Measurement of the resonant andCPcomponents inB¯0→J

Abstract

The resonant structure of the reaction (B) over bar (0) --> J/psi pi(+)pi(-) is studied using data from 3 fb(-1) of integrated luminosity collected by the LHCb experiment, one third at 7 TeV center-of-mass energy and the remainder at 8 TeV. The invariant mass of the pi(+)pi(-) pair and three decay angular distributions are used to determine the fractions of the resonant and nonresonant components. Six interfering pi(+)pi(-) states, rho(770), f(0)(500), f(2)(1270), rho(1450), omega(782) and rho(1700), are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative charge parity fractions of each of the resonant final states are determined. The f(0)(980) meson is not seen and the upper limit on its presence, compared with the observed f(0)(500) rate, is inconsistent with a model where these scalar mesons are formed from two quarks and two antiquarks (tetraquarks) at the eight standard deviation level. In the q (q) over bar model, the absolute value of the mixing angle between the f(0)(980) and the f(0)(500) scalar mesons is limited to be less than 17 degrees at 90% confidence level

The D0 decays into KS0 and f0(500), f0(980), a0(980)

“…TheB 0 → J/ψ f 0 (500), f 0 (500) → π + π − decay mode, together with the f 0 (980) one have been identified in Ref. [34] through a partial wave analysis, and the rates obtained are comparable with the findings of Ref. [17].…”

“…[17]. Further analyses in the line of [34] would be most welcome to separate these important contributions of the…”

Averages of b-hadron, c-hadron, and $$\tau $$ τ -lepton properties as of summer 2016

“…[258,267] show large contributions from the ρ(770) 0 and f 0 (500) states, together with smaller contributions from higher resonances. Since modelling the f 0 (500) structure is challenging [268], it is difficult to determine reliably its associated CP violation parameters.…”

Dalitz plot analysis ofB0→D¯0π+π−decays

“…Other theory models based on QCD factorization and its extensions [57,58] predict that the f 0 ð500Þ and f 0 ð980Þ mixing angle φ mix for the qq model is 20°≲ φ mix ≲ 45°. The LHCb experiment, in the study of B 0 ðsÞ → J=ψπ þ π − decays [47][48][49], has already set stringent upper bounds on φ mix in B 0 (B 0 s ) decay: φ mix < 17°(< 7.7°) at 90% C.L. For the first time, the f 0 ð500Þ − f 0 ð980Þ mixing in the B 0 →D 0 π þ π − decay, both in qq and tetraquark pictures, is studied.…”