Concettina Sfienti | Johannes Gutenberg-Universität Mainz (original) (raw)
Papers by Concettina Sfienti
Physical Review C, 2007
Using the quantum molecular dynamics approach, we analyze the results of the recent INDRA Au+Au e... more Using the quantum molecular dynamics approach, we analyze the results of the recent INDRA Au+Au experiments at GSI in the energy range between 60 AMeV and 150 AMeV. It turns out that in this energy region the transition toward a participant-spectator scenario takes place. The large Au+Au system displays in the simulations as in the experiment simultaneously dynamical and statistical behavior which we analyze in detail: The composition of fragments close to midrapidity follows statistical laws and the system shows bi-modality, i.e. a sudden transition between different fragmentation pattern as a function of the centrality as expected for a phase transition. The fragment spectra at small and large rapidities, on the other hand, are determined by dynamics and the system as a whole does not come to equilibrium, an observation which is confirmed by FOPI experiments for the same system.
2008 IEEE Nuclear Science Symposium Conference Record, 2008
The P̄ANDA Experiment will be one of the large experiments of the future FAIR facility. The physi... more The P̄ANDA Experiment will be one of the large experiments of the future FAIR facility. The physics program requires a good kaon/pion-separation. To achieve this goal, three Cherenkov detectors are forseen. Around the interaction point a DIRC-barrel is planned with a readout-box inside the magnetic field. A radiator quality test is shown to point out the importance of the knowledge
The P&overbar;ANDA experiment (Pbar ANnihilations at DArmstadt) is a next generation hadron p... more The P&overbar;ANDA experiment (Pbar ANnihilations at DArmstadt) is a next generation hadron physics detector under design for the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. It will be using cooled antiproton beams with an energy between 1.5 GeV and 15 GeV interacting with various internal targets.The experiment is focusing on hadron spectroscopy, in particular the search for exotic states in the charmonium region, on the interaction of charm hadrons with the nuclear medium and on double-hypernuclei.With physics requiring precise partial wave analysis the experiment has almost 4π acceptance, a solenoid magnet for high pT tracks and a dipole magnet for the forward part of reaction products. A silicon vertex detector surrounds the interaction point. In both spectrometer parts tracking, charged particle identification, electromagnetic calorimetry and muon identification are available.The experiment is being designed to fully exploit the extraordinary physics potential arising from the availability of high-intensity, cooled antiproton beams.Significant progress beyond the present understanding of the field is expected thanks to improvements in statistics and precision of the data.
Physics of Unstable Nuclei - Proceedings of the International Symposium on the ISPUN07, 2008
In the previous approved DIPROTON experiment, we have studied the two-proton radioactivity of the... more In the previous approved DIPROTON experiment, we have studied the two-proton radioactivity of the 18 Ne 6.15MeV excited state by complete kinematical reconstruction. The results show the presence of both di-proton and democratic decay mechanisms. However, the poor statistic did not allow us to measure with precision the di-proton branching ratio of the 6.15 MeV level and to study the two-proton decay of other high-lying excited levels. With the aim of increasing the statistics of our previous measurements in order to definitely determine the di-proton decay characteristics of the 18 Ne nucleus we apply for 60 BTU .
International Journal of Modern Physics E, 2010
The decay of 18Ne excited states into 2p+16O channel has been studied. The 18Ne secondary beam, a... more The decay of 18Ne excited states into 2p+16O channel has been studied. The 18Ne secondary beam, at 33 AMeV incident energy, was produced by fragmentation of a primary 20Ne beam at the LNS-FRIBs facility. Coulomb excitation on a natPb secondary target was found to be the main interaction process leading to the population of 18Ne excited levels. The two-proton decay
Proceedings of the 12th Asia Pacific Physics Conference (APPC12), 2014
EPJ Web of Conferences, 2014
Proceedings of the 12th Asia Pacific Physics Conference (APPC12), 2014
Physical Review Letters, 2008
Two-proton decay from 18 Ne excited states has been studied by complete kinematical detection of ... more Two-proton decay from 18 Ne excited states has been studied by complete kinematical detection of the decay products. The 18 Ne nucleus has been produced as a radioactive beam by 20 Ne projectile fragmentation at 45 AMeV on a 9 Be target, using the FRIBs in-flight facility of the LNS. The 18 Ne at 33 AMeV incident energy has been excited via Coulomb excitation on a nat Pb target. The correlated 2p emission has been disentangled from the uncorrelated 2p emission using a high granularity particle detector setup allowing the reconstruction of momentum and angle correlations of the two emitted protons. The obtained results unambiguously show that the 6.15 MeV 18 Ne state two-proton decay proceeds through 2 He emission (31%) and democratic or virtual sequential decay (69%).
