2021/11/11 by Cihan Pazarbaşı, Pazarbaşı, Cihan
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Neutrino Physics Research #Noncommutative and Quantum Gravity Theories #Particle physics theoretical and experimental studies #Quantum Mechanics and Applications
paper · pdf · doi:10.48550/arxiv.2111.06204
openalex publication_date 2021/11/11 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
The pair production of scalar particles in electromagnetic background fields\nis analyzed using real proper time formulation of 1-loop effective action.\nAfter explaining how real proper time formulation keeps unitarity of the\nparticle creation process in an unambiguous way and discussing the (lack of)\npair production in uniform (magnetic) electric backgrounds, we apply these\nideas to general electric field backgrounds. Our approach is based on a\nrecursive perturbative expansion of the proper time propagator U(t) and we\nshow how the pair production probabilities can be obtained from its\nsingularities which arises upon a Pade summation of the expansion. We computed\nthe pair production probabilities for general space or time dependent electric\nfields in locally constant approximation and showed they match with the\nwell-known worldline instanton calculations of pulse and periodic backgrounds.\nLater, for one dimensional periodic electric and magnetic backgrounds, we\nshowed how the WKB integrals appear in the classical limit. We linked both\ncases to specific WKB cycles in different spectral regions of the WKB problem\nand computed the WKB actions by evaluating the WKB integrals as well as by\ntaking phase space integrals directly along Lefschetz thimbles. Finally, we\nexplain the equivalence of our construction with exact WKB method in the\nclassical limit by showing how the WKB cycles precisely contribute to the pair\nproduction process which is in complete agreement with our time dependent\nsetting.\n