Details

Autor(en) / Beteiligte

• Hartmann, Christine
• Shepherd, William
• Trott, Michael

Titel

The Z decay width in the SMEFT: y ^sub t^ and [lambda] corrections at one loop

Ist Teil von

• The journal of high energy physics, 2017-03, Vol.2017 (3), p.1

Ort / Verlag

Heidelberg: Springer Nature B.V

Erscheinungsjahr

2017

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• (ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract We calculate one loop y t and [lambda] dependent corrections to ... and the partial Z widths due to dimension six operators in the Standard Model Effective Field Theory (SMEFT), including finite terms. We assume CP symmetry and a U(3)5 symmetry in the UV matching onto the dimension six operators, dominantly broken by the Standard Model Yukawa matrices. Corrections to these observables are predicted using the input parameters ... extracted with one loop corrections in the same limit. We show that at one loop the number of SMEFT parameters contributing to the precise LEPI pseudo-observables exceeds the number of measurements. As a result the SMEFT parameters contributing to LEP data are formally unbounded when the size of loop corrections are reached until other data is considered in a global analysis. The size of these loop effects is generically a correction of order % to leading effects in the SMEFT, but we find multiple large numerical coefficients in our calculation at this order. We use a ... scheme, modified for the SMEFT, for renormalization. Some subtleties involving novel evanescent scheme dependence present in this result are explained.