A search is presented for the four-body decay $B^0\rightarrow p p \bar{ p} \bar{ p}$ in a sample of $471$ million $B\bar{ B}$ pairs collected with the BaBar detector, operated at the SLAC PEP-II asymmetric-energy $e^+e^-$ collider. The center-of-mass energy is $10.58$ GeV. From a fit to the distribution of the energy-substituted mass $m_{ \mathrm{ ES}}$, the result $\mathcal{ B}(B^0\rightarrow p p \bar{ p} \bar{ p})=(1.1 \pm 0.5 \pm 0.2) \times 10^{ -7}$ is extracted, where the first uncertainty is statistical and the second is systematic. The significance of the signal is $2.9$ standard deviations. The upper limit on the branching fraction is determined to be $2.0 \times 10^{ -7}$ at $90\%$ confidence level.
Categories: hep-ex