arXiv subjects

J. Segovia

Publications and source records attributed to J. Segovia.

59 records · Page 4Linked to original sources

arXiv2011

Renormalization approach to constituent quark models of Quarkonium

Constituent quark models, while successful, require a great deal of fine tuning of the short distance interactions by introducing phenomenological gluonic form factors which are ultimately designed to accurately reproduce the spectrum. We apply and develop renormalization ideas to reduce the short distance sensitivity and show that, as naively expected, but not explicitly implemented in the models, the physics of binding is entirely linked to the string tension whereas leptonic decays depend more on the gluon exchange potential. We also show how the spectrum of S- and D- $1^{--}$ states is successfully intertwined through the singular tensor interaction.

hep-ph↗

arXiv2010

A very broad X(4260) and the resonance parameters of the 3D vector charmonium state

We argue that the X(4260) enhancement contains a wealth of information on vector c-cbar spectroscopy. We discuss the shape of the X(4260) observed in the OZI-forbidden process "electron-positron into J/psi and a pair of charged pions", in particular at and near vector charmonium resonances as well as open-charm threshold enhancements. The resulting very broad X(4260) structure does not seem to classify itself as a vector charmonium resonance, but its detailed shape allows to identify new vector c-cbar states. Here, we estimate the resonance parameters of the psi(3D) state.

hep-ph↗

arXiv2010

Coupled channel approach to the structure of the X(3872)

We have performed a coupled channel calculation of the $1^{++}$ $c\bar c$ sector including $q\bar q$ and $DD^*$ molecular configurations. The calculation was done within a constituent quark model which successfully describes the meson spectrum, in particular the $c\bar c$ $1^{--}$ sector. Two and four quark configurations are coupled using the $^3P_0$ model. The elusive X(3872) meson appears as a new state with a high probability for the $DD^*$ molecular component. When the mass difference between neutral and charged states is included a large $D^0 {D^*}^0$ component is found which dominates for large distances and breaks isospin symmetry in the physical state. The original $c\bar c(2 ^3P_1)$ state acquires a sizable $DD^*$ component and can be identified with the X(3940). We study the $B\to K π^+ π^-J/ψ$ and $B\to K D^0 D^{*0}$ decays finding a good agreement with Belle and BaBar experimental data.

hep-ph↗

arXiv2010

The X(3872) and other possible $XYZ$ molecular states

We perform a coupled channel calculation of the $DD^*$ and $c\bar c$ sectors in the framework of a constituent quark model. The interaction for the $DD^*$ states is obtained using the Resonant Group Method (RGM) and the underlying quark interaction model. The coupling with the two quark system is performed using the $^3 P_0$ model. The X(3872) is found as a molecular state with a sizable $c\bar c$ component. A comparison with Belle and BaBar data has been done, finding a good agreement. Other possible molecular molecular states are discussed.

hep-ph↗

arXiv2008

Charm spectroscopy beyond the constituent quark model

We study the nature of the new charm and charmonium like states observed in the last few years, using a constituent quark model with an screened confinement potential. In the open charm sector we discuss different options for the $D_{sJ}(2860)$ including tetraquark configurations. In the hidden charm sector the new Y(4360) and Y(4660) are interpreted as $1^{--}$ states. The influence in the puzzling 3940 MeV region of multiquark configuration is discussed.

hep-ph↗