Search for the decay D-0 -> pi(+)pi(-)mu(+)mu(-)

Abstract

A search for the D0→ π +π −µ +µ − decay, where the muon pair does not originate from a resonance, is performed using proton-proton collision data corresponding to an integrated luminosity of 1.0 fb−1 recorded by the LHCb experiment at a centreof-mass energy of 7 TeV. No signal is observed and an upper limit on the relative branching fraction with respect to the resonant decay mode D0→ π +π −φ(→ µ +µ −), under the assumption of a phase-space model, is found to be B(D0→ π +π −µ +µ −)/B(D0 → π +π −φ(→ µ +µ −)) < 0.96 at 90% confidence level. The upper limit on the absolute branching fraction is evaluated to be B(D0→ π +π −µ +µ −) < 5.5 × 10−7 at 90% confidence level. This is the most stringent to date.