A bstract An amplitude analysis of B 0 → ( π + π − )( K + π − ) decays is performed in the two-body invariant mass regions 300 < m ( π + π − ) < 1100 MeV/ c 2 , accounting for the ρ 0 , ω , f 0 (500), f 0 (980) and f 0 (1370) resonances, and 750 < m ( K + π − ) < 1200 MeV/ c 2 , which is dominated by the K * (892) 0 meson. The analysis uses 3 fb −1 of proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The CP averages and asymmetries are measured for the magnitudes and phase differences of the con- tributing amplitudes. The CP -averaged longitudinal polarisation fractions of the vector-vector modes are found to be $$ {\tilde{f}}_{\rho {K}^{*}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mover> <mml:mi>f</mml:mi> <mml:mo>˜</mml:mo> </mml:mover> <mml:mrow> <mml:mi>ρ</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>*</mml:mo> </mml:msup> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> = 0 . 164 ± 0 . 015 ± 0 . 022 and $$ {\tilde{f}}_{\omega {K}^{*}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mover> <mml:mi>f</mml:mi> <mml:mo>˜</mml:mo> </mml:mover> <mml:mrow> <mml:mi>ω</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>*</mml:mo> </mml:msup> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> = 0 . 68 ± 0 . 17 ± 0 . 16, and their CP asymmetries, $$ {\mathcal{A}}_{\rho {K}^{*}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>ρ</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>*</mml:mo> </mml:msup> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> = −0 . 62 ± 0 . 09 ± 0 . 09 and $$ {\mathcal{A}}_{\omega {K}^{*}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>ω</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>*</mml:mo> </mml:msup> </mml:mrow> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> = −0 . 13 ± 0 . 27 ± 0 . 13, where the first uncertainty is statistical and the second systematic.
Tópico:
Particle physics theoretical and experimental studies
