, 72:1972,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 04 May 2012

Observation of X(3872) production in pp collisions at \(\sqrt{s}=7\mbox{~TeV}\)


Using 34.7 pb−1 of data collected with the LHCb detector, the inclusive production of the X(3872) meson in pp collisions at \(\sqrt{s}=7\mbox{~TeV}\) is observed for the first time. Candidates are selected in the X(3872)→J/ψπ + π decay mode, and used to measure where σ(ppX(3872)+anything) is the inclusive production cross section of X(3872) mesons with rapidity in the range 2.5–4.5 and transverse momentum in the range 5–20 GeV/c. In addition the masses of both the X(3872) and ψ(2S) mesons, reconstructed in the J/ψπ + π final state, are measured to be $$m_{X(3872)} = 3871.95 \pm0.48 \ (\mathrm{stat}) \pm0.12 \ (\mathrm {syst})\ \mathrm{MeV}/c^2 $$ and $$m_{\psi(2S)} = 3686.12\pm0.06 \ (\mathrm{stat}) \pm0.10 \ (\mathrm {syst})\ \mathrm{MeV}/c^2. $$