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Albaladejo, M., Fernandez-Soler, P., Nieves, J., & Ortega, P. G. (2018). Contribution of constituent quark model c(s)over-bar states to the dynamics of the D*s0 (2317) and Ds1(2460) resonances. Eur. Phys. J. C, 78(9), 722–22pp.
Abstract: The masses of the D*(s0) (2317) and D-s1(2460) resonances lie below the DK and D* K thresholds respectively, which contradicts the predictions of naive quark models and points out to non-negligible effects of the D(*) K loops in the dynamics of the even-parity scalar (J(pi) = 0(+)) and axial-vector (J(pi) = 1(+)) c (s) over bar systems. Recent lattice QCD studies, incorporating the effects of the D(*) K channels, analyzed these spin-parity sectors and correctly described the D*(s0)(2317) – D-s1(2460) mass splitting. Motivated by such works, we study the structure of the D*(s0)(2317) and D-s1(2460) resonances in the framework of an effective field theory consistent with heavy quark spin symmetry, and that incorporates the interplay between D(*) K meson-meson degrees of freedom and bare P-wave c (s) over bar states predicted by constituent quark models. We extend the scheme to finite volumes and fit the strength of the coupling between both types of degrees of freedom to the available lattice levels, which we successfully describe. We finally estimate the size of the D(*) K two-meson components in the D*(s0)(2317) and D-s1(2460) resonances, and we conclude that these states have a predominantly hadronic-molecular structure, and that it should not be tried to accommodate these mesons within c (s) over bar constituent quark model patterns.
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Alves, J. M., Botella, F. J., Branco, G. C., Cornet-Gomez, F., & Nebot, M. (2017). Controlled flavour changing neutral couplings in two Higgs Doublet models. Eur. Phys. J. C, 77(9), 585–18pp.
Abstract: We propose a class of two Higgs doublet models where there are flavour changing neutral currents (FCNC) at tree level, but under control due to the introduction of a discrete symmetry in the full Lagrangian. It is shown that in this class of models, one can have simultaneously FCNC in the up and down sectors, in contrast to the situation encountered in the renormalisable and minimal flavour violating 2HDM models put forward by Branco et al. (Phys Lett B 380: 119, 1996). The intensity of FCNC is analysed and it is shown that in this class of models one can respect all the strong constraints from experiment without unnatural fine-tuning. It is pointed out that the additional sources of flavour and CP violation are such that they can enhance significantly the generation of the Bbaryon asymmetry of the Universe, with respect to the standard model.
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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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Barenboim, G., & Salvado, J. (2017). Cosmology and CPT violating neutrinos. Eur. Phys. J. C, 77(11), 766–18pp.
Abstract: The combination charge conjugation-parity-time reversal (CPT) is a fundamental symmetry in our current understanding of nature. As such, testing CPT violation is a strongly motivated path to explore new physics. In this paper we study CPT violation in the neutrino sector, giving for the first time a bound, for a fundamental particle, in the CPT violating particle-antiparticle gravitational mass difference. We argue that cosmology is nowadays the only data sensitive to CPT violation for the neutrino-antineutrino mass splitting and we use the latest data release from Planck combined with the current baryonic-acoustic-oscillation measurement to perform a full cosmological analysis. To show the potential of the future experiments we also show the results for Euclid, a next generation large scale structure experiment.
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Pavao, R., & Oset, E. (2018). Coupled channels dynamics in the generation of the Omega (2012) resonance. Eur. Phys. J. C, 78(10), 857–8pp.
Abstract: We look into the newly observed Omega (2012) state from the molecular perspective in which the resonance is generated from the (K) over bar Xi*, eta Omega and (K) over bar Xi channels. We find that this picture provides a natural explanation of the properties of the Omega (2012) state. We stress that the molecular nature of the resonance is revealed with a large coupling of the Omega (2012) to the (K) over bar Xi* channel, that can be observed in the Omega (2012) -> (K) over bar pi Xi decay which is incorporated automatically in our chiral unitary approach via the use of the spectral function of Xi* in the evaluation of the (K) over bar Xi* loop function.
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