Llanes Estrada, Felipe JoséGómez Nicola, ÁngelPeláez Sagredo, José Ramón2023-06-202023-06-202002-12-120370-2693https://hdl.handle.net/20.500.14352/58814©2002 Elsevier Science B.V. All rights reserved. The authors thank A. Dobado for useful comments and discussions. F.J.Ll.-E. thanks P. Bicudo, S. Cotanch, P. Maris, E. Ribeiro and A. Szczepaniak too. Work supported from the Spanish CICYT projects, FPA2000-0956, PB98-0782 and BFM2000-1326.We present the pion-pion elastic scattering amplitude at finite temperature to one-loop in chiral perturbation theory. The thermal scattering amplitude properly defined allows to generalize the perturbative unitarity relation to the T 0 0 case. Our result provides a model independent prediction of an enhanced pion-pion low-energy phase shift with the temperature and it has physical applications within the context of relativistic heavy ion collisions.engjournal articlehttp://dx.doi.org/10.1016/S0370-2693(02)02959-3http://arxiv.org/abs/hep-ph/0203134http://www.sciencedirect.com/open access53Rho-MesonReaction-RatesField-TheoryRulesLagrangiansImaginaryLengthsMassFísica (Física)22 Física