arXiv subjects

J. M. Alcaraz-Pelegrina

Publications and source records attributed to J. M. Alcaraz-Pelegrina.

3 recordsLinked to original sources

arXiv2026

Hidden-charm $uds\,c\bar c$ pentaquarks as flavor eigenstates in a constituent quark model

We use a diffusion Monte Carlo (DMC) algorithm to solve the Schrödinger equation that describes $udsc\bar c$ pentaquarks within the framework of a non-relativistic constituent quark model. We considered only multiquark states with defined values of parity, color, spin and isospin, selected to be compatible with the experimentally favored assignment $J^P=1/2^-$ for one of the candidates, and assumed $I=0$. However, we found that, to explain the existence of the $P_{cs}(4338)$ and $P_{cs}(4459)$ pentaquarks, we need the total wavefunction to be also an eigenvector of the SU(3) {\em flavor} operator. When we impose that condition, we obtain two structures compatible with the masses extracted from the $J/ψΛ$ spectrum. In addition, two states are predicted below the $J/ψΛ$ threshold but above the $η_cΛ$ one that would not appear in that channel. If we only impose the $I=0$ condition, we obtain a {\em single} (not two) structure compatible with the experimental quantum numbers, with a mass below the $J/ψΛ$ threshold.

hep-ph↗

arXiv2024

A diffusion Monte Carlo calculation of fully heavy pentaquarks

Using a diffusion Monte Carlo algorithm, we calculated the spectra of all possible $S$-wave fully heavy pentaquarks within the framework of the quark model. Our aim was to compare the masses of different spin-color configurations corresponding to the same spatial wavefunction for each quark composition. In particular, we computed the masses of the configuration with the maximum number of undistinguishable quarks and those of all the possible baryon+meson splittings compatible with the total number of $b$'s and $c$'s for a given pentaquark. What we found was that, in all cases, compact baryon+meson configurations had lower masses than their more symmetric counterparts. Moreover, those "molecular" associations were unstable (with larger masses) that their infinitely separated non-interacting pieces except int the case of $(ccb)(c\bar{b})$ and $(bbc)(b\bar{c})$ pentaquarks. In any case, even for unstable arrangements, the excess masses are so small ($\sim$20-60 MeV) as to make those compact molecular structures serious candidates to be experimentally detected.

hep-ph↗

arXiv2022

Diffusion Monte Carlo calculations of fully-heavy compact hexaquarks

We used a diffusion Monte Carlo technique to describe the properties of fully-heavy compact arrangements (no dibaryon molecules) including six quarks and no antiquarks within the framewok of a constituent quark model. Only arrangements whose wavefunctions were eigenvectors of $L^2$ with eigenvalue $\ell$ = 0 were taken into account, what means that we only considered the subset of all the possible color-spin combinations that make the total wavefunctions antisymmetric with respect to the interchange of any two quarks of the same type. This means arrangements with spin $S=0$ for $cccccc$, $bbbbbb$, $cccccb$, $bbbbbc$ and $cccbbb$ and spin $S=0,1,2$ for the $ccccbb$ and $bbbbcc$ hexaquarks. In all cases, the masses of the six-quark arrangements are larger that the ones corresponding to the sum of any of the two baryons we can split them into, but smaller that the ones for a set of six isolated quarks, i.e., all them are bound systems. The analysis of their structure indicates that all the hexaquarks considered in this work are compact objects, except the $cccbbb$, that appears to be a loose association of two baryons.

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