Effect of fourth generation $CP$ phase on $b\to s$ transitions

A. Arhrib; W.-S. Hou

doi:doi:10.1140/epjc/s2003-01154-0

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

2023 Impact factor 4.2

Particles and Fields

Eur. Phys. J. C 27, 555-561 (2003)
DOI: 10.1140/epjc/s2003-01154-0

Effect of fourth generation CP phase on $b\to s$ transitions

A. Arhrib^{1, 2} and W.-S. Hou³

¹ Max-Planck Institut für Physik, Föhringer Ring 6, 80805 München, Germany
² LPHEA, Physics Department, Faculty of Science-Semlalia, P.O.B. 2390, Marrakesh, Morocco
³ Department of Physics, National Taiwan University, Taipei, Taiwan 10764, R.O.C.

(Received: 20 November 2002 / Published online: 7 March 2003 )

Abstract
We study the effect of a sequential fourth generation on $b\to s\gamma$ , B_s mixing, $B\to K^{(*)}\ell^+\ell^-$ , $X_s\ell^+\ell^-$ and $\phi K_{\mathrm {S}}$ , taking into account the presence of a new CP phase in quark mixing. We find that the effects via electromagnetic and strong penguins, such as in $b\to s\gamma$ or CP-violation in $B\to \phi K_{\mathrm {S}}$ , are rather mild, but the impact via boxes or Z penguins is quite significant. Not only can one have a B_s mixing much larger than expected, even if it is measured near the present limit, mixing-dependent CP-violation could become maximal. For electroweak penguin modes, the fourth generation can provide the enhancement that perhaps may be needed, while the $m_{\ell^+\ell^-}$ dependence of the forward-backward asymmetry in $B\to K^{*}\ell^+\ell^-$ can further probe for the fourth generation. These effects can be studied in detail at the B factories and the Tevatron.