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.

First Observation of CP Violation and Measurement of Polarization in B⁺ → ρ(770)⁰ K* (892)⁺ Decays / R. Aaij, A. . .A.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 136:2(2026 Apr), pp. 021803.1-021803.16. [10.1103/9zhl-kkwg]

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

S. Cesare;C. Mancuso;D. Marangotto;A. Merli;N. Neri;G. Tonani;T. Tork;Z. Wang;
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.
Settore PHYS-01/A - Fisica sperimentale delle interazioni fondamentali e applicazioni
   European Particle physics Latin American NETwork
   EPLANET
   European Commission
   SEVENTH FRAMEWORK PROGRAMME - SP3-People - Marie-Curie Actions
   246806
apr-2026
14-gen-2026
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/1251304
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