arXiv subjects

Marián Kolesár

Publications and source records attributed to Marián Kolesár.

4 recordsLinked to original sources

arXiv2026

Subthreshold parameters of $ππ$ scattering revisited

Using a variety of experimental results and lattice QCD calculations of $ππ$ scattering lengths, while employing dispersive representations of the amplitude based on Roy equations, we compute the subthreshold parameters of this process. We use Monte Carlo sampling to numerically model the probability distribution of the results based on all uncertainties in the inputs. We also investigate the dependence of the results on a theoretical correlation between the $ππ$ scattering lengths $a^0_0$ and $a^2_0$, which was previously established in the framework of two-flavor chiral perturbation theory.

hep-ph↗

arXiv2024

Application of Bayesian statistics to the sector of decay constants in three-flavour ChPT

The sector of decay constants of the octet of light pseudoscalar mesons in the framework of 'resummed' $SU(3)$ chiral perturbation theory is investigated. A theoretical prediction for the decay constant of $η$-meson is compared to a range of available determinations. Compatibility of these determinations with the latest fits of the $SU(3)$ low energy coupling constants is discussed. Using a Bayesian statistical approach, constraints on the low energy coupling constants $L_4^r$ and $L_5^r$, as well as higher order remainders to the decay constants $F_K$ and $F_η$, are extracted from the most recent experimental and lattice QCD inputs for the values of the decay constants.

hep-ph↗

arXiv2020

Three-flavour order parameters of chiral symmetry in low-energy QCD

The current state of knowledge of the order parameters of the spontaneously broken chiral symmetry, the quark condensate and the pseudoscalar decay constant in the chiral limit, is briefly reviewed, based on available phenomenological fits and lattice QCD calculations. We argue that while the theory is pretty well understood in the two-flavour case, there is still a gap in the knowledge of the characteristics of the QCD vacuum in the three-flavour one. Our constraints for the three-flavour parameters obtained by a Bayesian statistical analysis of the decays of eta to three pions are presented. Possible implications of a new analysis of subthreshold parameters of pion-pion scattering is outlined.

hep-ph↗

arXiv2019

Application of Bayesian statistics to $η$-meson decay constant in $χ$PT

The decay constant of the $η$-meson in the framework of 'resummed' chiral perturbation theory is discussed. A theoretical prediction is compared to the available determinations. Compatibility of these determinations with the latest fits of the SU(3) low energy coupling constants is investigated. Preliminary results for the obtained constraints on the low energy coupling constants $L^r_5$ and $L^r_4$, using Bayesian statistical approach, are presented.

hep-ph↗