Large Electroweak Penguin Effects in B and K physics Makiko Nagashima Dept. of Physics, NTU Dept. of Physics, NTU Collider and New physics Mini-Workshop II July , National Taiwan University

Contents Summer Institute Introductions of introduction … CP Violation in B physics Paper hep-ph/ (W.S.Hou, M.N, A. Soddu) Impact of 4 th generation on B→Kπ Direct CP Paper in preparation (W.S.Hou, M.N, A. Soddu) 4 th 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 data Experiments tell us a lot !! We can/must use all of them !! try to understand the physics behind them!!

Observables of CP Violation Direct CP asymmetry We focus on DCPV in this talk see directly the difference of yield Time dependent CP asymmetry B Bf ( 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, 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 s u u dd b W 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 4 th generation and and B physics and K physics B physics and K physics

Introduction: result on DCPV in Kπ PUZZLE

The puzzle still persists 5σ5σ

Why this indicates a riddle ? QCDF (BBNS) SM3 kT PQCD (KLS) away sub-dominant can be negligible No Phase differences between them !! Theoretical expectations within different treatment of the hadronic matrix element (2003) (2001) contradiction

extra comparable contributions bringing phase differences toward 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 4 th generation scenariopenguinNew physics consistent with ~12%

A. Arhrib and W-S. Hou, EPJC27,555 T. Yanir, JHEP06, 044 Minimum Setup 4 th generation scenario A sequential 4 th 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 Belle(04) B(b→sll) gets greatly enhanced Δm is lower than EXP. bound 4 th generation effects are not excluded!!

Result kTPQCD in the SM 4 th generation + sizable splitting between Roughly, described as It naturally generates the phase diff. and sizable mag. of the extra term

Confess ….. Naively assumed did 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-suppressed tree (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 (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 Violation Kπ DCPV puzzle and 4 th 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 4 th 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 Large strong phase comes from annihilation process a hard gluon kicks spectator At leading process is introduced to cure the endpoint singularities