The energies and widths of several D^0 meson bound states for different nuclei are obtained using a D-meson selfenergy in the nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized coupled-channel theory. The kernel of the meson-baryon interaction is based on a model that treats heavy pseudoscalar and heavy vector mesons on equal footing, as required by heavy quark symmetry. We find D^0 bound states in all studied nuclei, from 12C up to 208Pb. The inclusion of vector mesons is the keystone for obtaining an attractive D-nucleus interaction that leads to the existence of D^0-nucleus bound states, as compared to previous studies based on SU(4) flavor symmetry. In some cases, the half widths are smaller than the separation of the levels, what makes possible their experimental observation by means of a nuclear reaction. This can be of particular interest for the future PANDA@FAIR physics program. We also find a D^+ bound state in 12C, but it is too broad and will have a significant overlap with the energies of the continuum.
In this paper the search for eta-mesic nuclei with particular focus on light $η$-He bound states is reviewed. A brief description of recent theoretical studies and experimental results is presented.
The binding system of a hadron and a nucleus is a topic of great interest for investigating the hadron properties. In the heavy-flavor region, the attraction between a $P(=\bar{D},B)$ meson and a nucleon $N$ can appear, where the $PN-P^\ast N$ mixing plays an important role in relation to the heavy-quark spin symmetry. The attraction can produce exotic heavy mesic nuclei that are stable against the strong decay. We study an exotic system where the $\bar{D}$ ($B$) meson and nucleus are bound. The meson-nucleus interaction is given by a folding potential with single-channel $PN$ interaction and …
There is much speculation and a modest amount of evidence that certain mesons might form quasi-bound states with nuclei to produce really exotic states of matter. For this to be a practical possibility, the interaction between the meson and nucleons at low energies must be strong and attractive and the production rates "healthy". The conditions for this are surveyed for the light mesons. How this might lead to quasi-bound states is then discussed in a few typical cases.
Eta-mesic nucleus or the quasibound nuclear state of an eta ($η$) 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 studied since its prediction in 1986. In this paper, we review and analyze in great detail the models of the fundamental $η$--nucleon interaction leading to the formation of an $η$--mesic nucleus, the methods used in calculating the properties of a bound $η$, and the approaches employed in the interpretation of the pertinent experimental data. In view of the succes…
Even if the theoretical definition of an unstable state is straightforward, its experimental identification often depends on the method used in the analysis and extraction of data. A good example is the case of eta mesic nuclei where strong hints of their existence led to about three decades of extensive theoretical and experimental searches. Considering the still undecided status of these states and the limitations in the understanding of the eta-nucleon as well as the eta-nucleus interaction, the present article tries to look back at some unresolved problems in the production mechanism and f…
Macroscopic study of $ϕ$-mesic nuclei in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the PACIAE model
Central China Normal University（华中师范大学）；Wuhan Textile University（武汉纺织大学）；Guizhou Normal University（贵州师范大学）；Shaanxi Normal University（陕西师范大学）；Sichuan University（四川大学）；China Institute of Atomic Energy（中国原子能科学研究院）；Nanjing University of Aeronautics and Astronautics（南京航空航天大学）
We investigate the structure and formation of charmed meson--nucleus systems, with the aim of understanding the charmed meson--nucleon interactions and the properties of the charmed mesons in the nuclear medium. The $\bar{D}$ mesic nuclei are of special interest, since they have tiny decay widths due to the absence of strong decays for the $\bar{D} N$ pair. Employing an effective model for the $\bar{D} N$ and $D N$ interactions and solving the Klein--Gordon equation for $\bar{D}$ and $D$ in finite nuclei, we find that the $D^{-}$-${}^{11}\rm{B}$ system has $1 s$ and $2p$ mesic nuclear states a…
Feasibility of the observation of $η^{\prime}$ mesic nuclei in the semi-exclusive $^{12}$C($p, dp$) reaction
