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Study of the pygmy dipole resonance using neutron inelastic scattering at GANIL-SPIRAL2/NFS
Get PDFThe pygmy dipole resonance (PDR) has been the subject of numer- ous studies, both experimental and theoretical. Indeed, the study of the PDR has been and still is of great interest since it allows to constrain the symmetry energy, an important ingredient of the equation of state of nuclear matter that describes the matter within neutron stars. Moreover, the PDR is predicted to play a key role in the r-process via the increase of the neutron capture rate. However, despite numerous experiments dedicated to the study of the PDR, a consistent description is still missing. In this context, we have proposed to study the PDR using a new probe: the neutron inelastic scattering reaction (n,n’γ). An experiment to study the pygmy resonance in 140Ce using the (n,n’γ) reaction has been performed in Septem- ber 2022. This experiment has been made possible thanks to the high-intensity proton beam of the new accelerator SPIRAL2 at GANIL and the NFS (Neutron For Science) facility. The experimental setup was composed of the new generation multi-detectors PARIS, for the detection of γ-rays coming from the de-excitation of the PDR, and MONSTER, for the detection of scattered neutrons. In this article, the experiment motivation and description are presented
Spectra of N=Z nuclei in a formalism of quartets
Get PDFWe describe the spectra of even-even N = Z nuclei in a formalism of quartets. Quartets are α-like four-body structures characterized by an isospin T = 0. The structure of the quartets is fixed by resorting to the use of proper intrinsic states. Various types of intrinsic states are introduced which generate different sets of quartets for a given nucleus. Energy spectra are constructed via configuration-interaction calculations in the spaces built with these quartets. Some applications of this formalism are discussed for nuclei in the sd and pf shells. A good description of the low-lying spectra of these nuclei is achieved
10Be clustering states investigation at LNS
Get PDFThe study of the formation of cluster structures in light nuclei plays an important role in the understanding of nuclear forces and nucleon-nucleon correlations. Clustering states can be investigated via break-up reactions showing, especially in radioactive neutron-rich nuclei, molecular structures of α clusters held together by valence neutrons. The CLIR experiment, carried out at Laboratori Nazionali del Sud of INFN, fits into this context to investigate the cluster structure of various light neutron-rich nuclei. This paper will report some recent results on the analysis, still ongoing, for the 10Be case, obtained by means of the FARCOS array
Monitoring and Predicting Forest Growth and Dynamics
Get PDFThe current book describes how to monitor and predict the growth and development of forest ecosystems by employing a bio-geochemical, bio-physical process-based model. The book is a practical manual describing the theoretical assumptions and main equations adopted from the "Three-Dimensional – Coupled Model of the Carbon Cycle – Forest Ecosystem Module" (3D-CMCC-FEM). The manual presents the scientific underlying theories upon which the model is based, detailing the logical structure and scientific foundations that have shaped the model development and the forest module in particular. It provides an accurate description of the model's evolution, detailing past developments, anticipating future advancements, and the various iterations over the years. Additionally, it outlines how the model simulates processes regulating the life of forest ecosystems and their functioning in relation to forest diverse management practices and future climate change. Thus, the manual allows for a thorough understanding of this innovative tool in forest ecology and eco-physiology research
Search for CP violation in the interactions of the Higgs boson with vector bosons with the ATLAS experiment
Get PDFOne of the primary research objectives at CERN’s Large Hadron Collider (LHC) is to comprehensively understand the Higgs boson and how it inter- acts with other particles. Advanced analysis methods are used to extract the best information from data on how the Higgs boson couples with fundamental particles. Several investigations aimed at exploring any unusual effects in the way the Higgs boson interacts with vector bosons and its charge-parity properties are presented. These studies are conducted using a dataset of 139 fb−1 gathered by the ATLAS experiment through proton-proton collisions at a center-of-mass energy of 13 TeV
Measurement of the High Mass Drell-Yan process in di-tau final states and leptoquark searches with the ATLAS experiment at the LHC
Get PDFLeptoquarks constitute one of the most prominent candidates in the context of new physics models interpreting B physics anomalies recently mea- sured in the Standard Model flavour sector. An analysis is presented, searching for leptoquark particles through the precision study of the Drell-Yan process with tau leptons in the final state, performed by the ATLAS Collaboration, exploiting 139 fb−1 of pp collision data from the LHC. The full analysis strategy is outlined and projections of the final exclusion limit on leptoquark models are reported
Status of the MUonE experiment
Get PDFThe MUonE experiment wants to measure with an innovative
method the vacuum polarization term of the muon magnetic moment. Its theoretical uncertainty represents the major one in the g − 2 prediction. In 2021 and 2022 some tests have been carried out to study the performances of the MUonE
detectors. In 2023 a test run has been performed to validate the methodology and finalize the experimental proposal. The status of the experiment will be presented
The description of meson and glueball spectra within the graviton soft-wall model
Get PDFIn this paper the main predictions of the holographic graviton softwall model have been discussed. In particular, the glueball and meson spectra have been shown. Results are in very good agreement with lattice calculations and
experimental data. Moreover, the model has been minimally modified to take into account the chiral symmetry-breaking mechanism to describe the pion
Phenomenology of hyperon nonleptonic decays
Get PDFRecent results published in Nature Physics (2019) by the BESIII Collaboration revealed a substantial discrepancy in the Λ baryon decay parameter value compared to the world average at the time. This development was taken as the
starting point for a feasibility study of CP violation tests in strange baryon decays at next-generation J/ψ factories. The proposed formalism allows for a direct comparison of particle and antiparticle properties, analyzing the weight of spin-correlation and polarization terms on such tests. The same weak nonleptonic decays can be studied using chiral perturbation theory (χPT), where S- and P-wave amplitudes
are computed up to one-loop corrections. The behavior of such partial-wave amplitudes is investigated in light of the recent experimental updates and in a fully relativistic framework
Employing approximate symmetries for hidden pole extraction
Get PDFRecent lattice analyses of the Dπ scattering by Hadron Spectrum Collaboration (HadSpec) report only one pole in the D∗0 channel. This is in odds with the unitarised chiral perturbation theory analyses, which predict the D∗0 (2300)
as the interplay of two poles. We provide an explanation for this contradiction—the existence of a hidden pole. We further show that the hidden pole can be better extracted from the lattice data by imposing SU(3) flavour constraints on the fitting amplitudes