Multiphoton amplitude in a constant background field
Department of Physics, Gomal University, 29220 D.I. Khan, K.P.K., Pakistan.
2 Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio C-3, Ciudad Universitaria, Morelia 58040 Michoacán, México.
3 Center for Relativistic Laser Science, Institute for Basic Science, Gwangju 61005, Korea.
4 Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Universitá di Modena e Reggio Emilia, Via Campi 213/A, I-41125 Modena, Italy.
5 INFN, Sezione di Bologna, Via Irnerio 46, I-40126 Bologna, Italy.
6 Department of Physics, Kunsan National University, Kunsan 54150, Korea.
Published online: 9 January 2018
In this contribution, we present our recent compact master formulas for the multiphoton amplitudes of a scalar propagator in a constant background field using the worldline fomulation of quantum field theory. The constant field has been included nonperturbatively, which is crucial for strong external fields. A possible application is the scattering of photons by electrons in a strong magnetic field, a process that has been a subject of great interest since the discovery of astrophysical objects like radio pulsars, which provide evidence that magnetic fields of the order of 1012G are present in nature. The presence of a strong external field leads to a strong deviation from the classical scattering amplitudes. We explicitly work out the Compton scattering amplitude in a magnetic field, which is a process of potential relevance for astrophysics. Our final result is compact and suitable for numerical integration.
© The Authors, published by EDP Sciences, 2018
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