Measurement of the $B^0$$\rightarrow$$D^{∗−}$$\pi^+$$\pi^−$$\pi^+$ branching fraction by B A B AR

The BaBar collaboration measured the decay branching fraction Br(B0→D∗−π+π−π+)=(7.26±0.11(stat.)±0.31(syst.))×10−3Br(B0→D∗−π+π−π+)=(7.26±0.11(stat.)±0.31(syst.))×10−3 using a sample of (470.9±2.8)×106 BB¯¯¯(470.9±2.8)×106 BB¯ pairs. This measurement will facilitate the measurement of Br(B0→D∗−τ+ντ)Br(B0→D∗−τ+ντ) with τ+→π+π−π+ν¯¯¯ττ+→π+π−π+ν¯τ at hadronic colliders, improving the experimental precision on the normalization branching fraction Br(B0→D∗−π+π−π+)Br(B0→D∗−π+π−π+).