Mixing of Pseudo-Goldstone Bosons and Effects on HERA High-Q2 Events

We study the mixing of pseudo-Goldstone bosons predicted by technicolor theory and the effects on HERA high-Q² events. We find that: (a) there eyist two F = 0 scalar leptoquarks P₃′ with m(P₃′) = 200 GeV and P₃⁰ with m(₃⁰) =225 GeV for β₁ = β₂ = 0.4; (b) the P₃′ and P₃⁰ can contribute the required cross section to account for the excesses of NC and CC high-Q² events; (c) the coexistence of P₃′ and P₃⁰ may be responsible for the splitting of averaged mass of the H1 and ZEUS high-Q² neutral current events.     

B-B Mixing in Dynimically Broken Theory

The B_d-B_d mixing is investigated in a dynamically broken electroweak theory such as the minimal technicolor theory with a monophagic coupling of quarks and pseudo-Goldstone bosons. The contrbutions of the technicolor pseudo-Goldstone bosons, enhanced by QCD color fowors, dominate the process for a wide range of parameters. If the topdown quark Kobayashi-Maskawa matrix element is not near the minimal allowed value, the pseudo-Goldstone bosone plus W boson can adequately account for the observed mixing large of the pseudo-Goldstone boson and top quark mass.     

Negative Vertex Contributions to Parameters S and T From Charged Pseudo-Goldstone Boson

We describe how to incorporate the one-loop vertex corrections on Zbb coming from the virtual charged pseudo-Goldstone bosons (PGB) P^± and P₈^± in one-generation technicolor model into the estimation for the value of Peskin-Takeuchi parameters S and T. We findthat the vertex contributions S_V and T_V are all negative and can cancel out the positiveoblique contributions Shad and Thad. NOW the value of S can be negative and T is also muchsmaller than the traditional estimation.     

Corrections from PGB to the Single-Top-Quark Production at the Fermilab Tevatron in the Technicolor Models

We calculate one-loop PGB (pseudo-Goldstone bosons) corrections to the cross section for the single-topquarkproduction via qq' → tb at the Fermilab Tevatron in the MWTCM (multiscale walking technicolor model) and topcolor assisted MWTCM. The corrections from PGB in the topcolor assisted MWTCM decrease the production cross section only a few percent, and the corrections from PGB in the MWTCM are found to exceed -l0%, which might be observable at a high-luminosity Tevatron.d:\PDF\.pdf     

Technicolor pseudo-Goldstone boson couplings to gluon fields

Using the formalism of effective, chiral and gauge covariant, lagrangians, we discuss some phenomenological implications of the couplings of technicolor pseudo-Goldstone bosons to gluons. The interest of associated production of color triplet states in $\text{p}\text{p}$ collisions is pointed out.     

New physical effects on the decay Bs→γγ in the technicolor model

In this paper we calculate the contributions to the branching ratio of Bs→γγ from charged pseudo-Goldstone bosons appearing in the one generation Technicolor model. We find that the theoretical value of the branching ratio, BR(Bs→γγ), including the contributions of PGBs, P± and P±8, is very different from the standard model (SM) prediction. The new physical effects can provide a one to two order of magnitude enhancement of the SM results. It is shown that the decay Bs→γγ can test new physical signals from the technicolor model.     

人工色动力学对Wb耦合的修正

考虑了一代人工色（ＯＧＴＣ）模型和ｔｏｐｃｏｌｏｒ援助的多标度人工色（ＴＯＰＣＭＴＣ）模型中的规范玻色子对Ｗｔｂ耦合的贡献。发现对角ＥＴＣ玻色子的交换对Ｗｔｂ耦合没有直接贡献，运用ＬＥＰ给出的Ｒｂ的数值，发现对于一定范围内的参数值来说，ＯＧＴＣ模型中的ＥＴＣ规范玻色子交换和ＴＯＰＣＭＴＣ模型中的ＥＴＣ规范玻色子交换和ｃｏｌｏｒｎ交换对ＣＫＭ矩阵元Ｖｔｂ的贡献都是相当大的，Ｖｔｂ可能被费米实验室ＴｅｖａｔｒｏｎＲｕｎ３探测到。     

The alignment of the vacuum in theories of technicolor

We study a class of models of dynamical weak-interaction symmetry breaking suggested by the work of Weinberg and Susskind. We demonstrate in these models some simple relations which determine the alignment of weakly gauged subgroups and the masses of pseudo-Goldstone bosons. We illustrate these methods by computing the spectrum of pseudo-Goldstone bosons in three models recently examined by Dimopoulos. These models are seen to contain a very light charged Higgs boson, whose mass we estimate by the use of chiral perturbation theory. In one of these models, we observe that the energetically preferred vacuum is a phenomenologically unpleasant one.     

Study on the Radiative Decays of B Mesons in the Multiscale Walking Technicolor Model

We calculate PGB (pseudo-Goldstone boson) corrections to the decays B → X_sγ and B → K^*γ in the MWTCM (multiscale walking technicolor model). The presence of PGBs in the MWTCM leads to large enhancements in the rates of B → X_sγ and B → K^*γ. But these results are in conflict with the recent CLEO data on the branching ratios BR (B → X_sγ) and BR(B → K^*γ). If topcolor is further introduced, the calculated results in the topcolor assisted MWTCM can be suppressed and be in agreemet with the CLEO data for a certain range of parameters. We also estimate the branching ratio BR (B → X_sg) in the topcolor assisted MWTCM, and this estimate is roughly one order higher than that in the standard model.     

