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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…
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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…
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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…
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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…
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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)…