${\mathit {\mathit c}}$ ${\mathit {\overline{\mathit c}}}$ MESONS
(including possibly non- ${\mathit {\mathit q}}$ ${\mathit {\overline{\mathit q}}}$ states)
INSPIRE search

${{\boldsymbol \chi}_{{c1}}{(3872)}}$

$I^G(J^{PC})$ = $0^+(1^{+ +})$ 

also known as ${{\mathit X}{(3872)}}$
This state shows properties different from a conventional ${{\mathit q}}{{\overline{\mathit q}}}$ state. A candidate for an exotic structure. See the review on non- ${{\mathit q}}{{\overline{\mathit q}}}$ states. First observed by CHOI 2003 in ${{\mathit B}}$ $\rightarrow$ ${{\mathit K}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit J / \psi}{(1S)}}$ decays as a narrow peak in the invariant mass distribution of the ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit J / \psi}{(1S)}}$ final state. Isovector hypothesis excluded by AUBERT 2005B and CHOI 2011 . AAIJ 2013Q perform a full five-dimensional amplitude analysis of the angular correlations between the decay products in ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit \chi}_{{c1}}{(3872)}}{{\mathit K}^{+}}$ decays, where ${{\mathit \chi}_{{c1}}{(3872)}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , which unambiguously gives the $\mathit J{}^{PC} = 1{}^{++}$ assignment under the assumption that the ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit J / \psi}}$ are in an ${\mathit S}{\mathrm -wave}$. AAIJ 2015AO extend this analysis with more data to limit ${\mathit D}{\mathrm -wave}$ contributions to $<$ 4$\%$ at 95$\%$ CL. See the review on “Spectroscopy of Mesons Containing Two Heavy Quarks.”
${{\mathit \chi}_{{c1}}{(3872)}}$ MASS FROM ${{\mathit J / \psi}}{{\mathit X}}$ MODE   $3871.65 \pm0.06$ MeV 
 
${{\mathit \chi}_{{c1}}{(3872)}}$ MASS FROM ${{\overline{\mathit D}}^{*0}}{{\mathit D}^{0}}$ MODE
 
${\mathit m}_{{{\mathit \chi}_{{c1}}{(3872)}}}–{\mathit m}_{{{\mathit J / \psi}}}$   $775 \pm4$ MeV 
 
${\mathit m}_{{{\mathit \chi}_{{c1}}{(3872)}}}–{\mathit m}_{{{\mathit \psi}{(2S)}}}$
 
${{\mathit \chi}_{{c1}}{(3872)}}$ WIDTH   $1.19 \pm0.21$ MeV (S = 1.1)
 
${{\mathit \chi}_{{c1}}{(3872)}}$ WIDTH FROM ${{\overline{\mathit D}}^{*0}}{{\mathit D}^{0}}$ MODE
 
$\Gamma_{1}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$  $<2.8\times 10^{-6}$ CL=90% 1936
 
$\Gamma_{2}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit J / \psi}{(1S)}}$  $(3.8\pm{1.2})\%$ 650
 
$\Gamma_{3}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit J / \psi}{(1S)}}$  not seen 588
 
$\Gamma_{4}$ ${{\mathit \omega}}{{\mathit \eta}_{{c}}{(1S)}}$  $<33\%$ CL=90% 368
 
$\Gamma_{5}$ ${{\mathit \omega}}{{\mathit J / \psi}{(1S)}}$  $(4.3\pm{2.1})\%$ -1
 
$\Gamma_{6}$ ${{\mathit \phi}}{{\mathit \phi}}$  not seen 1646
 
$\Gamma_{7}$ ${{\mathit D}^{0}}{{\overline{\mathit D}}^{0}}{{\mathit \pi}^{0}}$  $(49^{+18}_{-20})\%$ 116
 
$\Gamma_{8}$ ${{\overline{\mathit D}}^{*0}}{{\mathit D}^{0}}$  $(37\pm{9})\%$ -1
 
$\Gamma_{9}$ ${{\mathit \gamma}}{{\mathit \gamma}}$  $<11\%$ CL=90% 1936
 
$\Gamma_{10}$ ${{\mathit D}^{0}}{{\overline{\mathit D}}^{0}}$  $<29\%$ CL=90% 519
 
$\Gamma_{11}$ ${{\mathit D}^{+}}{{\mathit D}^{-}}$  $<19\%$ CL=90% 502
 
$\Gamma_{12}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{c2}}}$  $<4\%$ CL=90% 273
 
$\Gamma_{13}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{c1}}}$  $(3.4\pm{1.6})\%$ 319
 
$\Gamma_{14}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{{c0}}}}$  $<70\%$ CL=90%  
 
$\Gamma_{15}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}_{{c}}{(1S)}}$  $<14\%$ CL=90% 745
 
$\Gamma_{16}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \chi}_{{c1}}}$  $<7\times 10^{-3}$ CL=90% 218
 
$\Gamma_{17}$ ${{\mathit p}}{{\overline{\mathit p}}}$  $<2.4\times 10^{-5}$ CL=95% 1693
 
FOOTNOTES