2,490 research outputs found

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

    Get PDF
    We show that the K2(1430)K^*_2(1430), K3(1780)K^*_3(1780), K4(2045)K^*_4(2045), K5(2380)K^*_5(2380) and a not yet discovered K6K_6^* resonance are basically molecules made of an increasing number of ρ(770)\rho(770) and one K(892)K^*(892) mesons. The idea relies on the fact that the vector-vector interaction in s-wave with spins aligned is very strong both for ρρ\rho\rho and KρK^*\rho. We extend a recent work, where several resonances showed up as multi-ρ(770)\rho(770) molecules, to the strange sector including the K(892)K^*(892) into the system. The resonant structures show up in the multi-body 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 equations

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

    Get PDF
    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 provides an insight and practical rules for evaluating couplings of the resonances to external sources and how to deal with final state interaction in production processes. As an application of the formalism we evaluate the wave functions of the two Λ(1405)\Lambda(1405) states in the πΣ\pi \Sigma, KˉN\bar{K} N and other coupled channels.Comment: 23 pages, 3 figures. v2: Added a section to calculate form factor

    Formation of ϕ\phi mesic nuclei

    Full text link
    We study the structure and formation of the ϕ\phi mesic nuclei to investigate the in-medium modification of the ϕ\phi-meson spectral function at finite density. We consider (pˉ,ϕ{\bar p},\phi), (γ,p\gamma,p) and (π,n\pi^-,n) reactions to produce a ϕ\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 Kˉ{\bar K} selfenergy in medium to the ϕ\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 attractions, it is very difficult to observe clear peaks and we may need to know the spectrum shape in a wide energy region to deduce the properties of ϕ\phi.Comment: 11 pages, 8 figure

    In--Flight (K,pK^-,p) Reactions for the Formation of Kaonic Atoms and Kaonic Nuclei in Green function method

    Full text link
    We study theoretically the kaonic atom and kaonic nucleus formations in the in--flight (K,pK^-,p) reactions using the Green function method, which is suited to evaluate formation rates both of stable and unstable bound systems. We consider 12^{12}C and 16^{16}O as the targets and calculate the spectra of the (K,pK^-,p) reactions. We conclude that a no peak structure due to kaonic nucleus formation is expected in the reaction spectra calculated with the chiral unitary kaon--nucleus optical potential. In the spectra with the phenomenological deep kaon--nucleus potential, we may have possibilities to observe some structures due to kaonic nucleus states. For all cases, we have peaks due to the kaonic atom formations in the reaction spectra.Comment: 10 pages, 9 figures, newly calculated results added, revisions and updated references, to appear in Physical Review

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

    Full text link
    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 6^6Li target cases for the formation of heavy meson-α\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-α\alpha bound states can be around half of the elementary cross sections at the recoilless kinematics with small distortions.Comment: 1 table, 10 figures, 8 page

    Experimental status of deeply bound kaonic states in nuclei

    Full text link
    We review recent claims of the existence of deeply bound kaonic states in nuclei. Also we study in details the (K-,p) reaction on C12 with 1 GeV/c momentum kaon beam, based on which a deep kaon nucleus optical potential was claimed in [1]. In our Monte Carlo simulation of this reaction we include not only the quasi-elastic K- p scattering, as in [1], but also K- absorption by one and two nucleons followed by the decay of the hyperon in pi N, which can also produce strength in the region of interest. The final state interactions in terms of multiple scattering of the K-, p and all other primary particles on their way out of the nucleus is also considered. We will show that all these additional mechanisms allow us to explain the observed spectrum with a "standard" shallow kaon nucleus optical potential obtained in chiral models. [1] T. Kishimoto et al., Prog. Theor. Phys. 118, 181 (2007).Comment: 5 pages, 3 figures. To be published in the Proceedings of the International Workshop on Chiral Symmetry in Hadrons and Nuclei (Chiral10), Valencia, Spain, June 21-24, 201

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

    Get PDF
    We perform a theoretical study of the spectrum of protons with kinetic energies of around 600 MeV, emitted following the interaction of 1 GeV/c kaons with nuclei. A recent experimental analysis of this (K-,p) reaction on 12C, based on the dominant quasielastic process, has suggested a deeply attractive kaon nucleus potential. Our Monte Carlo simulation considers, in addition, the one-and two-nucleon K- absorption processes producing hyperons that decay into \pi N pairs. We find that this kaon in-flight reaction is not well suited to determine the kaon optical potential due, essentially, to the limited sensitivity of the cross section to its strength, but also to unavoidable uncertainties from the coincidence requirement applied in the experiment. A shallow kaon nucleus optical potential obtained in chiral models is perfectly compatible with the observed spectrum.Comment: To appear in the proceedings of the 10th International Conference on Hypernuclear and Strange Particle Physics, Tokai, Ibaraki (Japan), 14-18 September, 200
    corecore