  Let $G$ denote a complex semisimple linear algebraic group, $P$ a parabolic
subgroup of $G$ and $\mathcal{P}=G/P$. We identify the quantum multiplication
by divisors in $T^*\mathcal{P}$ in terms of stable basis, which is introduced
by Maulik and Okounkov. Using this and the restriction formula for stable
basis, we show that the $G\times\mathbb{C}^*$-equivariant quantum
multiplication formula in $T^*\mathcal{P}$ is conjugate to the conjectured
formula by Braverman.
