Unified description of BaBar and Belle data on the bottomonia decays Upsilon(mS) -> Upsilon(nS) pi+ pi-

We present a unified analysis of the decays of bottomonia Upsilon(mS) -> Upsilon(nS) pi pi (m>n, m=2,3,4,5, n=1,2,3), charmonia J/psi -> phi (pi pi, K antiK), psi(2S) -> J/psi pi pi and the isoscalar S-wave processes pi pi -> pi pi, K antiK, eta eta. In this analysis we extend our recent study of low-lying (m=2,3) radial excitations of bottomonia to modes involving higher (m=4,5) excited states. Similarly as for the data on lower radial excitations, we confirm that the data for higher radially excited states from the BaBar and Belle collaborations can be described under conditions that the final bottomonium is a spectator and the multichannel pi pi scattering is considered in a model-independent approach based on analyticity, unitarity and the uniformization procedure. Indeed we show that the dipion mass distributions in the two-pion transitions of both charmonia and bottomonia states are explained by a unified mechanism based on the contribution of the pi pi and K antiK coupled channels including their interference (final-state interactions). Therefore, our main result is that the lower and higher radially excited states of charmonia and bottomonia have no specific features in mutual comparison and can be understood in a unified picture, e.g. proposed by our approach.Comment: 8 page

The scalar mesons in multi-channel ππ\pi\pi scattering and decays of the ψ\psi and Υ\Upsilon families

The $f_0$ mesons are studied in a combined analysis of data on the isoscalar S-wave processes $\pi\pi\to\pi\pi,K\overline{K},\eta\eta$ and on decays $J/\psi\to\phi(\pi\pi, K\overline{K})$, $\psi(2S)\to J/\psi(\pi\pi)$, and $\Upsilon(2S)\to\Upsilon(1S)\pi\pi$ from the Argus, Crystal Ball, CLEO, CUSB, DM2, Mark II, Mark III, and BES II collaborations. The method of analysis, based on analyticity and unitarity and using an uniformization procedure, is set forth with some details. Some spectroscopic implications from results of the analysis are discussed.Comment: Lecture read by Yu. Surovtsev at the Helmholtz International Summer School "Physics of Heavy Quarks and Hadrons - 2013", July 2013, Dubna, Russi

Beam-spin asymmetry Σ\boldsymbol{\Sigma} for Σ−\Sigma^- hyperon photoproduction off the neutron

We report a new measurement of the beam-spin asymmetry $\boldsymbol{\Sigma}$ for the $\vec{\gamma} n \rightarrow K^+\Sigma^-$ reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions from an isobar model indicate strong sensitivity to $N(1720)3/2^+$, $\Delta(1900)1/2^-$, and $N(1895)1/2^-$, with the latter being a state not considered in previous photoproduction analyses. When our data are incorporated in the fits of partial-wave analyses, one observes significant changes in $\gamma$-$n$ couplings of the resonances which have small branching ratios to the $\pi N$ channel.Comment: 9 pages, 4 figures, Hadron Spectroscop

High Resolution Hypernuclear Spectroscopy at Jefferson Lab Hall A

The characteristics of the Jefferson Lab electron beam, together with those of the experimental equipment, offer a unique opportunity to study hypernuclear spectroscopy via electromagnetic induced reactions. Experiment 94-107 started a systematic study on 1p-shell targets, $^{12}C$, $^{9}Be$ and $^{16}O$. For $^{12}C$ for the first time measurable strength in the core-excited part of the spectrum between the ground state and the p state was shown in $^{12}_{\Lambda}B$ spectrum. A high-quality $^{16}_{\Lambda}N$ spectrum was produced for the first time with sub-MeV energy resolution. A very precise $\Lambda$ binding energy value for $^{16}_{\Lambda}N$, calibrated against the elementary (e,e'K^+) reaction on hydrogen, has also been obtained. $^{9}_{\Lambda}Li$ spectrum shows some disagreement in strength for the second and third doublet with respect to the theory

Studying ΛN interactions through the

The hyperon puzzle, the observation that the two-solar-mass neutron star existence is hardly explained by all models predicting the appearance of hyperons in the neutron star core, is currently one of the unsolved key issues in the physics of compact stars. To solve the hyperon puzzle an experimental program has been proposed by the Jefferson lab hypernuclear collaboration and approved by the Jefferson Lab (JLab) PAC. This program consists in the study of the reaction (e, e’K) on 40Ca and 48Ca nuclei, aimed at investigating the isospin dependence of hyperon dynamics, and in the study of the reaction (e, e’K) on 208Pb nucleus, which is the subject of this paper and which will take advantage of the fact that 208Pb properties largely reflects those of the uniform nuclear matter present in the interior of the neutron stars making it the ideal tool to investigate neutron star features. The proposal of the study of the reaction (e, e’K) on 208Pb was approved by the Jlab PAC in 2020

Study of Strangeness Photo-production in the Threshold Region at LNS-Tohoku(I. Nuclear Physics)

We have successfully measured neutral kaons, bombarding a liquid deuterium target with a photon beam in the threshold region from 0.8 to 1.1GeV. It was the first data for K^0 photoproduction on the deuteron in this energy region. The momentum spectra of K^0 production were compared with theoretical spectra calculated assuming isobar models for the elementary process and a realistic deuteron wave function for the target The present experiment has demonstrated a usefulness of the neutral kaon measurement for the investigation of photo strangeness production reactions