Liang, W. H., Chen, H. X., Oset, E., & Wang, E. (2019). Triangle singularity in the J/psi -> K+K- f(0)(980)(a(0)(980)) decays. Eur. Phys. J. C, 79(5), 411–11pp.
Abstract: We study the J/psi -> K+K- f(0)(980)(a(0)(980)) reaction and find that the mechanism to produce this decay develops a triangle singularity around M-inv(K- f(0)/K- a(0)) approximate to 1515 MeV. The differential width d Gamma/dM(inv)(K- f(0)/K- a(0)) shows a rapid growth around the invariant mass being 1515 MeV as a consequence of the triangle singularity of this mechanism, which is directly tied to the nature of the f(0)(980) and a(0)(980) as dynamically generated resonances from the interaction of pseudoscalar mesons. The branching ratios obtained for the J/psi -> K+K- f(0)(980)(a(0)(980)) decays are of the order of 10(-5), accessible in present facilities, and we argue that their observation should provide relevant information concerning the nature of the low-lying scalar mesons.
|
Liang, W. H., Bayar, M., & Oset, E. (2017). Lambda(b) -> pi(-)(D-S(-)) Lambda(C)(2595), pi(-)(D-S(-)) Lambda(C)(2625) decays and DN, D*N molecular components. Eur. Phys. J. C, 77(1), 39–9pp.
Abstract: From the perspective that Lambda(C)(2595) and Lambda(C)(2625) are dynamically generated resonances from the DN, D*N interaction and coupled channels, we have evaluated the rates for Lambda(b) -> pi(-)Lambda(C)(2595) and Lambda(b) -> pi(-)Lambda(C)(2625) up to a global unknown factor that allows us to calculate the ratio of rates and compare with experiment, where good agreement is found. Similarly, we can also make predictions for the ratio of rates of the, yet unknown, decays of Lambda(b) -> D-s(-)Lambda(C)(2595) and Lambda(b) -> D-s(-)Lambda(c)(2625) and make estimates for their individual branching fractions.
|
Liang, W. H., Ban, T., & Oset, E. (2024). B0 → K(*)0X, B- K(*) -X, Bs-η(η1;φ)X from the X(3872) molecular perspective. Phys. Rev. D, 109(5), 054030–9pp.
Abstract: We study the decays B over bar 0 – over bar K0X, B- – K-X, B over bar 0s – eta(eta 1)X, B over bar 0 – over bar K*0X, B- – K*-X, B over bar 0s – phi X, with X equivalent to X(3872), from the perspective of the X(3872) being a molecular state made from the interaction of the D*+D-; D*0 over bar D0, and c:c: components. We consider both the external and internal emission decay mechanisms and find an explanation for the over bar K0X and K-X production rates, based on the mass difference of the charged and neutral D*D over bar components. We also find that the internal and external emission mechanisms add constructively in the B over bar 0 – over bar K0X, B- – K-X reactions, while they add destructively in the case of widths of the present measurements and allows us to make predictions for the unmeasured modes of B over bar 0s – eta(eta 1)X(3872) and B- – K*-X(3872). The future measurement of these decay modes will help us get a better perspective on the nature of the X(3872) and the mechanisms present in production reactions of that state. B over bar 0 – over bar K*0X, B- – K*-X reactions. This feature explains the decay
|
Liang, W. H., Albaladejo, M., & Oset, E. (2013). Searching for a hidden charm h(1) state in the X(4660) -> eta h(1) and X(4660) -> eta D*(D)over-bar* decays. Phys. Rev. D, 88(7), 074027–7pp.
Abstract: We explore the possibility of experimentally detecting a predicted h(1) inverted right perpendicular I-G(J(PC)) = 0(-)(1(+-))inverted left perpendicular state of hidden charm made out from the D*(D) over bar* interaction. The method consists in measuring the decay of X(4660) into eta D*(D) over bar* and determining the binding energy with respect to the D*(D) over bar* threshold from the shape of the D*(D) over bar* invariant mass distribution. A complementary method consists in looking at the inclusive X(4660) -> eta X decay and searching for a peak in the X invariant mass distribution. We make calculations to determine the partial decay width of X(4660) -> eta h(1) from the measured X(4660) -> eta D*(D) over bar* distribution. This estimation should serve in an experiment to foresee the possibility of detecting the h(1) state on top of the background of inclusive events.
|
Li, J. T., Lin, J. X., Zhang, G. J., Liang, W. H., & Oset, E. (2022). The (B)over-bar(s)(0) -> J/psi pi(0)eta decay and the a(0)(980)- f(0)(980) mixing. Chin. Phys. C, 46(8), 083108–6pp.