Nuclear Physics B - Proceedings Supplements, 2009
Silicon Carbide (SiC) Schottky diodes of different dopant concentration have been used to detect ... more Silicon Carbide (SiC) Schottky diodes of different dopant concentration have been used to detect 12 C ions at 14.2, 28.1 and 37.6 MeV incident energies. The relation between the applied reverse bias and the thickness of the depleted epitaxial region is studied for different dopant concentrations. The results show that SiC diodes with lower dopant concentration require lower reverse bias values to deplete the same thickness. Moreover, the radiation damage, produced by irradiating SiC diodes with 16 O ions at 35.2 MeV, was evaluated by measuring the degradation of both the signal pulse-height and the energy resolution as a function of the 16 O fluence. Diodes having a factor 20 lower dopant concentration show a radiation hardness reduced by 60%.
Nuclear Physics A, 2004
A wide range of projectile, target masses and incident energies have been investigated at the LNS... more A wide range of projectile, target masses and incident energies have been investigated at the LNS (Catania).
Nuclear Physics A, 2004
A wide range of projectile, target masses and incident energies have been investigated at the LNS... more A wide range of projectile, target masses and incident energies have been investigated at the LNS (Catania).
Nuclear Physics A, 2010
The detection properties of SiC diodes of different dopant concentration irradiated with light io... more The detection properties of SiC diodes of different dopant concentration irradiated with light ions are investigated. Moreover, the radiation damage, produced by irradiating SiC diodes with 16 O ions at 35.2 MeV, is evaluated from the degradation of the signal pulseheight as a function of the ions fluence.
Nuclear Physics A, 2010
The FRIBs facility at the Laboratori Nazionali del Sud produces since a few years, Radioactive Io... more The FRIBs facility at the Laboratori Nazionali del Sud produces since a few years, Radioactive Ion Beams (RIBs) at intermediate energies, by projectile fragmentation. The possibility of using the produced RIBs as secondary beams in nuclear physics experiments by applying the tagging technique, i.e. the identification, event-by-event, in charge, mass and energy of each ion of the RIBs cocktail selected by the fragment separator, before it interacts with the secondary target, has been demonstrated. Status and perspectives of the facility are discussed.
Nuclear Physics A, 2010
The decay of 18 Ne excited states trought the simultaneous emission of two protons has been studi... more The decay of 18 Ne excited states trought the simultaneous emission of two protons has been studied. 18 Ne nuclei, produced at the FRIBs facility of the Laboratori Nazionali del Sud (LNS), have been excited by Coulomb excitation on a nat Pb target and their decay has been studied by complete kinematical reconstruction of the decay products. The relative angle and momentum correlations of the proton pairs emitted from the 6.15 MeV state, unambiguously show that in a two-proton decay the two protons can be emitted as a 2 He resonance.
Journal of Physics: Conference Series, 2011
... References [1] Raciti G, Rapisarda E, Sfienti C, Amorini F, Carace F, Cardella G, Cosentino G... more ... References [1] Raciti G, Rapisarda E, Sfienti C, Amorini F, Carace F, Cardella G, Cosentino G, Del Carmine P, Stefanini AA, Shchepunov V, 2003, Proceeding of the 10th International Conference on Nuclear Reaction Mechanisms, Varenna 11 [2] Raciti G, Rapisarda E, De ...
Journal of Physics: Conference Series, 2008
The decay of 18 Ne excited states into 2p+ 16 O channel has been studied. The 18 Ne secondary bea... more The decay of 18 Ne excited states into 2p+ 16 O channel has been studied. The 18 Ne secondary beam, at 33 AMeV incident energy, was produced by fragmentation of a primary 20 Ne beam at the LNS-FRIBs facility. Coulomb excitation on a nat Pb secondary target was found to be the main interaction process leading to the population of 18 Ne excited levels. The two-proton decay of the 6.15 MeV (1 − ) level has been confirmed, but in addition other highlying states decaying via 2p emission were observed. A significant branching ratio of 2 He decay has been deduced from the analysis of the relative angle and energy correlation spectra of the two protons emitted from the 6.15 MeV (1 − ) state.
Few-Body Systems, 2013
ABSTRACT At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak ... more ABSTRACT At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak decays (MWD) of electroproduced Λ-hypernuclei were performed. A unique setup was realized to use the broad momentum-band kaon spectrometer Kaos at zero degree angle with respect to the high-intensity electron beam direction to tag strangeness producing processes. A sample of order 10^3 MWD from a beryllium target was collected by the coincidence technique with the high-resolution multi-spectrometer facility of the A1 Collaboration. It is conjectured that this sample contains monochromatic two-body decays from stopped hyperfragment decays as well as a wide momentum distribution of quasi-free produced Λ- and Σ-hyperon decays and three-body decays from hyperfragments. Stopped hyperfragments will be identified as monochromatic peaks in the π − momentum spectrum from which their masses can be extracted with a precision of 50 keV/c^2.
