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.

  • Evidence for CP violation in Λb0→ΛK+K– decays

    This week, at a CERN seminar, the LHCb collaboration presented new results that provide evidence for CP violation in Λb0→ΛK+K– decays. LHCb is an experiment designed to study physics phenomena including “CP violation”, which is closely linked to the disappearance of antimatter soon after the Big Bang leaving only matter to survive and build the…

  • End of successful proton-proton collision data taking period

    The 2024 proton-proton collision period at the LHC ended this week. This period was particularly successful for LHCb, also owing to the excellent performance of the LHC. The rate at which the experiment was able to acquire integrated luminosity was spectacularly higher than in previous years, as shown in the luminosity plots presented in this…

  • Test of lepton flavour universality with Bs0 → ϕℓ+ℓ− decays

    The LHCb collaboration submitted today a paper reporting new tests of lepton flavour universality, one of the cornerstone of the Standard Model (SM) of particle physics. It implies that the SM treats the three charged leptons (electrons, muons and taus) identically, except for differences due to their masses. The results were also presented at the…

  • First observation of muonic Dalitz decays of χb mesons

    The LHCb collaboration submitted today a paper reporting precise measurements of the mass values and splittings of the hidden-beauty particles that exist within the bb quark bound system called bottomonium. The first observation of the so-called muonic Dalitz decays of the χb1(1P), χb2(1P), χb1(2P) and χb2(2P) mesons to the Υ(1S) was an essential part of…

  • 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…