Xie, J. J., Martinez Torres, A., Oset, E., & Gonzalez, P. (2011). Plausible explanation for the Delta(5/2)+(2000) puzzle. Phys. Rev. C, 83(5), 055204–11pp.
Abstract: From a Faddeev calculation for the pi-(Delta rho)(N5/2)-(1675) system we show the plausible existence of three dynamically generated I (J(P)) = 3/2(5/2(+)) baryon states below 2.3 GeV, whereas only two resonances, Delta(5/2)+ (1905)( ) and Delta(5/2)+(2000)(**), are cataloged in the Particle Data Book Review. Our results give theoretical support to data analyses extracting two distinctive resonances, Lambda(5/2)+(similar to 1740) and Lambda(5/2)+(similar to 2200), from which the mass of Delta(5/2)+ (2000) is estimated. We propose that these two resonances should be cataloged instead of Delta(5/2)+(2000). This proposal gets further support from the possible assignment of the other baryon states found in the approach in the I = 1/2, 3/2 with J(P) = 1/2(+), 3/2(+), 5/(2)+ sectors to known baryonic resonances. In particular, Delta(1/2)+(1750)(*) is naturally interpreted as a pi N-1/2-(1650) bound state.
|
Pavon Valderrama, M., Xie, J. J., & Nieves, J. (2012). Are there three Xi (1950) states? Phys. Rev. D, 85(1), 017502–5pp.
Abstract: Different experiments on hadron spectroscopy have long suspected the existence of several cascade states in the 1900-2000 MeV region. They are usually labeled under the common name of Xi (1950). As we argue here, there are also theoretical reasons supporting the idea of several Xi (1950) resonances. In particular, we propose the existence of three Xi (1950) states: one of these states would be part of a spinparity 1/2(-) decuplet and the other two probably would belong to the 5/2(+) and 5/2(-) octets. We also identify which decay channels are more appropriate for the detection of each of the previous states.
|
Liu, B. C., & Xie, J. J. (2012). The K- p -> eta Lambda reaction in an effective Lagrangian model. Phys. Rev. C, 85(3), 038201–4pp.
Abstract: We report on a theoretical study of the K- p -> eta Lambda reaction near threshold by using an effective Lagrangian approach. The role of s-channel Lambda(1670), t-channel K*, and u-channel proton pole diagrams are considered. We show that the total cross section data are well reproduced. However, only including the s-wave Lambda(1670) state and the background contribution from t and u channels is not enough to describe the bowl structures in the angular distribution of the K- p -> eta Lambda reaction, which indicates that there should be higher partial waves contributing to this reaction in some energy region. Indeed, if we considered the contributions from a D-03 resonance, we could describe the bowl structures; however, a rather small width (similar to 2 MeV) of this resonance would be needed.
|
Xie, J. J., & Oset, E. (2012). The DN, pi Sigma(c) interaction in finite volume and the Lambda(c)(2595) resonance. Eur. Phys. J. A, 48(10), 146–10pp.
Abstract: In this work the interaction of the coupled channels DN and pi Sigma(c) in an SU(4) extrapolation of the chiral unitary theory, where the Lambda(c)(2595) resonance appears as dynamically generated from that interaction, is extended to produce results in finite volume. Energy levels in the finite box are evaluated and, assuming that they would correspond to lattice results, the inverse problem of determining the phase shifts in the infinite volume from the lattice results is solved. We observe that it is possible to obtain accurate pi Sigma(c) phase shifts and the position of the Lambda(c)(2595) resonance, but it requires the explicit consideration of the two coupled channels. We also observe that some of the energy levels in the box are attached to the closed DN channel, such that their use to induce the pi Sigma(c) phase shifts via Luscher's formula leads to incorrect results.
|
Garcia-Recio, C., Geng, L. S., Nieves, J., Salcedo, L. L., Wang, E., & Xie, J. J. (2013). Low-lying even parity meson resonances and spin-flavor symmetry revisited. Phys. Rev. D, 87(9), 096006–18pp.
Abstract: We review and extend the model derived in Garcia-Recio et al. [Phys. Rev. D 83, 016007 (2011)] to address the dynamics of the low-lying even-parity meson resonances. This model is based on a coupled-channels spin-flavor extension of the chiralWeinberg-Tomozawa Lagrangian. This interaction is then used to study the S-wave meson-meson scattering involving members not only of the pi octet, but also of the rho nonet. In this work, we study in detail the structure of the SU(6)-symmetry-breaking contact terms that respect (or softly break) chiral symmetry. We derive the most general local (without involving derivatives) terms consistent with the chiral-symmetry-breaking pattern of QCD. After introducing sensible simplifications to reduce the large number of possible operators, we carry out a phenomenological discussion of the effects of these terms. We show how the inclusion of these pieces leads to an improvement of the description of the J(P) = 2(+) sector, without spoiling the main features of the predictions obtained in the original model in the JP = 0(+) and J(P) = 1(+) sectors. In particular, we find a significantly better description of the I-G(J(PC)) =0(+)(2(++)), 1(-)(2(++)) and the I(JP)=1/2(2(+)) sectors, which correspond to the f(2)(1270), a(2)(1320), and K-2(*)(1430) quantum numbers, respectively.
|
Garzon, E. J., Xie, J. J., & Oset, E. (2013). Case in favor of the N*(1700)(3/2(-)). Phys. Rev. C, 87(5), 055204–12pp.
