0000000000306293
AUTHOR
Jacopo Ferretti
showing 14 related works from this author
A study of ccc¯c¯ tetraquark decays in 4 muons and in D(⁎)D¯(⁎) at LHC
2020
Abstract We perform a quantitative analysis of the decays of c c c ¯ c ¯ tetraquarks with J P C = 0 + + , 2 + + into 4 muons and into hidden- and open-charm mesons and estimate, for the first time, the fully charmed tetraquark decay width. The calculated cross section upper limit is ∼ 39 ( 780 ) fb for the 4 muons channel, and ∼ 42 ( 616 ) pb for the D ( ⁎ ) D ¯ ( ⁎ ) → e μ channel, in the 0 + + ( 2 + + ) case. Decay widths depend upon the additional parameter ξ = | Ψ T ( 0 ) | 2 / | Ψ J / ψ ( 0 ) | 2 , which can be computed with a considerable error. We find Γ ( 0 + + ) ∼ Γ ( 2 + + ) = 97 ± 30 . On the basis of our results and with the present sensitivity, LHCb should detect both 0 + + and…
Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS
2019
Abstract The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ). In this view measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections are performed with high-accuracy. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β-β- decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challe…
β -decay rates of Rh115,117 into Pd115,117 isotopes in the microscopic interacting boson-fermion model
2020
The structure of odd-$A ^{115,117}\mathrm{Rh}$ and $^{115,117}\mathrm{Pd}$ isotopes is studied by means of the neutron-proton interacting boson-fermion model (IBFM-2). ${J}^{P}={\frac{1}{2}}^{+}$ quantum number assignment for the $^{115,117}\mathrm{Pd}$ ground states is critically discussed and the predicted energy levels are compared to the existing experimental data. The resulting nuclear wave functions are used to compute the $\ensuremath{\beta}$-decay $ft$ values of the transitions from $^{115,117}\mathrm{Rh}$ to $^{115,117}\mathrm{Pd}$ in the microscopic IBFM-2 and the results compared with the data.
Hidden-charm and bottom tetra- and pentaquarks with strangeness in the hadro-quarkonium and compact tetraquark models
2020
In two recent papers, we used the hadro-quarkonium model to study the properties of hidden-charm and bottom tetraquarks and pentaquarks. Here, we extend the previous results and calculate the masses of heavy-quarkonium-kaon/hyperon systems. We also compute the spectrum of hidden-charm and bottom tetraquarks with strangeness in the compact tetraquark (diquark-antidiquark) model. If heavy-light exotic systems with non-null strangeness content were to be observed experimentally, it might be possible to distinguish among the large variety of available theoretical pictures for tetra- and pentaquark states and, possibly, rule out those which are not compatible with the data. peerReviewed
Recent results on heavy-ion direct reactions of interest for 0νββ decay at INFN - LNS
2020
Abstract Neutrinoless double beta decay of nuclei, if observed, would have important implications on fundamental physics. In particular it would give access to the effective neutrino mass. In order to extract such information from 0νββ decay half-life measurements, the knowledge of the Nuclear Matrix Elements (NME) is of utmost importance. In this context the NUMEN and the NURE projects aim to extract information on the NME by measuring cross sections of Double Charge Exchange reactions in selected systems which are expected to spontaneously decay via 0νββ. In this work an overview of the experimental challenges that NUMEN is facing in order to perform the experiments with accelerated beams…
New Results from the NUMEN Project
2018
International audience; NUMEN aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. First evidence about the possibility to get quantitative information about NME from experiments is found for the (^18O,^18Ne) and (^20Ne,^20O) reactions. Moreover, to infer the neutrino average masses from the possible measurement of the half-life of 0νββ decay, the knowledge of the NME is a crucial aspect. The key tools for this project are the high resolution Superconducting Cyclotron beam…
Spectrum of fully-heavy tetraquarks from a diquark+antidiquark perspective
2019
Using a relativized diquark model Hamiltonian, we calculate the masses of $J^{PC}=0^{++}$ ground-state tetraquarks in the following systems: $b s \bar b \bar s$, $bb \bar n \bar n$ ($n=u, d$), $bb \bar s \bar s$, $cc\bar c \bar c$, $b b \bar b \bar b$, $b c\bar b \bar c$ and $b b \bar c \bar c$. We also compute extensive spectra for the fully-heavy quark flavour combinations. Finally, as a test of the diquark model approach, we compute the masses of fully-heavy baryons in the diquark model. Our results may be compared soon to the forthcoming experimental data for fully-heavy three-quark systems.
