# First evidence for the two-body charmless baryonic decay $B^0 \to p \bar{p}$

Abstract : The results of a search for the rare two-body charmless baryonic decays $B^0 \to p \bar{p}$ and $B_s^0 \to p \bar{p}$ are reported. The analysis uses a data sample, corresponding to an integrated luminosity of 0.9 fb$^{-1}$, of $pp$ collision data collected by the LHCb experiment at a centre-of-mass energy of 7 TeV. An excess of $B^0 \to p \bar{p}$ candidates with respect to background expectations is seen with a statistical significance of 3.3 standard deviations. This is the first evidence for a two-body charmless baryonic $B^0$ decay. No significant $B_s^0 \to p \bar{p}$ signal is observed, leading to an improvement of three orders of magnitude over previous bounds. If the excess events are interpreted as signal, the 68.3% confidence level intervals on the branching fractions are {eqnarray} \cal{B}(B^0 \to p \bar{p}) & = & (1.47 \,^{+0.62}_{-0.51} \,^{+0.35}_{-0.14}) \times 10^{-8} \,, *{0.3cm} \cal{B}(B_s^0 \to p \bar{p}) & = & (2.84 \,^{+2.03}_{-1.68} \,^{+0.85}_{-0.18}) \times 10^{-8} \,, {eqnarray} where the first uncertainty is statistical and the second is systematic.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00904575
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Submitted on : Thursday, November 14, 2013 - 5:08:10 PM
Last modification on : Thursday, December 16, 2021 - 2:10:05 PM

### Citation

R. Aaij, Y. Amhis, S. Barsuk, O. Callot, J. He, et al.. First evidence for the two-body charmless baryonic decay $B^0 \to p \bar{p}$. Journal of High Energy Physics, Springer, 2013, 10, pp.005. ⟨10.1007/JHEP10(2013)005⟩. ⟨in2p3-00904575⟩

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