Large Electroweak Penguin Effects in B and K physics

Makiko NagashimaMakiko Nagashima

Dept. of Physics, NTUDept. 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

Paper in preparation (W.S.Hou, M.N, A. Soddu)

4th generation scenario and K physics

Long Introduction

Neither just “the second letter of the alphabet” nor “a mark given to student’s work”…

Introductions of Introduction …

What is the B physics ?

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

SU(2) singlet

CKM matrix

Unitarity Triangle

3 mixing angles

1 CP phase+

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

Experimental result on DCPV of B→Kπ seemingly allow accommodations for the NP …

Parts of decay modes

Accumulation of dataExperiments tell us a lot !!

We can/must use all of them !!try to understand the physics behind them!!

Observables of CP Violation

Direct CP asymmetryDirect CP asymmetry

We focus on DCPV in this talk

see directly the difference of yield

Time dependent CP asymmetryTime dependent CP asymmetry

BB f

( Direct CPV )

( Mixing-induced CPV )

Only for neutral meson

(irrelevant to weak int.)

What is the indication of non-zero DCPV ?

Suppose the amplitude can be expressed in terms of,

for the anti-particle process, CPchange of the sign

(i) given by single term

(ii) no relative phases goes away

Simple explanation about TREE and PENGUIN diagrams

Tree diagram

su

u

d d

bW

b

u

u

u

u

s

W>1/Nc

b

d

W

g u

s

d

u

Penguin diagram

b

d

u

s

d

u

W

Z,γ>

sub-dominant

Large EW penguin from 4Large EW penguin from 4thth generation generation and and B physics and K physicsB physics and K physics

Introduction: result on DCPV in KπPUZZLE

The puzzle still persists 5σ

Why this indicates a riddle ?

QCDF (BBNS)

SM3

kT PQCD (KLS)

away

sub-dominantcan be negligible

No Phase differences between them !!

Theoretical expectations within different treatment of the hadronic matrix element

(2003) (2001) contradiction

extra comparable contributionsbringing phase differencestoward

We call for Large with an extra weak phase

We employ kTPQCD approach

We saw that …

must not be negligible

How to explain the deviation ?

Assemble

4th generation scenariopenguinNew physics

consistent with ~12%

A. Arhrib and W-S. Hou, EPJC27,555

T. Yanir, JHEP06, 044

Minimum Setup

4th generation scenario

A sequential 4th generation in addition to the SM particles

well-known

unknown

same quantum number

follows WS parameterization

Effective Hamiltonian

Tree

QCD Penguin

EW/EM Penguin

t' effects well-satisfy b → sγrate and DCPV

Large enhancement

Wilson coefficient

Dividing ΔCi by QCD penguin

Constraint

PDG04

PDG04

Belle(04)

B(b→sll) gets greatly enhanced

Δm is lower than EXP. bound

4th generation effects are not excluded!!

Result

kTPQCD in the SM

4th generation+

sizable splitting between

Roughly,

described as

It naturally generates the phase diff. and sizable mag. of the extra term

Confess …..

Naively assumeddid not care about

One may have suspicion that b→s would spill over into s→d is not necessarily ~ 0

Our result is at leading order in kTPQCD.A recent result finds a much larger color-suppressedtree (C) at next-to-leading order. (talk by S. Mishima at Super B WSII, Hawaii April 2005)

should be all intertwined …

From previous study

W.S. Hou et al.PLB 192 441 (1987)

We need to deal with the mixing matrix in detail

Constraint on s ↔ d from K physics

Andrea’s talk at PPP6

(J. Bijnens et al.)

(E. Pallante et al.)

Therefore….

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 ViolationKπ DCPV puzzle and 4th generation constraint from b→sll and Bs mixing kTPQCD + large EW effect4x4 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 SLIDEBACKUP SLIDE

strong phase source in kTPQCD

Large strong phase comes from annihilation process

a hard gluon kicks spectatorAt leading process

is introduced to cure the endpoint singularities