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arXiv · hep-ex/0312021

Observation of the Narrow State $X(3872)\to J/ψπ^{+}π^{-}$ in $\bar{p}p$ Collisions at $\sqrt{s}=1.96 \TeV$

the CDF II Collaboration·D. Acosta·T. Affolder·M. H. Ahn·T. Akimoto·M. G. Albrow·D. Ambrose·S. Amerio·D. Amidei·A. Anastassov·K. Anikeev
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Abstract

We report the observation of a narrow state decaying into $J/ψπ^+π^-$ and produced in $220 pb^{-1}$ of $\bar{p} p $ collisions at $\sqrt{s}=1.96 TeV$ in the CDF II experiment. We observe $ 730 \pm 90 $ decays. The mass is measured to be $3871.3 \pm 0.7 (stat) \pm 0.4 (syst) MeV/c2$, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.

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the CDF II Collaboration, D. Acosta, T. Affolder, M. H. Ahn, T. Akimoto, M. G. Albrow, D. Ambrose, S. Amerio, D. Amidei, A. Anastassov, K. Anikeev. 2003-12-05. Observation of the Narrow State $X(3872)\to J/ψπ^{+}π^{-}$ in $\bar{p}p$ Collisions at $\sqrt{s}=1.96 \TeV$. https://doi.org/10.1103/physrevlett.93.072001

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