Formation of Slow Heavy Mesons in Nuclei

Abstract We study ϕ meson production in the C 12 ( p ¯ , ϕ ) reaction at p p ¯ = 1.3 GeV/c . We also discuss the interest in and the difficulties of studying heavy meson-nucleus systems.

Branching ratios of mesonic and nonmesonic antikaon absorptions in nuclear medium

The branching ratios of K^- absorption at rest in nuclear matter are theoretically investigated in order to understand the mechanism of K^- absorption into nuclei. For this purpose mesonic and nonmesonic absorption potentials are evaluated as functions of nuclear density, the kaon momentum and energy from one- and two-body K^- self-energy, respectively. By using a chiral unitary approach for the s-wave Kbar N amplitude we find that both the mesonic and nonmesonic absorption potentials are dominated by the Lambda(1405) contributions. The fraction of the mesonic and nonmesonic absorptions are evaluated to be respectively about 70% and 30% at the saturation density almost independently on the …

Proton emission off nuclei induced by kaons in flight

We study the (K-, p) reaction on nuclei with a 1 GeV/c momentum kaon beam, paying special attention to the region of emitted protons having kinetic energy above 600 MeV, which was used to claim a deeply attractive kaon nucleus optical potential. Our model describes the nuclear reaction in the framework of a local density approach and the calculations are performed following two different procedures: one is based on a many-body method using the Lindhard function and the other is based on a Monte Carlo simulation. The simulation method offers flexibility to account for processes other than kaon quasielastic scattering, such as K- absorption by one and two nucleons, producing hyperons, and all…

Formation of Meson Nucleus Systems

Couplings in coupled channels versus wave functions in the case of resonances: application to the two $\Lambda(1405)$ states

In this paper we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on shell approach for the scattering matrix, commonly used, is also obtained in Quantum Mechanics with a separable potential, which allows one to write wave functions in a trivial way. We develop useful relationships among the couplings of the dynamically generated resonances to the different channels and the wave functions at the origin. The formalism provides an intuitive picture of the resonances in the coupled channel approach, as bound states of one bound channel, which decays into open ones. It also pr…

Selected topics on Hadrons in Nuclei

In this talk we report on selected topics on hadrons in nuclei. The first topic is the renormalization of the width of the $\Lambda(1520)$ in a nuclear medium. This is followed by a short update of the situation of the $\omega$ in the medium. The investigation of the properties of $\bar{K}$ in the nuclear medium from the study of the $(K_{flight},p)$ reaction is also addressed, as well as properties of X,Y,Z charmed and hidden charm resonances in a nuclear medium. Finally we address the novel issue of multimeson states.

Formation of phi Mesic Nuclei

We study the structure and formation of the $\phi$ mesic nuclei to investigate the in-medium modification of the $\phi$-meson spectral function at finite density. We consider (${\bar p},\phi$), ($\gamma,p$) and ($\pi^-,n$) reactions to produce a $\phi$-meson inside the nucleus and evaluate the effects of its medium modifications to the reaction cross sections. We also estimate the consequences of the uncertainties of the ${\bar K}$ selfenergy in medium to the $\phi$-nucleus interaction. We find that it may be possible to see a peak structure in the reaction spectra for the strong attractive potential cases. On the other hand, for strong absorptive interaction cases with relatively weak attr…

The (K-, p) reaction on nuclei with in-flight kaons

10th International Conference on Hypernuclear and Strange Particle Physics. Tokai, JAPAN, SEP 14-18, 2009

Couplings in coupled channels versus wave functions in the case of resonances: Application to the twoΛ(1405)states

In this paper we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on-shell approach for the scattering matrix, commonly used, is also obtained in quantum mechanics with a separable potential, which allows one to write wave functions in a trivial way. We develop useful relationships among the couplings of the dynamically generated resonances to the different channels and the wave functions at the origin. The formalism provides an intuitive picture of the resonances in the coupled channel approach, as bound states of one bound channel, which decays into open ones. It also pr…

