A flavour-tagged decay-time-dependent amplitude analysis of Bs0 → (K+π−)(K−π+) decays is presented in the K±π∓ mass range from 750 to 1600MeV/c2. The analysis uses pp collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb−1. Several quasi-two-body decay modes are considered, corresponding to K±π∓ combinations with spin 0, 1 and 2, which are dominated by the K0*(800)0 and K0*(1430)0, the K*(892)0 and the K2*(1430)0 resonances, respectively. The longitudinal polarisation fraction for the Bs0→K∗(892)°K¯∗(892)0 decay is measured as fL = 0.208 ± 0.032 ± 0.046, where the first uncertainty is statistical and the second is systematic. The first measurement of the mixing-induced CP-violating phase, ϕsdd¯, in b→ dd¯ s transitions is performed, yielding a value of ϕsdd¯=−0.10±0.13(stat)±0.14 (syst) rad.

First measurement of the CP-violating phase ϕsdd¯ in Bs0 → (K + π −)(K − π +) decays

Brundu, D.;Contu, A.;Dettori, F.;Loi, A.;Manca, G.;Oldeman, R.;Saitta, B.;
2018-01-01

Abstract

A flavour-tagged decay-time-dependent amplitude analysis of Bs0 → (K+π−)(K−π+) decays is presented in the K±π∓ mass range from 750 to 1600MeV/c2. The analysis uses pp collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb−1. Several quasi-two-body decay modes are considered, corresponding to K±π∓ combinations with spin 0, 1 and 2, which are dominated by the K0*(800)0 and K0*(1430)0, the K*(892)0 and the K2*(1430)0 resonances, respectively. The longitudinal polarisation fraction for the Bs0→K∗(892)°K¯∗(892)0 decay is measured as fL = 0.208 ± 0.032 ± 0.046, where the first uncertainty is statistical and the second is systematic. The first measurement of the mixing-induced CP-violating phase, ϕsdd¯, in b→ dd¯ s transitions is performed, yielding a value of ϕsdd¯=−0.10±0.13(stat)±0.14 (syst) rad.
2018
B physics; CP violation; Flavour changing neutral currents; Hadron-Hadron scattering (experiments); Oscillation; Nuclear and high energy physics
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/254554
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 21
  • ???jsp.display-item.citation.isi??? 19
social impact