Ei-ichiro Kawai

A large mixing effect on η,η′ and ι

Abstract We quantitatively investigate a possible large mixing effect on η(549), η′(958) and ι(1440) in a phenomenological way, taking both SU(3) symmetry breaking and gluon intervention into due account.

Particle ratios in electroproduction of kaons and symmetry properties of the quark-parton model

Previously (~), we reported a work on the particle ratios of hadrons (7: • K• and ~) produced in electron-proton (cp), electron-neutron (en) and electron-deuteron (ed) scattering in the framework of the quark-par ton model. The assumptions made were the following: i) The distribution functions of the sea quarks are SU3 symmetric, if) There are only one independent favoured fragmentat ion function, D~ and only one independent unfavoured fragmentat ion function, D~ for pions, iii) Similarly, for kaons, there are only two independent fragmentation functions, i.e., one favoured o n e , D K and one unfavoured one, D~:. Among the interesting results we derived, there are, for example, expressions for the rat ios of fragmentation functions which depend only on the experimental particle ratios but not on the distribution functions of quarks within the target . Unfortunately, however, the results could not be checked clearly with the available experimental da ta due to large errors. Based on the same assumptions as in ref. (~), we investigate in this note the further consequences by considering the different particle ratios, K• • off the same target. We shall est imate the approximate values of the fragmentation functions for kaons, ~)K and DE by using the experimental da ta (2). The particle ratios in electroproduction, are expressed as follows: for the proton target

Hierarchies of evolution equations associated with certain symmetric spaces

Hierarchies of evolution equations associated with certain symmetric spaces are presented. Main examples of such symmetric spaces are Hermitian symmetric spaces and the obtained evolution equations include generalized nonlinear Schrodinger equations. Those results are obtained by extending the Lie algebra in the Ablowitz–Kaup–Newell–Segur scheme from sl(2,C) to more general one.

A novel feature of the Kac-Moody algebra and nonlinear integrable models

Abstract New light is shed on the Kac-Moody algebra to reveal its remarkable unknown feature which can be traced back to its curious connection with the Virasoro algebra. Further implication of this novel feature is examined and explicated in the context of nonlinear integrable models.

Glueball Production in High Energy e+ e- Collision

Inclusive glueball production via two· photon subprocess in high energy e+ e- collision is discussed. Formulae for the cross section are shown and then numerically evaluated. It is demonstrated that considerably large cross section can be expected with feasible rate for near future experiments. The quantum chromodynamics (QCD) strongly suggests the existence of glueballs (gluonic bound states with no valence quarks). Such entities are analogues to quarkonia and expected to gain an equal footing in particle physics. We think it is crucial to the well-tried QCD whether the glueball can really be established, for gluons in the color singlet sector should necessarily make bound states by virtue of the non-linear strong self-couplings among themselves. Masses of glueballs have been conjectured, on the basis of various models,1)-5) to lie near those of usual quarkonia (typically say, 1.5 Ge V or so). If it is the case, some of those glueballs may have already been detected and mistaken for quarkonia (e. g., t(1440) in ¢~rKKJ[6),7) and 8(1640) in ¢~rrJ7J;7) these being likely to be regarded as pseudoscalar and tensor glueballs, respectively). Since the 021 rule forbids the glueballs to decay fast into conventional hadrons, the low lying levels should appear as fairly narrow states. This narrowness becomes an effective clue for glueball search. At the same time, this means the glueball production should be quite suppressed as far as its experiments are done with use of the hadronic collisions. Then it may be difficult to find good signals for glueballs out of considerably large background noises. On the contrary, we should be able to evade such disadvantage if we avail high energy e+ e- collision for the observation of glueballs. Its reason is, as elucidated soon,*) that the high energy e+ e- collision becomes predominated by two almost real photons which are rich in soft gluons. Then it is of much interest *) In this context, it is quite important to observe that the photon is a fundamental 0. e., pointlike) particle as well as the quark and the gluon. This fact means, in the Kogut-Susskind picture for the partonometry or the extended version of the equivalent quantum approximation, that the photon itself behaves as a kind of parton and turns out, in contrast with the composite hadrons, to be able to evolve through the relevant QED Born term by virtue of the perturbative QeD interaction (see Ref. 10) for further details).