Lin, J. X., Li, J. T., Liang, W. H., Chen, H. X., & Oset, E. (2024). J/ψ decays into ω(φ) f1(1285) and ω(φ) “f1(1420)”. Eur. Phys. J. C, 84(1), 52–8pp.
Abstract: We perform a theoretical study of the J/psi -> omega (Phi)K* K + c.c. -> omega(Phi)K-0 pi+ K- reactions with the assumption that the f1(1285) is dynamically generated from a single channel K*K + c.c interaction in the chiral unitary approach. Two peaks in the K-0 pi+ K- invariant mass distribution are observed, one clear peak locates at the f(1)(1285) nominal mass, the other peak locates at around 1420MeV with about 70MeV width. We conclude that the former peak is associated with the f(1)(1285) and the latter peak is not a genuine resonance but a manifestation of the kinematic effect in the higher energy region caused by the K* K + c.c. decay mode of the f(1)(1285).
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Song, J., Feijoo, A., & Oset, E. (2022). Role of meson interactions in the D-s(+) -> pi(+) pi(+) pi(-) eta decay. Phys. Rev. D, 106(7), 074027–20pp.
Abstract: We perform a theoretical study of the D-s(+) ->pi(+)pi(+)pi(-)eta decay. We look first at the basic D-s(+) decay at the quark level from external and internal emission. Then we hadronize a pair or two pairs of q (q) over bar states to have mesons at the end. Posteriorly the pairs of mesons are allowed to undergo final state interaction, by means of which the a(0)(980), f(0)(980), a(1)(1260), and b(1)(1235) resonances are dynamically generated. The G parity is used as a filter of the possible channels, and from those with negative G parity only the ones that can lead to pi(+)pi(+)pi(-)eta at the final state are kept. Using transition amplitudes from the chiral unitary approach that generates these resonances and a few free parameters, we obtain a fair reproduction of the six mass distributions reported in the BESIII experiment.
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Jiang, S. J., Sakai, S., Liang, W. H., & Oset, E. (2019). The chi c J decay to phi K*(K)over-bar, phi h(1)(1380) testing the nature of axial vector meson resonances. Phys. Lett. B, 797, 134831–5pp.
Abstract: We perform a theoretical study of the chi(cJ) -> phi K*(K) over bar -> phi K pi(K) over bar reaction taking into account the K*(K) over bar final state interaction, which in the chiral unitary approach is responsible, together with its coupled channels, for the formation of the low lying axial vector mesons, in this case the h(1)(1380) given the selection of quantum numbers. Based on this picture we can easily explain why in the chi(c0) decay the h(1)(1380) resonance is not produced, and, in the case of chi(c1) and chi(c2) decay, why a dip in the K+ pi K-0(-) mass distribution appears in the 1550-1600 MeV region, that in our picture comes from a destructive interference between the tree level mechanism and the rescattering that generates the h(1)(1380) state. Such a dip is not reproduced in pictures where the nominal h(1)(1380) signal is added incoherently to a background, which provides support to the picture where the resonance appears from rescattering of vector-pseudoscalar components.
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Hinarejos, M., Bañuls, M. C., & Perez, A. (2013). A Study of Wigner Functions for Discrete-Time Quantum Walks. J. Comput. Theor. Nanosci., 10(7), 1626–1633.
Abstract: We perform a systematic study of the discrete time Quantum Walk on one dimension using Wigner functions, which are generalized to include the chirality (or coin) degree of freedom. In particular, we analyze the evolution of the negative volume in phase space, as a function of time, for different initial states. This negativity can be used to quantify the degree of departure of the system from a classical state. We also relate this quantity to the entanglement between the coin and walker subspaces.
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Rodas, A., Pilloni, A., Albaladejo, M., Fernandez-Ramirez, C., Mathieu, V., & Szczepaniak, A. P. (2022). Scalar and tensor resonances in J/psi radiative decays. Eur. Phys. J. C, 82(1), 80–17pp.
Abstract: We perform a systematic analysis of the J/psi -> gamma pi(0)pi(0) and -> gamma(KSKS0)-K-0 partial waves measured by BESIII. We use a large set of amplitude parametrizations to reduce the model bias. We determine the physical properties of seven scalar and tensor resonances in the 1-2.5 GeV mass range. These include the well known f(0)(1500) and f(0)(1710), that are considered to be the primary glueball candidates. The hierarchy of resonance couplings determined from this analysis favors the latter as the one with the largest glueball component.
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Lin, J. X., Li, J. T., Jiang, S. J., Liang, W. H., & Oset, E. (2021). The D-s(+) -> a(0)(980)e(+)nu(e) reaction and the a(0)(980) – f(0)(980) mixing. Eur. Phys. J. C, 81(11), 1017–8pp.