Double charge exchange reactions as a probe for neutrinoless double beta decay nuclear matrix elements
2020
Abstract The formalism to describe heavy-ion double charge exchange (DCE) processes in the eikonal and small-momentum transfer approximations introduced in Phys. Rev. C 98, 061601(R) (2018) is briefly discussed. It is also shown that, under the previous approximations, the heavy-ion DCE cross-section can be factorized in terms of a reaction and a nuclear part. A double charge exchange effective potential is explicitly derived in the closure approximation and also for the first time the explicit form of the DCE nuclear matrix elements, that are of the form of double Gamow-Teller and double Fermi. The recent hypothesis of a linear correlation between double Gamow-Teller neutrinoless double be…
Recent results on Heavy-Ion induced reactions of interest for 0νββ decay
2019
An updated overview of recent results on Heavy-Ion induced reactions of interest for neutrinoless double beta decay is reported in the framework of the NUMEN project. The NUMEN idea is to study heavy-ion induced Double Charge Exchange (DCE) reactions with the aim to get information on the nuclear matrix elements for neutrinoless double beta (0νββ) decay. Moreover, to infer the neutrino average masses from the possible measurement of the half- life of 0νββ decay, the knowledge of the nuclear matrix elements is a crucial aspect. Uma visão geral atualizada dos resultados recentes sobre reações induzidas por íons pesados de interesse para o decaimento beta duplo sem neutrinos é relatada na es…
Diquark correlations in hadron physics: Origin, impact and evidence
2020
The last decade has seen a marked shift in how the internal structure of hadrons is understood. Modern experimental facilities, new theoretical techniques for the continuum bound-state problem and progress with lattice-regularised QCD have provided strong indications that soft quark+quark (diquark) correlations play a crucial role in hadron physics. For example, theory indicates that the appearance of such correlations is a necessary consequence of dynamical chiral symmetry breaking, viz. a corollary of emergent hadronic mass that is responsible for almost all visible mass in the universe; experiment has uncovered signals for such correlations in the flavour-separation of the proton's elect…
Quark structure of the $$\chi _{\mathrm{c}}(3P)$$ and X(4274) resonances and their strong and radiative decays
2020
AbstractWe calculate the masses of $$\chi _{\mathrm{c}}(3P)$$χc(3P) states with threshold corrections in a coupled-channel model. The model was recently applied to the description of the properties of $$\chi _{\mathrm{c}}(2P)$$χc(2P) and $$\chi _{\mathrm{b}}(3P)$$χb(3P) multiplets (Ferretti and Santopinto in Phys Lett B 789:550, 2019]. We also compute the open-charm strong decay widths of the $$\chi _{\mathrm{c}}(3P)$$χc(3P) states and their radiative transitions. According to our predictions, the $$\chi _{\mathrm{c}}(3P)$$χc(3P) states should be dominated by the charmonium core, but they may also show small meson-meson components. The X(4274) is interpreted as a $$c {{\bar{c}}}$$cc¯$$\chi …
Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
2022
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molec…
β-decay rates of 115,117Rh into 115,117Pd isotopes in the microscopic interacting boson-fermion model
2020
The structure of odd-A 115,117Rh and 115,117Pd isotopes is studied by means of the neutron-proton interacting boson-fermion model (IBFM-2). JP=12+ quantum number assignment for the 115,117Pd ground states is critically discussed and the predicted energy levels are compared to the existing experimental data. The resulting nuclear wave functions are used to compute the β-decay ft values of the transitions from 115,117Rh to 115,117Pd in the microscopic IBFM-2 and the results compared with the data. peerReviewed
A study of ccc¯c¯ tetraquark decays in 4 muons and in D(⁎)D¯(⁎) at LHC
2020
We perform a quantitative analysis of the decays of ccc¯c¯ tetraquarks with JPC=0++,2++ into 4 muons and into hidden- and open-charm mesons and estimate, for the first time, the fully charmed tetraquark decay width. The calculated cross section upper limit is ∼39(780) fb for the 4 muons channel, and ∼42(616) pb for the ⁎⁎D(⁎)D¯(⁎)→eμ channel, in the 0++(2++) case. Decay widths depend upon the additional parameter ξ=|ΨT(0)|2/|ΨJ/ψ(0)|2, which can be computed with a considerable error. We find Γ(0++)∼Γ(2++)=97±30. On the basis of our results and with the present sensitivity, LHCb should detect both 0++ and 2++ fully-charmed tetraquarks. peerReviewed