Liang, W. H., Xie, J. J., & Oset, E. (2015). (B)over-bar(0) decay into D-0 and f(0)(500), f(0)(980), a(0)(980), rho and (B)over-bar(s)(0) decay into D-0 and kappa(800), K*(0). Phys. Rev. D, 92(3), 034008–9pp.
Abstract: We make predictions for ratios of branching fractions of (B) over bar (0) decays into D-0 and the scalar mesons f(0)(500), f(0)(980), a(0)(980), plus (B) over bar (0)(s) decay into D-0 and kappa(800). We also compare the pi(+)pi(-) production in the scalar channel with that observed in the rho channel and make predictions for the (B) over bar (0)(s) decay into D-0 and K*(892), comparing the strength of this channel with that of kappa(800) production. The work is based on results of the chiral unitary approach where the scalar resonances are generated from the pseudoscalar-pseudoscalar interaction. Up to an arbitrary normalization, the mass distributions and rates for decays into the scalar resonances are predicted with no free parameters. Comparison with experimental data is done when available.
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Xie, J. J., & Oset, E. (2015). Photoproduction of the f(2)(1270) resonance. Eur. Phys. J. A, 51(9), 111–7pp.
Abstract: We have performed a calculation of the gamma(p) -> pi(+) p-p reaction, where the two pions have been separated in D-wave producing the f(2)(1270) resonance. We use elements of the local hidden gauge approach that provides the interaction of vector mesons in which the f(2)(1270) resonance appears as rho-rho. molecular state in L = 0 and spin 2. The vector meson dominance, incorporated in the local hidden gauge approach converts a photon into a rho(0) meson and the other meson connects the photon with the proton. The picture is simple and has no free parameters, since the parameters of the theory have been constrained in the previous study of the vector-vector states. In a second step we introduce new elements, not present in the local hidden gauge approach, adapting the rho propagator to Regge phenomenology and introducing the rho NN tensor coupling. We find that both the differential cross section as well as the t dependence of the cross section are in good agreement with the experimental results and provide support for the molecular picture of the f(2)(1270) resonance in the first baryonic reaction where it has been tested.
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Xie, J. J., & Oset, E. (2014). (B)over-bar(0) and (B)over-bar(s)(0) decays into J/psi and f(0)(1370), f(0)(1710), f(2)(1270), f(2)'(1525), K-2*(1430). Phys. Rev. D, 90(9), 094006–7pp.
Abstract: We make predictions for the ratios of branching fractions of (B) over bar (0) and (B) over bar (0)(s) decays into J/psi and the scalar mesons f(0)(1370), f(0)(1710) or tensor mesons f(2)(1270), f(2)'(1525), K-2*(1430). The theoretical approach is based on results of chiral unitary theory where these resonances are shown to be generated from the vector meson-vector meson interaction. Eight independent ratios can be predicted, and comparison is made with the recent data on (B) over bar (0)(s) decay into J/psi f(2)'(1525) versus the (B) over bar (0)(s) decay into J/psi f(2)(1270).
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Xie, J. J., Dai, L. R., & Oset, E. (2015). The low lying scalar resonances in the D-0 decays into K-s(0) and f(0)(500), f(0)(980), a(0)(980). Phys. Lett. B, 742, 363–369.
Abstract: The D-0 decay into K-s(0) and a scalar resonance, f(0)(500), f(0)(980), a(0)(980), are studied obtaining the scalar resonances from final state interaction of a pair of mesons produced in a first step in the D-0 decay into K-s(0) and the pair of pseudoscalar mesons. This weak decay is very appropriate for this kind of study because it allows to produce the three resonances in the same decay in a process that is Cabibbo-allowed, hence the rates obtained are large compared to those of (B) over bar (0) decays into J/psi and a scalar meson that have at least one Cabibbo-suppressedvertex. Concretely the a(0)(980) production is Cabibbo-allowedhere, while it cannot be seen in the (B) over bar (0)(s) decay into J/psi a(0)(980) and is doubly Cabibbo-suppressedin the (B) over bar (0) decay into J/psi a(0)(980) and has not been identified there. The fact that the three resonances can be seen in the same reaction, because there is no isospin conservation in the weak decays, offers a unique opportunity to test the ideas of the chiral unitary approach where these resonances are produced from the interaction of pairs of pseudoscalar mesons.
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Wang, E., Xie, J. J., & Nieves, J. (2014). Regge signatures from forward CLAS Lambda(1520) photoproduction data. Phys. Rev. C, 90(6), 065203–10pp.
Abstract: The γp→K+Λ(1520) reaction mechanism is investigated within a Regge--effective Lagrangian hybrid approach based on our previous study of this reaction [Physical Review C89, 015203 (2014)]. Near threshold and for large K+ angles, both the CLAS and LEPS data can be successfully described by considering the contributions from the contact, t-channel K¯ exchange, u-channel Λ(1115) hyperon pole, and the s-channel nucleon pole and N∗(2120) resonance contributions. However, for higher energies and forward K+ angles, systematic discrepancies with data appear, which hint the possible existence of sizable quark-gluon string mechanism effects. We show how the inclusion of a K¯ Regge--trajectory exchange in the t-channel leads to an efficient description of the Λ(1520) photoproduction channel over the whole energy and angular ranges accessible in the CLAS experiment.
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