\documentclass[a4paper,12pt]{report}
\usepackage{amsmath}
\usepackage{xepersian}
\begin{document}
\begin{align}
\lr{D}+^3\lr{He}&{\longrightarrow}&^4He~(3.67~MeV)+p~(14.68~MeV)\nonumber\\
D+D&{\longrightarrow}&\lr{^3He~(0.082~MeV)+n~(2.45~MeV)}\nonumber\\
D+D&{\longrightarrow}&~~T~~(1.01~MeV)~~+p~(3.02~MeV)\nonumber\\
D+T&{\longrightarrow}&^4He~(3.5~MeV)+n~(14.1~MeV)
\end{align}
\end{document}