scholarly journals NEW ANGLE ON THE STRONG CP AND CHIRAL SYMMETRY PROBLEMS FROM A ROTATING MASS MATRIX

2009 ◽  
Vol 24 (01) ◽  
pp. 101-112 ◽  
Author(s):  
JOSÉ BORDES ◽  
HONG-MO CHAN ◽  
TSOU SHEUNG TSUN
Keyword(s):  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Mass Matrix ◽  
Energy Scale ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Quark Masses ◽  
Chiral Transformation ◽  
The Masses ◽  
Fermion Mass Matrix

It is shown that when the mass matrix changes in orientation (i.e. rotates) in generation space for a changing energy scale, the masses of the lower generations are not given just by its eigenvalues. In particular, these masses need not be zero even when the eigenvalues are zero. In that case, the strong CP problem can be avoided by removing the unwanted θ term by a chiral transformation not in contradiction with the nonvanishing quark masses experimentally observed. Similarly, a rotating mass matrix may shed new light on the problem of chiral symmetry breaking. That the fermion mass matrix may so rotate with the scale has been suggested before as a possible explanation for up–down fermion mixing and fermion mass hierarchy, giving results in good agreement with experiment.

scholarly journals A SOLUTION TO THE STRONG CP PROBLEM TRANSFORMING THE THETA ANGLE TO THE KM CP-VIOLATING PHASE

2010 ◽  
Vol 25 (32) ◽  
pp. 5897-5911 ◽  
Author(s):  
JOSÉ BORDES ◽  
HONG-MO CHAN ◽  
SHEUNG TSUN TSOU
Keyword(s):  
Mass Matrix ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Order Unity ◽  
Ckm Matrix ◽  
Cp Violations ◽  
Fermion Mass Matrix

It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta angle term in the QCD action of topological origin can be eliminated by chiral transformations, while giving still nonzero masses to all quarks. Instead, the effects of such transformations get transmitted by the rotation to the CKM matrix as the KM phase giving, for θ of order unity, a Jarlskog invariant typically of order 10-5, as experimentally observed. Strong and weak CP violations appear then as just two facets of the same phenomenon.

scholarly journals A first test of the framed standard model against experiment

2015 ◽  
Vol 30 (11) ◽  
pp. 1550051 ◽  
Author(s):  
José Bordes ◽  
Hong-Mo Chan ◽  
Sheung Tsun Tsou
Keyword(s):  
Standard Model ◽  
Mass Matrix ◽  
Internal Symmetry ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Order Unity ◽  
Changing Scale ◽  
The Standard Model ◽  
Symmetry Space ◽  
Fermion Mass Matrix

The framed standard model (FSM) is obtained from the standard model by incorporating, as field variables, the frame vectors (vielbeins) in internal symmetry space. It gives the standard Higgs boson and 3 generations of quarks and leptons as immediate consequences. It gives moreover a fermion mass matrix of the form: m = mTαα†, where α is a vector in generation space independent of the fermion species and rotating with changing scale, which has already been shown to lead, generically, to up–down mixing, neutrino oscillations and mass hierarchy. In this paper, pushing the FSM further, one first derives to 1-loop order the RGE for the rotation of α, and then applies it to fit mass and mixing data as a first test of the model. With 7 real adjustable parameters, 18 measured quantities are fitted, most (12) to within experimental error or to better than 0.5 percent, and the rest (6) not far off. (A summary of this fit can be found in Table 2 of this paper.) Two notable features, both generic to FSM, not just specific to the fit, are: (i) that a theta-angle of order unity in the instanton term in QCD would translate via rotation into a Kobayashi–Maskawa phase in the CKM matrix of about the observed magnitude (J ~ 10-5), (ii) that it would come out correctly that mu < md, despite the fact that mt ≫ mb, mc ≫ ms. Of the 18 quantities fitted, 12 are deemed independent in the usual formulation of the standard model. In fact, the fit gives a total of 17 independent parameters of the standard model, but 5 of these have not been measured by experiment.

scholarly journals Electroweak SU(2)L × U(1)Y model with strong spontaneously fermion-mass-generating gauge dynamics

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Petr Beneš ◽  
Jiří Hošek ◽  
Adam Smetana
Keyword(s):  
Chiral Symmetry Breaking ◽  
Axial Vector ◽  
Higgs Sector ◽  
Dyson Equation ◽  
Mass Splitting ◽  
Fermion Mass ◽  
Goldstone Bosons ◽  
The Standard Model ◽  
Exploratory Stage ◽  
The Masses

Abstract Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor SU(3)f symmetry with scale Λ. Anomaly freedom requires addition of three νR. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies Σf(p2) has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) Σf(p2) = $$ {M}_{fR}^2/p $$ M fR 2 / p where three Majorana masses MfR of νfR are of order Λ. (2) Σf(p2) = $$ {m}_f^2/p $$ m f 2 / p where three Dirac masses mf = m(0)1 + m(3)λ3 + m(8)λ8 of SM fermions are exponentially suppressed w.r.t. Λ, and degenerate for all SM fermions in f. (1) MfR break SU(3)f symmetry completely; m(3), m(8) superimpose the tiny breaking to U(1) × U(1). All flavor gluons thus acquire self-consistently the masses ∼ Λ. (2) All mf break the electroweak SU(2)L × U(1)Y to U(1)em. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) three νR-composed Higgses χi with masses ∼ Λ. (2) Two new SM-fermion-composed Higgses h3, h8 with masses ∼ m(3), m(8), respectively. (3) The SM-like SM-fermion-composed Higgs h with mass ∼ m(0), the effective Fermi scale. Σf(p2)-dependent vertices in the electroweak Ward-Takahashi identities imply: the axial-vector ones give rise to the W and Z masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in f. At the present exploratory stage the splitting comes out unrealistic.

