arXiv subjects
Publications and source records attributed to Harald Fritzsch.
We show that the observed quark masses seem to be consistent with a simple scaling law. Due to the precise values of the heavy quarks we are able to calculate the quark masses in the light quark sector. We discuss a possible value for the strange quark mass. We show that the u-type quark masses obey the scaling law very well.
This is the summary talk for the theoretical part of ICFP03. The contents of the talk are reviewed and a general outlook is given.
Last year I talked at this meeting about a possible time dependence of the QCD coupling constant $α_s$. This year I shall look into the problem once more, without fully repeating the arguments given last year. Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of grand unification. A variation of the electromagnetic coupling constant could either be generated by a corresponding time variation of the unified coupling constant or by a time variation of the unification scale, or by both. The various possibilities, differing substantially in their implications for the variation of low energy physics parameters like the nuclear mass scale, are discussed. The case in which the variation is caused by a time variation of the unification scale is of special interest. It is supported in addition by recent hints towards a time change of the proton-electron mass ratio.
We reexamine the democratic neutrino mixing ansatz, in which the mass matrices of charged leptons and Majorana neutrinos arise respectively from the explicit breaking of S(3)_L x S(3)_R and S(3) flavor symmetries. It is shown that a democracy term in the neutrino sector can naturally allow the ansatz to fit the solar neutrino mixing angle θ_sun \approx 33^\circ. We predict \sin^2 2θ_atm \approx 0.95 for atmospheric neutrino mixing and J \approx 1.2% for leptonic CP violation in neutrino oscillations without any fine-tuning. Direct relations between the model parameters and experimental observables are also discussed.
The inclusive and exclusive B decays into the eta' meson plus others are investigated in a model based on the QCD anomaly. The invariant mass distribution is discussed. The constraint of the effective coupling is obtained from the data of the exclusive decay modes. The branching ratio of J/psi -> eta'eta gamma is predicted to be as large as 5.4*10^{-5}, which can be tested in the forthcoming CLEO-c experiments.
We show that the four-zero texture of Hermitian quark mass matrices can survive current experimental tests: it is able to yield sufficiently large predictions for the flavor mixing parameter $|V_{ub}/V_{cb}|$ and the CP-violating parameter $\sin 2β$, without fine-tuning of the input values of quark masses, provided the (2,2), (2,3) and (3,3) elements of up and down mass matrices roughly satisfy a geometrical hierarchy. The successful relations $|V_{us}| \approx \sqrt{m_u/m_c + m_d/m_s}$ and $|V_{td}/V_{ts}| \approx \sqrt{m_d/m_s}$ obtained previously from the six-zero texture of Hermitian quark mass matrices remain unchanged in the new ansatz.
After receiving many requests for reprints of this article, describing the original ideas on the quark gluon gauge theory, which we later named QCD, we decided to place the article in the e-Print archive.
Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of grand unification. A variation of the electromagnetic coupling constant could either be generated by a corresponding time variation of the unified coupling constant or by a time variation of the unification scale, of by both. The various possibilities, differing substantially in their implications for the variation of low energy physics parameters like the nuclear mass scale, are discussed. The case in which the variation is caused by a time variation of the unification scale is of special interest. It is supported in addition by recent hints towards a time change of the proton-electron mass ratio. Implications for the analysis of the Oklo remains and for quantum optics tests are discussed.
Starting from astrophysical indications that the fine structure constant might undergo a small cosmological time shift, we discuss the implications of such an effect from the point of view of particle physics. Grand unification implies small time shifts for the nucleon mass, the magnetic moment of the nucleon and the weak coupling constant as well. The relative change of the nucleon mass is about 40 times larger than the relative change of alpha. Laboratory measurements using very advanced methods in quantum optics might soon reveal small time shifts of the nucleon mass, the magnetic moment of the nucleon and the fine structure constant.
We present a classification of possible parametrizations of the 3x3 lepton flavor mixing matrix in terms of the rotation and phase angles. A particular parametrization, which is most convenient to describe the observables of neutrino oscillations and that of the neutrinoless double beta decay, is studied in detail. The possibility to determine the Dirac- and Majorana-type CP-violating phases are also discussed.
We compute the Higgs mass in a model for the electroweak interactions based on a confining theory. This model is related to the standard model by the complementarity principle. A dynamical effect due to the large typical scale of the Higgs boson shifts its mass above that of the W-bosons. We obtain m_H=129.6 GeV.
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay $μ\to e γ$ is expected to occur with a branching ratio of the same order as the present experimental limit.
We consider phenomenological implications of a model recently proposed for the electroweak interactions based on a SU(2)_L confining theory. We concentrate on the production of excited states of the electroweak bosons at future colliders and we consider their contribution to the reaction W^+ + W^- \to W^+ + W^-. We expect large deviations from the standard model in the TeV region.
With the help of the light-quark triangle, which is essentially congruent to the rescaled unitarity triangle for a variety of textures of the quark mass matrices, we calculate the CP-violating quantity \sin 2βand the ratio of |V_{ub}| to |V_{cb}|. We find that \sin 2βis most likely to lie in the range 0.45 \leq \sin 2β\leq 0.60, a result compatible very well with the present BaBar and Belle measurements. On the other hand, |V_{ub}/V_{cb}| \geq 0.8 is disfavored. Our bounds on both \sin 2βand |V_{ub}/V_{cb}| can soon be confronted with more precise data to be accumulated from the asymmetric B-meson factories.
We discuss an alternative version of the electroweak standard model, in which only the heavy t quark, not the light fermions, couples to the Higgs boson with a strength given by the standard model. The Higgs particle decays dominantly into two gluons jets. The branching ratio for the 2 gamma decay is about 3.5%. The Higgs particle would be a narrow object (width about 60 KeV), and its mass might be consistent with the value given by typical estimates of radiative effects measured by the LEP experiments.
We consider a model for the electroweak interactions based on the assumption that physical particles are singlets under the gauge group SU(2). The concept of complementarity explains why the standard model works with such an extraordinary precision although the fermions and bosons of the model can be viewed as composite objects of some more fundamental fermions and bosons. We study the incorporation of QED in the model. Furthermore we consider possible deviations from the standard model at very high energies, e.g. excited states of the weak bosons.
We discuss a simple model of lepton mixing and CP violation based on the flavor democracy of charge leptons and the mass degeneracy of neutrinos. A nearly bi-maximal flavor mixing pattern, which is favored by current data on atmospheric and solar neutrino oscillations, emerges naturally from this model after explicit symmetry breaking. The rephasing-invariant strength of CP or T violation can be as large as one percent, leading to significant probability asymmetries between ν_μ\to ν_e and \barν_μ\to \barν_e (or ν_e \to ν_μ) transitions in the long-baseline neutrino experiments. The possible matter effects on CP- and T-violating asymmetries are also taken into account.
We propose a phenomenological model of lepton mixing and CP violation based on the flavor democracy of charge leptons and the mass degeneracy of neutrinos. A nearly bi-maximal flavor mixing pattern, which is favored by current data on atmospheric and solar neutrino oscillations, emerges naturally from this model after explicit symmetry breaking. The rephasing-invariant strength of CP or T violation can be as large as one percent, leading to significant probability asymmetries between ν_μ\to ν_e and \barν_μ\to \barν_e (or ν_e \to ν_μ) transitions in the long-baseline neutrino experiments. The possible matter effects on CP- and T-violating asymmetries are also taken into account.