BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:First observation and branching fraction measurement of the Σ⁺ 
 → pμ⁺μ⁻ decay at LHCb
DTSTART:20250717T113000Z
DTEND:20250717T123000Z
DTSTAMP:20260809T142500Z
UID:indico-event-3905@indico.e5.physik.tu-dortmund.de
CONTACT:maik.becker@tu-dortmund.de\;serena.maccolini@cern.ch
DESCRIPTION:Speakers: Gabriele Martelli (Universität Perugia)\n\nThe Σ
 ⁺ → pμ⁺μ⁻ decay is observed for the first time at the LHCb exper
 iment using proton-proton collision data corresponding to an integrated lu
 minosity of 5.4 fb⁻¹ at a centre-of-mass energy of 13 TeV. This flavour
 -changing neutral current process is highly suppressed in the Standard Mod
 el and sensitive to potential contributions from physics beyond the Standa
 rd Model\, such as new mediators or short-distance dynamics. In particular
  the HyperCP experiment years ago presented an evidence of this decay with
  a hint of a possible unknown intermediate particle. This was excluded by 
 LHCb already in 2018. The new measurement presents a highly significant ob
 servation and a measurement of its integrated branching fraction and dimuo
 n invariant mass distribution. This is the rarest baryon decay ever observ
 ed.\nThe start of the seminar has been postponed to 13:30\n\nhttps://indic
 o.e5.physik.tu-dortmund.de/event/3905/
LOCATION:CP-03-123 (TU Dortmund)
URL:https://indico.e5.physik.tu-dortmund.de/event/3905/
END:VEVENT
END:VCALENDAR