Radiative E1 decays of X(3872)

Abstract

Radiative E1 decay widths of $\mathrm{X}(3872)$ are calculated through the relativistic Salpeter method, with the assumption that $\mathrm{X}(3872)$ is the ${\chi }_{c1}$(2P) state, which is the radial excited state of ${\chi }_{c1}$(1P). We firstly calculated the E1 decay width of ${\chi }_{c1}$(1P), the result is in agreement with experimental data excellently, then we calculated the case of $\mathrm{X}(3872)$ with the assignment that it is ${\chi }_{c1}$(2P). Results are: $Γ({\rm X(3872)}\rightarrow γ\sl J/ψ)=33.0$ keV, $\Gamma (\mathrm{X}(3872)\to \gamma \psi (2S))=146$ keV and $\Gamma (\mathrm{X}(3872)\to \gamma \psi (3770))=7.09$ keV. The ratio ${{\rm Br(X(3872)}\rightarrowγψ(2{\rm S}))}/{{\rm Br(X(3872)}\rightarrow γ{\sl J}/ψ)}=4.4$ agrees with experimental data by BaBar, but larger than the new up-bound reported by Belle recently. With the same method, we also predict the decay widths: $\Gamma ({\chi }_{b1}(1\mathrm{P}))\to \gamma \mathrm{{\rm Y}}(1\mathrm{S}))=30.0$ keV, $\Gamma ({\chi }_{b1}(2\mathrm{P}))\to \gamma \mathrm{{\rm Y}}(1\mathrm{S}))=5.65$ keV and $\Gamma ({\chi }_{b1}(2\mathrm{P}))\to \gamma \mathrm{{\rm Y}}(2S))=15.8$ keV, and the full widths: $\Gamma ({\chi }_{b1}(1\mathrm{P}))\sim 85.7$ keV, $\Gamma ({\chi }_{b1}(2\mathrm{P}))\sim 66.5$ keV.

9 pages, 4 figures, 2 tables, version to be published in Phys. Lett. B

References in corpus (10)

• Higher Charmonia and X,Y,Z states with Screened Potential
• X(3872) and Other Possible Heavy Molecular States
• Is X(3872) {\sl Really} a Molecular State?
• Reconciling the X(3872) with the near-threshold enhancement in the D^0\bar{D}^{*0} final state
• Estimate for the X(3872) to gamma J/psi decay width
• Line Shapes of the X(3872)
• Decays of the X(3872) and ${\chi }_{c1}(2P)$ charmonium
• The Effects of Charged Charm Mesons on the Line Shapes of the X(3872)
• Charmonium spectroscopy above thresholds
• Decay constants of $P$-wave mesons