Article révisé par les pairs
Résumé : We study the triple-α reaction process at low temperatures, which is known to play an important role in stellar physics. The Schrödinger equation for three α particles is solved by using hyperspherical coordinates, while a complex absorbing potential is introduced in order to describe correctly the three-body continuum states. We use an angular-momentum-independent α-α potential and introduce three-body potentials to reproduce the energies of both the Hoyle state and the first 2+ state. The triple-α reaction rate is computed accurately at temperatures from T=0.01 to 10 GK and compared with those available in the literature. Our reaction rate is found to be up to three orders of magnitude larger than the NACRE rate at low temperatures T≈0.01 GK, while we find a reasonable agreement between them at higher temperatures T 0.1 GK.