122653467
Fusion of 28Si + 28Si: oscillations above the barrier and the behavior down to 1μb
Fusion excitation functions of light heavy-ion systems show oscillatory struc- tures above the Coulomb barrier, caused by resonances or due to the penetration of suc- cessive centrifugal barriers well separated in energy. In heavier systems, the amplitude of oscillations decreases and the peaks get nearer to each other. This makes the measure- ments very challenging. We have performed a first experiment for 28 Si + 28 Si, by measuring fusion cross sections ( ) in an energy range of'15 MeV above the barrier, with a small Elab = 0.5 MeV step. Three regular oscillations are clearly observed, which are best revealed by plotting the energy-weighted derivative of the excitation function. The excitation function has been recently measured down to cross sections 1 b with larger energy steps. Coupled-channel (CC) calculations based on a shallow potential in the entrance channel are able to reproduce the oscillations. A further analysis will provide a stringent test for the calculations, in particular for the choice of the ion-ion potential, because the sub- barrier excitation function has to be reproduced as well.
5034444
Study of the multi-nucleon transfer reactions of 136Xe + 198Pt for producing exotic heavy nuclei
The feasibility of the multi-nucleon transfer (MNT) reaction in the 136 Xe + 198 Pt system was investigated for synthesizing neutron-rich heavy nuclei around mass number A 200 of astrophysical interest. Identification of the projectile-like fragments (PLF's) was successfully performed by using VAMOS++ spectrometer. The isotopic distributions of the PLF's produced by two-proton stripping and pickup reactions were compared with each other, demonstrating the properties of the MNT reactions observed in the present system. The two-proton pickup channels strongly populated than the two- proton stripping channels were observed. The isotopic distributions for di erent total kinetic energy loss (TKEL) ranges are also discussed. The overall enhancement of the strength of the two-proton pickup compared with the two-proton stripping appears to be related to the MNT reactions with relatively moderate energy dissipation.
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.
53654548
gamma spectroscopy of calcium nuclei around doubly magic Ca-48 using heavy-ion transfer reactions
This work was supported by the Italian Istituto Nazionale di Fisica Nucleare and partially by the Spanish MICINN (AIC10-D-000568 bilateral action and FPA2008-06419) and Generalitat Valenciana (Grant PROMETEO/2010/101). The work has also been partially supported by the Polish Ministry of Science and Higher Education (Grant No. N N202 309135)
5029078
Study of shape transition in the neutron-rich Os isotopes
The neutron-rich isotopes of tungsten, osmium and platinum have different shapes in their ground states and present also shape transitions phenomena. Spectroscopic information for these nuclei is scarce and often limited to the gamma rays from the decay of isomeric states. For the neutron-rich even-even osmium isotopes 194 Os and 198 Os, a shape transition between a slightly prolate deformed to an oblate deformed ground state was deduced from the observed level schemes. For the even-even nucleus lying in between, 196 Os, no gamma ray transition is known. In order to elucidate the shape transition and to test the nuclear models describing it, this region was investigated through gamma-ray spectroscopy using the AGATA demonstrator and the large acceptance heavy-ion spectrometer PRISMA at LNL, Italy. A two-nucleon transfer from a 198 Pt target to a stable 82 Se beam was utilized to populate medium-high spin states of 196 Os. The analysis method and preliminary results, including the first life-time measurement of isomeric states with AGATA, are presented.
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)
55022201
Artificial neutrino source experiment in Borexino
An experiment with an artificial neutrino source in Borexino is presented. The neutrino source can be located outside the detector or eventually, at the end of the solar neutrino phase, could be deployed inside. The physics case for the source experiment includes the search for short-baseline neutrino oscillations, neutrino-electron scattering at sub-MeV range, neutrino magnetic moment. Preliminary predictions of the sensitivity are reported for the sterile neutrino search.