Roca, L., Song, J., & Oset, E. (2024). Molecular pentaquarks with hidden charm and double strangeness. Phys. Rev. D, 109(9), 094005–8pp.
Abstract: We analyze theoretically the coupled-channel meson-baryon interaction with global flavor c<overline>cssn and c<overline>csss, where mesons are pseudoscalars or vectors, and baryons have JP = 1/2+ or 3/2+. The aim is to explore whether the nonlinear dynamics inherent in the unitarization process within coupled channels can dynamically generate double- and triple-strange pentaquark-type states (Pcss and Pcsss, respectively), for which there is no experimental evidence to date. We evaluate the s-wave scattering matrix by implementing unitarity in coupled channels, using potential kernels obtained from t-channel vector meson exchange. The required PPV and VVV vertices are obtained from Lagrangians derived through appropriate extensions of the local hidden gauge symmetry approach to the charm sector, while capitalizing on the symmetry of the spin and flavor wave function to evaluate the BBV vertex. We find four different poles in the double strange sector, some of them degenerate in spin. For the triple-strange channel, we find the meson-baryon interaction insufficient to generate a bound or resonance state through the unitary coupled-channel dynamics.
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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.
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Lin, J. X., Chen, H. X., Liang, W. H., Xiao, C. W., & Oset, E. (2024). (B)over-bars0 → Ds1(2460)+ K-, Ds1(2536)+ K- and the nature of the two Ds1 resonances. Eur. Phys. J. C, 84(4), 439–8pp.
Abstract: Starting from the molecular picture for the D-s1(2460) and D-s1(2536) resonances, which are dynamically generated by the interaction of coupled channels, the most important of which are the D* K for the D-s1(2460) and DK* for the D-s1(2536), we evaluate the ratio of decay widths for the (B) over bar (0)(s) -> D-s1(2460)(+) K- and (B) over bar (0)(s) -> D-s1(2536)(+) K- decays, the latter of which has been recently investigated by the LHCb collaboration, and we obtain a ratio of the order of unity. The present results should provide an incentive for the related decay into the D-s1(2460) resonance to be performed, which would provide valuable information on the nature of these two resonances.
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Ikeno, N., Liang, W. H., & Oset, E. (2024). Molecular nature of the Ωc(3120) and its analogy with the Ω(2012). Phys. Rev. D, 109(5), 054023–7pp.
Abstract: We make a study of the omega c(3120) , one of the five omega c states observed by the LHCb Collaboration, which is well reproduced as a molecular state from the Xi*cK over bar and omega*c17 channels mostly. The state with JP = 3/2- decays to Xi cK over bar in the D wave, and we include this decay channel in our approach, as well as the effect of the Xi*c width. With all these ingredients, we determine the fraction of the omega c(3120) width that goes into Xi cK over bar K , which could be a measure of the Xi*cK over bar molecular component, but due to a relatively big binding, compared to its analogous omega(2012) state, we find only a small fraction of about 3%, which makes this measurement difficult with present statistics. As an alternative, we evaluate the scattering length and effective range of the Xi*c K over bar and omega*c17 channels, which, together with the binding and width of the omega c(3120) state, could give us an answer to the issue of the compositeness of this state when these magnitudes are determined experimentally, something feasible nowadays, for instance, measuring correlation functions.
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Molina, R., Liu, Z. W., Geng, L. S., & Oset, E. (2024). Correlation function for the a0(980). Eur. Phys. J. C, 84(3), 328–8pp.
Abstract: We have conducted a model independent analysis of the (K+K0) pair correlation function obtained from ultra high energy pp collisions, with the aim of extracting the information encoded in it related to the KK interaction and the coupled channel pi(+)eta. With the present large errors at small relative (K+K0) momenta, we find that the information obtained about the scattering matrix suffers from large uncertainties. Even then, we are able to show that the data imply the existence of the a(0) resonance, a(0)(980), showing as a strong cusp close to the KK threshold. We also mention that the measurement of the pi(+)eta correlation function will be essential in order to constrain more the information on KK dynamics that can be obtained from correlation functions.
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