330 likes | 406 Views
Enhanced KL to pi0 nu nubar from Direct CP Violation in B to K pi with Four Generations. Makiko Nagashima (NTU) ICFP2005, Oct. 3-8 NCU. Contents. Paper hep-ph/0508237 (W.S.Hou, M.N, A. Soddu) 4th generation scenario and
E N D
Enhanced KL to pi0 nu nubar from Direct CP Violation in B to K pi with Four Generations Makiko Nagashima (NTU) ICFP2005, Oct. 3-8 NCU
Contents Paper hep-ph/0508237 (W.S.Hou, M.N, A. Soddu) 4th generation scenario and Implications for K and B physics Paper hep-ph/0503072 (W.S.Hou, M.N, A. Soddu) to appear in Phys. Rev. Lett. Impact of 4th generation on B to K pi Direct CPV motivated byextend our study to s → d b → s b → d
Standard Model and CKM mechanism 3 generation 3mixing angles 1 CP phase Quark sector SU(2) doublet CKM matrix SU(2) singlet Unitarity Triangle Study of CPV / Test of SM / Search for NP
vs Direct CP Violation (DCPV) given by single term Difference of Yields no relative phases DCPV goes away CP
b u W u u u u s W s u b u u sub-dominant W W b s b s d d d d d d g Z,γ u u TREE and PENGUIN diagrams Tree diagram > 1/Nc Penguin diagram >
Result on DCPV in Kπ PUZZLE
The puzzle still persists It calls for New Physics ?
K pi DCPV riddle sub-dominant If one neglects EWP and C, No phase differences Theoretical expectations within different treatment of the hadronic matrix element SM3 up to LO calculation QCDF (BBNS) kT PQCD (KLS) contradiction (2001) away (2003)
We call for Large with an extra weak phase The deviation must not be negligible Assemble 4th generation scenario We employ kTPQCD approach consistent with ~12%
At leading process a hard gluon kicks spectator is introduced to cure the endpoint singularities kTPQCD approach Large strong phase comes from annihilation process
T. Yanir, JHEP06, 044 A. Arhrib and W-S. Hou, EPJC27,555 4th generation scenario A sequential 4th generation in addition to the SM particles same quantum number well-known unknown Simple parameterization follows WS parameterization
Remind 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
Tree QCD Penguin EW/EM Penguin Effective Hamiltonian Dividing ΔCi by QCD penguin Large enhancement Wilson coefficient Natural ability of 4th generation to large enhancement of EWP t' effects well-satisfy b → sγrate and DCPV
PDG04 Belle(04) PDG04 Constraint 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
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
Naively assumed One may have suspicion that b→s would spill over into s→d is not necessarily ~ 0 did not care about
should be all intertwined … PLB 192 441 (1987) by W.S. Hou et al. Precisely, should be written by 6 mixing angles and 3 CP phases
We have some constraint on from From K pi study, we learned Keep Be moderate Impose be close to the Cabibbo angle
(1) (2) 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
Outcome for We find enhancing to or even higher !! we take Current Upper Bound It is very hard to measure but challenging… It might be even larger than !!
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 ) ( )
Our anxiety FROM PDG04
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 ?
Extra generation vs. EW precision data V.A. Novikov et al., PLB529, 111 mH>113 GeV, mD=130 GeV mD=200, mU=220, mE=100 [GeV] mN [GeV] Δm=sqrt(mU^2-mD^2) [GeV] Ng Ng
MICPV is rather little sensitive to strong phases Specially, MICPV due to b→s transition behaves like naïve factorization + 4th gene.
Naïve Factorization ⊗ Final StateRescattering OtherwiseDouble Counting Another framework: extra strong phase from Final State Interaction George W.S. Hou, BCP JC, Oct. 14 (2002) No Rescattering
ICHEP04 We followed Mod.Phys.Lett. A18,1763 by C-K. Chua, W-S. Hou and K-C. Yang It accounts for (strong phase) problem (strong phase)
EW penguin would be brought into amplitude from We performed analysis by incorporating t’ effects There is no solution re-scattering happens between This FSI picture doesn’t help for resolving the puzzle