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arXiv · 1205.0299

Electroweak two-loop corrections to sin^2θ(eff,bb) and R(b) using numerical Mellin-Barnes integrals

A. Freitas·Yi-Cheng Huang
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Abstract

Multi-loop integrals can be evaluated numerically using Mellin-Barnes representations. Here this technique is applied to the calculation of electroweak two-loop correction with closed fermion loops for two observables: the effective weak mixing angle for bottom quarks, sin^2θ(eff,bb), and the branching ratio of the Z boson into bottom quarks, R(b). Good agreement with a previous result for sin^2θ(eff,bb) is found. The result for R(b) is new, and a simple parametrization formula is provided which approximates the full result within integration errors.

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A. Freitas, Yi-Cheng Huang. 2013-09-13. Electroweak two-loop corrections to sin^2θ(eff,bb) and R(b) using numerical Mellin-Barnes integrals. https://doi.org/10.1007/jhep08(2012)050%2C%2010.1007%2Fjhep05(2013)074%2C%2010.1007%2Fjhep10(2013)044

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