Tottori University（鸟取大学）；Graduate School of Maritime Sciences, Kobe University（神户大学海事科学研究生院）；Department of Physics, Nara Women’s University（奈良女子大学物理系）；Department of Physics, School of Science, Institute of Science Tokyo（东京科学大学理学院物理系）；RIKEN Nishina Center for Accelerator-Based Science, RIKEN（RIKEN西村加速器科学中心）；RIKEN Cluster for Pioneering Research, RIKEN（RIKEN先锋研究集群）；Department of Physics, The University of Osaka（大阪大学物理系）；Department of Physics, Kyoto University（京都大学物理系）；Department of Physics, Kyoto Sangyo University（京都产业大学物理系）；Universität Giessen（吉森大学）
The isoscalar $η$ and $η'$ 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 work in the nuclear environment. In contrast to pionic and kaonic atoms which are mainly bound by the Coulomb interaction with some corrections due to the strong force (Coulomb assisted binding), the $η$ and $η'$ as neutral mesons can only be bound by the strong interaction. Is this interaction strong enough? This topic has inspired a vigorous program of experiments…
In this contribution we report on theoretical studies of $η$ nuclear quasi-bound states in few- and many-body systems performed recently by the Jerusalem-Prague Collaboration [1-5]. Underlying energy-dependent $ηN$ 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 subthreshold $ηN$ amplitudes is discussed. Quite large downward energy shift together with rapid decrease of the $ηN$ amplitudes below threshold result in relatively small binding energies and widths of the calculat…
Study of light $ϕ$-mesic nuclei with HAL QCD $ϕN$ interactions
North Carolina Central University（北卡罗来纳中央大学）；New York City College of Technology, The City University of New York（纽约市立学院技术学院，纽约市立大学）；The Graduate School and University Center, The City University of New York（研究生院和大学中心，纽约市立大学）；Long Island University（长岛大学）
The $η$ mesic nucleus is considered to be one of the interesting exotic many body systems and has been studied since 1980's theoretically and experimentally. Recently, the formation of the $η$ mesic nucleus in the fusion reactions of the light nuclei such as $d + d \rightarrow (η+ α) \rightarrow X$ has been proposed and the experiments have been performed by WASA-at-COSY. We develop a theoretical model to evaluate the formation rate of the $η$ mesic nucleus in the fusion reactions and show the calculated results. We find that the $η$ bound states could be observed in the reactions in cases wit…
We have investigated the 6Li(gamma,d) reaction theoretically for the formation of the eta'(958) mesic nucleus close to the recoilless kinematics. We have developed the theoretical formula and reported the quantitative results of the formation spectra for various cases in this article. We have found that the formation cross sections are reduced by the effects of the fragile deuteron form factor.
Excitation-energy spectra of $^{11}$C nuclei near the $η^\prime$-meson production threshold have been measured by missing-mass spectroscopy using the $^{12}$C($p$,$d$) reaction. A carbon target has been irradiated with a 2.5 GeV proton beam supplied by the synchrotron SIS-18 at GSI to produce $η^\prime$ meson bound states in $^{11}$C nuclei. Deuterons emitted at $0^\circ$ in the reaction have been momentum-analyzed by the fragment separator (FRS) used as a high-resolution spectrometer. No distinct structure due to the formation of $η^\prime$-mesic states is observed although a high statistical…
Recent results for the $η_c$- and $J/ψ$-nucleus bound state energies for various nuclei are presented. The attractive potentials for the $η_c$ and $J/ψ$ mesons in the nuclear medium originate, respectively, from the in-medium enhanced $DD^{*}$ and $D\bar{D}$ loops in the $η_c$ and $J/ψ$ self energies. Our results suggest that the $η_c$ and $J/ψ$ mesons should form bound states with all the nuclei considered.
Heavy mesons in nuclear matter and nuclei are analyzed within different frameworks, paying a special attention to unitarized coupled-channel approaches. Possible experimental signatures of the properties of these mesons in matter are addressed, in particular in connection with the future FAIR facility at GSI.
The present status in the field of strange mesons in nuclei and neutron stars is reviewed. In particular, the $\bar K N$ interaction, that is governed by the presence of the $Λ(1405)$, is analyzed and the formation of the $\bar K NN$ bound state is discussed. Moreover, the properties of $\bar K$ in dense nuclear matter are studied, in connection with strangeness production in nuclear collisions and kaon condensation in neutron stars.
