can be understood physically as a balance of partial dynamical screening of the Coulomb interactions by electron-hole pairs and mass enhancement of the same quasiparticles by pairs. This situation is in sharp contrast to the case of a vanishing [ *indirect*]{} band gap, for which to leading order in the long-range Coulomb interaction electrons and holes are separately conserved, so there is no screening by virtual electron-hole pairs, and exciton formation destabilizes the putative gapless state[@halperin].

Using the RG, we can evaluate the anomalous dimension of any physical operator. By charge conservation, $[\psi^{\dagger}\psi]=d$. Due to the isotropy of the fixed point, there are only two non-trivial values for the other charge-conserving fermion bilinears. We obtain , $[\psi^{\dagger} \Gamma_a \psi] =d+
\eta_1$ , $[\psi^{\dagger} \Gamma_{ab} \psi]=d+\eta_{12} $, , where $\Gamma_a$ are the (time-reversal invariant) Dirac gamma matrices, $\Gamma_{ab} = -\frac{i}{2}[\Gamma_a,\Gamma_b]$ are time-reversal odd, and $a,b=1,2,\cdots,5$. Using the standard operator insertion technique, we find $\eta_{1} = - \frac{6 }{15 N_f +4}\varepsilon$ and $\eta_{12} =- \frac{3 }{15 N_f +4}\varepsilon$. These operators describe many physical observables, [*e.g.*]{} the “angular momentum" operator $J_z \sim
\psi^{\dagger} (-\Gamma_{34} -\frac{1}{2} \Gamma_{12}) \psi $. The negative anomalous dimension of these operators suggests the a schematic picture of power-law excitons 