Quasi-two-body decays B(s)→Pρ→Pππ in the perturbative QCD approach

Abstract

In this work, we calculate the CP -averaged branching ratios and the direct CP -violating asymmetries of the quasi-two-body decays B (s) → P (ρ →)ππ by employing the perturbative QCD (PQCD) approach (here P stands for a light pseudoscalar meson π, K, η or η ′ ). The vector current timelike form factor Fπ, which contains the final-state interactions between the pion pair in the resonant region associated with the P -wave states ρ(770) along with the two-pion distribution amplitudes, is employed to describe the interactions between the ρ and the pion pair under the hypothesis of the conserved vector current. We found that (a) the PQCD predictions for the branching ratios and the direct CP -violating asymmetries for most considered B (s) → P (ρ →)ππ decays agree with currently available data within errors, (b) for B(B → π 0 ρ 0 → π 0 (π + π − ), the PQCD prediction is much smaller than the measured one, and (c) for the B + → π + (ρ 0 →)π + π − decay mode, there is a negative CP asymmetry (−27.5 +3.0 −3.7 )%, which agrees with other theoretical predictions but is different in sign from those reported by BABAR and LHCb Collaborations.

Three-body decays B→ϕ(ρ)Kγ in perturbative QCD approach

“…The coordinates θ K ∼ 33°and 58°happen to locate on the two sides of a peak, explaining why the results in Eqs. (35) and (37) …”

“…The resonant contributions from the states K 1 ð1270Þ and K Ã ð1680Þ to the ρK system dominate [33,34]. Therefore, the parametrization of the DAs Φ ρK follows that for quasitwo-body B meson decays [17,18,35,36], namely, the Breit-Wigner model.…”

Photon-assisted entanglement and squeezing generation and decoherence suppression via a quadratic optomechanical coupling

“…For macroscopic systems, entanglement between an optical field and a macroscopic vibrating mirror has been shown to be generated by radiation pressure [14][15][16][17][18][19][20][21]. Meanwhile, entanglement between different mechanical oscillators has also been studied in various optomechanical systems [22][23][24][25][26][27]. Quantum squeezing is instead potentially useful for surpassing the quantum noise limit [5].…”

Switchable bipartite and genuine tripartite entanglement via an optoelectromechanical interface

“…With quantum-engineered time-reversal symmetry to generate uni-directionality, nonreciprocal transmission via opto-and electro-mechanical interface has been studied recently [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. With blue-detuned driving, the generation of bipartite entanglement between various optical, electrical, and mechanical modes have been proposed [42][43][44][45][46][47][48][49][50][51][52][53][54]. In recent works, people have also studied the generation of tripartite entanglement via mechanical systems [55][56][57][58].…”