# Evidence for the decay $B_c^+ \rightarrow J/\psi 3\pi^+ 2\pi^-$

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## Abstract

Evidence is presented for the decay $B_c+\rightarrow J/\psi 3\pi^+2\pi^-$ using proton-proton collision data, corresponding to an integrated luminosity of 3fb$^{-1}$, collected with the LHCb detector. A signal yield of $32\pm8$ decays is found with a significance of 4.5 standard deviations. The ratio of the branching fraction of the $B_c^+\rightarrow J/\psi 3\pi^+ 2\pi^-$ decay to that of the $B_c^+ \rightarrow J/\psi \pi^+$ decay is measured to be $$\frac{Br (B_c^+ \rightarrow J/\psi 3\pi^+2\pi^)}{Br (B_c^+ \rightarrow J/\psi \pi^+)} = 1.74\pm0.44\pm0.24,$$ where the first uncertainty is statistical and the second is systematic.

## Figures and captions

 Mass distribution for selected $B _ c ^+ \!\rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} 3\pi ^+ 2\pi ^-$ candidates. The result of a fit using the model described in the text (red solid line) is shown together with the background component (blue dashed line). [Failure to get the plot] Background-subtracted distribution of five-pion mass from $B _ c ^+ \!\rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} 3\pi ^+ 2\pi ^-$ events (points with error bars). The model prediction from Ref. [14] is shown by a red solid line, and the expectation from the phase space model is shown by a blue dashed line. [Failure to get the plot] Mass distribution for selected $B _ c ^+ \!\rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \pi ^+$ candidates. The result of a fit using the model described in the text (red solid line) is shown together with the background component (blue dashed line). [Failure to get the plot]

## Tables and captions

 Signal parameters of the unbinned extended maximum likelihood fit to the ${ J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} 3\pi ^+ 2\pi ^-$ mass distribution. Uncertainties are statistical only. Table_1.pdf [78 KiB] HiDef png [34 KiB] Thumbnail [6 KiB] tex code Relative systematic uncertainties for the ratio $R_{5\pi }$. The total uncertainty is the quadratic sum of the individual components. Table_2.pdf [63 KiB] HiDef png [113 KiB] Thumbnail [17 KiB] tex code

Created on 19 April 2019.Citation count from INSPIRE on 24 April 2019.