| Article | |
| Report number | arXiv:2404.03643 ; CERN-TH-2024-044 |
| Title | Exploring scalar contributions with $K^+ \to \pi^+ \ell^+ \ell^-$ |
| Related title | Exploring scalar contributions with K+ → π+ℓ+ℓ− |
| Author(s) | D'Ambrosio, G. (INFN, Naples) ; Iyer, A.M. (Indian Inst. Tech., New Delhi) ; Mahmoudi, F. (IP2I, Lyon ; CERN ; IUF, Paris) ; Neshatpour, S. (IP2I, Lyon) |
| Publication | 2024-06-26 |
| Imprint | 2024-04-04 |
| Number of pages | 4 |
| In: | Phys. Lett. B 855 (2024) 138824 |
| DOI | 10.1016/j.physletb.2024.138824 (publication) |
| Subject category | hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology |
| Abstract | The rare kaon decay $K^+ \to \pi^+\ell^+\ell^-$ offers insights into Standard Model (SM) physics and beyond. Driven by vector form factor in the SM, it can also probe non-standard contributions. In this letter we study the scalar contribution, $f_S$. Using differential decay width and Forward-Backward Asymmetry we propose a simultaneous fit to vector and scalar contributions which is necessary for a consistent analysis. Novel bounds on $|f_S|$ are presented for the first time through a reinterpretation of the E865, NA48/2, and NA62 experimental results. The analysis results in the most precise bound $f_S < 7.9\times 10^{-6}$ at 90$\%$ confidence level. |
| Copyright/License | preprint: (License: CC BY 4.0) publication: © 2024 The Author(s) (License: CC BY 4.0) |
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Record created 2024-04-06, last modified 2024-09-19