{
  "id": 14526380,
  "title": "Rare particle decays hint at deviations from Standard Model predictions",
  "url": "https://urgent.news/2026/10/14/rare-particle-decays-hint-at-deviations-from-standard-model",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-14T19:50:01.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-10-rare-particle-decays-hint-deviations.html"
  },
  "original_language": "en",
  "account": "Recent particle physics research conducted at the International Conference on High Energy Physics (ICHEP) has revealed intriguing hints of potential deviations from the predictions of the Standard Model. One such process under investigation is the transformation of a beauty quark into a strange quark, muon, and oppositely charged antimuon (b→sμ⁺μ⁻). Fluctuations in the behavior of these quark transitions could indicate the presence of undiscovered particles or interactions beyond the Standard Model.\n\nThe b→sμ⁺μ⁻ transition is particularly rare, occurring once in every 10 million decays of beauty particles. Over the past decade, there have been hints that this transition might not occur as anticipated. To explore this further, the CMS and LHCb collaborations analyzed the decays of beauty particles into particles containing strange quarks alongside muons and antimuons. The study involved measuring the individual rates of these decays, described by branching fractions, and examined six types of these decays simultaneously to ensure consistent treatment of background signals and uncertainties in the data.\n\nCMS collected a significantly larger sample of data from these decays compared to previous analyses, utilizing a new trigger that enabled precise measurements of branching fractions with unprecedented statistical uncertainty. In parallel, the LHCb collaboration analyzed one of the six decay types: the transition of a neutral beauty meson containing an antibeauty quark to an excited kaon containing a strange quark (B⁰→K*μ⁺μ⁻). This analysis provided a measurement of the property P₅, which describes the angles at which the decay products travel after being produced.\n\nLHCb's measurement using a new model-independent analysis technique indicated a slight difference compared to the predictions made using the Standard Model. This observation, along with similar findings from CMS, suggests small but consistent deviations from the Standard Model predictions. While these results are not conclusive, they provide strong motivation for further investigation of the b→sμ⁺μ⁻ transition.\n\nModel-independent angular analysis of the B⁰→K*μ⁺μ⁻ decay also revealed a small discrepancy from the Standard Model predictions. However, neither result provides conclusive evidence of physics beyond the Standard Model. As researchers continue to take increasingly detailed measurements of rare processes, hints of unknown particles or interactions may become more apparent, potentially leading to a deeper understanding of the fundamental forces that govern our universe.",
  "summary": "Studying rare processes is part and parcel of particle physics, providing stringent tests of the Standard Model. At the recent International Conference on High Energy Physics (ICHEP), the CMS and LHCb collaborations presented their latest research into one such process: the transformation of a beauty quark into a strange quark, a muon and the oppositely charged antimuon (b→sμ⁺μ⁻).",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}