Physical Review C, 2007
Using the quantum molecular dynamics approach, we analyze the results of the recent INDRA Au+Au e... more Using the quantum molecular dynamics approach, we analyze the results of the recent INDRA Au+Au experiments at GSI in the energy range between 60 AMeV and 150 AMeV. It turns out that in this energy region the transition toward a participant-spectator scenario takes place. The large Au+Au system displays in the simulations as in the experiment simultaneously dynamical and statistical behavior which we analyze in detail: The composition of fragments close to midrapidity follows statistical laws and the system shows bi-modality, i.e. a sudden transition between different fragmentation pattern as a function of the centrality as expected for a phase transition. The fragment spectra at small and large rapidities, on the other hand, are determined by dynamics and the system as a whole does not come to equilibrium, an observation which is confirmed by FOPI experiments for the same system.
2008 IEEE Nuclear Science Symposium Conference Record, 2008
The P̄ANDA Experiment will be one of the large experiments of the future FAIR facility. The physi... more The P̄ANDA Experiment will be one of the large experiments of the future FAIR facility. The physics program requires a good kaon/pion-separation. To achieve this goal, three Cherenkov detectors are forseen. Around the interaction point a DIRC-barrel is planned with a readout-box inside the magnetic field. A radiator quality test is shown to point out the importance of the knowledge
The P&overbar;ANDA experiment (Pbar ANnihilations at DArmstadt) is a next generation hadron p... more The P&overbar;ANDA experiment (Pbar ANnihilations at DArmstadt) is a next generation hadron physics detector under design for the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. It will be using cooled antiproton beams with an energy between 1.5 GeV and 15 GeV interacting with various internal targets.The experiment is focusing on hadron spectroscopy, in particular the search for exotic states in the charmonium region, on the interaction of charm hadrons with the nuclear medium and on double-hypernuclei.With physics requiring precise partial wave analysis the experiment has almost 4π acceptance, a solenoid magnet for high pT tracks and a dipole magnet for the forward part of reaction products. A silicon vertex detector surrounds the interaction point. In both spectrometer parts tracking, charged particle identification, electromagnetic calorimetry and muon identification are available.The experiment is being designed to fully exploit the extraordinary physics potential arising from the availability of high-intensity, cooled antiproton beams.Significant progress beyond the present understanding of the field is expected thanks to improvements in statistics and precision of the data.
Physics of Unstable Nuclei - Proceedings of the International Symposium on the ISPUN07, 2008
In the previous approved DIPROTON experiment, we have studied the two-proton radioactivity of the... more In the previous approved DIPROTON experiment, we have studied the two-proton radioactivity of the 18 Ne 6.15MeV excited state by complete kinematical reconstruction. The results show the presence of both di-proton and democratic decay mechanisms. However, the poor statistic did not allow us to measure with precision the di-proton branching ratio of the 6.15 MeV level and to study the two-proton decay of other high-lying excited levels. With the aim of increasing the statistics of our previous measurements in order to definitely determine the di-proton decay characteristics of the 18 Ne nucleus we apply for 60 BTU .
International Journal of Modern Physics E, 2010
The decay of 18Ne excited states into 2p+16O channel has been studied. The 18Ne secondary beam, a... more The decay of 18Ne excited states into 2p+16O channel has been studied. The 18Ne secondary beam, at 33 AMeV incident energy, was produced by fragmentation of a primary 20Ne beam at the LNS-FRIBs facility. Coulomb excitation on a natPb secondary target was found to be the main interaction process leading to the population of 18Ne excited levels. The two-proton decay
Proceedings of the 12th Asia Pacific Physics Conference (APPC12), 2014
EPJ Web of Conferences, 2014
Proceedings of the 12th Asia Pacific Physics Conference (APPC12), 2014
Physical Review Letters, 2008
Two-proton decay from 18 Ne excited states has been studied by complete kinematical detection of ... more Two-proton decay from 18 Ne excited states has been studied by complete kinematical detection of the decay products. The 18 Ne nucleus has been produced as a radioactive beam by 20 Ne projectile fragmentation at 45 AMeV on a 9 Be target, using the FRIBs in-flight facility of the LNS. The 18 Ne at 33 AMeV incident energy has been excited via Coulomb excitation on a nat Pb target. The correlated 2p emission has been disentangled from the uncorrelated 2p emission using a high granularity particle detector setup allowing the reconstruction of momentum and angle correlations of the two emitted protons. The obtained results unambiguously show that the 6.15 MeV 18 Ne state two-proton decay proceeds through 2 He emission (31%) and democratic or virtual sequential decay (69%).
