The Effects of Fourth Generation on the double Lepton Polarization in B \rar K \ell^+ \ell^- decay

TL;DR

This paper explores how the hypothetical fourth generation quarks could influence double lepton polarizations in B meson decays, providing a potential indirect method to detect new physics beyond the Standard Model.

Contribution

It introduces the impact of fourth generation quarks on lepton polarization in B decays, highlighting their sensitivity as a new probe for new physics effects.

Findings

Double lepton polarizations are highly sensitive to fourth generation quarks.

The study's parameters are consistent with existing B decay and mixing measurements.

Lepton polarization measurements could serve as indirect evidence for fourth generation quarks.

Abstract

This study investigates the influence of the fourth generation quarks on the double lepton polarizations in B \rar K \ell^+ \ell^- decay. Taking |V_{t's}V_{t'b}|\sim \{0.01-0.03\} with phase about 100^\circ, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Delta m_{B_s}$, we obtain that the double lepton(muon and tau) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to indirect search for the fourth generation quarks(t', b').