Zusammenfassung
We calculate the tree and penguin amplitudes in the \$B^0\to\pi^+\pi^-\$ decay
channel employing the perturbative QCD factorization approach. Using the
amplitudes as input with the theoretical uncertainties sufficiently considered,
we constrain the UT angle \$\gamma\$ to \$51^\circłeq\gammałeq64^\circ\$, from
the measurements of the CP violation parameters \$C\_\pi^+\pi^-\$ and
\$S\_\pi^+\pi^-\$ in \$B^0\to\pi^+\pi^-\$. The U-spin breaking effect between
\$B^0\to\pi^+\pi^-\$ and \$B\_s^0K^+K^-\$ is estimated to be around 30\%.
Nutzer