Gluon condensates and c, b quark masses from quarkonia ratios of moments

TL;DR

This paper determines the ratio of gluon condensates and quark masses from charmonium sum rules, revealing potential symmetries in quark mass ratios relevant for grand unified theories.

Contribution

First extraction of the gluon condensate ratio from charmonium moments, providing updated quark mass values and insights into quark mass ratios at M_Z.

Findings

Gluon condensate ratio < g^3f_{abc}G^3 >/< alpha_s G^2 > = (31+-13) GeV^2

Charm quark mass m_c(m_c)=1260(18) MeV

Heavy quark mass ratios suggest possible underlying symmetries

Abstract

We extract (for the first time) the ratio of the gluon condensate < g^3f_{abc}G^3 >/< alpha_s G^2 > expressed in terms of the liquid instanton radius rho_c from charmonium moments sum rules by examining the effects of < alpha_s G^2 > in the determinations of both rho_c and the running MS mass m_c(m_c). Using a global analysis of selected ratios of moments at different Q^2=0, 4m_c^2 and 8m_c^2 and taking < alpha_s G^2 > from 0.06 GeV^4, where the estimate of rho_c is almost independent of < alpha_s G^2 >, we deduce: rho_c=0.98(21) GeV^{-1} which corresponds to < g^3f_{abc}G^3 > = (31+- 13) GeV^2 < alpha_s G^2 >. The value of m_c(m_c) is less affected (within the errors) by the variation of < alpha_s G^2 >, where a common solution from different moments are reached for < alpha_s G^2 > greater than 0.02 GeV^4. Using the values of < alpha_s G^2 >=0.06(2) GeV^4 from some other channels and the previous value of < g^3f_{abc}G^3 >, we deduce: m_c(m_c)=1260(18) MeV and m_b(m_b)=4173(10) MeV, where an estimate of the 4-loops contribution has been included. Our analysis indicates that the errors in the determinations of the charm quark mass without taking into account the ones of the gluon condensates have been underestimated. To that accuracy, one can deduce the running light and heavy quark masses and their ratios evaluated at M_Z, where it is remarkable to notice the approximate equalities: m_s/m_u= m_b/m_s= m_t/m_b= 51(4), which might reveal some eventual underlying novel symmetry of the quark mass matrix in some Grand Unified Theories.