dorsal/arxiv
View SchemaVariational Field Theoretic Approach to Relativistic Scattering
| Authors | C. Alexandrou, R. Rosenfelder, A. W. Schreiber |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9701036 |
| URL | https://arxiv.org/abs/nucl-th/9701036 |
| DOI | 10.1016/S0375-9474(98)00798-2 |
| Journal | Nucl.Phys. A628 (1998) 427-457 |
Abstract
Nonperturbative polaron variational methods are applied, within the so-called particle or worldline representation of relativistic field theory, to study scattering in the context of the scalar Wick - Cutkosky model. Important features of the variational calculation are that it is a controlled approximation scheme valid for arbitrary coupling strengths, the Green functions have all the cuts and poles expected for the exact result at any order in perturbation theory and that the variational parameters are simultaneously sensitive to the infrared as well as the ultraviolet behaviour of the theory. We generalize the previously used quadratic trial action by allowing more freedom for off-shell propagation without a change in the on-shell variational equations and evaluate the scattering amplitude at first order in the variational scheme. Particular attention is paid to the $s$-channel scattering near threshold because here non-perturbative effects can be large. We check the unitarity of a our numerical calculation and find it greatly improved compared to perturbation theory and to the zeroth order variational results.
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"abstract": "Nonperturbative polaron variational methods are applied, within the so-called\nparticle or worldline representation of relativistic field theory, to study\nscattering in the context of the scalar Wick - Cutkosky model. Important\nfeatures of the variational calculation are that it is a controlled\napproximation scheme valid for arbitrary coupling strengths, the Green\nfunctions have all the cuts and poles expected for the exact result at any\norder in perturbation theory and that the variational parameters are\nsimultaneously sensitive to the infrared as well as the ultraviolet behaviour\nof the theory. We generalize the previously used quadratic trial action by\nallowing more freedom for off-shell propagation without a change in the\non-shell variational equations and evaluate the scattering amplitude at first\norder in the variational scheme. Particular attention is paid to the\n$s$-channel scattering near threshold because here non-perturbative effects can\nbe large. We check the unitarity of a our numerical calculation and find it\ngreatly improved compared to perturbation theory and to the zeroth order\nvariational results.",
"arxiv_id": "nucl-th/9701036",
"authors": [
"C. Alexandrou",
"R. Rosenfelder",
"A. W. Schreiber"
],
"categories": [
"nucl-th",
"hep-th"
],
"doi": "10.1016/S0375-9474(98)00798-2",
"journal_ref": "Nucl.Phys. A628 (1998) 427-457",
"title": "Variational Field Theoretic Approach to Relativistic Scattering",
"url": "https://arxiv.org/abs/nucl-th/9701036"
},
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