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The European Organization for Nuclear Research (CERN) has recently approved a world-unique QCD facility in which an updated version of the external M2 beam line of the CERN SPS in conjunction with a universal spectrometer of the COMPASS experiment is used. One of its main goals is to use highly intense and energetic kaon beams to map out the complete spectrum of excited kaons with an unprecedented precision; having a broad impact not only on low-energy QCD phenomenology, but also on many high-energy particle processes where excited kaons appear, such as the study of CP violation in heavy-meson decays studied at LHCb and Belle II. In support of the experimental effort, the kaon spectrum is computed herein using a constituent quark model which has been successfully applied to a wide range of hadronic observables, from light to heavy quark sectors, and thus the model parameters are completely constrained. The model’s prediction can be used as a template against which to compare the already collected data and future experimental findings, in order to distinguish between conventional and exotic kaon states. We also compare our results with those available in the literature in order to provide some general statements, common to all calculations.

The discovery of the D s 0 ∗ ( 2317 ) and D s 1 ( 2460 ) resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between Q q ¯ and ( Q q ¯ ) ( q q ¯ ) Fock components. In contrast to the c s ¯ sector, there is no experimental evidence of J P = 0 + , 1 + bottom–strange states yet. Motivated by recent lattice studies, in this work the heavy-quark partners of the D s 0 ∗ ( 2317 ) and D s 1 ( 2460 ) states are analyzed within a heavy meson chiral unitary scheme. As a novelty, the coupling between the constituent quark-model P-wave B ¯ s scalar and axial mesons and the B ¯ ( ∗ ) K channels is incorporated employing an effective interaction, consistent with heavy-quark spin symmetry, constrained by the lattice energy levels.

A thorough theoretical analysis (DFT/B3LYP) of the potential energy surface of diethylsilanediol (DESD) allowed finding ten stable conformations of the molecule, differing on the relative arrangement of both ethyl and hydroxyl groups. The Boltzmann’s population analysis allowed establishing their stability order that was justified in terms of the anomeric effect analyzed by means of the Natural Bond Orbitals methodology. Besides, DESD was synthesized and characterized using FT-IR and Raman spectroscopies data, firstly reported in this work, combined with DFT calculations (B3LYP/aug-ccpVTZ). Finally some of the main structural and vibrational features of this and other closely related alkylsilanediols, i. e. DMSD and EMSD, have been put together in order to establish some trends that can allow a better understanding of the chemistry of these compounds.

The intrinsic instability of small alkylsilanediols and their propensity toward self-condensation have been the main determiners of the scarce number of experimental works dealing with their synthesis and vibrational characterization. This is the case of the title compound, ethylmethylsilanediol (EMSD), which preparation and purification is, to the best of our knowledge, firstly reported in the present work. Hence, we also report the first records of the IR and Raman spectra of the molecule that have been thoroughly analyzed and completely assigned with the support of DFT calculations. Further, as a previous step of the vibrational assignment, we accomplished a thorough conformational analysis that allowed indentifying five conformations that represent minima on the potential energy surface (PES) of the molecule, depending on the different arrangement that both, the alkyl side chain and the –OH groups, can adopt. Finally, natural bond orbital (NBO) calculations were implemented to justify the stability order and the calculated geometries for the set of conformers in terms of the stabilization derived from the anomeric effect.

The discovery of the [Formula omitted] and [Formula omitted] resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between [Formula omitted] and [Formula omitted] Fock components. In contrast to the [Formula omitted] sector, there is no experimental evidence of [Formula omitted] bottom-strange states yet. Motivated by recent lattice studies, in this work the heavy-quark partners of the [Formula omitted] and [Formula omitted] states are analyzed within a heavy meson chiral unitary scheme. As a novelty, the coupling between the constituent quark-model P-wave [Formula omitted] scalar and axial mesons and the [Formula omitted] channels is incorporated employing an effective interaction, consistent with heavy-quark spin symmetry, constrained by the lattice energy levels.

Since the discovery of the J /ψ, the quark model was very successful in describing the spectrum and properties of heavy mesons including only q̄ components. However since 2003, with the discovery of the X (3872), many states that can not be accommodated on the naive quark model have been discovered, and they made unavoidable to include higher Fock components on the heavy meson states. We will give an overview of the success of the quark model for heavy mesons and point some of the states that are likely to be more complicated structures such as meson-meson molecules.

The exploration of energies above the open-flavor threshold in the meson spectra has led to the appearance of unexpected states difficult to accommodate in the naive picture of a bound state of a quark and an antiquark. Many of such states are located close to meson-meson thresholds, which suggests that molecular structures may be a relevant component in the total wave function of such resonances. In this work, the state of meson-meson molecules calculations is reviewed, using a nonrelativistic constituent quark model that has been applied to a wide range of hadronic observables, and therefore all model parameters are completely constrained. The model has been able to reproduce, among others, the properties of the X(3872), described as a mixture of cc and DD * states, or the spectrum of the P-wave charm-strange mesons, which are well reproduced only if DK and D * K structures are taken into account. We show that such constituent quark model, which is able to describe the ordinary heavy meson spectra, is also capable of providing a good description of many new states recently reported.

In recent years states in the quarkonium spectrum not expected in the naive quark model have appeared and created a lot of interest. In the theoretical side the study of the effect of meson-meson thresholds in the spectrum have been performed in different approximations. In a quark model framework, and in the spirit of the Cornell model, when a meson-meson threshold is included, the coupling to all the quark-antiquark states have to be considered. In practice only the closest states are included perturbatively. In this contribution we will present a framework in which we couple quark-antiquark states with meson-meson states non-perturbatively, taking into account effectively the coupling to all quark-antiquark states. The method will be applied to the study of the X(3872) and a comparison with the perturbative calculation will be performed.

Since the discovery of the \\(J/\\psi\\), the quark model was very successful in describing the spectrum and properties of heavy mesons including only \\(q\\bar q\\) components. However since 2003, with the discovery of the \\(X(3872)\\), many states that can not be accommodated on the naive quark model have been discovered, and they made unavoidable to include higher Fock components on the heavy meson states. We will give an overview of the success of the quark model for heavy mesons and point some of the states that are likely to be more complicated structures such as meson-meson molecules.