Download ppt - 2005 Taipei Summer Institute on Strings, Particles and Fields

Large Electroweak Penguin
Effects in B and K physics
Makiko Nagashima
Dept. of Physics, NTU
Collider and New physics Mini-Workshop II
July 21- 22,
National Taiwan University
Contents
Summer Institute
 Introductions of introduction …
CP Violation in B physics
Paper hep-ph/0503072 (W.S.Hou, M.N, A. Soddu)
 Impact of 4th generation on B→Kπ Direct CP
Long Introduction
Paper in preparation (W.S.Hou, M.N, A. Soddu)
 4th generation scenario and K physics
Introductions of Introduction …
What is the B physics ?
Neither just “the second letter of the alphabet”
nor “a mark given to student’s work”…
Physics related to B meson
containing (anti) bottom quark
Why B physics ...?
What can we learn from B physics (experiments) ?
 CP is violating (C: charge conjugation, P: parity)
 Origin of CP Violation ?
We still don’t have any convincing solution
 Better understanding
Close to the early universe
(need High Energy experiment but cannot reach Ultra-HE…)
CPV in fundamental particle processes
TEST OF THE STANDARD MODEL (current understanding)
SEARCH FOR NEW PHYSICS (we don’t know now)
Standard Model and CKM mechanism
3 generation
SU(2) doublet
3 mixing angles
+
SU(2) singlet
1 CP phase
Unitarity Triangle
CKM matrix
B physics: comparable
K physics: one side would be too small
That is why B physics has succeeded in study of CP violation.
Determination of the Unitarity Triangle
One of the clues to test of SM / search for NP
Parts of decay modes
Accumulation of data
Experiments tell us a lot !!
We can/must use all of them !!
try to understand the physics behind them!!
Experimental result on DCPV of B→Kπ
seemingly allow accommodations for the NP …
Observables of CP Violation
Time dependent CP asymmetry
B
B
Direct CP asymmetry
f
see directly
the difference of yield
( Direct CPV )
( Mixing-induced CPV )
Only for
neutral meson
We focus on DCPV in this talk
What is the indication of non-zero DCPV ?
Suppose the amplitude can be expressed in terms of,
(irrelevant to weak int.)
for the anti-particle process,
CP
change of the sign
(i) given by single term
(ii) no relative phases
goes away
Simple explanation about TREE and PENGUIN diagrams
Tree diagram
b
u
s
u
d
d
W
b
>
u
W
u
s
u
1/Nc
u
Penguin diagram
sub-dominant
W
b
g
d
s
u
u
d
>
d
b
d
s
W
Z,γ
u
u
Large EW penguin from 4th generation
and
B physics and K physics
Introduction: result on DCPV in Kπ
PUZZLE
The puzzle still persists
5σ
Why this indicates a riddle ?
sub-dominant
can be negligible
No Phase differences between them !!
SM3
Theoretical expectations
within different treatment of the hadronic matrix element
QCDF (BBNS)
(2003)
kT PQCD (KLS)
(2001)
contradiction
away
How to explain the deviation
extra comparable contributions
bringing phase differences
toward
We saw that …
must not be negligible
Assemble
We call for Large
New physics
with an extra weak phase
penguin
4th generation scenario
We employ kTPQCD approach
consistent with ~12%
?
4th generation scenario
A sequential 4th generation in addition to the SM particles
same quantum number
well-known
unknown
Minimum Setup
follows WS parameterization
T. Yanir, JHEP06, 044
A. Arhrib and W-S. Hou, EPJC27,555
Effective Hamiltonian
Dividing ΔCi by QCD penguin
Tree
QCD Penguin
Large
enhancement
EW/EM Penguin
Wilson coefficient
t' effects well-satisfy b → sγrate and DCPV
Constraint
PDG04
Belle(04)
B(b→sll) gets greatly enhanced
Δm is lower than EXP. bound
PDG04
4th generation effects
are not excluded!!
Result
kTPQCD in the SM
+
4th generation
sizable splitting between
It naturally generates the phase diff. and sizable mag. of the extra term
Confess …..
Our result is at leading order in kTPQCD.
A recent result finds a much larger color-suppressed
tree (C) at next-to-leading order.
(talk by S. Mishima at Super B WSII, Hawaii April 2005)
Naively assumed
did not care about
One may have suspicion that
b→s would spill over into s→d
is not necessarily ~ 0
W.S. Hou et al.
PLB 192 441 (1987)
should be all intertwined …
We need to deal with the mixing matrix in detail
From previous study
Constraint on s ↔ d from K physics
(J. Bijnens et al.)
(E. Pallante et al.)
Therefore….
Andrea’s talk at PPP6
well-satisfy
Implication for
Current Upper Bound
It is very hard to measure
but challenging…
The rate gets enhanced by almost two order of magnitude !!
is not in trouble (currently
)
Summary
Introductions of Introduction
B physics and CP Violation
Kπ DCPV puzzle and 4th generation
constraint from b→sll and Bs mixing
kTPQCD + large EW effect
4x4 mixing matrix and K physics
constraints on s→d transition
Implication for
4th generation effects, constrained by B physics, are sizable in K physics.
 Have a nice lunch time
 C.P. Yuan’s lecture “ Collider Physics IV”
will be started from 13:30 !
BACKUP SLIDE
strong phase source in kTPQCD
At leading process
a hard gluon kicks spectator
is introduced to cure the endpoint singularities
Large strong phase comes from
annihilation process