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Mikel F. Barbat

Publications and source records attributed to Mikel F. Barbat.

3 recordsLinked to original sources

Scattering and Femtoscopic Correlation Functions of the $\Sigma_c^{++}\pi^{+}$, $\Sigma_c^{0}\pi^{-}$ and $\Sigma_b^{+}\pi^{+}$ Systems

We present predictions for scattering observables and femtoscopic correlation functions (CFs) of the $I=2$ $\Sigma_c^{++}\pi^{+}$, $\Sigma_c^{0}\pi^{-}$ systems and its heavy-flavor counterpart $\Sigma_b^{+}\pi^{+}$. In both heavy-quark sectors, the strong interaction is formulated within two distinct theoretical frameworks, each constrained to reproduce the lowest-lying odd-parity isoscalar spin-$1/2$ resonances, $\Lambda_c(2595)$ and $\Lambda_b(5912)$, respectively. While the $\Sigma_c^{0}\pi^{-}$ pair is governed solely by the strong interaction, electrostatic contributions are included in the other two channels involving charged particles through relativistic Coulomb wave functions. We show that the differences observed in the scattering observables between the two strong-interaction models arise mainly from the specific ultraviolet regularization schemes employed. The inclusion of Coulomb effects induces only a very small increase in both the scattering length and the effective range. The resulting CFs in the charm and bottom sectors display analogous global features, in agreement with expectations from heavy-quark flavor symmetry. Both, the $\Sigma_c^{++}\pi^+$ and $\Sigma_b^{+}\pi^{+}$ CFs, when computed including only the strong interaction, exhibits substantial discriminating power among the different models. However, once Coulomb effects are incorporated, the CFs become largely affected by the repulsive electrostatic interaction, which diminishes their sensitivity to the details of the underlying strong dynamics, thereby reducing the capability to differentiate between theoretical descriptions. Thus, the $\Sigma_c^{0}\pi^{-}$ CF-being free from Coulomb effects-provides the most suitable observable for constraining the strong dynamics of the isotensor $\Sigma_c\pi$ system.

hep-ph

Femtoscopy of $DN$ and $\bar{D}N$ systems

The capability of the ALICE@LHC and STAR@RHIC experiments to reconstruct $D$ mesons has enabled femtoscopic correlation measurements of open-charm mesons in both small and large systems. In this work, we present a theoretical calculation of the correlation functions of $D$ and $\bar{D}$ mesons with nucleons, based on the Koonin-Pratt formalism. We employ an effective Lagrangian to model the interaction between charmed mesons and baryons and apply the TROY formalism to obtain the off-shell $T$-matrix in coupled channels, incorporating the effect of the Coulomb interaction when the pair involves two charged particles. The resulting full coupled-channel wave function is inserted into the Koonin-Pratt equation with channel weights derived from a thermal model. Additionally, we compute the correlation functions using the Lednický-Lyuboshitz approximation with low-energy scattering parameters extracted from the unitarized amplitudes. We compare these two approaches and provide predictions for different correlated pairs. Our results can be tested against current and future experimental data from the ALICE and STAR collaborations in both proton-proton and heavy-ion collisions.

hep-ph

Comprehensive study of compact stars with dark matter

We present a comprehensive study of compact stars admixed with non-self annihilating self-interacting fermionic dark matter, delineating the dependence on the nuclear equation of state by considering the two limiting parametrized equations of state for neutron star matter obtained by smoothly matching the low-density chiral effective theory and the high-density perturbative QCD. These two parametrizations are the limiting cases of a wide variety of smooth equations of state, i.e. the softest and stiffest possible one without a phase transition, that generate masses and radii compatible with 2M$_\odot$ observations and the tidal constraint from GW170817. With an exhaustive analysis of the possible stable mass-radius configurations, we determine the quantity of dark matter contained in stars with masses and radii compatible with the aforementioned astrophysical constraints. We find that for dark particle masses of a few tenths of GeV, the dark core collapses and no stable solutions are found for the two limiting ordinary matter equations of state. For lower masses, the dark matter fraction is limited to 10%, being at most 1% for masses ranging from 0.1 to 10 GeV for the limiting soft nuclear equation of state. For the limiting stiff nuclear equation of state, the dark matter fraction can reach values of more than 10%, but the dark particle mass is being constrained to 0.3 GeV and 10 GeV for the weak self-interacting case and has to be at least 5 GeV for the strong self-interacting one. For dark particle masses of less than 0.1 GeV, stable neutron star configurations should have less than 1% of self-interacting dark matter to be compatible with the constraint of the tidal deformability from GW170817 for the two limiting ordinary matter equations of state studied.

astro-ph.HE