Doubly charged pseudo-goldstone bosons and dynamical SU(2) × U(1) breaking

An alternative structure of electroweak symmetry breaking based on an SU(4)/SU (2) symmetry breaking pattern is discussed. An effective chiral lagrangian describing the pseudo-Goldstone bosons and gauge bosons is constructed and their interactions are analyzed. It is shown that the model contains doubly charged pseudo-Goldstone bosons which couple to two similarly charged W's. The question of vacuum alignment is considered, and it is shown that if an additional discrete symmetry is imposed, a custodial SU (2) preserving vacuum is a global minimum of the potential (for a range of coefficients in the effective chiral lagrangian).     

Technicolor and the asymptotic behavior of dynamically generated masses

We propose a technicolor model where, as a consequence of a hard asymptotic behavior for dynamically generated masses, effects of flavor changing neutral currents are highly suppressed and pseudo-Goldstone boson masses are at least ofO (30–90 GeV).     

Corrections to Zbb Vertex from Heavy PG Bosons and Phenomenology

In the framework of one generation technicolor model we calculated the virtual effects from heavy PG bosons to the Zbb vertex. Within parameter space the largest reduction from thk charged PGB's and top quark to the partial width Γ_b was 71 MeV while the maximum correction to the branching ratio R_b was about 14%. From the comparison of theoretical. predictions with the corresponding data we are able to put an "primary" upper bound on the mass of P₈^±: M_p2 < 280 GeV for given M_t = 200 GeV.     

Gauge-invariant effective lagrangians for goldstone-like particles of supersymmetric technicolor models

We point out that generally the low-energy spectrum in supersymmetric technicolor models contains quasi-Goldstone fermions and quasi-Goldstone bosons in addition to the usual (pseudo)- Goldstone bosons. Using the language of Kähler geometry, we present a step-by-step procedure for constructing gauge-invariant non-linear lagrangians involving the fermionic and bosonic Goldstone particles in situations in which supersymmetry is preserved. Both the cases of fully gauged and partially gauged global symmetries are considered. We discuss the dynamical version of the super-Higgs mechanism, and we illustrate it with the supersymmetric Susskind-Weinberg technicolor model.     

Research of bb Production in the Topcolor Assisted Technicolor Model

In the framework of topcolor assisted technicolor (TC2) model, we calculate the contributions of cross section from the pseudo Goldstone bosons and new gauge bosons to e⁺e^－ →bb. We find that, within reasonable ranges of the parameters, the corrections arising from technipions and new gauge bosons are negligibly small; and the top pions afford dominate contribution, the maxim cross section corrections can reach 43% with the c.m. energy √s=500GeV; whereas in case of √s=1500GeV, the maxim cross section relative corrections is only 3.1%. It might open a window to detect topcolor assisted technicolor model in the experiment of next generation linear collider.     

Photoproduction of W bosons at HERA: QCD corrections

W bosons can be produced in the channels at HERA thus allowing to probe for anomalous trilinear couplings among the gauge bosons. We discuss the next-to-leading order (NLO) QCD corrections to the photoproduction of W bosons with finite transverse momentum at HERA. The higher-order QCD corrections reduce the factorization scale dependence significantly and modify the leading-order (LO) cross sections by . Received: 18 April 2002 / Published online: 30 August 2002 RID="*" ID="*" Present address: Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany     

Subgroup alignment in hypercolor theories

To analyze the physical consequences of a dynamically broken theory of the weak interactions, we must know how the weak gauge group is aligned in an approximate flavor-symmetry group. For a large class of models, spectral-function sum rules enables us to determine this alignment explicitly. We work out the pattern of the electroweak symmetry breakdown for several sample models. Critical values of weak mixing angles are found at which the breakdown pattern changes discontinously. We compute pseudo-Goldstone boson masses, and find that some models contain unusually light charged or colored pseudo-Goldstone bosons.     

The Anomaly Coupling of Axigluon and Technicolor Neutral Pseudo Goldstone Bosons

By gauging the anomaly terms according to the gauge group SU(3)_cl x SU(3)_cr × SU(2)_l × U(l)_Y in the technicolor theory, we obtain various possibld anomaly vertices involving technicolor pseudo Goldstone boson and gauge boson (γ, Z, g, g_A). We estimate the decay rates of g_A → gP⁰, g_A → P_A⁰³γ and g_A → P_A⁰³Z.     

Corrections to the Zτ +τ− vertex in topcolor-assisted technicolor theory

We calculate the corrections to the Zτ⁺τ^? vertex in the one-family topcolor-assisted technicolor models without exact custodial symmetry contributed from the exchange of extended technicolor (ETC) sideways and diagonal gauge bosons and the topcolor gauge boson Z′. The precise measurements of the τ asymmetry parameter Aτ give strong constraint on the free parameters in the topcolor-assisted technicolor models.     

Top Quark Pair Production at e^＋e^— Colliders in the Topcolor—Assisted Technicolor Model

In the framework of topcolor-assisted technicolor model we calculate the contributions from the preudo Goldstone bosons and new gauge bosons to e^ e^-→ttk.We find that for reasonable ranges of the parameters,the preudo Goldstone bosons afford dominate contribution,the correction arising from new gauge bosons is negligibly small,the maximum of the relative corrections is-10% with the center-of-mass energy √s=500GeV;whereas in the case of √s=1500 GeV,the relative corrections could be up to 16%.Thus large new physics might be observable at the experiments of next-generation linear colliders.     

Universally coupled extraZ bosons from extended technicolor models

We show that in extended technicolor models there are several neutralZ bosons whose couplings to fermions are independent of family. TheseZ bosons are therefore additional to that of the standard model and induce corrections to the low energy effective Hamiltonian. These corrections are calculated in the most general model which includes technileptons (introduced to give mass to leptons).