A measurement of the exclusive and semi-exclusive production of charged pion pairs in proton-proton collisions,
pp→p(p∗)+π+π−+p(p∗), where the π+π− pair is emitted at central rapidities,
and the scattered protons stay intact (p) or diffractively dissociate (p∗) without detection is presented in these proceedings.
The measurement is performed with the CMS detector at the LHC, using a data sample corresponding to an
integrated luminosity of 450μb−1 collected at a center-of-mass energy of 7 TeV.
The dipion cross section, measured for single-pion transverse momentum pT>0.2 GeV and rapidity |y|<2, is
26.5±0.3(stat.)±5.0(syst.)±1.1μb. The differential cross sections measured as a function of the invariant mass and pT of the pion pair are compared to phenomenological predictions.
