Gildener-Weinberg Higgs Bosons

Jon Butterworth, Ken Lane, David Sperka, Joshua Giblin-Burnham

A study was performed at the Les Houches workshop 2019, see Confronting Gildener-Weinberg Higgs bosons with LHC measurements in [125] for the model details etc. Essentially the model imposes a relationship between the Higgs masses indicated by the purple line on the mass plot. These were the results at that time:

(\(\tan\beta = 0.5\))

(for points on the purple line in the previous plot). Note the inverted defintion of \(\tan\beta\) described in the proceedings. Updated results are given below (skip to the end for the latest).

The Les Houches were updated for Contur 2.0.x:

where the measurements added since Les Houches can be seen to have an impact. The final states which contribute can be seen below.

The model is now disfavoured at the one sigma level over most of the region allowed region, for \(\tan\beta = 0.5\).

The full run 2 dilepton search from ATLAS, not included above, also has some sensitivity at the one sigma level, extending to even lower \(\tan\beta\) at high masses. However, the dileptons entering the search region are not from a resonance and so the “bump hunt” approach of the search is unreliable. An eventual high luminosity dilepton measurement should however have some impact.

A further update (Summer 2022) was made using the data available in Rivet 3.1.6 and the Contur 2.4 release candidate. As well as new data, this includes some improved treatment of error correlations in Contur, and an emphasis on using the SM predictions directly as background. The exclusion in this mode is:

The white line shows the new 95% exclusion using data as background; it is significantly extended to lower \(\tan\beta\) by the new data compared to the limits in the plots above.

The solid black and dashed black contours now show the limits where the SM predictions for the background are used directly. The exclusion is weaker than the white line, because not all measurements yet have SM predictions available in Contur, and in part because the SM uncertainties are no longer neglected. Nevertheless, the limits are much stronger than the initial study, excluding most of a band around charged Higgs masses of 320 GeV or so. They are also quite close to the expect exclusion (dotted black line).

For the mass correlation with SM as background we have further excluded the majority of the region at a one sigma level for \(\tan\beta = 0.5\), with the majority of masses at 300 GeV or above being disfavoured at one sigma. The two sigma exclusion has also expanded over the central region and with the data as background the whole model is disfavoured at one sigma over this region at \(\tan\beta = 0.5\).

The main analyses responsible for the exclusion are illustrated below. New photon measurements (ATLAS_13_GAMMA pool) are responsible for most of the excluded region at \(\tan\beta = 0.5\), with the four-lepton analyses contributing at lower \(M_H\), and missing energy plus jets (LMETJET, mainly semileptonic top measurements in this case) contributing at higher masses. When data was used as background, dilepton-plus-jet signature also contributed (orange region in the first plot showing the pools). For several of these measurement Contur does not currently have access to the SM predictions, so they are not used here.

Over the full mass and \(\tan\beta\) range, the WW analyses (L1L2METJET) and and W (LMETJET) analysis dominate, and lower and higher masses respectively.

The model files are available in the G-W directory here