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cc by (c) LHCb Collaboration, 2012
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/58750

Measurement of the isospin asymmetry in B→K(∗)μ+μ− decays

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Abstract

The isospin asymmetries of B → K (∗) μ + μ − decays and the partial branching fractions of B 0 → K 0 μ + μ − and B + → K ∗+ μ + μ − are measured as a function of the di-muon mass squared q 2 using an integrated luminosity of 1.0 fb−1 collected with the LHCb detector. The B → Kμ + μ − isospin asymmetry integrated over q 2 is negative, deviating from zero with over 4 σ significance. The B → K ∗ μ + μ − decay measurements are consistent with the Standard Model prediction of negligible isospin asymmetry. The observation of the decay B 0 → K S μ + μ − is reported with 5.7 σ significance. Assuming that the branching fraction of B 0 → K 0 μ + μ − is twice that of B 0 → K S μ + μ −, the branching fractions of B 0 → K 0 μ + μ − and B → K ∗+ μ + μ − are found to be (0.31−0.06) × 10−6 and (1.16 ± 0.19) × 10−6, respectively.

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ABELLAN BETETA, Carlos, et al. Measurement of the isospin asymmetry in B→K(∗)μ+μ− decays. Journal of High Energy Physics. 2012. Vol. 7, num. 133, pags. 1-19. ISSN 1126-6708. [consulted: 19 of August of 2026]. Available at: https://hdl.handle.net/2445/58750

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