Abstract
A search for the rare double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of . A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the decay as normalization, the branching fraction is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions.
- Received 8 May 2023
- Accepted 14 June 2023
DOI:https://doi.org/10.1103/PhysRevLett.131.091903
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
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