#### ${\mathit m}_{{{\mathit \chi}_{{c1}}{(3872)}}}–{\mathit m}_{{{\mathit \psi}{(2S)}}}$

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$185.598$ $\pm0.067$ $\pm0.068$ 15.6k 1
LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit X}}$
$185.54$ $\pm0.06$ 19.8k 2
 2020 S
LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit X}}$
$187.4$ $\pm1.4$ 25 3
 2005 R
BABR ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit J / \psi}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
 1 Using ${{\mathit \chi}_{{c1}}{(3872)}}$ produced in inclusive ${{\mathit b}}$-hadron decays. Breit-Wigner parametrization. Superseded by the combined value in AAIJ 2020S.
 2 Combining ${\mathit m}_{{{\mathit \chi}_{{c1}}{(3872)}}}–{\mathit m}_{{{\mathit \psi}{(2S)}}}$ = $185.49$ $\pm0.06$ $\pm0.03$ MeV from AAIJ 2020S and the measured mass difference from AAIJ 2020AD. Breit-Wigner parametrization.
 3 Superseded by AUBERT 2006 .
References:
PR D102 092005 Study of the lineshape of the $\chi_{c1}(3872)$ state
JHEP 2008 123 Study of the $\psi_2(3823)$ and $\chi_{c1}(3872)$ states in $B^+ \rightarrow \left( J\psi\pi^+\pi^-\right)K^+$ decays
PR D71 071103 Study of the ${{\mathit B}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ Decay and Measurement of the ${{\mathit B}}$ $\rightarrow$ ${{\mathit X}{(3872)}}{{\mathit K}^{-}}$ Branching Fraction