Femtoscopic signatures of the lightest S-wave scalar open-charm mesons

The authors would like to thank Otón Vázquez Doce for valuable discussions. This work was supported by the Spanish Ministerio de Ciencia e Innovación (MICINN) under Contracts No. PID2020–112777 GB-I00 and No. PID2020–114767 GB-I00, by Generalitat Valenciana under Contract No. PROMETEO/2020/023 and Junta de Andalucía Grant No. FQM-225. This project has received funding from the European Union Horizon 2020 research and innovation program under the program H2020-INFRAIA-2018-1, Grant Agreement No. 824093 of the STRONG-2020 project. M. A. is supported through Generalitat Valenciana (GVA) Grant No. CIDEGENT/2020/002 and thanks the warm support of ACVJLI.We predict femtoscopy correlation functions for S-wave D(s)ϕ pairs of lightest pseudoscalar open-charm mesons and Goldstone bosons from next-to-leading-order unitarized heavy-meson chiral perturbation theory amplitudes. The effect of the two-state structure around 2300 MeV can be clearly seen in the (S,I)=(0,1/2) Dπ, Dη, and Ds¯K correlation functions, while in the scalar-strange (1,0) sector, the D∗s0(2317)± state lying below the DK threshold produces a depletion of the correlation function near threshold. These exotic states owe their existence to the nonperturbative dynamics of Goldstone-boson scattering off D(s). The predicted correlation functions could be experimentally measured and will shed light into the hadron spectrum, confirming that it should be viewed as more than a collection of quark model states.ACVJLIGeneralitat Valenciana PROMETEO/2020/023 GVAMinisterio de Ciencia e Innovación PID2020–112777 GB-I00, PID2020–114767 GB-I00 MICINNHorizon 2020 824093, CIDEGENT/2020/002, H2020-INFRAIA-2018-1Junta de Andalucía FQM-22

Deeply bound levels in kaonic atoms

Using a microscopic antikaon-nucleus optical potential recently developed by Ramos and Oset [10] from a chiral model, we calculate strong interaction energy shifts and widths for K- atoms. This purely theoretical potential gives an acceptable description of the measured data (chi(2)/num.data = 3.8), though it turns out to be less attractive than what can be inferred from the existing kaon atomic data. We also use a modified potential, obtained by adding to the latter theoretical one a s-wave term which is fitted to known experimental kaonic data (chi(2)/degree of freedom = 1.6), to predict deeply bound K- atomic levels, not yet detected. This improved potential predicts, in general, states even narrower than those recently reported by Friedman and Gal [9]. This reinforces the idea that these deeply atomic states can be detected and resolved by using suitable nuclear reactions. Besides, we also study K- and (K) over bar(0) nuclear bound states and compute binding energies and widths, for both species of antikaons, in C-12, Ca-40 and Pb-208. Despite of restricting our study only to potentials obtained from best fits to the known kaonic atom data, the dynamics of these nuclear bound states depends dramatically on the particular optical potential used

Exclusive c -> s, d semileptonic decays of ground-state spin-1/2 and spin-3/2 doubly heavy cb baryons

We evaluate exclusive semileptonic decays of ground-state spin-1/2 and spin-3/2 doubly heavy cb baryons driven by a c→s, d transition at the quark level. We check our results for the form factors against heavy quark spin symmetry constraints obtained in the limit of very large heavy quark masses and near zero recoil. Based on those constraints we make model-independent, though approximate, predictions for ratios of decay widths

Photon emission in neutral-current interactions at intermediate energies

Neutral-current photon emission reactions with nucleons and nuclei are studied. These processes are important backgrounds for nu(mu) -> nu(e) ((nu) over bar (mu) -> (nu) over bar (e)) appearance oscillation experiments where electromagnetic showers instigated by electrons (positrons) and photons are not distinguishable. At intermediate energies, these reactions are dominated by the weak excitation of the Delta(1232) resonance and its subsequent decay into N gamma. There are also nonresonant contributions that, close to threshold, are fully determined by the effective chiral Lagrangian of strong interactions. In addition, we have also included mechanisms mediated by nucleon excitations (N*) from the second resonance region above the Delta(1232). From these states, the contribution of the D-13 N*(1520) turns out to be sizable for (anti) neutrino energies above 1.5 GeV. We have extended the model to nuclear targets taking into account Pauli blocking, Fermi motion, and the in-medium Delta resonance broadening. We present our predictions for both the incoherent and coherent channels, showing the relevance of the nuclear corrections. We also discuss the target mass dependence of the cross sections. This study is important to reduce systematic effects in neutrino oscillation experiments

