Comparing fragmentation of strange quark in Z0 decays and K+p reactions

Abstract

The ratios of the production rates K * 0 (892)/K, φ/K, ρ 0 /π, ω/π, ∆ ++ ( The vector and pseudoscalar mesons, or decuplet and octet baryons, differ in the relative orientation of the quark spins. Therefore the ratios of their production rates, V /P and D/O, provide us with important information on spin dependence in fragmentation. Hadronization models predict V /P and D/O for promptly produced particles, not resulting from decays of other particles or resonances. Therefore apart from the models based on Monte-Carlo generators, such as the JETSET model [1], these predictions are difficult to test experimentally.In the nonrelativistic quark model, the mass difference of the vector and pseudoscalar mesons, decuplet and octet baryons is explained by the hyperfine mass splitting. The production rates exhibit a strong mass dependence. Therefore the vector-to-pseudoscalar and decuplet-to-octet suppressions could also be explained, at least qualitatively, by the hyperfine mass splitting [2,3] provided that the rates of promptly produced particles were reliably estimated.The simplest spin model of fragmentation, such as the model suggested in [4] and subsequently developed by Anisovich and his collaborators in many other papers, is a random combination of quark spin states giving V /P = 3 1 E-mail address: chliapnikov@mx.ihep.su (P.V. Chliapnikov)

Relating production and masses of the vector and P-wave mesons for light and heavy flavours at LEP

“…Although the JETSET model predictions for the ratios of the promptly produced vector and pseudoscalar mesons are also quite compatible with experiment[12].…”

“…The limited accuracy of the phenomenological formulae (11) results in additional systematic uncertainty, not accounted for in the mass estimates given in Eqs. (12) and (13). It can roughly be estimated from the mass relation…”

“…For the tensor mesons, they are close to 1. This facilitates the analysis of the vector and tensor meson direct rates in comparison with the more difficult situation for the pseudoscalar mesons [11,12]…”

R-axion detection at LHC

“…For example, if we are require p π /p jet > 0.7, the background is suppressed by O(10 −2 ) (see Ref. [49]). Furthermore, the photo-production from the π 0 is always accompanied by a photon which is not converted into a muon pair.…”

“…For example, if we are require p K /p jet > 0.7, the background is suppressed by O(10 −2 ) (see the K meson spectrum in a light jet given in Ref. [49]). Therefore, the background events are suppressed by 10 −(11−12) , and hence, the background from the K meson decay is subdominant for p T 100 GeV where the cross section of jets is less than about 1 µb.…”