相关论文: Eta bound states in nuclei: a probe of flavour-sin…
The optical potential for the $\eta$-meson is calculated. This is based on a new determination of a large $\eta$-N scattering length and recent experiments of $\eta$ production in two nucleon collisions. These determine the $\eta$ - nuclear…
The search for a quasi bound $\eta$ meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally.
The possible existence of \eta'-nucleus bound states has been put forward through theoretical and experimental studies. It is strongly related to the \eta' mass at finite density, which is expected to be reduced because of the interplay…
The existence of etamesic nuclei has been speculated for a long time without firm experimental evidence. Much of the effort has taken place in final state interactions on production. One crucial factor in seeing a quasibound state is its…
A microscopic treatment of $\eta$--nucleus scattering is presented. When applying the underlying exact integral equations, the excitation of the target are neglected, and an input $\eta N$ amplitude is chosen which reproduces the…
Eta-mesic nucleus or the quasibound nuclear state of an eta ($\eta$) meson in a nucleus is caused by strong-interaction force alone. This new type of nuclear species, which extends the landscape of nuclear physics, has been extensively…
The large values of the singlet and triplet scattering lengths locate the two-nucleon system close to the unitary limit, the limit in which these two values diverge. As a consequence, the system shows a continuous scale invariance which…
The isoscalar $\eta$ and $\eta'$ mesons are special in QCD, being linked both to chiral symmetry and to non-perturbative glue associated with the axial anomaly. The properties of these mesons in medium are sensitive to how these dynamics…
The role played by subthreshold meson-baryon dynamics is demonstrated in kaonic-atom, Kbar-nuclear and eta-nuclear bound-state calculations within in-medium models of Kbar-N and eta-N interactions. New analyses of kaonic atom data reveal…
We study the binding energy and the width of the $\Theta^+$ in nuclei, associated to the $K N$ and $ K \pi N$ components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind…
Masses and topological charges of the eta and eta' mesons are expressed in terms of the singlet-octet mixing angle theta. Contributions of the pseudoscalar 0- continuum are evaluated in a model independant way. Applications to the decay eta…
Using multiple scattering theory the scattering lengths of $\eta$ mesons on helium nuclei are calculated and checked against final state $\eta$ interactions from the $pd \rightarrow \eta ^3$He and $dd \rightarrow \eta ^4$He reactions. The…
The in-medium mass of the $\eta^{\prime}$ meson is discussed in a context of partial restoration of chiral symmetry in nuclear medium. The $\eta^{\prime}$ mass is expected to be reduced by order of 100 MeV at the saturation density. The…
The scattering lengths of eta-meson collisions with light nuclei d,t,3He, and 4He are calculated on the basis of few-body equations in coherent approximation. It is found that the eta-nucleus scattering length depends strongly on the number…
The \eta-meson collision with light nuclei, ^2H, ^3H, ^3He, and ^4He, is considered on the basis of a microscopic approach which utilises Faddeev type and Lippmann-Schwinger equations. The nuclear hamiltonian is approximated by the finite…
Back in the mid eighties, a new branch of investigation which was related to the interaction of eta mesons with nuclei came into existence. It started with the theoretical prediction of possible exotic states of eta mesons and nuclei bound…
The search for a quasi bound $\eta$ meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally. The theory starts from elastic $\eta$ nucleon scattering which is derived from production data…
The in-medium Eta-N interaction near and below threshold is constructed from a free-space chirally-inspired meson-baryon coupled-channel model that captures the physics of the N(1535) baryon resonance. Nucleon Pauli blocking and hadron…
The couplings of the eta and eta' mesons to the nucleon are obtained from the U_A(1) Goldberger-Treiman relation. The chiral symmetry breaking corrections are very large and bring the calculated values of the coupling constants G_etaNN and…
$\eta_c$-nucleus bound state energies are calculated for various nuclei. Essential input for the calculations, namely the medium-modified $D$ and $D^{*}$ meson masses, as well as the density distributions in nuclei, are calculated within…