Amplitude analysis of the D ⁺ ? p ^- p ⁺ p ⁺ decay and measurement of the p ^- p ⁺ S-wave amplitude

An amplitude analysis of the D + ? p - p + p + decay is performed with a sample corresponding to 1.5 fb -1 of integrated luminosity of pp collisions at a centre-of-mass energy s = 8 TeV collected by the LHCb detector in 2012. The sample contains approximately six hundred thousand candidates with a signal purity of 95%. The resonant structure is studied through a fit to the Dalitz plot where the p - p + S-wave amplitude is extracted as a function of p - p + mass, and spin-1 and spin-2 resonances are included coherently through an isobar model. The S-wave component is found to be dominant, followed by the ?(770)0 p + and f 2(1270)p + components. A small contribution from the ?(782) ? p - p + decay is seen for the first time in the D + ? p - p + p + decay. [Figure not available: see fulltext.]