POLARIZATION IN ${{\mathit B}}$ DECAY

In decays involving two vector mesons, one can distinguish among the states in which meson polarizations are both longitudinal ($\mathit L$) or both are transverse and parallel ($\parallel$) or perpendicular ($\perp$) to each other with the parameters $\Gamma _{L}/\Gamma $, $\Gamma _{}/\Gamma $, and the relative phases $\phi _{\parallel}$ and $\phi _{\perp}$. See the definitions in the note on “Polarization in ${{\mathit B}}$ Decays” review in the ${{\mathit B}^{0}}$ Particle Listings.

$\mathit P_{\tau }({{\mathit B}}$ $\rightarrow$ ${{\mathit D}^{*}}{{\mathit \tau}^{+}}{{\mathit \nu}_{{{\tau}}}}$)

INSPIRE   JSON  (beta) PDGID:
S049A01
Measures difference in decay widths with positive and negative ${{\mathit \tau}^{+}}$ helicities normalized to the sum of those decay widths.
VALUE DOCUMENT ID TECN  COMMENT
$-0.38$ $\pm0.51$ ${}^{+0.21}_{-0.16}$ 1
HIROSE
2017
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \Upsilon}{(4S)}}$
1  Uses a fully reconstructed ${{\mathit B}}$ meson as a tag on the recoil side.
References