Search for a $\mu^+ \mu^{\mathstrut -}$ resonance in four-muon final states at Belle II

Sumitted to PubDB: 2023-08-11

Category: Physics / performance paper

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Principal Authors Giacomo De Pietro, Enrico Graziani, Gianluca Inguglia, Martina Laurenza, Rajesh Kumar Maiti
Date 2024-06-01
Working group Dark Sector and Low Multiplicity
Belle II Number BELLE2-PUB-PH-2023-007
Abstract We report on a search for a resonance $X$ decaying to a pair of muons in $e^{+}e^{-}\rightarrow \mu^+ \mu^- X$ events in the 0.212-9.000 GeV/$c^{2}$ mass range, using 178 fb$^{-1}$ of data collected by the BelleII experiment at the SuperKEKB collider at a center of mass energy of 10.58 GeV. The analysis probes two different models of $X$ beyond the standard model: a $Z^{\prime}$ vector boson in the $L_{\mu}-L_{\tau}$ model and a muonphilic scalar. We observe no evidence for a signal and set exclusion limits at the 90$\%$ confidence level on the products of cross section and branching fraction for these processes, ranging from 0.046 fb to 0.97 fb for the $L_{\mu}-L_{\tau}$ model and from 0.055 fb to 1.3 fb for the muonphilic scalar model. For masses below 6 GeV/$c^{2}$, the corresponding constraints on the couplings of these processes to the standard model range from 0.0008 to 0.039 for the $L_{\mu}-L_{\tau}$ model and from 0.0018 to 0.040 for the muonphilic scalar model. These are the first constraints on the muonphilic scalar from a dedicated search.
ArXiv https://arxiv.org/abs/2403.02841
Inspire https://inspirehep.net/literature/2764835
DOI 10.1103/PhysRevD.109.112015
Reference Phys.Rev.D 109, 112015 (2024)
Bibtex 
@article{Belle-II:2024wtd,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Search for a {\ensuremath{\mu}}+{\ensuremath{\mu}}- resonance in four-muon final states at Belle II}",
    eprint = "2403.02841",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "2024-007, 2023-55",
    doi = "10.1103/PhysRevD.109.112015",
    journal = "Phys. Rev. D",
    volume = "109",
    number = "11",
    pages = "112015",
    year = "2024"
}
Journal Phys.Rev.D

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