pp̄ Annihilation at rest into mesons in the quark rearrangement model and the quark annihilation modelt

pp? annihilation at rest into mesons is calculated in the quark rearrangement model in which 3 quarks and 3 antiquarks rearrange into 3 mesons and in the quark annihilation model in which one or two quark-antiquark pairs are annihilated and a quark-antiquark pair is created to form two or three mesons. The constants of the quark-meson coupling are adjusted such that the meson-nucleon interactions agree with experiment. The radial dependences of the quark-meson couplings are all assumed to be the same. This is determined by the vector-meson-quark interaction derived from the charge form factor of the proton. In the case of the decay into three mesons both rearrangement and annihilation models explain with similar reliability the branching ratio of the decay products. In the case of the decay into two-meson annihilation gives a better agreement with experiment than rearrangement.     

One-particle and two-particle inclusive deep-inelastic electron-positron annihilation in a massive quark model

A massive quark model is reviewed and elaborated upon. The model is applied to deep-inelastic electron-positron annihilation into hadrons. Definite predictions are given for one-particle inclusive and two-particle inclusive annihilations. Predictions for multiplicities, angular distributions, transverse momentum distribution in two-particle inclusive reactions, correlations, and threshold behavior are given. Exclusive annihilation into two mesons is also calculated.     

Contribution of coloured Higgs bosons to e+e− annihilation into two jets

We examine the effect of the coloured Higgs bosons (of the integer-charge quark model) on electron-positron annihilation into two jets. The overall angular distribution of the quark + gluon + Higgs jets in the scaling limit is found to be 1+0.57 cos²θ.     

Something,but not much follows from the quark line rule in nucleon-antinucleon annihilations

Validity and consequences of the quark line rule (QLR) in nucleon (N)— antinucleon (¯N) annihilations into two or three mesons at LEAR energies are investigated. Recent data on proton-antiproton annihilation into anη orη′ together with additional non-strange pseudoscalar or vector meson (s) is used to successfully test the rule. We find that for present data any pseudoscalar meson mixing angle Φ_PS restricted to ?26⁰<Φ_PS0 is approximately consistent with the QLR. Since the assumptions leading to this test are valid in any present-day quark model of nucleon-antinucleon annihilation, improvement of the data will be of utmost importance. If proven valid, the QLR can be used to test if quark-antiquark annihilation dominates over quark exchange inN¯N → mesons at LEAR energies or vice versa. Previously proposed tests of the quark line diagrams (annihilation or rearrangement) describing the quark flavor flux under either of these assumptions are worked out. We investigate without a definite conclusion if dominance of annihilation over rearrangement is consistent with present data onp¯p → π⁰ π⁰,ηη, π⁰ρ⁰, π⁰ω, ηρ⁰,ηω, ρ⁰ρ⁰,ωω. As a main consequence, dominance of annihilation predicts without any ambiguity equality of the proton-antiproton annihilation cross sections σ(ωω) and σ(ρ⁰ρ⁰). Further consequences of dominance of either annihilation or rearrangement diagrams for proton-antiproton annihilation into two or three mesons are also worked out. We compare the predictions of the models we discuss to the sparse present data. It is emphasized that our predictions only exploit the quark flavor flux within the quark line diagrams that are assumed to dominate. They thus are independent of gluon contributions to these diagrams.     

重夸克偶素质量谱的相对论夸克模型研究（已撤稿）

使用量子场论中准势途径的相对论夸克模型,计算了重夸克偶素的质量谱.所采用的同味正反夸克间的有效相互作用包括通常的直接单胶子交换、单胶子湮没及具有相对论修正的标量和矢量线性禁闭的混合.得到了与实验上肯定的数据符合较好的拟合计算结果，并讨论了湮没项和相对论修正各项对能谱超精细分裂的作用. 关键词： 重夸克偶素 质量谱 相对论修正 湮没势     

Study of Baryon Antibaryon Rapidity Correlation in e+e- Annihilation by Quark Combination Model

We use quark combination model to study baryon antibaryon rapidity correlation in e⁺e^- annihilation and compare our predictions with the available data. We find that these results and relevant properties are all consistent with data. So the evidence to rule out quark combination model which has long been cited in literatures does not exist.     

