Holographic model for heavy-vector-meson masses

¹ Instituto de Física, Universidade Federal do Rio de Janeiro - Caixa Postal 68528, Rio de Janeiro, RJ 21941-972, Brazil
² High Energy Group, Department of Physics, Universidad de los Andes - Carrera 1, No 18A - 10, Bloque Ip, ZIP 111711, Bogotà, Colombia

^(a) braga@if.ufrj.br
^(b) smdiles@if.ufrj.br
^(c) ma.martin41@uniandes.edu.co

Received: 29 June 2016
Accepted: 23 August 2016

Abstract

The experimentally observed spectra of heavy-vector-meson radial excitations show a dependence on two different energy parameters. One is associated with the quark mass and the other with the binding energy levels of the quark-antiquark pair. The first is present in the large mass of the first state while the other corresponds to the small mass splittings between radial excitations. In this article we show how to reproduce such a behavior with reasonable precision using a holographic model. In the dual picture, the large energy scale shows up from a bulk mass and the small scale comes from the position of anti-de Sitter (AdS) space where field correlators are calculated. The model determines the masses of four observed S-wave states of charmonium and six S-wave states of bottomonium with 6.1% rms error. In consistency with the physical picture, the large energy parameter is flavor dependent, while the small parameter, associated with quark-antiquark interaction is the same for charmonium and bottomonium states.