Pierre Auger collaboration (513 authors)Abreu, PedroAndringa, SofiaAssis, PedroBrogueira, PedroCazon, LorenzoConceição, RubenDiogo, FranciscoEspadanal, JoaoGonçalves, PatríciaPimenta, MárioSanto, Catarina ESantos, EvaTomé, Bernardo2019-02-032019-02-032012-08http://dx.doi.org/10.1103/PhysRevLett.109.062002http://hdl.handle.net/10400.26/26243We report a measurement of the proton-air cross-section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analysing the tail of the distribution of the shower maxima, a proton-air cross-section of $[505\pm22(stat)^{+28}_{-36}(sys)]$ mb is found.engjournal article2019-02-03