Meson emission model ofΨ→NN¯mcharmonium strong decays

Abstract

In this paper we consider a sequential ''meson emission'' mechanism for charmonium decays of the type É ! N " Nm, where É is a generic charmonium state, N is a nucleon, and m is a light meson. This decay mechanism, which may not be dominant in general, assumes that an N " N pair is created during charmonium annihilation, and the light meson m is emitted from the outgoing nucleon or antinucleon line. A straightforward generalization of this model can incorporate intermediate N à resonances. We derive Dalitz plot event densities for the cases É ¼ c , J=c , c0 , c1 , and c 0 ; and m ¼ 0 , f 0 , and ! (and implicitly, any 0 Àþ , 0 þþ , or 1 ÀÀ final light meson). It may be possible to separate the contribution of this decay mechanism to the full decay amplitude through characteristic event densities. For the decay subset É ! p " p 0 the two model parameters are known, so we are able to predict absolute numerical partial widths for ÀðÉ ! p " p 0 Þ. In the specific case J=c ! p " p 0 the predicted partial width and M p event distribution are intriguingly close to experiment. We also consider the possibility of scalar meson and glueball searches in É ! p " pf 0 . If the meson emission contributions to É ! N " Nm decays can be isolated and quantified, they can be used to estimate meson-nucleon strong couplings fg NNm g, which are typically poorly known, and are a crucial input in meson exchange models of the NN interaction. The determination of g NN from J=c ! p " p 0 and the (poorly known) g NN! and the anomalous ''strong magnetic'' coupling NN! from J=c ! p " p! are considered as examples.

Revisiting the production of charmonium plus a light meson atP¯ANDA

“…0 c0 , p " p ! 0 c1 and [16] 7-10:5 0 Nucleon EM form factors [17] 20:86 AE 0:25 À0:16 AE 0:01 QCD sum rule [18] 18 AE 8 0:8 AE 0:4 3 P 0 quark model [11] -À3=2 Light meson emission model [10] 23 AE 3 0 14:6 AE 2:0 À3=2 FIG. 2 (color online).…”

“…At present, the coupling constants of Dirac and Pauli couplings of pp! and pp are determined by some theoretical groups by different processes and different models [10][11][12][13][14][15][16][17][18]. Thus, we adopt these determined cou-pling constants in our calculation, which includes the total cross sections, the differential cross sections hd=di.…”

Production of the charmoniumlike state Y(4220) through the pp¯→Y(<

“…In this work, we propose to study the Y(4220) state in the low energy pp annihilation within the effective Lagrangian approach. The effective Lagrangian approach has been widely used to study the charmonium production in pp annihilation [22][23][24][25][26][27][28][29]. However, only the contribution from exchanged nucleon N was considered in these previous works.…”

PSI TO N NBAR m

“…A pole model for low energy pp associated charmonium production using an effective hadron Lagrangian was proposed in 1982 by Gaillard et al 8 , who considered aspects of the reaction pp → J/ψπ 0 at LEAR. A similar model has since been applied to Ψ = η c , J/ψ, χ 0 , χ 1 and m = π 0 , σ and ω (and flavor partners) in a series of papers by Barnes, Li and Roberts, 9,10,11 who have calculated pp → Ψπ 0 differential and total cross sections 9 and Ψ → ppm Dalitz plot densities 11 . When applied to Ψ → ppm this model assumes dominance by the Feynman diagrams of Fig.2.…”

“…Since the ω plays a very important role in N N force models as the origin of short-ranged N N repulsion, and the ppω Dalitz plot event distribution has been shown to be quite sensitive to the anomalous coupling κ ω in the hadron pole model, 11 it would be very interesting to carry out such a study.…”