A. Bracco

Bio: A. Bracco is an academic researcher from University of Milan. The author has contributed to research in topics: Neutron & Dipole. The author has an hindex of 39, co-authored 399 publications receiving 5825 citations. Previous affiliations of A. Bracco include University of Valencia & Istituto Nazionale di Fisica Nucleare.

AGATA - Advanced GAmma Tracking Array

Abstract: The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

Constraints on the symmetry energy and on neutron skins from the pygmy resonances in 68Ni and 132Sn

Abstract: Correlations between the behavior of the nuclear symmetry energy, the neutron skins, and the percentage of energy-weighted sum rule (EWSR) exhausted by the pygmy dipole resonance (PDR) in $^{68}\mathrm{Ni}$ and $^{132}\mathrm{Sn}$ are investigated by using different random phase approximation (RPA) models for the dipole response, based on a representative set of Skyrme effective forces plus meson-exchange effective Lagrangians. A comparison with the experimental data has allowed us to constrain the value of the derivative of the symmetry energy at saturation. The neutron skin radius is deduced under this constraint.

Evidence for the wobbling mode in nuclei.

Abstract: The nucleus ${}^{163}\mathrm{Lu}$ has been populated through the fusion-evaporation reaction ${}^{139}\mathrm{La}{(}^{29}\mathrm{Si},5n{)}^{163}\mathrm{Lu}$ with a beam energy of 152 MeV. The electromagnetic properties of several connecting transitions between two presumably triaxial, strongly deformed (TSD) bands have been studied. Evidence is presented for the assignment of the excited TSD band as a wobbling mode built on the yrast TSD band, based on comparisons to new calculations in which an aligned particle is coupled to a strongly deformed triaxial rotor. The wobbling mode is uniquely related to triaxiality in nuclei.

Giant Resonances : Nuclear Structure at Finite Temperature

Abstract: This volume presents a comprehensive introduction to the study of nuclear structure at finite temperature. By measuring the frequencies of the high-energy photons emitted or absorbed by an atomic nucleus it is possible to visualize the structure of that nucleus. In such experiments it is observed that the atomic nucleus displays resonant behavior, absorbing or emitting photons within a relatively narrow range of frequencies. To study emission processes one measures the y-decay of compound nuclei, and by this means it is possible to probe the structure of the nucleus at finite temperature. This book is divided into two main parts: the study of giant resonances based on the atomic nucleus ground state (zero temperature), and the study of the y-decay of giant resonances from compound (finite temperature) nuclei. As this work is an outgrowth of their lectures to fourth-year students at the University of Milan, the authors have placed special emphasis on the general concepts that form the foundation of the phenomenon of giant resonances. This basic subject matter is supplemented with material taken from work going on at the forefront of research on the structure of hot nuclei. Thus, this volume will serve as an essential reference for both young researchers and experienced practitioners.

Search for the pygmy dipole resonance in 68Ni at 600 MeV/nucleon.

Abstract: The $\ensuremath{\gamma}$ decay from Coulomb excitation of $^{68}\mathrm{Ni}$ at $600\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$ on a Au target was measured using the RISING setup at the fragment separator of GSI. The $^{68}\mathrm{Ni}$ beam was produced by a fragmentation reaction of $^{86}\mathrm{Kr}$ at $900\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$ on a $^{9}\mathrm{Be}$ target and selected by the fragment separator. The $\ensuremath{\gamma}$ rays produced at the Au target were measured with HPGe detectors at forward angles and with ${\mathrm{BaF}}_{2}$ scintillators at backward angles. The measured spectra show a peak centered at approximately 11 MeV, whose intensity can be explained in terms of an enhanced strength of the dipole response function (pygmy resonance). Such pygmy structure has been predicted in this unstable neutron-rich nucleus by theory.

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Random Matrix Theories in Quantum Physics: Common Concepts

Abstract: We review the development of random-matrix theory (RMT) during the last decade. We emphasize both the theoretical aspects, and the application of the theory to a number of fields. These comprise chaotic and disordered systems, the localization problem, many-body quantum systems, the Calogero-Sutherland model, chiral symmetry breaking in QCD, and quantum gravity in two dimensions. The review is preceded by a brief historical survey of the developments of RMT and of localization theory since their inception. We emphasize the concepts common to the above-mentioned fields as well as the great diversity of RMT. In view of the universality of RMT, we suggest that the current development signals the emergence of a new "statistical mechanics": Stochasticity and general symmetry requirements lead to universal laws not based on dynamical principles.

Multi-messenger Observations of a Binary Neutron Star

Abstract: This program was supported by the the Kavli Foundation, Danish National Research Foundation, the Niels Bohr International Academy, and the DARK Cosmology Centre. The UCSC group is supported in part by NSF grant AST-1518052, the Gordon & Betty Moore Foundation, the Heising-Simons Foundation, generous donations from many individuals through a UCSC Giving Day grant, and from fellowships from the Alfred P. Sloan Foundation (R.J.F.), the David and Lucile Packard Foundation (R.J.F. and E.R.) and the Niels Bohr Professorship from the DNRF (E.R.). AMB acknowledges support from a UCMEXUS-CONACYT Doctoral Fellowship. Support for this work was provided by NASA through Hubble Fellowship grants HST-HF-51348.001 (B.J.S.) and HST-HF-51373.001 (M.R.D.) awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. This paper includes data gathered with the 1 meter Swope and 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.r (AGILE) The AGILE Team thanks the ASI management, the technical staff at the ASI Malindi ground station, the technical support team at the ASI Space Science Data Center, and the Fucino AGILE Mission Operation Center. AGILE is an ASI space mission developed with programmatic support by INAF and INFN. We acknowledge partial support through the ASI grant No. I/028/12/2. We also thank INAF, Italian Institute of Astrophysics, and ASI, Italian Space Agency.r (ANTARES) The ANTARES Collaboration acknowledges the financial support of: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cite d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania;...