Measurements of Higgs boson production cross-sections in the H → τ+τ− decay channel in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

Abstract

Measurements of the production cross-sections of the Standard Model (SM) Higgs boson (H) decaying into a pair of τ-leptons are presented. The measurements use data collected with the ATLAS detector from pp collisions produced at the Large Hadron Collider at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 139 fb−1. Leptonic (τ → ℓνℓντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. All measurements account for the branching ratio of H → ττ and are performed with a requirement |yH| < 2.5, where yH is the true Higgs boson rapidity. The cross-section of the pp → H → ττ process is measured to be 2.94 ±$$ 0.21{\left(\mathrm{stat}\right)}_{-0.32}^{+0.37} $$ 0.21 stat − 0.32 + 0.37 (syst) pb, in agreement with the SM prediction of 3.17 ± 0.09 pb. Inclusive cross-sections are determined separately for the four dominant production modes: 2.65 ±$$ 0.41{\left(\mathrm{stat}\right)}_{-0.67}^{+0.91} $$ 0.41 stat − 0.67 + 0.91 (syst) pb for gluon-gluon fusion, 0.197 ±$$ 0.028{\left(\mathrm{stat}\right)}_{-0.026}^{+0.032} $$ 0.028 stat − 0.026 + 0.032 (syst) pb for vector-boson fusion, 0.115 ±$$ 0.058{\left(\mathrm{stat}\right)}_{-0.040}^{+0.042} $$ 0.058 stat − 0.040 + 0.042 (syst) pb for vector-boson associated production, and 0.033 ±$$ 0.031{\left(\mathrm{stat}\right)}_{-0.017}^{+0.022} $$ 0.031 stat − 0.017 + 0.022 (syst) pb for top-quark pair associated production. Measurements in exclusive regions of the phase space, using the simplified template cross-section framework, are also performed. All results are in agreement with the SM predictions.

Quartic Gauge-Higgs couplings: constraints and future directions

“…In concrete UV extensions, some of which we alluded to above, the answer is immediately provided by examining the H 2 V 2 operators and their relation to the theories' input parameters; they will not be free parameters and typically be predictions of BSM electroweak input parameters that are more precisely determined from other measurements. 4 As the analyses and measurements of [36,38] are model-independent in the sense that they modify certain parameters whilst keeping others entirely SM-like, our task is to house these assumptions in a theoretically meaningful way. This requires an approach with which correlations are not plagued by inconsistencies displayed by eq.…”

“…The observation of H → γγ with a rate in agreement with the SM prediction indicated alignment of the fermion-Higgs interactions as part of the Higgs discovery for the top quark. Later analyses in other fermion decay modes of the Higgs boson [3][4][5][6] have further established the Higgs boson as SM-like.…”

Constraining the Higgs boson self-coupling in a combined measurement of single and double Higgs boson channels at the ATLAS experiment

“…The detailed discussion of the sources of systematic uncertainty implemented in the individual analyses is described in Ref. [10][11][12][13][14][15][16][17][18][19], and the correlation model adopted for the systematic uncertainties within the single-Higgs combination is described in detail in Ref. [21].…”

“…This combination is used to set constraints on the production cross-section and on . More stringent constraints on are also reported, from the combination of results with the combination of recent single-Higgs analyses in the , * , + − , * , and ¯ [13][14][15][16][17][18][19] decay channels at ATLAS. The single-Higgs measurements of the simplified template cross-sections (STXS) and the results have been parameterised to take into account the impact of and the other coupling modifiers.…”

Development of novel experimental techniques to improve the understanding of the Higgs sector by the ATLAS experiment

“…VBF H → ττ : For the analysis of vector boson fusion (VBF) production of a Higgs boson that decays to τ-leptons (Ref. [14], referred to as VBF H → ττ ), the irreducible Z(ττ)+jets background MC prediction suffers from modelling inaccuracies due to the simulation of τ-decays inside the ATLAS detector volumne. To correct this a kinematic object embedding procedure was adopted, akin to that of the b-jet embedding procedure of Ref.…”