${\mathit {\mathit c}}$ ${\mathit {\overline{\mathit c}}}$ MESONS
(including possibly non-${\mathit {\mathit q}}$ ${\mathit {\overline{\mathit q}}}$ states)
INSPIRE   JSON PDGID:
M176

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

$I^G(J^{PC})$ = $0^+(1^{+ +})$ 

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   $3871.64 \pm0.06$ 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
$\Gamma_{1}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$   $<2.7\times 10^{-7}$ CL=90% 1936
 
$\Gamma_{2}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$   $<8\times 10^{-3}$ CL=90% 1924
 
$\Gamma_{3}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit J / \psi}{(1S)}}$   $(3.5\pm{0.9})\%$ 650
 
$\Gamma_{4}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit J / \psi}{(1S)}}$   not seen 588
 
$\Gamma_{5}$ ${{\mathit \omega}}{{\mathit \eta}_{{{c}}}{(1S)}}$   $<30\%$ CL=90% 368
 
$\Gamma_{6}$ ${{\mathit \rho}{(770)}^{0}}{{\mathit J / \psi}{(1S)}}$   $(2.8\pm{0.7})\%$  
 
$\Gamma_{7}$ ${{\mathit \omega}}{{\mathit J / \psi}{(1S)}}$   $(4.1\pm{1.4})\%$ -1
 
$\Gamma_{8}$ ${{\mathit \phi}}{{\mathit \phi}}$   not seen 1646
 
$\Gamma_{9}$ ${{\mathit D}^{0}}{{\overline{\mathit D}}^{0}}{{\mathit \pi}^{0}}$   $(45\pm{21})\%$ 116
 
$\Gamma_{10}$ ${{\overline{\mathit D}}^{*0}}{{\mathit D}^{0}}$   $(34\pm{12})\%$ -1
 
$\Gamma_{11}$ ${{\mathit \gamma}}{{\mathit \gamma}}$   $<10\%$ CL=90% 1936
 
$\Gamma_{12}$ ${{\mathit D}^{0}}{{\overline{\mathit D}}^{0}}$   $<26\%$ CL=90% 519
 
$\Gamma_{13}$ ${{\mathit D}^{+}}{{\mathit D}^{-}}$   $<17\%$ CL=90% 502
 
$\Gamma_{14}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{{c2}}}}$   $<4\%$ CL=90% 273
 
$\Gamma_{15}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{{c1}}}}$   $(3.1^{+1.5}_{-1.3})\%$ 319
 
$\Gamma_{16}$ ${{\mathit \pi}^{0}}{{\mathit \chi}_{{{c0}}}}$   $<13\%$ CL=90% 411
 
$\Gamma_{17}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}_{{{c}}}{(1S)}}$   $<13\%$ CL=90% 745
 
$\Gamma_{18}$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \chi}_{{{c0}}}}$   $<6\%$ CL=90% 347
 
$\Gamma_{19}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \chi}_{{{c0}}}}$   $<2.0\%$ CL=90% 340
 
$\Gamma_{20}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \chi}_{{{c1}}}}$   $<7\times 10^{-3}$ CL=90% 218
 
$\Gamma_{21}$ ${{\mathit p}}{{\overline{\mathit p}}}$   $<2.2\times 10^{-5}$ CL=95% 1693
 
FOOTNOTES