We study a new K → ππ decay channel with gluons in intermediate state which is normally neglected within the factorization framework. Both short-distance and long-distance parts of the amplitude are calculated. The chiral Lagrangian approach is used for obtaining the long-distance contribution. The nonperturbative contribution gives an additional enhancement to K → ππ decay amplitude with ∆I = ...

We report on recent progress in studying two aspects of B physics, in which penguin amplitudes play an important role: 1. Bounds on penguin pollution in B(t) → ππ constraining the CKM parameters ρ and η, and a lower bound on B → ππ improving precision in sin 2α. 2. A suggestion for measuring the photon polarization in electroweak penguin decay, B → K1(1400)γ, providing a test of the Standard Mo...

We present the alternative way of derivation of the Wandzura-Wilczek relations between the kinematical twist-3 and twist-2 functions, parameterizing hadronic matrix element in two-photon processes γπ → γπ and γγ → ππ. The new equations, providing the independence of the physical cross-sections on the choice of the light-cone direction, are suggested and explored. The amplitude of γγ → ππ up to ...

K → ππ, KL-KS mass difference, KL → γγ and the Dalitz decays of KL are studied systematically by assuming that their amplitude can be described in terms of a sum of short distance and long distance contributions. