Breakdown Of Discrete Symmetry Research Articles

Another calculation of the Higgs mass and the top mass from the principles of H. B. Nielsen: $m_H\cong 163$ GeV for $M_t\cong 190$ GeV

We calculate the Higgs mass and the top mass starting from the principle that there are two, essentially degenerate minima in the Higgs effective potential; the second is at about the Planck energy scale M P = 1.2 × 1019 GeV. Thus the parameter of the quartic self-coupling λ h vanishes, as does β λH at M P. The new element is the addition of a quantum interaction term which couples the square of the Higgs field to the square of a pseudoscalar field, in the domain of the energy scale between about 1014 GeV and M P. We modify β λH at one loop. The pseudoscalar field which is introduced may be the field which is responsible for a spontaneous breakdown of discrete symmetry — for CP noninvariance at an energy scale of (1015–1016) GeV. The result is then a closer value for m H ≅ 163 GeV for the top pole-mass M t ≅ 190 GeV; both values are now close to the electroweak scale parameter \(\langle {\phi _H}\rangle /\sqrt 2 = 175{\text{ GeV}}\). In terms of dimensionless running coupling parameters, which determine the masses near to the electroweak scale, we get \(\sqrt {{\lambda _H}} \cong 0.06\) and \(gt/\sqrt 2 \cong 0.72\), values that are close to each other and close to unity.

Domain walls in superstring models

Abstract Superstring models usually have a domain wall problem associated with the breakdown of discrete symmetries. We show that the dynamical origin of the parameters of the low energy theory can make these domain walls consistent with observations. We also show that the axionic domain wall problem can be solved in superstring models in a very natural way.

Tests for complete breakdown of discrete symmetry in $$D^0 - \bar D^0 $$

Implications of the conservation of probability without assumingCPT invariance, but allowing for the existence of a direct superweak (δC=2) interaction are studied for the charmed system\(D^0 - \bar D^0 \). We find that the values of the decay widths of the particles with definite mass lead to considerable simplifications in the phenomenological description of this neutral system. These simplifications do not occur in the\(K^0 - \bar K^0\) system. In particular, we obtain the expressions for the particle number per unit time, at time τ measured in the D0-meson rest frame, arising from an initially pure beam of D0 mesons. By considering the anomalous part of the particle number expression, we find means of distinguishing between the various forms of discrete-symmetry breakdown.

Thomas precession and the operational meaning of the Lorentz-group elements

When space-reflection and time-reversal symmetries are broken, the Thomas precession formulas derived by Thomas' method and from the BMT equation differ from each other. This apparent contradiction is resolved by pointing out that the breakdown of discrete symmetries may lead to a change in the operational meaning of the Lorentz-group elements.