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Exotic states of fully heavy hadrons
Get PDFQCD supports the existence of hadrons with a structure richer than quark-antiquark mesons and three-quark baryons that are conventionally referred to as exotic. Many candidates for such states have been discovered experimentally in the spectrum of heavy quarks, with their minimal quark content being fourquark: two heavy plus two light quarks. In addition, recent results of the LHCb
Collaboration on the double-J/ψ production near the threshold hint at the existence of fully charmed tetraquark states. A coupled-channel analysis of the LHCb data and a possible theoretical interpretation of the near-threshold exotic state predicted by this analysis are discussed. In the hadronic molecule interpretation, the strength of the interaction in the double-J/ψ system mediated by soft-gluon exchanges is proportional to the chromopolarisability of the J/ψ. The same low-energy parameter evaluated for a fully heavy baryon appears several times larger than that for the
heavy quarkonium composed of the heavy quarks of the same flavour. Thus a theoretical interpretation of the LHCb observation results in the prediction of a possible existence of di-baryon molecules formed by fully heavy baryons
Heavy-quark production in small collision systems
Get PDFQuarkonium measurements in proton-proton (pp) collisions represent a fundamental tool for studying quantum chromodynamics due to the involvement of both perturbative and non-perturbative regimes and their interplay in the
resonance formation process. The ALICE experiment has measured quarkonia in various collision systems at the LHC through their dilepton decays. Quarkonia can be reconstructed in the e+e− decay mode at midrapidity (|y| < 0.9) in the central barrel, and at forward rapidity (2.5 <y< 4.0) in the muon spectrometer, through their μ+μ− decay channel. This contribution will summarize some recent ALICE
quarkonium measurements in small collision systems, compared with available theoretical models
Programmatic access to PDG data
Get PDFThe data published by the Particle Data Group (PDG) in the Review of Particle Physics has traditionally been made available to the HEP community and beyond as a biennial publication in a scientific journal, in print as the PDG Book and the Particle Physics Booklet, and more recently primarily via the PDG website and the interactive pdgLive web application. Except for a number of data files
downloadable from the PDG website, these formats are aimed at human reading and do not support programmatic access. In order to make all PDG data easily accessible in machine-readable format for different use cases, PDG is developing a
set of new tools, namely a REST API, a downloadable database file containing the PDG data, and an associated Python package. This article presents these tools and discusses the status of their implementation at the time of the HADRON 2023 conference
Two-particle angular correlations of identified particles in pp collisions at s√=13 TeV with ALICE
Get PDFTwo-particle angular correlation is one of the most powerful tools to study the mechanism of particle production in proton-proton (pp) collision systems by relating the difference between the azimuthal angle (Δϕ) and the rapidity
(Δy) of the particles from a pair. Hadronization processes are influenced by various physical phenomena, such as resonance decay, Coulomb interactions, laws of conservation of energy and momentum and others, because of the quark content of the particles involved. Therefore, each correlation function is unique and shows a different dependence on transverse momentum pT and/or multiplicity. The angular correlation functions reported by the ALICE Collaboration in pp collisions showed an anticorrelation in short range of (Δy, Δϕ) for baryon pairs which is not predicted by any theoretical model. In this contribution, this behavior will be investigated by studying identified charged hadrons (i.e., π±, K±, and p(¯p)) in the Δy, Δϕ space in pp collisions at √s = 13 TeV recorded by ALICE. In addition, to distinguish the various physical contributions, collisions with different multiplicities are analyzed
separately and diverse normalization methods are applied
Light flavour resonance production with ALICE at the LHC
Get PDFHadronic resonances produced in high-energy collisions at the LHC are powerful tools to investigate the hadron formation and, at the same time, describe the state of strongly interacting matter formed in heavy-ion collisions. Due to their short lifetimes, resonances experience the competing effects of regeneration and rescattering of their decay products in the hadronic medium. The study of how
these processes affect the experimentally measured yields can extend the current understanding of the properties of the hadronic phase and the mechanisms that determine the shape of particle transverse momentum spectra. The f0(980) resonance was observed several years ago in ππ scattering experiments. Despite a long history of experimental and theoretical studies, the nature of this short-lived resonance is far from being understood, and there is no agreement about its quark content. According to different models, it has been associated with a meson, considered as
