Search for the rare decays $B^{0}\to J/\psi \gamma$ and $B^{0}_{s} \to J/\psi \gamma$

Information

LHCb-PAPER-2015-044
CERN-PH-EP-2015-276
arXiv:1510.04866 [PDF]

(Submitted on 16 Oct 2015)
Phys. Rev. D92 (2015) 112002
Inspire 1398352

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Abstract

A search for the rare decay of a $B^{0}$ or $B^{0}_{s}$ meson into the final state $J/\psi\gamma$ is performed, using data collected by the LHCb experiment in $pp$ collisions at $\sqrt{s}=7$ and $8$ TeV, corresponding to an integrated luminosity of 3 fb$^{-1}$. The observed number of signal candidates is consistent with a background-only hypothesis. Branching fraction values larger than $1.7\times 10^{-6}$ for the $B^{0}\to J/\psi\gamma$ decay mode are excluded at 90 confidence level. For the $B^{0}_{s}\to J/\psi\gamma$ decay mode, branching fraction values larger than $7.4\times 10^{-6}$ are excluded at 90 confidence level, this is the first branching fraction limit for this decay.

Figures and captions

Feynman diagram of the leading contribution to the decay $ B _{(s)}\rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \gamma$ in the Standard Model. Radiation of the photon from the other quarks is suppressed by a factor of $\Lambda_{\rm{QCD}}/m_{b}$ [1].	Bs2Jps[..].pdf [9 KiB] HiDef png [165 KiB] Thumbnail [96 KiB] *.C file
Mass distribution of signal candidates with the fit result overlaid, allowing for a $ B ^0_ s \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \gamma$ signal.	data_fit.pdf [34 KiB] HiDef png [460 KiB] Thumbnail [340 KiB] *.C file
Observed $\mathrm{CL}_{\mathrm{S}}$ (black points), expected $\mathrm{CL}_{\mathrm{S}}$ (continuous line) and expected 1 and 2 $\sigma$ uncertainty (shaded bands) value as a function of the hypothesized branching fraction for the $ B ^0_ s \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \gamma$ decay (left) and $ B ^0 \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \gamma$ decay (right). The dashed line represents the branching fraction excluded at 90% C.L..	cls.pdf [15 KiB] HiDef png [249 KiB] Thumbnail [175 KiB] *.C file
	cls_bd.pdf [15 KiB] HiDef png [273 KiB] Thumbnail [191 KiB] *.C file
Animated gif made out of all figures.	PAPER-2015-044.gif Thumbnail

Tables and captions

Summary of systematic uncertainties. Each source is listed with the corresponding uncertainty on the branching fraction for the signal.

Table_1.pdf [45 KiB]
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tex code

Supplementary Material [file]

Supplementary material full pdf	supple[..].pdf [209 KiB]
	Fig1-S.pdf [17 KiB] HiDef png [259 KiB] Thumbnail [200 KiB] *C file
	Fig2-S.pdf [49 KiB] HiDef png [457 KiB] Thumbnail [348 KiB] *C file
	Fig3a-S.pdf [34 KiB] HiDef png [455 KiB] Thumbnail [347 KiB] *C file
	Fig3b-S.pdf [33 KiB] HiDef png [462 KiB] Thumbnail [353 KiB] *C file