scholarly journals DEVELOPING THE FRAMED STANDARD MODEL

2012 ◽  
Vol 27 (17) ◽  
pp. 1250087 ◽  
Author(s):  
MICHAEL J. BAKER ◽  
JOSÉ BORDES ◽  
HONG-MO CHAN ◽  
TSOU SHEUNG TSUN
Keyword(s):  
Standard Model ◽  
Mass Matrix ◽  
Higgs Field ◽  
Fermion Mass ◽  
Ckm Matrix ◽  
Changing Scale ◽  
Rank One ◽  
Distinguishing Features ◽  
Fermion Mass Matrix

The framed standard model (FSM) suggested earlier, which incorporates the Higgs field and three fermion generations as part of the framed gauge theory (FGT) structure, is here developed further to show that it gives both quarks and leptons hierarchical masses and mixing matrices akin to what is experimentally observed. Among its many distinguishing features which lead to the above results are (i) the vacuum is degenerate under a global su(3) symmetry which plays the role of fermion generations, (ii) the fermion mass matrix is "universal," rank-one and rotates (changes its orientation in generation space) with changing scale μ, (iii) the metric in generation space is scale-dependent too, and in general nonflat, (iv) the theta-angle term in the quantum chromodynamics (QCD) action of topological origin gets transformed into the CP-violating phase of the Cabibbo–Kobayashi–Maskawa (CKM) matrix for quarks, thus offering at the same time a solution to the strong CP problem.

scholarly journals THERMAL RESTORATION OF CHIRAL SYMMETRY IN SUPERSYMMETRIC NAMBU–JONA-LASINIO MODEL WITH SOFT SUSY BREAKING

1998 ◽  
Vol 13 (15) ◽  
pp. 1235-1240 ◽  
Author(s):  
J. HASHIDA ◽  
T. MUTA ◽  
K. OHKURA
Keyword(s):  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Susy Breaking ◽  
Fermion Mass ◽  
Coupling Constant ◽  
Field Coupling ◽  
Unified Field ◽  
Supersymmetric Version ◽  
First Order Phase ◽  
Breaking Term

The supersymmetric version of the Nambu–Jona-Lasinio model is investigated in connection with the chiral symmetry breaking induced by a soft SUSY breaking term. It is found that the broken chiral symmetry due to the soft breaking term is restored at suitably high temperature and the symmetry restoration occurs as first-order phase transitions. The critical temperature at which the chiral symmetry is restored is determined as a function of the strength of the soft breaking term and the field coupling constant. The dynamical fermion mass is calculated at finite temperature. Some possible applications to the breaking scenario of unified field theories are discussed.

NEUTRAL PION PHOTOPRODUCTION ON THE PROTON AND THE CLOUDY-BAG MODEL

1992 ◽  
Vol 07 (21) ◽  
pp. 5231-5244
Author(s):  
A.N. TABACHENKO
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Electric Dipole ◽  
Neutral Pion ◽  
Chiral Symmetry Breaking ◽  
Pion Photoproduction ◽  
Additional Contribution ◽  
Bag Model ◽  
Neutral Pions ◽  
Quark Masses

In the cloudy-bag model, the value of the electric dipole amplitude of the photoproduction of neutral pions off protons at threshold connected with the additional contribution from the chiral symmetry breaking interaction is evaluated. If this additional contribution is included in the amplitude of the photoproduction of neutral pions off protons at threshold, the discrepancy between the LET predictions and the measured value of the electric dipole amplitude [Formula: see text] can be resolved for the values of quark masses and bag radii which are close to the generally used values.

scholarly journals CHIRAL PARTNERS IN A CHIRALLY BROKEN WORLD

2009 ◽  
Vol 24 (02n03) ◽  
pp. 229-236 ◽  
Author(s):  
STEFAN LEUPOLD ◽  
MARKUS WAGNER
Keyword(s):  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Axial Vector ◽  
Vector Current ◽  
The Other ◽  
Other Hand ◽  
Chiral Transformation ◽  
Pion Interaction ◽  
Hadronic Level ◽  
Prominent Peak

The isovector–vector and the isovector–axial-vector current are related by a chiral transformation. These currents can be called chiral partners at the fundamental level. In a world where chiral symmetry was not broken, the corresponding current-current correlators would show the same spectral information. In the real world chiral symmetry is spontaneously broken. A prominent peak — the ρ-meson — shows up in the vector spectrum (measured in e+e--collisions and τ-decays). On the other hand, in the axial-vector spectrum a broad bump appears — the a1-meson (also accessible in τ-decays). It is tempting to call ρ and a1 chiral partners at the hadronic level. Strong indications are brought forward that these "chiral partners" do not only differ in mass but even in their nature: The ρ-meson appears dominantly as a quark-antiquark state with small modifications from an attractive pion-pion interaction. The a1-meson, on the other hand, can be understood as a meson-molecule state mainly formed by the attractive interaction between pion and ρ-meson. A key issue here is that the meson-meson interactions are fixed by chiral symmetry breaking. It is demonstrated that one can understand the vector and the axial-vector spectrum very well within this interpretation. It is also shown that the opposite cases, namely ρ as a pion-pion molecule or a1 as a quark-antiquark state lead to less satisfying results. Finally speculations on possible in-medium changes of hadron properties are presented.

Sign in / Sign up

Export Citation Format

Share Document