Ultrahigh-Energy Neutrino-Nucleon Cross Sections and Perturbative Unitarity
نویسندگان
چکیده
Unitarity relates the total cross section for neutrino-nucleon scattering to the neutrino-nucleon forward scattering amplitude. Assuming the validity of the perturbative expansion of the forward amplitude in the weak coupling constant, we derive a unitarity bound on the inelastic cross section. The inelastic cross section saturates this bound at a typical neutrino energy Eν ≃ 108 GeV. This implies that calculations of the inelastic cross section that use current parton distribution functions and lowest order weak perturbation theory are unreliable above this energy. 13.15.+g ,25.30.Pt ,98.70.Sa Typeset using REVTEX ∗[email protected] †[email protected] ‡[email protected] §[email protected] 1
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