SciPost Submission Page
Search for heavy scalar or pseudoscalar states in $\mathrm{t \bar{t}}$ events at CMS
by Laurids Jeppe for the CMS collaboration
Submission summary
| Authors (as registered SciPost users): | Laurids Jeppe |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2411.18414v1 (pdf) |
| Date submitted: | 2024-12-02 12:21 |
| Submitted by: | Jeppe, Laurids |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | The 17th International Workshop on Top Quark Physics (TOP2024) |
| Ontological classification | |
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| Academic field: | Physics |
| Specialties: |
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| Approach: | Experimental |
Abstract
A search for scalar or pseudoscalar states decaying to a top quark-antiquark pair ($\mathrm{t \bar{t}}$), using $138\,\mathrm{fb}^{-1}$ of pp collision data taken at $\sqrt{s} = 13\,\mathrm{TeV}$ using the CMS detector, is presented. Events with one or two leptons are analyzed using the invariant $\mathrm{t \bar{t}}$ mass ($m_{\mathrm{t \bar{t}}}$) as well as angular and spin correlation observables. An excess in the data is observed for low values of $m_{\mathrm{t \bar{t}}}$, preferring a pseudoscalar over a scalar hypothesis. It is interpreted in terms of a generic model of (pseudo)scalar boson production, as well as a simplified model of a $\mathrm{t \bar{t}}$ bound state ($\eta_{\mathrm{t}}$), yielding good agreement with the data. Moreover, limits on the couplings of additional (pseudo)scalar bosons to top quarks are set.
Current status:
Reports on this Submission
Report #1 by Samuel Calvet (Referee 1) on 2025-1-7 (Invited Report)
Strengths
1- Important result revealing potential new bound state, the first one in the top quark sector
2- New limits on the A/H production with the largest dataset analyzed by CMS for this search (138fb-1)
Weaknesses
1- Some sentences need to be clarified
2- Some important details could be added
Report
This proceedings are a very good summary of the very interesting result presented at TOP2024, on the search for new (pseudo)scalar decaying into top quark pairs.
It reports the evidence of a new bound state, $\eta_{top}$, the very first one in the top sector. Assuming this new state, predicted by the Standard Model of particle physics, it provided new limits on the production of Beyond the Standard Model (pseudo)scalars.
I highly recommend its publication once a few minor changes have been made.
Requested changes
1- " It consists of a generic spin0, color-singlet, pseudoscalar resonance coupling directly to gluons and top quarks". Could you provide the couplings values that have been used ? And what is the actual width of $\eta_{top}$
2- " due to the coarse experimental mt¯t resolution ". Could you provide the values of the resolution ? This detail was provided in the answer to questions asked at Saint-Malo
3- "an energy correction factor is applied for events with exactly three jets" Could you say on what assumptions this factor is computed ?
4- Explain what are $c_{hel}$ and $c_{han}$ or provide a reference
Recommendation
Ask for minor revision