|
|
Oset, E., Ramos, A., Garzon, E. J., Molina, R., Tolos, L., Xiao, C. W., et al. (2012). Interaction of vector mesons with baryons and nuclei. Int. J. Mod. Phys. E, 21(11), 1230011–18pp.
Abstract: After some short introductory remarks on particular issues on the vector mesons in nuclei, in this paper, we present a short review of recent developments concerning the interaction of vector mesons with baryons and with nuclei from a modern perspective using the local hidden gauge formalism for the interaction of vector mesons. We present results for the vector-baryon interaction and in particular for the resonances which appear as composite states, dynamically generated from the interaction of vector mesons with baryons, taking also the mixing of these states with pseudoscalars and baryons into account. We then venture into the charm sector, reporting on hidden charm baryon states around 4400 MeV, generated from the interaction of vector mesons and baryons with charm, which have a strong repercussion on the properties of the J/Psi N interaction. We also address the interaction of K* with nuclei and make suggestions to measure the predicted huge width in the medium by means of transparency ratio. The formalism is extended to study the phenomenon of J/psi suppression in nuclei via J/psi photo-production reactions.
|
|
|
|
Oset, E., Bayar, M., Dote, A., Hyodo, T., Khemchandani, K. P., Liang, W. H., et al. (2016). Two-, Three-, Many-body Systems Involving Mesons. Multimeson Condensates. Acta Phys. Pol. B, 47(2), 357–365.
Abstract: In this paper, we review results from studies with unconventional many-hadron systems containing mesons: systems with two mesons and one baryon, three mesons, some novel systems with two baryons and one meson, and finally, systems with many vector mesons, up to six, with their spins aligned forming states of increasing spin. We show that in many cases, one has experimental counterparts for the states found, while in some other cases, they remain as predictions, which we suggest to be searched in BESIII, Belle, LHCb, FAIR and other facilities.
|
|
|
|
Li, H. P., Yi, J. Y., Xiao, C. W., Yao, D. L., Liang, W. H., & Oset, E. (2024). Correlation function and the inverse problem in the BD interaction. Chin. Phys. C, 48(5), 053107–7pp.
Abstract: We study the correlation functions of the (BD+)-D-0, (B+D0) system, which develops a bound state of approximately 40MeV, using inputs consistent with the T-cc(3875) state. Then, we address the inverse problem starting from these correlation functions to determine the scattering observables related to the system, including the existence of the bound state and its molecular nature. The important output of the approach is the uncertainty with which these observables can be obtained, considering errors in the (BD+)-D-0, (B+D0) correlation functions typical of current values in correlation functions. We find that it is possible to obtain scattering lengths and effective ranges with relatively high precision and the existence of a bound state. Although the pole position is obtained with errors of the order of 50% of the binding energy, the molecular probability of the state is obtained with a very small error of the order of 6%. All these findings serve as motivation to perform such measurements in future runs of high energy hadron collisions.
|
|
|
|
Xiao, C. W., Aceti, F., & Bayar, M. (2013). The small K pi component in the K* wave functions. Eur. Phys. J. A, 49(2), 22–5pp.
Abstract: We use a recently developed formalism which generalizes Weinberg's compositeness condition to partial waves higher than s-wave in order to determine the probability of having a K pi component in the K* wave function. A fit is made to the K pi phase shifts in p-wave, from where the coupling of K* to K pi and the K pi loop function are determined. These ingredients allow us to determine that the K* is a genuine state, different from a K pi component, in a proportion of about 80%.
|
|
|
|
Xiao, C. W., & Oset, E. (2013). Three methods to detect the predicted D(D)over-bar scalar meson X(3700). Eur. Phys. J. A, 49(4), 52–6pp.
Abstract: In analogy to the f(0)(500), which appears as a pi pi resonance in chiral unitary theory, and the f(0)(980), which appears as a quasibound K (K) over bar state, the extension of this approach to the charm sector also predicts a quasibound D (D) over bar state with mass around 3720 MeV, named as X(3700), for which some experimental support is seen in the e(+)e(-) -> J/psi D (D) over bar reaction close to the D (D) over bar threshold. In the present work we propose three different experiments to observe it as a clear peak. The first one is the radiative decay of the psi(3770), psi(3770) -> gamma X(3700) -> gamma eta eta'. The second one proposes the analogous reaction psi(4040) -> gamma X(3700) -> gamma eta eta' and the third reaction is the e(+)e(-) -> J/psi X(3700) -> J/psi eta eta'. Neat peaks are predicted for all the reactions and the calculated rates are found within measurable range in present facilities.
|
|
|
|
Xiao, C. W., & Oset, E. (2013). Hidden beauty baryon states in the local hidden gauge approach with heavy quark spin symmetry. Eur. Phys. J. A, 49(11), 139–12pp.
