The gauge-Higgs legacy of the LHC Run I

Abstract

The effective Lagrangian expansion provides a framework to study effects of new physics at the electroweak scale. To make full use of LHC data in constraining higher-dimensional operators we need to include both the Higgs and the electroweak gauge sector in our study. We first present an analysis of the relevant di-boson production LHC results to update constraints on triple gauge boson couplings. Our bounds are several times stronger than those obtained from LEP data. Next, we show how in combination with Higgs measurements the triple gauge vertices lead to a significant improvement in the entire set of operators, including operators describing Higgs couplings.

Modeling BSM effects on the Higgs transverse-momentum spectrum in an EFT approach

“…The c g , c t and c b parameters are chosen in the ballpark suggested by the studies of refs. [83][84][85], while still keeping the inclusive cross section within about 20% of its SM value, Indeed, many combinations of c g , c t and c b can be found which mildly affect the total cross section, while significantly changing the shape of the spectrum.…”

“…Many groups translated the data already collected by the LHC as well as earlier experiments into bounds on the Wilson coefficients of dimension-six SMEFT operators (see e.g., refs. [80][81][82][83][84][85]). …”

Same-sign WW scattering at the LHC: can we discover BSM effects before discovering new states?

“…They are presently known to agree with the SM within a few per cent (For a combined analysis of LEP and Run I LHC data, see e.g. [14]), which translates into stringent limits on the dimension-6 operators.…”

Multiboson interactions at the LHC

“…For instance in the recent theoretical analysis of (Butter et al, 2016) it was concluded that diboson measurements at the LHC set better bounds on operators that contribute to aTGCs than LEP. The analysis of (Butter et al, 2016) is not incorrect. The LHC can indeed measure VBF and diboson production at high p T enormously better than LEP.…”

“…In (Butter et al, 2016) a fit was performed demonstrating the increased sensitivity that the LHC had from Run I compared to LEP, an example being shown in Figure 4. However, this increased sensitivity as described in (Butter et al, 2016) comes from the high p T regions available at the LHC.…”