Nuclear Physics B - Proceedings Supplements, 2009
Silicon Carbide (SiC) Schottky diodes of different dopant concentration have been used to detect ... more Silicon Carbide (SiC) Schottky diodes of different dopant concentration have been used to detect 12 C ions at 14.2, 28.1 and 37.6 MeV incident energies. The relation between the applied reverse bias and the thickness of the depleted epitaxial region is studied for different dopant concentrations. The results show that SiC diodes with lower dopant concentration require lower reverse bias values to deplete the same thickness. Moreover, the radiation damage, produced by irradiating SiC diodes with 16 O ions at 35.2 MeV, was evaluated by measuring the degradation of both the signal pulse-height and the energy resolution as a function of the 16 O fluence. Diodes having a factor 20 lower dopant concentration show a radiation hardness reduced by 60%.
Nuclear Physics A, 2004
A wide range of projectile, target masses and incident energies have been investigated at the LNS... more A wide range of projectile, target masses and incident energies have been investigated at the LNS (Catania).
Nuclear Physics A, 2004
A wide range of projectile, target masses and incident energies have been investigated at the LNS... more A wide range of projectile, target masses and incident energies have been investigated at the LNS (Catania).
Nuclear Physics A, 2010
The detection properties of SiC diodes of different dopant concentration irradiated with light io... more The detection properties of SiC diodes of different dopant concentration irradiated with light ions are investigated. Moreover, the radiation damage, produced by irradiating SiC diodes with 16 O ions at 35.2 MeV, is evaluated from the degradation of the signal pulseheight as a function of the ions fluence.
Nuclear Physics A, 2010
The FRIBs facility at the Laboratori Nazionali del Sud produces since a few years, Radioactive Io... more The FRIBs facility at the Laboratori Nazionali del Sud produces since a few years, Radioactive Ion Beams (RIBs) at intermediate energies, by projectile fragmentation. The possibility of using the produced RIBs as secondary beams in nuclear physics experiments by applying the tagging technique, i.e. the identification, event-by-event, in charge, mass and energy of each ion of the RIBs cocktail selected by the fragment separator, before it interacts with the secondary target, has been demonstrated. Status and perspectives of the facility are discussed.
Nuclear Physics A, 2010
The decay of 18 Ne excited states trought the simultaneous emission of two protons has been studi... more The decay of 18 Ne excited states trought the simultaneous emission of two protons has been studied. 18 Ne nuclei, produced at the FRIBs facility of the Laboratori Nazionali del Sud (LNS), have been excited by Coulomb excitation on a nat Pb target and their decay has been studied by complete kinematical reconstruction of the decay products. The relative angle and momentum correlations of the proton pairs emitted from the 6.15 MeV state, unambiguously show that in a two-proton decay the two protons can be emitted as a 2 He resonance.
Journal of Physics: Conference Series, 2011
... References [1] Raciti G, Rapisarda E, Sfienti C, Amorini F, Carace F, Cardella G, Cosentino G... more ... References [1] Raciti G, Rapisarda E, Sfienti C, Amorini F, Carace F, Cardella G, Cosentino G, Del Carmine P, Stefanini AA, Shchepunov V, 2003, Proceeding of the 10th International Conference on Nuclear Reaction Mechanisms, Varenna 11 [2] Raciti G, Rapisarda E, De ...
Journal of Physics: Conference Series, 2008
The decay of 18 Ne excited states into 2p+ 16 O channel has been studied. The 18 Ne secondary bea... more The decay of 18 Ne excited states into 2p+ 16 O channel has been studied. The 18 Ne secondary beam, at 33 AMeV incident energy, was produced by fragmentation of a primary 20 Ne beam at the LNS-FRIBs facility. Coulomb excitation on a nat Pb secondary target was found to be the main interaction process leading to the population of 18 Ne excited levels. The two-proton decay of the 6.15 MeV (1 − ) level has been confirmed, but in addition other highlying states decaying via 2p emission were observed. A significant branching ratio of 2 He decay has been deduced from the analysis of the relative angle and energy correlation spectra of the two protons emitted from the 6.15 MeV (1 − ) state.
Few-Body Systems, 2013
ABSTRACT At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak ... more ABSTRACT At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak decays (MWD) of electroproduced Λ-hypernuclei were performed. A unique setup was realized to use the broad momentum-band kaon spectrometer Kaos at zero degree angle with respect to the high-intensity electron beam direction to tag strangeness producing processes. A sample of order 10^3 MWD from a beryllium target was collected by the coincidence technique with the high-resolution multi-spectrometer facility of the A1 Collaboration. It is conjectured that this sample contains monochromatic two-body decays from stopped hyperfragment decays as well as a wide momentum distribution of quasi-free produced Λ- and Σ-hyperon decays and three-body decays from hyperfragments. Stopped hyperfragments will be identified as monochromatic peaks in the π − momentum spectrum from which their masses can be extracted with a precision of 50 keV/c^2.