This Letter presents results from a combination of searches for Higgs boson pair production using 126-140ââfb^{-1} of proton-proton collision data at sqrt[s]=13ââTeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.4 assuming no Higgs boson pair production. Constraints on the Higgs boson self-coupling modifier Îș_{λ}=λ_{HHH}/λ_{HHH}^{SM}, and the quartic HHVV coupling modifier Îș_{2V}=g_{HHVV}/g_{HHVV}^{SM}, are derived individually, fixing the other parameter to its SM value. The observed 95% CL intervals are -1.2<Îș_{λ}<7.2 and 0.6<Îș_{2V}<1.5, respectively, while the expected intervals are -1.6<Îș_{λ}<7.2 and 0.4<Îș_{2V}<1.6 in the SM case. Constraints obtained for several interaction parameters within Higgs effective field theory are the strongest to date, offering insights into potential deviations from SM predictions.
Combination of Searches for Higgs Boson Pair Production in đâąđ Collisions at âđ =13ââTeV with the ATLAS Detector
M. Cristoforetti;A. Di Luca
2024-01-01
Abstract
This Letter presents results from a combination of searches for Higgs boson pair production using 126-140ââfb^{-1} of proton-proton collision data at sqrt[s]=13ââTeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.4 assuming no Higgs boson pair production. Constraints on the Higgs boson self-coupling modifier Îș_{λ}=λ_{HHH}/λ_{HHH}^{SM}, and the quartic HHVV coupling modifier Îș_{2V}=g_{HHVV}/g_{HHVV}^{SM}, are derived individually, fixing the other parameter to its SM value. The observed 95% CL intervals are -1.2<Îș_{λ}<7.2 and 0.6<Îș_{2V}<1.5, respectively, while the expected intervals are -1.6<Îș_{λ}<7.2 and 0.4<Îș_{2V}<1.6 in the SM case. Constraints obtained for several interaction parameters within Higgs effective field theory are the strongest to date, offering insights into potential deviations from SM predictions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.