a tetraquark or as a KK molecule. The ALICE experiment’s excellent tracking and particle identification capabilities are exploited to measure the pT-differential spectrum and integrated yield of the f0(980) meson produced in pp collisions at the energy of √s = 5 TeV. These results are discussed in comparison with models and the properties of other hadrons. The new preliminary results and overall status of light-flavour resonances production measured in pp, p-Pb, Pb-Pb and Xe-Xe collisions at different collision energies in ALICE are shown and discussed. The Blast-Wave model, several Monte Carlo models such as EPOS3 and MUSIC with UrQMD and SMASH afterburner and statistical hadronization model predictions are also shown and compared to the results
Overview and new directions about light (anti)nuclei measurements with ALICE
Get PDFThe production of light (anti)nuclei has been measured by the ALICE experiment in the last decade. Despite the abundance of experimental results, the production mechanism of light (anti)nuclei is still mysterious and under
intense debate in the scientific community. The experimental data are typically described using two different phenomenological models: the statistical hadronization
model and the baryon coalescence. In this contribution, an overview of recent ALICE results on light (anti)nuclei production measurements will be presented. The global picture emerging from these measurements will be discussed in the context of the available phenomenological models. Recently, ALICE has performed pioneering measurements of the (anti)deuteron coalescence parameter in and out of jets in small collision systems where unexpected and intriguing results were obtained. These will be presented along with perspectives for further developments of this research line
in the LHC Run 3
Open strange mesons in (magnetized) nuclear matter
Get PDFWe investigate the mass modifications of open strange mesons (vector K∗ and axial vector K1) in isospin asymmetric nuclear matter using quantum chromodynamics sum rule (QCDSR) approach. The in-medium decay widths of K → Kπ and K1 → K∗π are studied from the mass modifications of K1, K∗ and K mesons, using a light quark-antiquark pair creation model, namely the 3P0 model. The in-medium decay width for K1 → K∗π is compared with the decay widths calculated using a phenomenological Lagrangian. The effects of magnetic
fields are also studied on mass and partial decay width of vector K∗ meson decaying to Kπ
Pion-nucleon σ term by the pion deep bound states
Get PDFThe pion deep bound states are one of the most important systems to deduce the pion properties in nuclear medium. The pion-nucleon σ term can be determined, in principle, in the bound states by observing the modification of the pion properties at finite density. We investigate the possibility to determine the value of the pion-nucleon σ term precisely by the experimental observables of the deeply bound pionic atoms. We discuss the sensitivity of the observables to the σ term, and find that the gap of the binding energies and the width of the deep bound states are good quantities for the σ term determination
Cambiamo il linguaggio e cambieremo il mondo. Superare le barriere culturali attraverso l’uso corretto delle parole in tema di disabilità
Get PDFLa ricerca che ha dato luogo alla pubblicazione del Manuale di progettazione per
l’accessibilità e la fruizione ampliata del patrimonio culturale. Dai funzionamenti della persona ai funzionamenti dei luoghi della cultura, edito da CNR Edizioni e curato dagli scriventi, ha generato una “rivoluzione copernicana”, basandosi su tutti quei fattori che, mediante la loro assenza o presenza in tale ambito, possono migliorare il funzionamento degli individui riducendo quindi le disabilità. Questi includono servizi, sistemi e politiche volti a incrementare il coinvolgimento delle persone, in tutte le aree di vita. Esaminare come gli interventi pubblici e il dibattito sociale possano affrontare e approfondire il tema della comunicazione, mediante l’utilizzo adeguato delle parole, costituisce un quid pluris alle tematiche trattate nel manuale. “Le parole sono contenitori. Dentro c’è la vita. Ci sono le persone. Con la loro dignità”. Con questa riflessione Franco Bomprezzi, giornalista (1952-2014), indicava il potere propositivo, ma anche distruttivo, delle parole, che debbono essere utilizzate in maniera appropriata, per superare tutte le barriere culturali e sociali inerenti sia al singolo sia all’intera comunità, negli ambiti esistenziali.
Parole non corrette possono generare atteggiamenti discriminatori. Il manuale ha
affrontato diffusamente il tema dell’accessibilità nei luoghi della cultura, presentando un ampio range di contenuti. Il lessico rientra a pieno titolo in questa ricerca. Le tematiche e il linguaggio, infatti, sono cambiati nel tempo grazie al progresso della società e alla conseguente evoluzione normativa. Restano, tuttavia, ancor oggi, difformità sulle modalità di utilizzo della comunicazione e delle parole corrette, su cui avviare una riflessione
p - and sd-shell Λ-hypernuclei with shell model approach
Get PDFAs a higher stage of hypernuclear studies, new experiments with high intensity and high resolution are being planned at the Japan Proton Accelerator Research Complex and the Jefferson Laboratory. We focus our attention on the
interplay between the hyperon motion and the nuclear core states. Taking two typical examples of the p-shell hypernucleus 10 ΛBe and the sd-shell hypernucleus 27
ΛMg, we discuss novel coupling features of the pΛ orbital and the core deformation within the extended shell-model framework