Abstract: Using an interaction extracted from the local hidden-gauge Lagrangians, which brings together vector and pseudoscalar mesons, and the coupled channels rho N (s wave), pi N (d wave), pi Delta (s wave), and pi Delta (d wave), we look in the region ofv root s = 1400-1850 MeV and find two resonances dynamically generated by the interaction of these channels, which are naturally associated to N*(1520)(3/2(-)) and N*(1700)(3/2(-)). N*(1700)(3/2(-)) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the pi N (d-wave) data. Both the real and imaginary parts of the pi N amplitude vanish in our approach in the vicinity of this resonance, which is similar to what happens in experimental determinations and which makes this signal very weak in this channel. This feature could explain why this resonance does not show up in some experimental analyses, but the situation is analogous to that of the f(0)(980) resonance, the second scalar meson after sigma[f(0)(500)] in the pi pi(d-wave) amplitude. The unitary coupled channel approach followed here, in connectionwith the experimental data, leads automatically to a pole in the 1700-MeV region and makes this second 3/2-resonance unavoidable.
|
Xie, J. J., Albaladejo, M., & Oset, E. (2014). Signature of an h(1) state in the J/psi -> eta h(1) -> eta K*(0)(K)over-bar*(0) decay. Phys. Lett. B, 728, 319–322.
Abstract: The BES data on the J/psi -> eta K*(0)(K) over bar*(0) reaction show a clear enhancement in the K*(0)(K) over bar*(0) mass distribution close to the threshold of this channel. Such an enhancement is usually a signature of an L = 0 resonance around threshold, which in this case would correspond to an h1 state with quantum numbers I-G(J(Pc))= 0(-)(1(+-)). A state around 1800 MeV results from the interaction of the K*TC* using the local hidden gauge approach. We show that the peak observed in J/psi -> eta K*(0)(K) over bar*(0) naturally comes from the creation of this h(1) state with mass and width around 1830 MeV and 110 MeV, respectively. A second analysis, model independent, corroborates the first result, confirming the relationship of the enhancement in the invariant mass spectrum with the h(1) resonance.
|
Xie, J. J., Wang, E., & Nieves, J. (2014). Re-analysis of the A(1520) photoproduction reaction. Phys. Rev. C, 89(1), 015203–10pp.
Abstract: Based on previous studies that support the important role of the N*(2120)D-13 resonance in the gamma p -> K+ A(1520) reaction, we make a re-analysis of this A(1520) photoproduction reaction taking into account the recent CLAS differential cross-section data. In addition to the contact, t-channel (K) over bar exchange, s-channel nucleon pole, and N*(2120) [previously called N*(2080)] resonance contributions, which have been considered in previous works, we also study the u-channel A(1115) hyperon pole term. The latter mechanism has always been ignored in all theoretical analysis, which has mostly relied on the very forward K+ angular LEPS data. It is shown that when the contributions from the N*(2120) resonance and the A(1115) hyperon are taken into account, both the new CLAS and the previous LEPS data can be simultaneously described. We also show that the contribution from the u-channel A(1115) pole term produces an enhancement for large K+ angles, and it becomes more and more relevant as the photon energy increases, being essential to describe the CLAS differential cross sections at backward angles. Furthermore, we find that the new CLAS data also favor the existence of the N*(2120) resonance and that these measurements can be used to further constrain its properties.
|
Xie, J. J., Wang, E., & Zou, B. S. (2014). Role of the Delta*(1940) in the pi(+) p -> K+ Sigma(+)(1385) and pp -> nK(+) Sigma(+)(1385) reactions. Phys. Rev. C, 90(2), 025207–11pp.
Abstract: The pp -> nK(+)Sigma(+)(1385) reaction is a very good isospin 3/2 filter for studying Delta(++)* resonance decaying to K+Sigma(+)(1385). Within the effective Lagrangian method, we investigate the Sigma (1385) (spin parity J(P) = 3/2(+)) hadronic production in the pi(+) p -> K+Sigma(+)(1385) and pp -> nK(+)Sigma(+)(1385) reactions. For the pi(+) p -> K+Sigma(+)(1385) reaction, in addition to the “background” contributions from t-channel K*(0) exchange and u-channel Lambda(1115) and Sigma(0)(1193) exchange, we also consider the contribution from the s-channel Delta*(1940) resonance, which has significant coupling to the K Sigma(1385) channel. We show that the inclusion of the Delta*(1940) resonance leads to a fairly good description of the low-energy experimental total cross section data of pi(+)p -> K+Sigma(+)(1385) reaction. Basing on the study of the pi(+)p -> K+Sigma(+)(1385) reaction and with the assumption that the excitation of Delta*(1940) resonance dominates the pp -> nK(+)Sigma(+)(1385) reaction, we calculate the total and differential cross sections of the pp -> nK(+)Sigma(+)(1385) reaction. It is shown that the new experimental data support the important role played by the Delta*(1940) resonance with a mass in the region of 1940 MeV and a width of around 200 MeV. We also demonstrate that the invariant mass distribution and the Dalitz plot provide direct information of the Sigma(+)(1385) production, which can be tested by future experiments.
|
Oset, E., Albaladejo, M., Xie, J. J., & Ramos, A. (2014). Recent developments on hadron interaction and dynamically generated resonances. Int. J. Mod. Phys. E, 23(7), 1461008–8pp.
Abstract: In this talk I report on the recent developments in the subject of dynamically generated resonances. In particular I discuss the gamma p -> K-0 Sigma+ and gamma n -> K-0 Sigma(0) reactions, with a peculiar behavior around the K*(0)Lambda threshold, due to a 1/2(-) resonance around 2035 MeV. Similarly, I discuss a BES experiment, J/psi -> eta K*(0) (K) over bar*(0) decay, which provides evidence for a new h(1) resonance around 1830 MeV that was predicted from the vector-vector interaction. A short discussion is then made about recent advances in the charm and beauty sectors.
|
