Transcript スライド 1 - Institute of Physics Academia Sinica Taiwan

Large electroweak penguin effects
in B and K physics
Makiko Nagashima (NTU)
HEP seminar at IOPAS, Oct. 28 (2005)
Theory seminar KEK, Sep. 6 (2005)
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Contents
Kπ DCPV puzzle within 4th generation model
W.S.Hou, M.N, A. Soddu, Phys. Rev. Lett. 95, 141601(2005)
4th generation model and
indications from Kπ and K physics
W.S.Hou, M.N, A. Soddu, hep-ph/0508237, to appear in PRD
An enhanced
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Introduction
Standard Model and CKM mechanism
3 generation
Quark sector
SU(2) doublet
3 mixing angles
1 CP phase
CKM matrix
SU(2) singlet
Unitarity Triangle
Study of CPV / Test of SM / Search for NP
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Three sides are comparable
B physics has success
in studying of CP violation
In this talk, We will see
and for Bs system
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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
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Terminology: 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
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Part I
Large EWP effects on B→Kπ Direct CP
PDG2002
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Result on DCPV in Kπ
PUZZLE
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Lepton-Photon Symposium ‘05
The large discrepancy still persists
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Theoretical calculations in 2001
QCDF by M. Beneke et al., NPB606(2001)245
PQCD by Keum, Li and Sanda, PRD63(2001)054008
Two of DCPV behaves similar
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Improved calculations
Beneke and Neubert, NPB675(2003)333
Annihilation contributions
H-n. Li, S. Mishima and A.I. Sanda, hep-ph/0508041
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Direct CP Violation (DCPV)
Difference of Yields
vs
given by single term
no relative phases
DCPV goes away
CP
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In K pi amplitudes
sub-dominant
If one neglects EWP and C,
No phase differences
SM
up to leading order calculation
QCDF (BBNS)
kT PQCD (KLS)
contradiction
(2003)
(2001)
away
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How to explain deviation
The SM can explain
the different pattern of DCPVs
in Kpi modes completely
?
Of course, it is fine !!
This does not mean THERE IS NO NEW PHYSICS IN OUR NATURE
THE SM and THE NP can not be distinguished in Kpi DCPVs
From this aspect,
The different pattern of DCPVs remains a crucial hint of New Physics.
New Physics exists, its contribution appear in other processes,
and can be tested.
What can we learn for New Physics from Experimental results ?
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extra comparable contributions
bringing phase differences
toward
must not be negligible
Assemble
We call for Large
New physics
with an extra weak phase
penguin
4th generation scenario
We employ kTPQCD approach
naturally explain large
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kTPQCD approach
At leading process
a hard gluon kicks spectator
is introduced to cure the endpoint singularities
Large strong phase comes from
annihilation process
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4th generation scenario
A sequential 4th generation in addition to the SM particles
same quantum number
well-known
unknown
Minimum Setup ( meaning to be clear in Part II )
follows WS parameterization
T. Yanir, JHEP06, 044
A. Arhrib and W-S. Hou, EPJC27,555
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Our assumption
The low energy operators are the same as the SM
Neither Scalar OPE nor Tensor OPE.
R.H. dynamics is suppressed by ms/mb
New physics enters though loop processes,
and changes the short distance effects
Buras, et al.
Minimal flavor violation
Barger, et al.
Z’ model
Baek, et al.
Generic EWP
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Effective Hamiltonian
Dividing ΔCi by QCD penguin
Tree
QCD Penguin
Large
enhancement
EW/EM Penguin
Wilson coefficient
Natural ability of 4th generation to large enhancement of EWP
t' effects well-satisfy b → sγrate and DCPV
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Constraint
PDG04
Belle(04)
B(b→sll) gets greatly enhanced
Δm is lower than EXP. bound
PDG04
4th generation effects
are not excluded!!
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Result
kTPQCD in the SM
+
4th generation
sizable splitting between
It naturally generates the phase diff. and sizable mag. of the extra term
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Remark
Our result is at leading order in kTPQCD.
A recent result finds a much larger color-suppressed
tree (C) at next-to-leading order.
is less negative
(H-n. Li, S. Mishima and A.I. Sanda, hep-ph/0508041)
Comparably large C
would allow more parameter space for the 4th generation
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Some Curiosities
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MICPV is rather little sensitive to strong phases
Specially,
MICPV due to b→s transition behaves like
naïve factorization + 4th gene.
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Another framework:
extra strong phase from Final State Interaction
Naïve Factorization ⊗ Final State Rescattering
Otherwise
Double Counting
George W.S. Hou, BCP JC, Oct. 14 (2002)
No Rescattering
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We followed
Mod.Phys.Lett. A18,1763 by C-K. Chua, W-S. Hou and K-C. Yang
It accounts for
(strong phase)
ICHEP04
(strong phase)
problem
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We performed analysis by incorporating t’ effects
There is no solution
re-scattering happens between
EW penguin would be brought into
amplitude from
This FSI picture doesn’t help for resolving the puzzle
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Part II
Explore s→d and b→d implications
Naively assumed
did not care about
One may have suspicion that
b→s would spill over into s→d
is not necessarily ~ 0
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should be all intertwined …
PLB 192 441 (1987) by W.S. Hou et al.
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From K pi study, we learned
Keep
Be moderate
We have some constraint on
from
Impose
be close to the Cabibbo angle
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Allowed region from K processes
(shaded region)
(elliptic rings)
depends on
hadronic parameter
R6 and R8
is less stringent
standard (1)
Bijnens (2)
(simulated dots)
We found
(1)
(2)
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Outcome for
we take
Current Upper Bound
It is very hard to measure
but challenging…
We find enhancing
It might be even larger than
to
or even higher !!
!!
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Unfortunately,
US government cancelled the KOPIO experiment
We will have to wait longer to see whether such effects is really present…
Let us hope this stimulates the program at JPARC !!
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Furthermore…..
We also checked the impact on Bd and D system
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Summary
Starting point → Direct CP Violation in B→Kπ
4th generation is possible to generate Large EWP
Extend our study to Bd and K system
( to, phenomenologically, understand the possibilities
of having still fourth generation )
(
)
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BACKUP SLIDE
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Our anxiety
FROM PDG04
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We now know neutrinos have mass, will have CPV, and
more to be revealed. # of neutrino =3 is just one piece of info.
The rho parameter is less of a problem.
The S parameter is the real problem (it ‘s so for most NP models.)
What the situation changes
if the Higgs is not seen and actually heavy ?
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Extra generation vs. EW precision data
V.A. Novikov et al., PLB529, 111
mH>113 GeV, mD=130 GeV
[GeV]
Δm=sqrt(mU^2-mD^2) [GeV]
mN [GeV]
mD=200, mU=220, mE=100
Ng
Ng
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2D plots in different way
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