At J-PARC, we are conducting spectroscopic studies of strangeness -2 systems, such as ฮ- and double-ฮ hypernuclei. The experimental information on these systems is so far
limited with several emulsion events; the โNagaraโ event for ฮฮ6He and the โKisoโ event
for a strong candidate of a ฮ hypernucleus. In this talk, I will introduce a preliminary result
on ฮ12Be obtained in the pilot run of E05...
It is important to study \Xi N interaction in hypernuclear physics. However, due to no \Xi N scattering data, it is essentail to study \Xi hypernuclei. Recently, we observed a \Xi hypernuclues,called as Kiso event, to have a bound state for the first time. From this data, we found that \Xi N interaction should be attractive. In this conference, we discuss that what kind of \Xi N interaction...
In the last decade, heavy-ion collision experiments have brought new insight to the study of (anti-)hypernuclei. Experiments using heavy ion collisions for hypernuclear research focus on two distinct aspects: the production mechanism and the lifetime estimation, in particular for the hypetriton. The ALICE experimental observations which allow to test models of the production mechanism...
With various experiments studying heavy-ion collisions a demand exists in the hadron physics community for theoretical predictions of hadronic properties at temperatures and densities far from standard nuclear physics scenarios. In this work we will study the implications of light-quark mesonic matter at finite temperatures on the open and hidden charm mesons. We will apply a chiral unitary...
We investigate the in-medium masses of a $\bar{D}$ $(0^-)$ meson and a $\bar{D}_0^*$ $(0^+)$ meson, and spectral functions for $\bar{D}$
and $\bar{D}_0^*$
meson channels in nuclear matter.
These mesons are introduced as chiral partner in the chiral symmetry broken vacuum,
hence they are useful to explore the partial restoration of the broken chiral symmetry in nuclear matter.
We consider...
Mesic nuclei in which a meson is bound by the strong interactions to atomic nuclei have been predicted for antikaons, eta and eta', omega and phi mesons, and for other mesons of mass above 1 GeV. While experimental searches are ongoing in several accelerator facilities for antikaons, eta and eta' mesons, no unambiguous identification of mesic nuclei has ever been achieved, partly owing to...
The understanding of the strong interaction between hadrons in the strangeness sector are an
important testing ground for chiral SU(3) symmetry due to the large mass of the strange quark.
The antikaon-nucleon interaction at low energy is studied using non-perturbative coupled-
channel techniques based on chiral SU(3) effctive Lagrangians.
With SIDDHARTA kaonic hydrogen and helium atoms were...
Several experiments have been devoted to the study of the antikaon properties within nuclear matter to understand the interaction between antikaons and nucleons at different density conditions. Experimental evidence delivered by kaonic atoms, kaon scattering data and the existence of the L(1405) resonance proves the antikaon-nucleon interaction to be attractive in the vacuum but the behavior...
By embedding mesons into nuclei and studying the property change of those particles in nuclear media, one can access the physics at densities beyond standard nuclear density, e.g., in neutron star matter, as well as the origin of matter (hadron) mass, in which the standard scenario is that the hadron masses are generated by the spontaneous chiral symmetry breaking of the vacuum. In this...
Recently, a peak structure was observed near the $K^- p p$ threshold in the in-flight ${}^3 {\rm He} (K^- , \Lambda p) n$ reaction of the E15 experiment at J-PARC. This peak could be a signal of the lightest kaonic nuclei, that is, the $\bar{K} N N (I=1/2)$ state, which has been intensively studied both experimentally and theoretically in the last decade. In this contribution we theoretically...
Spectroscopy of meson-nucleus bound systems provide precious opportunities to study low-energy QCD in view of partial restoration of the chiral symmetry in nuclear medium. Non-perturbative nature of the QCD in the low energy region exhibits many interesting features, which include chiral symmetry breaking, non-trivial structure of vacuum, and so on. We will discuss recent progress and future...
We will report on the status of the search for the eta-mesic nuclei and the studies of the interaction of the eta and eta-prime meson with nucleons. The existence of the eta-mesic nucleus was postulated over twenty nine years ago, however, till now it was not confirmed experimentally. Such system in the form of the eta mesic-helium may be created for example in the deuteron-deuteron or...
The real part of the $\eta^\prime$-nucleus potential has been determined at low momenta by analyzing the $\eta^\prime$ kinetic energy distribution and the excitation function in photoproduction of of $\eta^\prime$ mesons off C in coincidence with forward going protons. The forward going protons take over most of the momentum of the incoming photon beam and thus their detection allows the study...
Recent theoretical studies of eta nuclear quasi-bound states in few- and many-body
systems are reviewed [1,2,3,4].
Underlying energy-dependent eta-N interactions are derived from coupled-channel models
that incorporate the N*(1535) resonance. The role of self-consistent treatment of the
strong energy dependence of the subthreshold eta-N amplitudes is discussed.
Binding energies and...
The nature of chiral symmetry restoration and the identification of its correct pattern in terms of $O(4)$ and $U(1)_A$ restoration are central problems for our present understanding of the QCD phase diagram, which are not fully settled in lattice simulations. We will present a theoretical analysis based on Ward Identities which sheds light on this issue and where partner degeneration is...
In a recent experiment performed at the electron accelerator MAMI a systematic study on the ground state binding energy of hyperhydrogen 4LH was performed. The energy was deduced from the spectroscopy of mono-energetic pions from the two-body decays of hyperfragments, which were produced and stopped in a 9Be target. While the ground state binding energy difference of DBL(0+g.s.)...
Spectroscopic study of Lambda hypernuclei has started at Jefferson Lab in 2000, the last year of the 20th century.
There were many experimental difficulties such as small production cross section, huge electron background and so on.
We, finally, established the Lambda hypernuclear spectroscopy with electron beam by introducing novel experimental techniques and efforts of more than a...
Recent high-precision measurements in light hypernuclei using magnetic spectrometers have changed our knowledge of the $\Lambda N$ interaction. Accessible observables are $\Lambda$ binding energies, excitation spectra (if particle-bound excited states exist), spins, lifetime and decay branching ratios. Substantial differences between emulsion studies and recent magnetic spectrometer...
In Universe there are many varieties of matter created by the strong interaction, such as hadrons,
nuclei and the very high density quark matter which might be formed inside a neutron star. Because
those particles and matter are generated by the strong interaction, the theory of strong interaction,
i.e. the Quantum Chromo dynamics(QCD), will give answers how those states are forming...
The mass and decay width of the $\phi$ meson in cold
nuclear matter are computed in an effective Lagrangian approach. The medium dependence of these properties are obtained by evaluating kaon-antikaon loop contributions to the $\phi$ self-energy, employing the medium-modified kaon masses, calculated using the quark-meson coupling model. The loop integral is regularized with a dipole form...