The (K-,p) reaction on C12 at KEK

We study the (K-,p) reaction on C12 with a kaon beam of 1 GeV momentum, paying a special attention to the region of emitted protons having kinetic energy above 600 MeV, which was used to claim a deep kaon nucleus optical potential [1]. The experiment looks for fast protons emitted from the absorption of in flight kaons by nuclei, but in coincidence with at least one charged particle in the decay counters sandwiching the target. The analysis of the data is done in [1] assuming that the coincidence requirement does not change the shape of the final spectra. However our detailed calculations show that this assumption doesn't hold, and, thus, the final conclusion of this experiment is doubtful.…

Latest Results for the Antikaon-Nucleon Optical Potential

The key question of this letter is whether the K-nucleus optical potential is deep, as it is prefered by the phenomenological fits to kaonic atoms data, or shallow, as it comes out from unitary chiral model calculations. The current experimental situation is reviewed.

Wave functions for dynamically generated resonances; the two $\Lambda(1405)$ and $\Lambda(1670)$

In this work we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on shell approach for the scattering matrix, commonly used, is also obtained in Quantum Mechanics with a separable potential, which allows one to write wave functions in a trivial way. We develop useful relationships among the couplings of the dynamically generated resonances to the different channels and the wave functions at the origin. The formalism provides an intuitive picture of the resonances in the coupled channel approach, as bound states of one bound channel, which decays into open ones. It also pro…

Precision Spectroscopy of Deeply Bound Pionic Atoms and Partial Restoration of Chiral Symmetry in Medium

We study theoretically the formation spectra of deeply bound pionic atoms expected to be observed by experiments with high energy resolution at RIBF/RIKEN, and we discuss in detail the possibilities to extract new information on the pion properties at finite density from the observed spectra, which may provide information on partial restoration of chiral symmetry in medium. We find that the non-yrast pionic states such as 2s are expected to be seen in the (d,3He) spectra, which will be helpful to reduce uncertainties of the theoretical calculations in the neutron wave functions in nucleus. The observation of the 2s state with the ground 1s state is also helpful to reduce the experimental un…

Formation of Heavy Meson Bound States by Two Nucleon Pick-up Reactions

We develop a model to evaluate the formation rate of the heavy mesic nuclei in the two nucleon pick-up reactions, and apply it to the $^6$Li target cases for the formation of heavy meson-$\alpha$ bound states, as examples. The existence of the quasi-deuteron in the target nucleus is assumed in this model. It is found that the mesic nuclei formation in the recoilless kinematics is possible even for heavier mesons than nucleon in the two nucleon pick-up reactions. We find the formation rate of the meson-$\alpha$ bound states can be around half of the elementary cross sections at the recoilless kinematics with small distortions.

V P gamma radiative decay of resonances dynamically generated from the vector meson-vector meson interaction

We evaluate the radiative decay into a vector, a pseudoscalar and a photon of several resonances dynamically generated from the vector-vector interaction. The process proceeds via the decay of one of the vector components into a pseudoscalar and a photon, which have an invariant mass distribution very different from phase space as a consequence of the two vector structure of the resonances. Experimental work along these lines should provide useful information on the nature of these resonances.

$VP��$ radiative decay of resonances dynamically generated from the vector meson-vector meson interaction

We evaluate the radiative decay into a vector a pseudoscalar and a photon of several resonances dynamically generated from the vector vector interaction. The process proceeds via the decay of one of the vector components into a pseudoscalar and a photon, which have an invariant mass distribution very different from phase space as a consequence of the two vector structure of the resonances. Experimental work along these lines should provide useful information on the nature of these resonances.

Nature of the K-2*(1430), K-3*(1780), K-4*(2045), K-5*(2380), and K-6* as K*-multi-rho states

We show that the K-2*(1430), K-3*(1780), K-4*(2045), K-5*(2380), and a not-yet-discovered K-6* resonance are basically molecules made of an increasing number of rho(770) and one K*(892) mesons. The idea relies on the fact that the vector-vector interaction in the s wave with spins aligned is very strong for both rho rho and K*rho. We extend a recent work, where several resonances showed up as multi-rho(770) molecules, to the strange sector including the K*(892) into the system. The resonant structures show up in the multibody scattering amplitudes, which are evaluated in terms of the unitary two-body vector-vector scattering amplitudes by using the fixed center approximation to the Faddeev …