Using a total of 9.0 fb-1 of e+e- collision data with center-of-mass energies between 4.15 and 4.30 GeV collected by the BESIII detector, we search for the processes e+e-→γX(3872) with X(3872)→π0χcJ for J=0, 1, 2. We report the first observation of X(3872)→π0χc1, a new decay mode of the X(3872), with a statistical significance of more than 5σ for all systematic fit variations. Normalizing to the previously established process e+e-→γX(3872) with X(3872)→π+π-J/ψ, we find B(X(3872)→π0χc1)/B(X(3872)→π+π-J/ψ)=0.88-0.27+0.33±0.10, where the first error is statistical and the second is systematic. We set 90% confidence level upper limits on the corresponding ratios for the decays to π0χc0 and π0χc2 of 19 and 1.1, respectively.
Observation of the Decay X (3872) →π0χc1 (1P)
Pacetti S.;
2019
Abstract
Using a total of 9.0 fb-1 of e+e- collision data with center-of-mass energies between 4.15 and 4.30 GeV collected by the BESIII detector, we search for the processes e+e-→γX(3872) with X(3872)→π0χcJ for J=0, 1, 2. We report the first observation of X(3872)→π0χc1, a new decay mode of the X(3872), with a statistical significance of more than 5σ for all systematic fit variations. Normalizing to the previously established process e+e-→γX(3872) with X(3872)→π+π-J/ψ, we find B(X(3872)→π0χc1)/B(X(3872)→π+π-J/ψ)=0.88-0.27+0.33±0.10, where the first error is statistical and the second is systematic. We set 90% confidence level upper limits on the corresponding ratios for the decays to π0χc0 and π0χc2 of 19 and 1.1, respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.