$\mathit CP$ VIOLATION PARAMETERS

$\alpha $

INSPIRE   PDGID:
S042ALP
For angle $\alpha (\phi _{2}$) of the CKM unitarity triangle, see the review on “$\mathit CP$ violation” in the reviews section.
VALUE ($^\circ{}$) DOCUMENT ID TECN  COMMENT
$\bf{ 84.1 {}^{+4.5}_{-3.8}}$ OUR EVALUATION  $~~$(Produced by HFLAV)
• • We do not use the following data for averages, fits, limits, etc. • •
$93.7$ $\pm10.6$ 1
VANHOEFER
2016
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \Upsilon}{(4S)}}$
$84.9$ $\pm13.5$ 1
VANHOEFER
2014
BELL Repl. by VANHOEFER 2016
$79$ $\pm7$ $\pm11$ 2
AUBERT
2010D
 BABR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \Upsilon}{(4S)}}$
$92.4$ ${}^{+6.0}_{-6.5}$ 1
AUBERT
2009G
 BABR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \Upsilon}{(4S)}}$
$78.6$ $\pm7.3$ 3
AUBERT
2007O
 BABR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \Upsilon}{(4S)}}$
$88$ $\pm17$ 4
SOMOV
2006
BELL Repl. by VANHOEFER 2014
$100$ $\pm13$ 5
AUBERT,B
2005C
 BABR Repl. by AUBERT 2009G
$102$ ${}^{+16}_{-12}$ $\pm14$ 6
AUBERT,B
2004R
 BABR Repl. by AUBERT,B 2005C
1  Based on an isospin analysis of the ${{\mathit B}}$ $\rightarrow$ ${{\mathit \rho}}{{\mathit \rho}}$ system.
2  Obtained using the time dependent analysis of ${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit a}_{{{1}}}{(1260)}^{\pm}}{{\mathit \pi}^{\mp}}$ and branching fraction measurements of ${{\mathit B}}$ $\rightarrow$ ${{\mathit a}_{{{1}}}{(1260)}}{{\mathit K}}$ and ${{\mathit B}}$ $\rightarrow$ ${{\mathit K}_{{{1}}}}{{\mathit \pi}}$. Uses SU(3) flavor relations.
3  The angle $\alpha _{{\mathrm {eff}}}$ is obtained using the measured $\mathit CP$ parameters of ${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit a}_{{{1}}}{(1260)}^{\pm}}{{\mathit \pi}^{\mp}}$ and choosing one of the four solutions that is compatible with the result of SM-based fits.
4  Obtained using isospin relation and selecting a solution closest to the CKM best fit average; the 90$\%$ CL allowed interval is 59$^\circ{}<\phi _{2}$ (${}\equiv\alpha $) $<$ 115$^\circ{}$.
5  Obtained using isospin relation and selecting a solution closest to the CKM best fit average; 90$\%$ CL allowed interval is 79$^\circ{}$ $<$ $\alpha $ $<$ 123$^\circ{}$.
6  Obtained from the measured $\mathit CP$ parameters of the longitudinal polarization by selecting the solution closest to the CKM best fit central value of $\alpha $ = 95$^\circ{}$ $-$ 98$^\circ{}$.
Conservation Laws:
$\mathit CP$ VIOLATION OBSERVED
References