Agradecimentos: We thank L. Jenkovszky, M. J. Menon and J. Soffer for useful discussions. A. G. acknowledges partial support by Spanish MEC (FPA2010-16696, AIC-D-2011-0818) and by Junta de Andalucia (FQM 6552, FQM 101). D. A. F. acknowledges the São Paulo Research Foundation (FAPESP) for financial support (contract: 2012/12908-4). G. P. thanks the MIT Center for Theoretical Physics for hospitality, and Y. N. S. thanks Northeastern University Physics Department Ver menos

Abstract: We describe the main features of recent LHC data on elastic pp scattering through a simple parametrization to the amplitude, inspired by a model proposed by Barger and Phillips in 1973, comprised of two exponentials with a relative phase. Despite its simplicity, this parametrization reproduces two essential aspects of the elastic differential cross section: the well-known precipitous descent in the forward direction and a sharp "dip'' structure. To include a complete description of data sets near -t =0 lecting the proton form factor. We find good descriptions of LHC7 and ISR data in either case. The form-factor model allows simple predictions for higher energies through asymptotic theorems and asymptotic sum rules in impact parameter space. We present predictions for this model at higher LHC energies, which can be used to test whether asymptotia is reached. The black-disk limit in this model is seen to be reached only for root S 10(6) TeV Ver menos