Abstract: We perform a study of the D-s(+) -> a(0)(980) (f(0)(980))e(+)nu(e) reactions investigating the different sources of isospin violation which make the production of the a0(980) possible. We find that loops involving kaons in the production mechanism provide a source of isospin violation since they do not cancel due to the different mass of charged and neutral kaons, but we also find that the main source comes from the breaking of isospin in the meson-meson transition T matrices, which contain information on the nature of the low lying scalar mesons. The reaction is thus very sensitive to the nature of the a(0)(980) and f(0)(980) resonances. Our results are consistent with the present upper bound for a(0)(980) production and only a factor three smaller, indicating that future runs with more statistics should find actual numbers for this reaction from where we can learn more about the origin of the scalar resonances and their nature.
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Feijoo, A., Dai, L. R., Abreu, L. M., & Oset, E. (2024). Correlation function for the Tbb state: Determination of the binding, scattering lengths, effective ranges, and molecular probabilities. Phys. Rev. D, 109(1), 016014–8pp.
Abstract: We perform a study of the (B*+B0), (BB+)-B-*0 correlation functions using an extension of the local hidden gauge approach which provides the interaction from the exchange of light vector mesons and gives rise to a bound state of these components in I = 0 with a binding energy of about 21 MeV. After that, we face the inverse problem of determining the low energy observables, scattering length and effective range for each channel, the possible existence of a bound state, and, if found, the couplings of such a state to each (B*+B0), (BB+)-B-*0 component as well as the molecular probabilities of each of the channels. We use the bootstrap method to determine these magnitudes and find that, with errors in the correlation function typical of present experiments, we can determine all these magnitudes with acceptable precision. In addition, the size of the source function of the experiment from where the correlation functions are measured can be also determined with a high precision.
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T2K Collaboration(Abe, K. et al), Antonova, M., Cervera-Villanueva, A., Fernandez, P., Izmaylov, A., & Novella, P. (2019). Search for light sterile neutrinos with the T2K far detector Super-Kamiokande at a baseline of 295 km. Phys. Rev. D, 99(7), 071103–10pp.
Abstract: We perform a search for light sterile neutrinos using the data from the T2K far detector at a baseline of 295 km, with an exposure of 14.7(7.6) x 10(20) protons on target in neutrino (antineutrino) mode. A selection of neutral-current interaction samples is also used to enhance the sensitivity to sterile mixing. No evidence of sterile neutrino mixing in the 3 + 1 model was found from a simultaneous fit to the charged-current muon, electron and neutral-current neutrino samples. We set the most stringent limit on the sterile oscillation amplitude sin(2)theta(24 )for the sterile neutrino mass splitting Delta m(41)(2 )< 3 x 10(-3 )eV(2)/c(4).
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Coloma, P., Esteban, I., Gonzalez-Garcia, M. C., & Maltoni, M. (2020). Improved global fit to Non-Standard neutrino Interactions using COHERENT energy and timing data. J. High Energy Phys., 02(2), 023–30pp.
Abstract: We perform a global fit to neutrino oscillation and coherent neutrino-nucleus scattering data, using both timing and energy information from the COHERENT experiment. The results are used to set model-independent bounds on four-fermion effective operators inducing non-standard neutral-current neutrino interactions. We quantify the allowed ranges for their Wilson coefficients, as well as the status of the LMA-D solution, for a wide class of new physics models with arbitrary ratios between the strength of the operators involving up and down quarks. Our results are presented for the COHERENT experiment alone, as well as in combination with the global data from oscillation experiments. We also quantify the dependence of our results for COHERENT with respect to the choice of quenching factor, nuclear form factor, and the treatment of the backgrounds.
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Murgui, C., Peñuelas, A., Jung, M., & Pich, A. (2019). Global fit to b -> c tau nu transitions. J. High Energy Phys., 09(9), 103–45pp.
Abstract: We perform a general model-independent analysis of b -> c tau(nu) over bar (tau) transitions, including measurements of R-D, R-D*, their q(2) differential distributions, the recently measured longitudinal D* polarization F-L(D)*, and constraints from the B-c -> tau(nu) over bar (tau) lifetime, each of which has significant impact on the fit. A global fit to a general set of Wilson coefficients of an effective low-energy Hamiltonian is presented, the solutions of which are interpreted in terms of hypothetical new-physics mediators. From the obtained results we predict selected b -> c tau(nu) over bar (tau) observables, such as the baryonic transition Lambda(b) -> Lambda(c)tau(nu) over bar (tau), the ratio R-J/psi, the forward-backward asymmetries A(FB)(D()*()), the tau polarization asymmetries P-tau(D()*()), and the longitudinal D* polarization fraction F-L(D)*. The latter shows presently a slight tension with any new-physics model, such that an improved measurement could have an important impact. We also discuss the potential change due the very recently announced preliminary R-D(*) measurement by the Belle collaboration.
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