Transcript Rare B decays in Warped Extra Dimension Model with

Rare B decays in Warped Extra Dimension
Model with Custodial Symmetry
Cheng Li
Theory Division, IHEP
Collaborate with Cai-Dian Lϋ
1
Outline




Introduction
Effective Hamiltonian and Branching Ratios
Results and Analysis
Summary and Outlook
2
Motivation


Rare B-decays induced by flavor changing
neutral currents provide a valuable search for
physics beyond the standard model indirectly.
Randall-Sundrum model, as a realistic model
of EW symmetry breaking, provide an
ambitious proposal to explain hierarchy
between the Planck and EW scale, meanwhile
one can naturally generate the hierarchies in
the fermion mass spectrum and mixing angle.
3
Introduction to the Model

The
metric is:
PRL.83,3370(1999)


The hierarchy problem is then solved by noting that
generic mass scales M in the 5D theory are scaled
down to
on the IR brane.
The bulk symmetry is:
and the Figure of the Model is
4
We need a Higgs bidoublet and appropriate
boundary conditions
JHEP09,064(2009)
5
Flavor Structure
6
Feynman Diagram for the Process
7
Effective Hamiltonian

Integrating out the particles above
scale
, we arrive at the effective
Hamiltonian
8
Neutral Current


In this model we have to consider three
gauge bosons with the corresponding mass
eigenstates , and .
The main results can be briefly summarized
as follows: the EW tree level contributions to
observables mediated by the new
weak gauge boson .
9
Branching Ratios

Important formulae for
10
11

Important formulae for
12
13
14
Results and Analysis

Forward Backward Asymmetry:
15

We have the opposite sign C7 within SM,
where the effective Hamiltonian is
16

the NP effects in rare B decays are generally
small (O(10%)) in the model
17
The Suppression
Induced by the Custodial Protection


We have
Taking into account the
symmetry
breaking effects on the UV brane, the
custodial protection mechanism is not exact
anymore, but still powerful enough to
suppress
by two orders of
magnitude.
18
Summary and Outlook


New physics contributions to rare K and B
decay, especially in
transitions, are
governed by tree level contributions from
boson in the warped extra dimension model
with custodial symmetry, which is consistent
with CDF data and will be test in LHCb.
The rare B decays can be used as a ideal
platform for testing physics beyond SM in the
LHC era.
19
Thank You!
20