Gauge boson pair production at the LHC: Anomalous couplings and vector boson scattering

We compare vector boson fusion and quark antiquark annihilation production of vector boson pairs at the LHC and include the effects of anomalous couplings. Results are given for confidence intervals for anomalous couplings at the LHC assuming that measurements will be in agreement with the standard model. We consider all couplings of the general triple vector boson vertex and their correlations. In addition we consider a gauge invariant dimension-six extension of the standard model. Analytical results for the cross sections for quark antiquark annihilation and vector boson fusion with anomalous couplings are given. Received: 24 June 1997 / Revised version: 10 November 1997 / Published online: 30 March 1998     

e~＋e~－湮没中不同味道夸克喷注带电粒子多重数差别

利用“夸克产生律”与“夸克组合律”计算了ｅ＋ｅ－湮没中重夸克喷注事例的带电粒子多重数，结果与实验符合．并与轻夸克喷注事例及平均夸克味道喷注事例的多重数做了比较．     

手征夸克模型下udss四夸克态的研究

在手征SU(3)夸克模型和扩展的手征SU(3)夸克模型的框架下, 用变分的方法系统地研究了同位旋为0、1, 自旋宇称为0⁺、1⁺和2⁺的udss四夸克系统6个低组态的能量. 模型的参数取自以前的工作, 它能很好地描述核子-核子散射相移以及核子-超子散射截面. S道相互作用的参数由拟合K介子和K^*介子的质量定出, 并且考虑了具有相同量子数的态之间的态混合效应. 结果表明, 同位旋为0且自旋宇称为1⁺的udss能量低于相应的K^*K^*,的阈能, 且该组态中KK^*的成分相当小, 因此该组态的宽度可能较小, 可视为一个可能的四夸克态的候选者.     

Exclusive annihilation pp-->gammagamma in a generalized Parton picture

Exclusive proton-antiproton annihilation into two photons at large s ( approximately 10 GeV2) and /t/,/u/ approximately s can be described by a generalized parton picture analogous to the "soft mechanism" in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a single fast quark and antiquark. The matrix element describing the transition of the pp system to a qq pair can be related to the timelike proton elastic form factors as well as to the quark/antiquark distributions measured in inclusive deep-inelastic scattering. The reaction could be studied with the proposed 1.5-15 GeV high-luminosity antiproton storage ring (HESR) at GSI.     

SU(3) analysis of antiproton-proton annihilation into two mesons

We analyse existing data on antiproton-proton annihilation into two mesons using as minimal assumptions charge conjugation invariance, the quark line rule and SU(3). The analysis is greatly facilitated by using a set of invariant SU(3) couplings which is directly related to the contributing quark line diagrams.     

NΩ束缚态问题的研究

从夸克 反夸克通过介子场耦合的模型出发研究了(N)LST是否存在束缚态的问题. 计算表明当考虑了u(d)湮灭K*为介子的机制后, (N)LST是有可能形成结合能较大的束缚态. The structures of (N)LST systems are studied in the SU(3)quark model， in which the coupling between quark antiquark and the meson fields are included. A resonating group method (RGM) calculation shows that (N)0212could be a bound state with considerably large binding energy， when the mechanism of u(d) annihilation to K* is considered.     

A Monte Carlo model to produce baryons ine + e − annihilation

A simple model is described extending the Field-Feynman model to baryon production in quark fragmentation. The model predicts baryon baryon correlations within jets and in opposite jets produced in electron-positron annihilation. Existing data is well described by the model.     

Low energy antiproton-proton annihilation and meson spectroscopy

Recent results in antiproton-proton annihilation at rest from the Crystal Barrel at CERN/LEAR are reviewed. Rates for annihilation at rest into various two-body channels have been measured. In spite of the complexity of the annihilation mechanism, simple tests based on the underlying quark constituents can be applied. The annihilation process is also useful to investigate the spectrum of light quark mesons and to search for exotic (non-q¯q) mesons. Three scalar states have been found in the 1500 MeV mass region. One of them is a good candidate for the ground state glueball.     

Low-Energy Kπ Phase Shifts in Chiral SU（3） Quark Model

The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU（3） quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel qq^- annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data.     

Strangeness production inp¯p annihilation at rest and the quark — diquark structure of nucleons

The importance of approximate isospin selection rules observed inN¯ N annihilation at rest into two strange mesons is emphasized. The selection rules are traced back to a symmetry between amplitudes describing annihilation by the flux of quarks. Presumably the symmetry reflects the symmetry of ¯qq annihilation vertices. The relation of the symmetry to a quark — diquark substructure of the nucleon is discussed.     

Quark model for the production of pseudoscalar mesons in annihilation

A modification of the quark model for annihilation permits the calculation of the relative probabilities of all observed channels with pseudoscalar mesons. Agreement with the experimental data on proton-antiproton annihilations at rest into three and more mesons is obtained.     

Low-Energy Kπ Phase Shifts in Chiral SU(3) Quark Model

The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel q(-q) annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data.