An amplitude analysis of the B+→(π+π-)(KS0π+) decay is performed in the mass regions 0.30<1.10 GeV/c2 and 0.75<1.20 GeV/c2, using pp collision data recorded with the LHCb detector corresponding to an integrated luminosity of 9 fb-1. The polarization fractions and CP asymmetries for B+→ρ(770)0K∗(892)+ decays are measured. Violation of the CP symmetry in the decay B+→ρ(770)0K∗(892)+ is observed for the first time, with a significance exceeding 9 standard deviations. The CP asymmetry is measured to be ACP=0.507±0.062(stat)±0.024(syst) and the CP-averaged longitudinal polarization fraction of fL=0.720±0.028(stat)±0.009(syst). The measurements help to shed light on the polarization puzzle of B mesons decaying to two vector mesons.

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2026). First Observation of CP Violation and Measurement of Polarization in B+ →ρ (770)0K∗(892)+ Decays. PHYSICAL REVIEW LETTERS, 136(2) [10.1103/9zhl-kkwg].

First Observation of CP Violation and Measurement of Polarization in B+ →ρ (770)0K∗(892)+ Decays

Anelli A.;Borsato M.;Calvi M.;Capelli S.;Carniti P.;Falcao L. N.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Kirsebom V. S.;Malentacca L.;Martinazzoli L.;Martinelli M.;Minotti A.;Pizzichemi M.;Salomoni M.;
2026

Abstract

An amplitude analysis of the B+→(π+π-)(KS0π+) decay is performed in the mass regions 0.30<1.10 GeV/c2 and 0.75<1.20 GeV/c2, using pp collision data recorded with the LHCb detector corresponding to an integrated luminosity of 9 fb-1. The polarization fractions and CP asymmetries for B+→ρ(770)0K∗(892)+ decays are measured. Violation of the CP symmetry in the decay B+→ρ(770)0K∗(892)+ is observed for the first time, with a significance exceeding 9 standard deviations. The CP asymmetry is measured to be ACP=0.507±0.062(stat)±0.024(syst) and the CP-averaged longitudinal polarization fraction of fL=0.720±0.028(stat)±0.009(syst). The measurements help to shed light on the polarization puzzle of B mesons decaying to two vector mesons.
Articolo in rivista - Articolo scientifico
Hadron Collider; CP symmetry; Flavour Physics;
English
14-gen-2026
2026
136
2
021803
open
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2026). First Observation of CP Violation and Measurement of Polarization in B+ →ρ (770)0K∗(892)+ Decays. PHYSICAL REVIEW LETTERS, 136(2) [10.1103/9zhl-kkwg].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/591244
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