LHCb experiment

LHCb is an experiment set up to explore what happened after the Big Bang that allowed matter to survive and build the Universe we inhabit today

Fourteen billion years ago, the Universe began with a bang. Crammed within an infinitely small space, energy coalesced to form equal quantities of matter and antimatter. But as the Universe cooled and expanded, its composition changed. Just one second after the Big Bang, antimatter had all but disappeared, leaving matter to form everything that we see around us — from the stars and galaxies, to the Earth and all life that it supports.

  • Measurement of the effective leptonic weak mixing angle

    Today, at the 42nd International Conference on High Energy Physics, ICHEP, Prague, Czech Republic, the LHCb collaboration reported a measurement of the effective leptonic weak mixing angle, sin2θleff, the parameter which is involved in the unification of the electromagnetic and weak forces. The result was obtained from the analysis of the forward-backward asymmetry in the…

  • Improved determination of the CKM angle γ

    Today, at the 42nd International Conference on High Energy Physics, ICHEP, Prague, Czech Republic, the LHCb collaboration reported an improved determination of the CKM angle γ with a precision better than 3°. This result was obtained by a simultaneous combination of measurements sensitive to the CP-violating angle γ of the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle, to…

  • Probing the nature of the mysterious particle χc1(3872)

    Today, at a CERN seminar, the LHCb collaboration reported precise measurements of the properties of the mysterious particle χc1(3872), also known as the X(3872), using radiative decays χc1(3872)→ψ(2S)γ and χc1(3872)→J/ψγ. Since its discovery 20 years ago physicists have been fascinated by this particle trying to understand if it is a conventional charmonium state composed of…

  • Observation of the rare Σ+→pμ+μ– decay

    The LHCb collaboration reported the observation of the Σ+→pμ+μ– rare decay at the XV International Conference on Beauty, Charm, Hyperons in Hadronic Interactions (BEACH 2024) in Charleston, South Carolina, USA. This is the rarest hyperon decay ever observed. Rare decays are among the most promising tools for discovery of physics beyond the Standard Model (SM)…

  • ECAL and RICH sub-detector enhancements approved for construction

    The LHCb experiment will upgrade the inner part of the Electromagnetic Calorimeter and the electronics of the Ring Imaging Cherenkov detectors in the next LHC Long Shutdown (LS3). On July 5, 2022, protons collided again at LHCb after a 3.5 year break known as Long Shutdown 2 (LS2) marking the start of the LHC Run…

  • LHCb observes the rare decay J/ψ→μ+μ–μ+μ–

    Today, at the Rencontres de Moriond QCD and High Energy Interactions, the LHCb collaboration reported the observation of the rare elecromagnetic decay J/ψ→μ+μ–μ+μ–. The simultaneous discovery of the J/ψ meson at Brookhaven and SLAC in November 1974 brought about a revolutionary change in the particle physics landscape. Prior to this revolution, in analogy to atomic…