Abstract: We study the (B) over bar (0)(s) -> J/psi f(0)(980) and (B) over bar (0)(s) -> J/psi a(0)(980) reactions, and pay attention to the different sources of isospin violation and mixing of f(0)(980) and a(0)(980) resonances where these resonances are dynamically generated from meson-meson interactions. We fmd that the main cause of isospin violation is isospin breaking in the meson-meson transition T matrices, and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of charged and neutral kaons. We obtain a branching ratio for a(0)(980) production of the order of 5 x 10(-6) . Future experiments can address this problem, and the production rate and shape of the pi(0)eta mass distribution will definitely help to better understand the nature of scalar resonances.
|
Li, H. P., Zhang, G. J., Liang, W. H., & Oset, E. (2023). Theoretical interpretation of the Ξ(1620) and Ξ(1690) resonances seen in Ξc+ → Ξ-π+π+ decay. Eur. Phys. J. C, 83(10), 954–7pp.
Abstract: We study the Belle reaction Xi(+)(c) -> Xi(-)pi(+)pi(+) looking at the mass distribution of pi(+)Xi, where clear signals for the Xi(1620) and Xi(1690) resonances are seen. These two resonances are generated dynamically from the interaction in coupled channels of pi Xi, (K) over bar Lambda, (K) over bar Xi and eta Xi within the chiral unitary approach. Yet, the weak decay process at the quark level, together with the hadronization to produce pairs of mesons, does not produce the pi pi Xi final state. In order to produce this state one must make transitions from the (K) over bar Lambda, (K) over bar Xi and eta Xi components to pi Xi, and this interaction is what produces the resonances. So, the reaction offers a good test for the molecular picture of these resonances. Adding the contribution of the Xi*(1530) and some background we are able to get a good reproduction of the mass distribution showing the signatures of the two resonances as found in the experiment.
|
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.
|
Kaskulov, M., Hernandez, E., & Oset, E. (2010). On the background in the gamma p -> omega(pi(0)gamma)p reaction and mixed event simulation. Eur. Phys. J. A, 46(2), 223–230.
Abstract: In this paper we evaluate sources of background of the gamma p -> omega p reaction, with the omega detected through its pi(0)gamma decay channel, to compare with the experiment carried out at ELSA. We find background from gamma p -> pi(0)pi(0)p followed by decay of a pi(0) into two gamma, recombining one pi(0) and one gamma, and from the gamma p -> pi(0)eta p reaction with subsequent decay of the eta into two photons. This background accounts for the data at pi(0)gamma invariant masses beyond 700 MeV, but strength is missing at lower invariant masses which was attributed to photon misidentification events, which we simulate to get a good reproduction of the experimental background. Once this is done, we perform an event mixing simulation to reproduce the calculated background and we find that the method provides a good description of the background. A closer look reveals this is accidental. We show that the mixed event generated background in the region of the omega mass and beyond is completely tied to the events at low pi(0)gamma invariant masses where the d sigma/dM(pi 0 gamma) distribution is much larger. This has as a consequence that the mixed event method produces the same background at high invariant masses independently of the actual background in that region, as a consequence of which, the method is unsuited to give the background at energies around the peak of the omega and beyond.
|
Kamiya, Y., Miyahara, K., Ohnishi, S., Ikeda, Y., Hyodo, T., Oset, E., et al. (2016). Antikaon-nucleon interaction and Lambda(1405) in chiral SU(3) dynamics. Nucl. Phys. A, 954, 41–57.
Abstract: The properties of the Lambda(1405) resonance are key ingredients for determining the antikaon-nucleon interaction in strangeness nuclear physics, and the novel internal structure of the Lambda(1405) is of great interest in hadron physics, as a prototype case of a baryon that does not fit into the simple three-quark picture. We show that a quantitative description of the antikaon-nucleon interaction with the Lambda(1405) is achieved in the framework of chiral SU(3) dynamics, with the help of recent experimental progress. Further constraints on the (K) over barN subthreshold interaction are provided by analyzing pi Sigma spectra in various processes, such as the K(-)d -> pi Sigma n reaction and the Lambda(c) -> pi pi Sigma decay. The structure of the Lambda(1405) is found to be dominated by an antikaon-nucleon molecular configuration, based on its wavefunction derived from a realistic (K) over barN potential and the compositeness criteria from a model-independent weak-binding relation.
|
Jido, D., Oset, E., & Sekihara, T. (2011). Kaon-induced Lambda(1405) production on a deuteron target at DAFNE. Eur. Phys. J. A, 47(3), 42–7pp.
Abstract: The K-- induced production of.(1405) in the K(-)d -> pi Sigma n reaction is investigated having in mind the conditions of the DAFNE facility at Frascati where kaons are obtained from the decay of slow-moving phi mesons. We find that the K(-)d -> Lambda(1405)n process favors the production of Lambda(1405) initiated by the K(-)p channel, which gives largest weight to the higher mass Lambda(1405) appearing at 1420MeV in chiral theories. We find that the fastest kaons from the decay of the phi are well suited to see this resonance, particularly if one selects forward going neutrons in the center of mass, which reduce the contribution of single scattering and make the double scattering dominate where the signal of the resonance appears clearer.
|
