: pQCD analysis in pursuit of determing ϒ Run-Hui Li 2018/11/19
Content Motivation & Background Calculation in pQCD •background &Frame of pQCD •Contributions to these channels Summary 2018/11/19
Motivation & background 2018/11/19
About γ In SM, the explanation for the CPVCKM Triangle of CKM in SM (Unitarity) Important task in Flavor Physics experiments: Extracting the CKM elements & test the unitarity 2018/11/19
γ: the worst precision β : measured in B-> J/ψ KS γ : B±-> DK± 2018/11/19
One method to extract γ , : CP even(odd) state definde: 2018/11/19
One method to extract γ Two physical observables: World average [CKMfitter group]: Observables not sensitive to γ 2018/11/19
Dynamics for B->DK in FA Small 2018/11/19
What about the ? ---- some background : Scalar meson : Tensor meson in quark model 2018/11/19
What about the ? ---- some background Two scenarios of scalar mesons Mesons Scenario I Scenario II Around 1 GeV: f0(600), f0(980), K0*(800), a0(980) Lowest lying states 4 quark bound states Around 1.5 GeV: f0(1370), f0(1500)/f0(1700), K0*(1430), a0(1450) Excited states 2018/11/19
What about the ? For scalar meson: For Tensor meson: is small SU(3) breaking effect, tiny Keenly to be large, physical observables more sensitive to γ W. Wang,PRD85,051301 2018/11/19
What about the ? Already been analyzed in FA. We will study it in pQCD. The difference between FA and pQCD. • FA: Only factorizable emission diagrams; Amplitude is real number, only give information to • pQCD: rich dynamics – factorizable, nonfactorizable, emission, annihilation; Amplitude with phases, can calculate both and W. Wang,PRD85,051301 2018/11/19
Calculation in pQCD 2018/11/19
Effective Hamiltonian in B physics In B meson decays, W, Z, top, … are very heavy, and never appear in the external lines. Integrate them out to get effective operators. Effective operator 2018/11/19
Charged Current Wilson coefficient G. Buchalla, A.J. Buras, M. E. Lautenbacher, Rev. Mod. Phys. 68,1125. 2018/11/19
In this calculation, only tree operators contribute. Charged Current Tree operators Flavor Changed Neutral Current In this calculation, only tree operators contribute. 2018/11/19
Deal with Factorization Else LQCD QCDF SCET PQCD LFQM LCSR Collinear kT Factorization ●●● ●●● 2018/11/19
KT Factorization x 0, kT is important. x: momentum fraction Sudakov factor: - Eliminate end point divergence - Suppress end point region Overlap of soft and collinear contributions Two body nonleptonic B decay. Behavior of Sudakov factor from kT resummation. Resummation to Sudakov 2018/11/19
Two body nonleptonic B decay in pQCD Wave functions: universal inputs Sudakov factors: process independent functions Hard kernel: specific to decays 2018/11/19
in pQCD In pQCD FA contributions Expected enhancement Annihilation to be explored In pQCD 2018/11/19
Our process & Preliminary estimation The analytic expressions are obtained. The expressions for the annihilation diagrams need check. For a preliminary estimation, the branching ratios of can reach the order of . , The similarity channels, whose time dependent observables can also be use to determine γ, will also be investigated: 2018/11/19
Summary decays are expected to have a better performance than decays in the determination of CKM angle ϒ. We investigate these decays in pQCD approach, which can offer the information of and . The BRs of these channels are estimated, which can reach , which is easy for the observation in experiments. We will also calculate the similar channel, which can offer information for the determination of γ as well. 2018/11/19