Exclusive c -> s, d semileptonic decays of ground-state spin-1/2 doubly charmed baryons

We evaluate exclusive semileptonic decays of ground-state spin-1/2 doubly heavy charmed baryons driven by a c→s,dc→s,d transition at the quark level. Our results for the form factors are consistent with heavy quark spin symmetry constraints which are valid in the limit of an infinitely massive charm quark and near zero recoil. Only a few exclusive semileptonic decay channels have been theoretically analyzed before. For those cases we find that our results are in a reasonable agreement with previous calculations

SU(6) extension of the Weinberg-Tomozawa meson-baryon Lagrangian

A consistent SU(6) extension of the Weinberg-Tomozawa meson-baryon chiral Lagrangian is constructed which incorporates vector meson and baryon decuplet degrees of freedom. The corresponding Bethe-Salpeter approximation predicts the existence of an isoscalar spin-parity 3/2 K(*)N bound state (strangeness +1) with a mass around 1.7-1.8 GeV. It is the highest hypercharge state of an antidecuplet SU(3) representation and it is unstable through K(*) decay. The estimated width of this state (neglecting d-wave KN decay) turns out to be small (Gamma (K) over bar (0)pK(+)pi(-) by looking at the three body pK(+)pi(-) invariant mass

Light flavor and heavy quark spin symmetry in heavy meson molecules

We propose an effective field theory incorporating light SU(3)-flavor and heavy quark spin symmetry to describe charmed meson-antimeson bound states. At lowest order the effective field theory entails a remarkable simplification: it only involves contact range interactions among the heavy meson and antimeson fields. We show that the isospin violating decays of the X(3872) can be used to constrain the interaction between the D and a (D) over bar* mesons in the isovector channel. As a consequence, we can rule out the existence of an isovector partner of the X(3872). If we additionally assume that the X(3915) and Y(4140) are D*(D) over bar* and D*(s)(D) over bar*(s) molecular states, we can determine the full spectrum of molecular states with isospin I = 0, 1/2 and 1

Neutrino induced weak pion production off the nucleon

We study neutrino-induced one-pion production off the nucleon in and around the Delta resonance region. A part from the Delta-pole mechanism we include background terms required by chiral symmetry. These background terms give size able contributions in all channels. To better reproduce the ANL q(2)-differential cross section data, we make a new fit of the C-5(A)(q(2)) axial nucleon to Delta form factor. The new result C-5(A)(0) = 0.867 +/- 0.075 is some 30% smaller than the commonly accepted value. This correction is compatible with most quark model estimates and a recent lattice calculation.(1

Single pion production in neutrino-nucleus scattering

We study 1 pi production in both charged and neutral current neutrino-nucleus scattering for neutrino energies below 2 GeV. We use a theoretical model for one pion production at the nucleon level that we correct for medium effects. The results are incorporated into a cascade program that apart from production also includes the pion final state interaction inside the nucleus. Besides, in some specific channels coherent pi production is also possible and we evaluate its contribution as well. Our results for total and differential cross sections are compared with recent data from the MiniBooNE Collaboration. The model provides an overall acceptable description of the data, better for neutral-current than for charged-current channels, although the theory is systematically below the data. Differential cross sections, folded with the full neutrino flux, show that most of the missing pions lie in the forward direction and at high energies

Charged and neutral current neutrino induced nucleon emission reactions

By means of a Monte Carlo cascade method, to account for the rescattering of the outgoing nucleon, we study the charged and neutral current inclusive one nucleon knockout reactions off nuclei induced by neutrinos. The nucleon emission process studied here is a clear signal for neutralcurrent neutrino driven reactions, and can be used in the analysis of future neutrino experiments.Nieves Pamplona,Juan Miguel, [email protected] ; Vicente Vacas, Manuel Jose, [email protected]