We report a measurement of the cross section for the process e+e− → π+π−J/ψ around the X(3872) mass in search for the direct formation of e+e− → X(3872) through the two-photon fusion process. No enhancement of the cross section is observed at the X(3872) peak and an upper limit on the product of electronic width and branching fraction of X(3872) → π+π−J/ψ is determined to be Γee × B(X(3872)) → π+π−J/ψ< 7.5 × 10−3 eV at 90% confidence level under an assumption of total width of 1.19 0.21 MeV. This is an improvement of a factor of about 17 compared to the previous limit. Furthermore, using the latest result of B(X(3872) → π+π−J/ψ, an upper limit on the electronic width Γee of X(3872) is obtained to be <0.32 eV at the 90% confidence level.
Measurement of the e+e−→π+π−J/ψ cross section in the vicinity of 3.872 GeV
Garzia, I.;Scodeggio, M.;
2023
Abstract
We report a measurement of the cross section for the process e+e− → π+π−J/ψ around the X(3872) mass in search for the direct formation of e+e− → X(3872) through the two-photon fusion process. No enhancement of the cross section is observed at the X(3872) peak and an upper limit on the product of electronic width and branching fraction of X(3872) → π+π−J/ψ is determined to be Γee × B(X(3872)) → π+π−J/ψ< 7.5 × 10−3 eV at 90% confidence level under an assumption of total width of 1.19 0.21 MeV. This is an improvement of a factor of about 17 compared to the previous limit. Furthermore, using the latest result of B(X(3872) → π+π−J/ψ, an upper limit on the electronic width Γee of X(3872) is obtained to be <0.32 eV at the 90% confidence level.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
