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Status and prospects of the LEPS2 solenoid spectrometer
Get PDFThe Laser Electron Photon Experiment at SPring-8 2 (LEPS2)
beamline is a photon beam facility focused on hadron physics research, located in Japan. Utilizing backward Compton scattering, it produces a γ-ray beam from an 8 GeV electron storage ring shot by UV-laser light. This beamline specializes in high polarization, achieving up to 90% near the maximum beam energy. The facility aims to study exotic hadrons such as exotic nuclei and meson-baryon molecule candidates. The investigation focuses on the production of hadrons containing strange quarks, with an emphasis on exploring the properties of kaons in nuclei, the Λ(1405) resonance, and related phenomena. The LEPS2 solenoid spectrometer, equipped with detectors for charged and neutral particles, has been operational since 2021, and
physics data collection has commenced. This article provides an update on the current status of the experiment
Proof-of-principle test for a charm baryon experiment at the LHC
Get PDFMagnetic and electric dipole moments of particles provide powerful probes for physics within and beyond the Standard Model. For the case of charm baryons these have not been experimentally accessible to date due to the difficulties
imposed by their short lifetimes. An experimental test at the insertion region 3 of LHC is foreseen during Run3 to demonstrate the feasibility of a fixed-target experiment with bent crystals. The goal of the proof-of-principle test and the perspective for a future experiment are described in this article along with projected sensitivities for different experimental scenarios
η(′)→π0γγ decays: Test of meson exchange models and searches of leptophobic B bosons
Get PDFWe analyze the vector and scalar meson exchange contributions
to the doubly radiative decays η(0) → π0γγ and η' → ηγγ, and study the sensitivity of these decays to a leptophobic B boson in the sub-GeV mass range. Our results are relevant for studies of these decays at existing (A2, BESIII, KLOE-2)
and forthcoming η/η-factories, such as the JEF and REDTOP experiments
L’Italia della tecnologia: che cosa mostrano i brevetti?
Get PDFL’analisi brevettuale permette di anticipare di qualche anno prodotti, processi e servizi che verranno introdotti sul mercato. Monitorare le tendenze dei brevetti è dunque assai utile per sapere quali saranno i settori emergenti a livello globale e verificare come un’impresa o un’intera nazione si posizionano in essi.
Nella quarta Relazione sulla Ricerca e l’Innovazione del DSU-CNR abbiamo verificato quali siano i settori emergenti sulla base delle statistiche brevettuali. I risultati mostrano che le tecnologie digitali sono ben lungi dall’aver terminato il proprio sviluppo e risulta anzi che continueranno la propria diffusione, anche grazie a inedite applicazioni in altri settori industriali. Inoltre, emerge una crescita particolarmente sostenuta nelle tecnologie digitali più direttamente collegate alla comunicazione e alla gestione. I dati confermano il ruolo secondario dell’Italia nei brevetti, con numero totale di invenzioni che è meno della metà di quelle registrate dagli inventori francesi e meno di un quinto di quelle registrate dagli inventori tedeschi. Le implicazioni per le politiche della ricerca e dell’innovazione richiamano la necessità di sostenere le attività delle imprese italiane affinché possano fondare la propria competitività non soltanto su fattori di costo e di design, ma anche sulle competenze tecnologiche
Rotational moments of inertia as indicators of the density dependence of the pairing functionals
Get PDFIt is known that the moment of inertia (MoI) for the collective rotation is strongly influenced by the pairing correlation. The ground-state MoI is investigated for about 1700 even-even nuclei from the proton drip line to the neutron drip line up to Z = 120 and N = 184 to discuss the pairing properties in exotic nuclei. To this end, the cranked Skyrme-Hartree-Fock-Bogoliubov equation is solved in the coordinate space. This model describes well the available experimental data of more than 300 nuclides possessing an appreciable deformation. I find that the predicted MoI near the drip line depend on the choice of the pairing functional having different density dependence. A systematic measurement of the excitation energy and the transition probability to the first Iπ = 2+ state in neutron-rich nuclei can constrain the density dependence of the pairing functional
Collective core effects and dineutron correlations in three-body nuclei
Get PDFTwo-neutron halo nuclei, such as 6He, 11Li or 14Be, are known to have a marked (core + n + n) three-body character, which is reflected in breakup, transfer or knockout reactions channels in nucleon-nucleon collisions. Their Bor- romean nature implies that the correlation between the valence halo neutrons is key to understand their properties, and their structure is also linked to spectra of the unbound core + n systems. Among other phenomena, the role of core collective excitations may be crucial to understand exotic properties such as parity inversion or shell gap quenching in the vicinity of nuclear halos and related systems. In this contribution it is shown that dineutron correlations can be succesfully probed in proton-target knockout reactions, and that core excitation may be an important ingredient for a proper understanding of experimental observations
