Dalitz plot studies ofD0→KS0π+

Abstract

The presently available high-statistics data of the D 0 → K 0 S π + π − processes measured by the Belle and BABAR Collaborations are analyzed within a quasi two-body factorization framework. Starting from the weak effective Hamiltonian, tree and annihilation amplitudes build up the D 0 → K 0 S π + π − decay amplitude. Two of the three final-state mesons are assumed to form a single scalar, vector or tensor state originating from a quark-antiquark pair so that the factorization hypothesis can be applied. The meson-meson final state interactions are described by Kπ and ππ scalar and vector form factors for the S and P waves and by relativistic Breit-Wigner formulae for the D waves. A combined χ 2 fit to a Belle Dalitz plot density distribution, to the total experimental branching fraction and to the τ − → K 0 S π − ντ decay data is carried out to fix the 33 free parameters. These are mainly related to the strengths of the scalar form factors and to unknown meson to meson transition form factors at a large momentum transfer squared equal to the D 0 mass squared. A good overall agreement to the Belle Dalitz plot density distribution is achieved. Another set of parameters fits equally well the BABAR Collaboration Dalitz plot model. The parameters of both fits are close, following from similar Dalitz density distribution data for both collaborations. The corresponding one-dimensional effective mass distributions display the contributions of the ten quasi two-body channels entering our D 0 → K 0 S π + π − decay amplitude. The branching fractions of the dominant channels compare well with those of the isobar Belle or BABAR models. The lower-limit values of the branching fractions of the annihilation amplitudes are significant. Built upon experimental data from other processes, the unitary Kπ and ππ scalar form factors, entering our decay amplitude and satisfying analyticity and chiral symmetry constraints, are furthermore constrained by the present Dalitz plot analysis. Our D 0 → K 0 S π + π − decay amplitude could be a useful input for determinations of D 0 -D 0 mixing parameters and of the CKM angle γ (or φ3).

$$f_0(500)$$ f 0 ( 500 ) , $$f_0(980)$$ f 0 ( 980 ) , and $$a_0(980)$$ a 0 ( 980 ) production in the $$\chi _{c1} \rightarrow \eta \pi ^+\pi ^-$$ χ c 1 → η π + π - reaction

“…[27] (see Ref. [28] for also an approach based on form factors). Yet, the present reaction, with its spectacular signal for a 0 (980) production, a large signal for f 0 (500) and the small signal for the f 0 (980), all seen in the same reaction, is a case that should not be missed to challenge this theoretical approach.…”

K¯-induced formation of thef0(980)anda0Xie1, Wu2, Oset3 2016Phys. Rev. C7180View full textAdd to dashboardCite

“…The study of B and D decays [23,24] has also offered a new valuable source of information on these states and has stimulated much theoretical work [25][26][27][28][29][30][31][32]. Yet, little is done in reactions involving baryons, with the exception of f 0 (980) photoproduction, done in Refs.…”

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

“…In Ref. [4] a thorough study is made of the D 0 → K 0 s π + π − reaction and the amplitude is parametrized in terms of form factors, resonance parameters and different couplings, amounting to a set of 33 free parameters, which are fitted to the Belle [5] and BaBar [6] data. The purpose there is to have a good amplitude that can be used to determine the D 0 − D * 0 mixing parameters and the Cabibbo-Kobayashi-Maskawa (CKM) angle γ.…”