Constraints of the fourth generation from $g_{\mu }-2$

Abstract

We investigate the newly observed muon $g_{\mu }-2$ anomaly in the framework of a sequential fourth generation model with a heavy fourth neutrino, ${\nu }^{\prime }$. We find that $g_{\mu }-2$ can exclude most values of $m_{{\nu }^{\prime }}$ and put a very stringent constraint on the existence of the fourth generation. We also obtain bounds of a $4\times 4$ leptonic mixing matrix elements, $V_{2{\nu }^{\prime }}$ if it really exists.

Comments: 7 pages, 3 figures, to appear in Phys. Lett. B