arXiv subjects

O. Lakhina

Publications and source records attributed to O. Lakhina.

3 recordsLinked to original sources

arXiv2007

Microscopic quark study of the eta and eta' masses

We show that it is necessary to go beyond the BCS (rainbow-ladder) approximation to split the $η$ and $η'$ masses from the $π$ and K masses. We determine the self-consistent set of one-quark-loop diagrams both for the Schwinger-Dyson quark mass gap equation and for the Bethe-Salpeter quark-antiquark boundstate equation. We identify the dominant diagrams, and we focus on the boundstate equation. We detail the Bethe-Salpeter equation, adding the dominant new diagram to the BCS kernel. The relevant numerical techniques are also discussed. The ideal cases of one, two and three light flavors, relevant to lattice QCD are also explored, together with the case of realistic current quark masses.

hep-ph↗

arXiv2006

Dynamic Properties of Charmonium

Nonrelativistic quark models of charmonia are tested by comparison of theoretical charmonium decay constants, form factors, and $γγ$ widths with experiment and lattice gauge computations. The importance of relativistic effects, a running coupling, and the correct implementation of bound state effects are demonstrated. We describe how an improved model and computational techniques resolve several outstanding issues in previous nonrelativistic quark models such as the use of `correction' factors in quark model form factors, artificial energy prescriptions in decay constant calculations, and ad hoc phase space modifications. We comment on the small experimental value of $f_{ψ''}$ and the D-wave component of the $J/ψ$. Decay constants and $γγ$ widths for bottomonium are also presented.

hep-ph↗

arXiv2004

Hybrid Meson Potentials and the Gluonic van der Waals Force

The chromoelectric polarizability of mesons governs the strength of the gluonic van der Waals force and therefore of non-quark-exchange processes in hadronic physics. We compute the polarizability of heavy mesons with the aid of lattice gauge theory and the Born--Oppenheimer adiabatic expansion. We find that the operator product expansion breaks down at surprisingly large quarks masses due to nonperturbative gluodynamics and that previous conclusions concerning $J/ψ$--nuclear matter interactions and $J/ψ$ dissociation in the quark-gluon plasma must be substantially modified.

hep-ph↗