Search for X(3872) and X(3915) decay into

V. Bhardwaj¹,

S. Jia²,

I. Adachi³

et al.

Abstract

We report a search for Xð3872Þ and Xð3915Þ in B þ → χ c1 π 0 K þ decays. We set an upper limit of BðB þ → Xð3872ÞK þ Þ × BðXð3872Þ → χ c1 π 0 Þ < 8.1 × 10 −6 and BðB þ → Xð3915ÞK þ Þ × BðXð3915Þ → χ c1 π 0 Þ < 3.8 × 10 −5 at 90% confidence level. We also measure BðXð3872Þ → χ c1 π 0 Þ=BðXð3872Þ → J=ψπ þ π − Þ < 0.97 at 90% confidence level. The results reported here are obtained from 772 × 10 6 BB events collected at the ϒð4SÞ resonance with the Belle detector at the KEKB asymmetric-energy e þ e − collider.

Search for $X(3872)\toπ^0χ_{c0}$ and $X(3872)\toππχ_{c0}$ at BESIII

“…Since BESIII recently measured B(X(3872)→π 0 χc1) B(X(3872)→π + π − J/ψ) = 0.88 +0.33 −0.27 ± 0.10 [9], we can measure both of these quantities at BESIII. The Belle Collaboration has also performed a search for X(3872) → π 0 χ c1 , and they set an upper limit on B(X(3872)→π 0 χc1) B(X(3872)→π + π − J/ψ) of 0.97 at 90% confidence level [17], which is consistent with the measurement of BESIII [9].…”

Decays of X(3872) to χcJπ0 and Zhou1, Yu2, Xiao3 2019Phys. Rev. D

“…Our result is smaller than the central value measured by BESIII [8], but we noticed that the result of BESIII has sizable uncertainties, and more data are needed to increase the statistics and reduce the error bar. In Belle's experiment, no significant evidence of the Xð3872Þ signal was observed in B þ → χ c1 π 0 K þ [9], though its upper limit of BðXð3872Þ→χ c1 π 0 Þ BðXð3872Þ→J=ψπ þ π − Þ does not contradict with BESIII's result. Recently, the Belle II Collaboration has started to accumulate data with higher statistics and it is expected that more accurate measurements could be obtained in the future.…”

“…Soon after, the Belle Collaboration made a search for Xð3872Þ in B þ → χ c1 π 0 K þ but did not find a significant signal of Xð3872Þ → χ c1 π 0 . They reported an upper limit [9] BðXð3872Þ → χ c1 π 0 Þ BðXð3872Þ → J=ψπ þ π − Þ < 0.97 ð2Þ at 90% confidence level.…”

The $XYZ$ states: experimental and theoretical status and perspectives

“…Previously, Belle measured B + → K + π 0 χ c1 and provided the background-subtracted π 0 χ c1 mass distribution without any structure at the X(3872) mass [89], but the bin width of that mass spectrum is too large to claim a contradictory result. Considering this, very recently Belle updated the analysis of B + → χ c1 π 0 K + decays to focus on the X(3872) mass region [90] using 772 × 10 6 BB events. No statistically significant X(3872) signal at around 3872 MeV can be seen in the χ c1 π 0 mass spectrum even with a much narrower bin width.…”