaction, provide the dependence on the Dynamical Dipole total emission yield with beam energy and they can be compared with theoretical expectations. The experimental results show a weak increase of the Dynamical Dipole total yield with beam energies and are in agreement with the prediction of a theoretical model based on the Boltzmann–Nordheim–Vlasov (BNV) approach. The measured trend with beam energy does not confirm the rise and fall behavior previously reported for the same fused compound but with a much higher dipole moment.
121575889
Lifetime Measurements of the Neutron-Rich N=30 Isotones Ca-50 and Sc-51: Orbital Dependence of Effective Charges in the fp Shell
The lifetimes of the first excited states of the N=30 isotones Ca-50 and Sc-51 have been determined using the Recoil Distance Doppler Shift method in combination with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This extends the lifetime knowledge beyond the f(7/2) shell closure and allows us to derive the effective proton and neutron charges in the fp shell near the doubly magic nucleus Ca-48, using large-scale, shell-model calculations. These results indicate an orbital dependence of the core polarization along the fp shell.
122075081
Solar neutrino results from borexino
Abstract Borexino is a large-volume liquid scintillator experiment for low energy neutrino detection, operating since May 2007, and installed at the National Laboratory of Gran Sasso. Borexino is the first experiment able to observe in real-time Solar neutrino interactions also in the sub-MeV range. We report with this work the main results achieved in the Solar neutrino sector by Borexino. In particular, we report the results on the measured interaction rates of 7 Be, 8 B, and pep neutrinos, and their impacts on the physics of neutrino oscillations.
121900736
THE BOREXINO DETECTOR
118577347
First Large Scale Production of Low Radioactivity Argon From Underground Sources
We report on the rst large-scale production of low radioactivity argon from underground gas wells. Low radioactivity argon is of general interest, in particular for the construction of large scale WIMP dark matter searches and detectors of reactor neutrinos for non-proliferation eorts. Atmospheric argon has an activity of about 1 Bq/kg from the decays of 39 Ar; the concentration of 39 Ar in the underground argon we are collecting is at least a factor of 100 lower than this value. The argon is collected from a stream of gas from a CO2 well in southwestern Colorado with a Vacuum Pressure Swing Adsorption (VPSA) plant. The gas from the well contains argon at a concentration of 400-600 ppm, and the VPSA plant produces an output stream with an argon concentration at the level of 30,000-50,000 ppm (3-5%) in a single pass. This gas is sent for further processing to Fermilab where it is puried by cryogenic distillation. The argon production rate is presently 0.5 kg/day.
117791829
Study of Solar and Geo-Neutrinos with the BOREXINO Detector
116991669
Study of the Rare Processes with the BOREXINO Detector
The status of the search for rare processes with the Borexino detector is reviewed. The discussed experimental results include searches for violation of the Pauli exclusion principle in nuclei, 5.5 MeV axions from p+d → 3He+A reaction on the Sun and magnetic moments of solar neutrinos. New limits on the probability of non-Paulian transitions in 12C nuclei [3], on the axion-electron, axion-photon and axion-nucleon coupling constants [4] and on the neutrino magnetic moments [2] are presented. 1 The Borexino detector Borexino is a real-time detector for solar neutrino spectroscopy located at the Gran Sasso Underground Laboratory. Its main goalis to measure low energy solar neutrinos via (ν,e)-scattering in an ultra-pure liquid scintillator. The extremely high radiopurity of the detector and its large mass allow to simultaneously address other fundamental questions in particle physics and astrophysics. The main features of the Borexino detector have been thoroughly described in [1]. Borexino is a scintillator detector with an active mass of 278 tons of pseudocumene (PC, C9H12), doped with the light shifter (C15H11NO). The ae-mail: derbin@pnpi.spb.ru be-mail: fomenko@jinr.ru