Regular Series


Vol. 33 (2002), No. 12, pp. 4041 – 4479


Fermion Generations and Mixing from Dualized Standard Model

abstract

The puzzle of fermion generations is generally recognized as one of the most outstanding problems of present particle physics. In these lectures, we review a possible solution based on a non-Abelian generalization of electric–magnetic duality derived some years ago. This non-Abelian duality implies the existence of another SU(3) symmetry dual to colour, which is necessarily broken when colour is confined and so can play the role of the “horizontal” symmetry for fermion generations. When thus identified, dual colour then predicts 3 and only 3 fermion generations, besides suggesting a special Higgs mechanism for breaking the generation symmetry. A phenomenological model with a Higgs potential and a Yukawa coupling constructed on these premises is shown to explain immediately all the salient qualitative features of the fermion mass hierarchy and mixing pattern, excepting for the moment CP violation. In particular, though treated on exactly the same footing, quarks and leptons are seen to have very different mixing patterns as experimentally observed, with leptons having generally larger mixings than quarks. The model offers further a perturbative method for calculating mixing parameters and mass ratios between generations. Calculations already carried out to 1-loop order is shown to give with only 3 adjustable parameters the following quantities all to within present experimental error: all 9 CKM matrix elements \(|V_{rs}|\) for quarks, the neutrino oscillation angles or the MNS lepton mixing matrix elements \(|U_{\mu 3}|, |U_{e 3}|\), and the mass ratios \(m_c\)/\(m_t\), \(m_s\)/\(m_b\), \(m_\mu \)/\(m_\tau \). The special feature of this model crucial for deriving the above results is a fermion mass matrix which changes its orientation (rotates) in generation space with changing energy scale, a feature which is shown to have direct empirical support, and although potentially dangerous for flavour-violation is found through detailed analysis not to be the case. With its parameters now so fitted, the resulting scheme is highly predictive giving in particular correlated predictions in low energy FCNC effects (meson mass splittings and decays, \(\mu \)–\(e\) conversion in nuclei, etc.) and in ultra-high energy (post-GZK) air showers from cosmic rays, both of which can hopefully be tested soon by experiment.


Novel Phase at High Density and Their Role in the Structure and Evolution of Neutron Stars

abstract

We present a pedagogic discussion on the role of novel phases of dense baryonic matter in “neutron” stars. Qualitative aspects of the physics that drives phase transitions and some of its astrophysical consequences are discussed. Observable aspects of neutron star structure and early evolution of the newly born neutron star are discussed in some detail.


Andreev Reflection in Superconducting QCD

abstract

In this paper we discuss the phenomenon of the Andreev reflection of quarks at the interface between the 2SC and the Color-Flavor-Locked (CFL) superconductors appeared in QCD at asymptotically high densities. We also give the general introduction to the Andreev reflection in the condensed matter systems as well as the review of this subject in high density QCD.


Diffractive Scattering

abstract

We discuss basic concepts and properties of diffractive phenomena in soft hadron collisions and in deep-inelastic scattering at low Bjorken-\(x\). The paper is not a review of the rapidly developing field but presents an attempt to show in simple terms the close inter-relationship between the dynamics of high-energy hadronic and deep-inelastic diffraction. Using the saturation model of Golec-Biernat and Wüsthoff as an example, a simple explanation of geometrical scaling is presented. The relation between the QCD anomalous multiplicity dimension and the Pomeron intercept is discussed.


Fluctuations in Heavy Ion Collisions

abstract

The physics of fluctuations in heavy ion collisions is discussed and a few examples for actual measurements are presented.


Thermal Approach to RHIC

abstract

Applications of a simple thermal model to ultra-relativistic heavy-ion collisions are presented. We compute abundances of various hadrons, including particles with strange quarks, the \(p_\perp \) spectra, and the HBT radii for the pion. Surprising agreement is found, showing that the thermal approach can be used successfully to understand and describe the RHIC data.


Lattice QCD for RHIC

abstract

I briefly introduce the methods by which lattice QCD predictions for RHIC are obtained. Next I deal with lattice determinations of strangeness production and event-to-event fluctuations of conserved quantities. I also present a new diagrammatic method for computing derivatives with respect to chemical potentials, and conclude with discussions of some tests of thermal perturbation theory which follow.


Comments on Systematic Effects in Heavy Ions Experiments

abstract

Comments on the comparison between results from two CERN-SPS heavy-ion experiments studying the production of strange particles.


CKM Parameters from \(|\Delta S |=1\) Processes

abstract

I briefly review how measurements in rare kaon decays and in hyperon decays will help unravel the CKM mixing angles. I then discuss recent work in selected kaon decay modes and in estimates for CP violation in non-leptonic hyperon decay.


Rare and Forbidden Decays

abstract

In these lectures I first cover radiative and semileptonic \(B\) decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors, are the second step. Small effects due to the long-distance, spectator contributions, etc. are discussed next. The second section we start with non-leptonic decays, typically \(B \to \pi \pi ,\;K\pi ,\; \rho \pi ,\dots \) We describe in more detail our predictions for decays dominated by the \(b\to s \eta _c\) transition. Reports on the most recent experimental results are given at the end of each subsection. In the second part of the lectures I discuss decays forbidden by the Lorentz and gauge invariance, and due to the violation of the angular momentum conservation, generally called the Standard Model-forbidden decays. However, the non-commutative QED and/or non-commutative Standard Model (NCSM), developed in a series of works in the last few years allow some of those decay modes. These are, in the gauge sector, \(Z\to \gamma \gamma ,\; gg\), and in the hadronic sector, flavour changing decays of the type \(K\to \pi \gamma \), \(B\to K\gamma \), etc. We shall see, for example, that the flavour changing decay \(D^+_{\rm S}\to \pi ^+ \gamma \) dominates over other modes, because the processes occur via charged currents, i.e. on the quark level they arise from the point-like photon \(\times \) current \(\times \) current interactions. In the last section we present the transition rate of “transverse plasmon” decay into a neutrino–antineutrino pair via non-commutative QED, i.e. \(\gamma _{\rm pl}\to \nu \bar \nu \). Such decays give extra contribution to the mechanism for the energy loss in stars.


Anomalous Magnetic Moment of the Muon

abstract

Standard Model prediction for the muon anomalous magnetic moment (\(g-2\)) is reviewed. Recent shifts in the QED and hadronic contributions are discussed. The result is compared with the latest Brookhaven E821 measurement.


CP and CPT Violation in \(K^0\) Decays

abstract

The job of the experimentalist is to give numbers, with as many digits behind the decimal point as possible. R. Feynman Physics is an experimental science! S. Glashow


CP Violation Measurements at \(B\) Factories

abstract

Recent results from KEK-B and PEP-II \(B\) factories are reviewed with an emphasis on measurements of CP violating effects involving \(B^{0}\) meson oscillations.


Pion Structure at High and Low Energies in Chiral Quark Models

abstract

Low and high energy properties of the pion are reviewed in the framework of chiral quark models. Particular emphasis is put on the simplest version of the SU(2) NJL model as prototype. The role of gauge invariance in this kind of calculations is stressed. The results are used as initial conditions for perturbative QCD evolution equations. At leading order the quark model scale is \(\mu _0 \sim 320 {\rm MeV}\) as determined from the pion distribution functions and the pion distribution amplitudes.


top

ver. 2024.03.17 • we use cookies and MathJax