NLO QCD effective field theory analysis of W+W− production at the LHC including fermionic operators

Abstract

We study the impact of anomalous gauge boson and fermion couplings on the production of W + W − pairs at the LHC. Helicity amplitudes are presented separately to demonstrate the sources of new physics contributions and the impact of QCD and electroweak corrections. The QCD corrections have important effects on the fits to anomalous couplings, in particular when one W boson is longitudinally polarized and the other is transversely polarized. In effective field theory language, we demonstrate that the dimension-6 approximation to constraining new physics effects in W + W − pair production fails at p

Electroweak and QCD corrections to Z and W pole observables in the standard model EFT

“…A program of calculations has begun to treat the SMEFT contributions at NLO, for both the QCD and electroweak (EW) contributions. The SMEFT QCD corrections to gauge boson pair production [11,12] and top quark production and decay [13][14][15][16] are known. The electroweak SMEFT corrections to Higgs decays to bb [17][18][19], γγ [20][21][22][23], Zγ [24,25], ZZ [24], and W W [20] have also been computed, along with partial corrections to the Drell Yan process [26].…”

NLO corrections to h → b$$ \overline{b} $$ decay in SMEFT

“…Because of the increased complexity of these calculations, results are available only for a handful of processes, and often contain a limited number of operators or are restricted to a particular set of corrections. There are many NLO SMEFT calculations which involve a subset of operators [27][28][29][30][31][32][33][34], or are restricted to QCD corrections only [35][36][37][38][39][40][41][42][43][44][45]. A calculation of Higgs pair production at NNLO in QCD involving dimension-6 operators which contain the Higgs field has also been performed [46].…”

Effect of fermionic operators on the gauge legacy of the LHC Run I

“…[17,18] discussed that changes in the couplings of gauge bosons to fermions, even within the constraints of electroweak precision data (EWPD), could lead to modifications of the kinematical distributions in gauge boson pair production of comparable size to the ones stemming from the purely anomalous TGC. This motivates us to revisit the analyses of the LHC Run I data on the leptonic W þ W − and W AE Z productions to quantify the impact of anomalous couplings of gauge bosons to fermion pairs on the TGC bounds when consistently including in the statistical analysis the EWPD that comprise Z peak observables [19], W observables [20] and the Higgs mass [21].…”