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

Journal article

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}) and = and (1.47 \,^{+0.62}_{-0.51} \,^{+0.35}_{-0.14}) \times 10^{-8} \,, *{0.3cm} \cal{B}(B_s^0 \to p \bar{p}) and = and (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.

Authors: collaboration, L; Aaij, R; Adeva, B; Adinolfi, M; Adrover, C

• Publication status: Published
• Journal: J. High Energy Phys.
• Volume: 10
• Issue: 10
• Pages: 005
• Publication date: 2013-08-05
• DOI: 10.1007/JHEP10(2013)005
• EISSN: 1029-8479
• ISSN: 1029-8479
• Keywords: hep-ex