2023/08/15 by Sumit Banik, Guglielmo Coloretti, Banik, Sumit +5 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle Detector Development and Performance #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2308.07953
openalex publication_date 2023/08/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Statistically significant tensions between the Standard Model (SM) predictions and the measured lepton distributions in differential top cross-sections emerged in LHC Run~1 data and became even more pronounced in Run~2 analyses. Due to the level of sophistication of the SM predictions and the performance of the ATLAS and CMS detectors, this is very remarkable. Therefore, one should seriously consider the possibility that these measurements are contaminated by beyond-the-SM contributions. In this article, we use differential lepton distributions from the latest ATLAS t t analysis to study a new physics benchmark model motivated by existing indications for new Higgses: a new scalar H is produced via gluon fusion and decays to S^′ (95 GeV) and S (152 GeV), which subsequently decay to b b and WW, respectively. In this setup, the total χ2 is reduced, compared to the SM, resulting in Δχ2=34 to Δχ2=158, depending on the SM simulation used. Notably, allowing mS to vary, the combination of the distributions points towards mS ≈ 150 GeV which is consistent with the existing γγ and WW signals, rendering a mismodelling of the SM unlikely. Averaging the results of the different SM predictions, a non-vanishing cross-section for pp→ H→ SS^′→ b b WW of ≈ 13pb is preferred. If S^′ is SM-like, this cross-section, at the same time explains the 95 GeV γγ excess, while the dominance of S→ WW suggests that S is the neutral component of the SU(2)L triplet with hypercharge~0.