Pair condensation in the excited states of nuclei
Get PDFThe low-lying excited states of neutrons or protons interacting by pairing forces are usually described by breaking a pair from the ground state pair condensate and replacing it with an ”excited” pair. In this study we focus on a particular type of excited states which have the structure of a pair condensate built by identical excited pairs. As an example, we discuss the properties of these states for the case of 108Sn
Nuclear energy density functionals constrained by collective nuclear excitations and parity violating electron scattering experiments
Get PDFRecent advancements, such as measurements of dipole polarizability and experiments involving parity-violating electron scattering on 48Ca (CREX) and 208Pb (PREX-II), have opened new perspectives for our understanding of nuclear en- ergy density functionals (EDF). In particular, these advancements shed light on the isovector channel of the EDFs, which plays a pivotal role in determining properties related to symmetry energy and the thickness of the neutron skin in nuclei. Recently, a novel relativistic EDF DD-PCX has been developed based on point coupling in- teraction, adjusted using not only the ground state properties of nuclei but also the properties of isoscalar giant monopole resonance and the dipole polarizability in 208Pb. The DD-PCX interaction describes well the nuclear ground state properties, including the thickness of the neutron skin, and provides reasonable descriptions of nuclear excited states. Furthermore, the symmetry energy and its slope are found to be consistent with previous studies. Moreover, by applying the relativistic EDF framework, the consequences of the CREX and PREX-II electron scattering data have been investigated for the symmetry energy of nuclear matter and the isovector properties of finite nuclei, such as neutron skin thickness and dipole polarizability. The weak-charge form factors extracted from the CREX and PREX-II experiments have been directly used to optimize the relativistic density-dependent point cou- pling EDFs. Notably, the EDF derived from the CREX data yields substantially smaller values for parameters associated with symmetry energy, neutron skin thick- ness, and dipole polarizability for both 48Ca and 208Pb, when compared to the EDF derived from the PREX-II data, as well as previously established EDFs. It has be- come evident that the CREX and PREX-II experiments have not yielded consistent constraints for the isovector sector of the EDFs. Consequently, further theoretical investigations and experimental studies are required to clarify these discrepancies
Temperature evolution of the nucleon effective mass and symmetry energy coefficient in the 68−78Ni isotopic chain
Get PDFThe effective mass is an essential characteristic of nuclear matter and finite nuclei. The temperature evolution of the effective mass plays a signifi- cant role in understanding the temperature evolution of the symmetry coefficient of the nuclear equation of state. In the present contribution, the single-(quasi)particle spectra for 68–78Ni isotopes at zero and finite temperature are obtained by solv- ing the Dyson equation in the basis of Dirac spinors. While the static part of the self-energy of the Dyson equation has its origin from a self-consistent mean field gen- erated by the effective mesons, the dynamical part takes into account the coupling between (quasi)particles and phonons. In the leading approximation beyond the mean field, the (quasi)particle-vibration coupling (qPVC) mechanism is responsible for the fragmentation of single-(quasi)particle spectra. The calculated spectra of nickel isotopes yield the temperature-dependent effective mass for the 0 to 2 MeV temperature interval, which is relevant for astrophysical modeling, such as core- collapse supernova simulations. The impact of the temperature dependence of the effective mass on the symmetry coefficient in the nickel isotopic chain is discussed
The ENUBET experiment and its implementation at CERN
Get PDFMonitored neutrino beams are a novel technology designed to provide measurements of the neutrino cross sections at GeV scale with a total uncertainty of O(1%), thus improving by one order of magnitude current experimental estimates. The ENUBET project is close to proving for the first time the feasibility of this concept and the Collaboration is preparing a proposal for a new neutrino beam at CERN based on the SPS accelerator and the ProtoDUNEs neutrino detectors that are already operative at the North Experimental Area. In this contribution, we discuss the final design of the horn-less transfer line and the instrumented decay tunnel which allows us to measure the charged leptons associated with neutrinos from kaon decays. Finally, we discuss the expected physics performance using the SPS accelerator and the ProtoDUNE-SP neutrino detector and future perspectives for the implementation of the entire facility at CERN North Area