[ \beginpmatrix |G\rangle \ |N\rangle \ |S\rangle \endpmatrix \quad \textwith masses \quad M \approx 1710 \ \textmod \ \delta ]
where ( |G\rangle ) is the glueball, ( |N\rangle = u\baru+d\bard ) and ( |S\rangle = s\bars ). The "mod" term appears when one imposes on the effective Lagrangian—specifically, requiring that the mixing angles be periodic under shifts of 1710 in a certain scalar potential. quark mod 1710
More concretely, the has a principal congruence subgroup (\Gamma(19)) whose index is 1710. That is: quark mod 1710