Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
1992-05-26
Phys.Lett. B303 (1993) 55-62
Physics
High Energy Physics
High Energy Physics - Phenomenology
17.p
Scientific paper
10.1016/0370-2693(93)90043-H
I remark that the weak mixing angle in the standard model may be computed even in the absence of a grand unification symmetry. In particular, if there is an additional gauged $U(1)$ symmetry at some large scale which can be made anomaly-free only by a Green-Schwarz (GS) mechanism, this typically results in a prediction for the weak angle. In the case of the standard model one can see that the standard Peccei-Quinn symmetry may be gauged and the anomalies cancelled through a GS mechanism. Remarkably enough, cancelation of anomalies works only for the `canonical' value $sin^2\theta _W=3/8$. In the case of the supersymmetric standard model one can also find $U(1)$ currents which may be made anomaly-free through a GS but the canonical value is only obtained in the absence of any Higgs multiplet. If the analysis is extended to include $U(1)$ R-symmetries, there is a unique class of $U(1)$s which give rise to the canonical value. The R-symmetry is only anomaly-free for $sin^2\theta _W=(4N_g-3)/(10N_g-3N_D-3)$, where $N_g,N_D$ are the number of generations and Higgs pairs. The natural context in which the above scenario may naturally arise is string theory. I also emphasize other interesting possibilities offered by the GS mechanism to model-building.
No associations
LandOfFree
Computing the Weak Mixing Angle from Anomaly Cancellation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Computing the Weak Mixing Angle from Anomaly Cancellation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Computing the Weak Mixing Angle from Anomaly Cancellation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-246892