Abstract: Using a coupled-channel unitary approach, combining the heavy quark spin symmetry and the dynamics of the local hidden gauge, we investigate the meson-baryon interaction with hidden beauty and obtain several new states of N around 11 GeV. We consider the basis of states eta (b) N, I'N, BI > (b) , BI pound (b) , B (*) I > (b) , B (*) I pound (b) , B (*) I pound (b) (*) and find four basic bound states which correspond to BI pound (b) , BI pound (b) (*) , B (*) I pound (b) and B (*) I pound (b) (*) , decaying mostly into eta (b) N and I'N and with a binding energy about 50-130 MeV with respect to the thresholds of the corresponding channel. All of them have isospin I = 1/2 , and we find no bound states or resonances in I = 3/2 . The BI pound (b) state appears in J = 1/2 , the BI pound (b) (*) in J = 3/2 , the B (*) I pound (b) appears nearly degenerate in J = 1/2 , 3/2 and the B (*) I pound (b) (*) appears nearly degenerate in J = 1/2 , 3/2, 5/2. These states have a width from 2-110 MeV, with conservative estimates of uncertainties, except for the one in J = 5/2 which has zero width since it cannot decay into any of the states of the basis chosen. We make generous estimates of the uncertainties and find that within very large margins these states appear bound.
|
|
|
|
Bayar, M., Liang, W. H., Uchino, T., & Xiao, C. W. (2014). Description of rho(1700) as a rho Kappa(sic) system with the fixed-center approximation. Eur. Phys. J. A, 50(4), 67–10pp.
Abstract: We study the system with the aim to describe the rho(1700) resonance. The chiral unitary approach has achieved success in the description of systems of the light hadron sector. With this method, the system in the isospin sector I = 0, is found to be a dominant component of the f (0)(980) resonance. Therefore, by regarding the system as a cluster, the f (0)(980) resonance, we evaluate the system applying the fixed-center approximation to the Faddeev equations. We construct the rho K unitarized amplitude using the chiral unitary approach. As a result, we find a peak in the three-body amplitude around 1732 MeV and a width of about 161 MeV. The effect of the width of the rho and f (0)(980) is also discussed. We associate this peak to the rho(1700) which has a mass of 1720 +/- 20MeV and a width of 250 +/- 100 MeV.
|
|
|
|
Liang, W. H., Uchino, T., Xiao, C. W., & Oset, E. (2015). Baryon states with open charm in the extended local hidden gauge approach. Eur. Phys. J. A, 51(2), 16–14pp.
Abstract: In this paper we examine the interaction of DN and D* N states, together with their coupled channels, by using an extension of the local hidden gauge formalism from the light meson sector, which is based on heavy quark spin symmetry. The scheme is based on the use of the impulse approximation at the quark level, with the heavy quarks acting as spectators, which occurs for the dominant terms where there is the exchange of a light meson. The pion exchange and the Weinberg-Tomozawa interactions are generalized and with this dynamics we look for states generated from the interaction, with a unitary coupled channels approach that mixes the pseudoscalar-baryon and vector-baryon states. We find two states with nearly zero width, which are associated to the I > (c) (2595) and I > (c) (2625). The lower state, with J (P) = 1/2(-), couples to DN and D* N, and the second one, with J (P) = 3/2(-), to D* N. In addition to these two I > (c) states, we find four more states with I = 0, one of them nearly degenerate in two states of J (P) = 1/2, 3/2. Furthermore we find three states in I = 1, two of them degenerate in J = 1/2, 3/2.
|
|
|
|
Holz, S., Plenter, J., Xiao, C. W., Dato, T., Hanhart, C., Kubis, B., et al. (2021). Towards an improved understanding of eta -> gamma*gamma *. Eur. Phys. J. C, 81(11), 1002–15pp.
Abstract: We argue that high-quality data on the reaction e(+)e(-) -> pi(+) pi(-) eta will allow one to determine the doubly-virtual form factor eta -> gamma*gamma* in a model-independent way with controlled accuracy. This is an important step towards a reliable evaluation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of themuon. When analyzing the existing data for e(+) e(-) -> pi(+) pi(-) eta for total energies squared k(2) > 1GeV(2), we demonstrate that the effect of the a(2) meson provides a natural breaking mechanism for the commonly employed factorization ansatz in the doubly-virtual form factor F-eta gamma*gamma* (q(2), k(2)). However, better data are needed to draw firm conclusions.
|
|
|
|
Xiao, C. W., Bayar, M., & Oset, E. (2011). NDK, (K)over-barDN, and ND(K)over-bar molecules. Phys. Rev. D, 84(3), 034037–8pp.
Abstract: We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, (D) over tilde, K, or (K) over tilde. The systems are studied using the fixed center approximation to the Faddeev equations. The study is made assuming scattering of a K or a (K) over tilde on a DN cluster, which is known to generate the Lambda(c)(2595), or the scattering of a nucleon on the D (D) over tilde cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of N on the KD cluster, which is known to generate the D*(s0)(2317). In all cases we find bound states, with the NDK system, of exotic nature, more bound than the (K) over tilde DN.
|
|
