The Gauge-Higgs legacy of the LHC run II

Abstract

We present a global analysis of the Higgs and electroweak sector based on LHC Run II and electroweak precision observables. We show which measurements provide the leading constraints on Higgs-related operators, and how the achieved LHC precision makes it necessary to combine rate measurements with electroweak precision observables. The SFitter framework allows us to include kinematic distributions beyond pre-defined ATLAS and CMS observables, independently study correlations, and avoid Gaussian assumptions for theory uncertainties. These Run II results are a step towards a precision physics program at the LHC, interpreted in terms of effective operators.

O new physics, where art thou? A global search in the top sector

“…where σ SM is the SM prediction, σ k are contributions arising from the interference of a single dimension-6 operator with the SM, and σ kl arise from the interference of two rate measurements or the total cross section, because they offer the best statistics and often minimize theoretical uncertainties. From global Higgs-electroweak analyses we know that a modified momentum dependence can be constrained most efficiently by high-energy tails of kinematic distributions or simplified template cross sections [8][9][10][11][12][13]. † Similarly, we know that for many kinematic distributions the few bins with the highest momentum transfer include the relevant information on individual operators, whereas for several operators with a different high-energy behavior there often exist several relevant regimes [104].…”

“…† Similarly, we know that for many kinematic distributions the few bins with the highest momentum transfer include the relevant information on individual operators, whereas for several operators with a different high-energy behavior there often exist several relevant regimes [104]. † Note that for a distribution to constrain a dimension-6 contribution in this phase space region it is not necessary that we actually observe the SM process in the same phase space region [12].…”

“…[8], rather than the numerically more complex toy measurements used in Ref. [12]. To cover the full 22-dimensional parameter space we use up to 2000 Markov chains giving up to 400 million parameter points.…”

“…Part of the SMEFT framework [1][2][3][4][5] was developed as a gauge-invariant description of anomalous gauge boson interactions at LEP [6,7]. Its biggest success has been the application to Higgs and electroweak boson measurements at the LHC [8][9][10][11][12][13]. Most recently, the same approach [14][15][16] has been used to systematically analyze top quark measurements at the LHC [17][18][19][20][21] and at future colliders [22,23] and their link to bottom sector [24].…”

Flavourful SMEFT likelihood for Higgs and electroweak data

“…A straightforward observation is that SMEFT operators may simultaneously affect both Higgs and electroweak observables. Therefore it makes sense to combine the two sets in order to increase the constraining power of data [6][7][8][9][10][11][12][13][14][15][16]. This work represents another step forward in this direction.In this paper we construct a likelihood for Wilson coefficients of dimension-6 SMEFT operators using a large set of Higgs and electroweak observables.…”