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Lorentz non-invariance, locality, unitarity and renormalizability in quantum gravity
No full textWe discuss problems of covariant renormalization of Lorentz noninvariant, local and unitary Hoˇrava gravity models in arbitrary spacetime dimensions, including perturbatively renormalizable projectable Hoˇrava gravity in (2 + 1)
and (3 + 1) dimensions. Renormalization group flow with asymptotically free UV fixed point is presented in (2 + 1)-dimensional theory. A related model of generalized unimodular gravity (GUMG) is shown to have interesting applications in cosmological inflation theory and within the cosmological dark energy problem. The unification of these two models sharing in common Lorentz symmetry violation, fixation of the lapse function and a number of other features is conjectured in the framework of generalized renormalization group approach
Metodi di analisi riconoscimento dei tunnidi allo stadio larvale
Get PDFUno dei periodi di vita più sensibili per ciascuna specie sono le prime fasi della vita (larvale e
giovanile). I tassi di sopravvivenza delle larve di pesci pelagici in queste fasi sono generalmente molto
bassi e soggetti a fluttuazioni, con conseguenze sul reclutamento delle nuove generazioni.
Il tonno rosso dell'Atlantico (ABT) (Thunnus thynnus, Linnaeus, 1758) è una delle specie più costose
al mondo. Alcuni studi hanno ipotizzato che le fluttuazioni del suo stock siano dettate da fattori
ambientali, in particolare nelle prime fasi della vita.
Anche il Tonno alalunga (Thunnus alalunga, Bonnaterre, 1788) e il tombarello (Auxis rochei, Risso,
1810) svolgono un ruolo ecologico essenziale come grandi predatori, sono obiettivi di pesca a livello
globale e hanno un'influenza fondamentale sulla struttura e sulla funzione delle comunità marine.
Pertanto, la loro gestione sostenibile è essenziale e dipende da una migliore comprensione della loro
storia di vita.
Dunque, appare necessario comprendere meglio la biologia e i processi di reclutamento di queste
specie, studio che può essere condotto analizzando le sue fasi larvali
Study of strangeness production in pp collisions as a function of multiplicity and effective energy with ALICE
No full textThe study of energy and multiplicity dependence of strange hadron production in proton-proton collisions provides a powerful tool to understand similarities and differences between small and large collision systems. In these proceedings, recent ALICE preliminary results are presented, which contribute to a better understanding of the strangeness production in pp collisions at √s = 13 TeV.
Multi-strange Ξ− and Ξ+ baryon yields are studied as a function of multiplicity and effective energy, i.e., the energy available for particle production in the event. The
main novelty of this analysis is the introduction of a new effective energy estimator, which is based on the energy deposited in ALICE Zero Degree Calorimeters. Such a
multi-differential approach allows disentangling initial and final-state effects in the strangeness production in pp collisions
A multi-channel approach to the study of the 18O+48Ti reaction within the NUMEN project
No full textThe study of the multi-nucleon transfer as competitive processes to the double charge exchange channel has a prominent position among the goals of the NUMEN project. Understanding the degree of competition between successive nucleon transfer and double charge exchange reactions is imperative for the description of the direct-meson exchange mechanism. Moreover, the study of these competing processes under the same experimental conditions provides the appropriate constraints in the experimental systematics that are particularly useful for the theoretical description of the reaction mechanism. To this extent, one- and two-nucleon transfer reactions in the 18O+48Ti collision at 275 MeV were measured for the first time, under the NUMEN and NURE experimental campaigns. Differential cross-section angular distribution measurements for the reaction ejectiles were performed by using the MAGNEX large acceptance magnetic spectrometer at INFN-LNS in Catania. Recent results for the one-nucleon and two-proton transfer reactions will be presented and discussed
Lead-halide perovskite thin-film for flexible and direct X-ray detectors
No full textLead-halide hybrid perovskites are recently emerging as promising materials for high energy radiation detection thanks to the combination of high absorption coefficient, excellent transport properties, even in polycrystalline films, and their solution processability. Here we present flexible perovskite X-ray detectors based on solution deposited thin films. A triple cation perovskite is deposited on a thin plastic foil reaching no more than 3 μm in total thickness. Thanks to its small thickness, the detector can be adapted to very complex surfaces. The photodetector showed a clear and box-like response to 150 kVp X-ray with a sensitivity of (6.30 ± 0.02) μCGy−1cm−2 when operated in passive mode
Data reduction of the 18O+48Ti elastic and inelastic scattering at 275 MeV in the context of the NUMEN project
No full textThe 18O + 48Ti reaction at 275 MeV bombarding energy was studied at the INFN-LNS within the framework of the NUMEN project. The elastic and inelastic scattering channels were measured using the MAGNEX magnetic spectrometer with the aim of extracting the initial-state interaction of the involved nuclei. The ray reconstruction method was applied to the experimental data to obtain the scattering angles and the momentum vectors of the ejectiles, at the target point
Fusion hindrance and Pauli blocking in 58Ni + 64Ni
No full textThe early experiments on fusion of Ni + Ni systems are well-known and indicated for the first time the possible influence of transfer reactions on subbarrier cross sections. The influence of the positive Q-value transfer channels on sub-barrier fusion cross sections of the system 58Ni + 64Ni was evidenced in an experiment by Beckerman et al. Subsequent experiments for the two systems 58Ni + 58Ni
and 64Ni + 64Ni showed that fusion hindrance is clearly present in both cases. The lowest measured cross section for 58Ni + 64Ni was relatively large (0.1 mb), so that no hindrance was observed. In the present measurement the excitation function has been extended by two orders of magnitude downward. The present experiment indicates that the flat trend of the sub-barrier cross sections for 58Ni + 64Ni continues down to the level of μb and the logarithmic slope of the excitation function increases slowly, showing a tendency to saturate at the lowest energies. No maximum of the astrophysical S-factor is observed, so fusion hindrance is not observed. This trend at far sub-barrier energies suggests that the presence of the transfer channel with Q > 0, effectively counterbalances the effect of Pauli repulsion that is predicted to reduce tunneling probability
Search for CP violation in D0 → K−K+ and D0 → π−π+ decays
No full textThe existence of CP violation has been recently proved by the LHCb experiment in neutral charm meson decays measuring the CP-violating difference ΔACP = ACP (K−K+) − ACP (π−π+). A measurement of the single ACP (K−K+) and ACP (π−π+) is presented making use of D0 → K−K+ and D0 → π−π+ decays
promptly produced in proton-proton collisions and reconstructed in data recorded by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to 6/fb of integrated luminosity. The flavour of the meson is determined by the charge of the pion in D∗+ → D0π+ decays. High-yield samples of Cabibbo-favoured D∗+, D+ and D+ s decays are used to subtract nuisance asymmetries due to production and detection effects
Configuration mixing investigation in germanium isotopes through measurement of E0 transition strengths
No full textExperimental and theoretical studies of the germanium isotopes on the neutron-rich side of the stability valley point increasingly toward the emergence of triaxiality, configuration mixing, and shape coexistence phenomena. Studies of the E0 strengths, which can provide a direct measure of the amount of configuration mixing, are lacking. Thus, determining E0 transition strengths is essential
for an understanding of the evolution of structures in the Ge isotopes. Beta-decay experiments populating excited states in the 72,74,76,78Ge isotopes were performed at the TRIUMF-ISAC radioactive beam facility. Gamma-ray and electron spectroscopic investigations have been performed, to measure E0 strengths between states of J > 0, exploiting the GRIFFIN spectrometer combined with the PACES silicon
detector array. Preliminary results from this study are presented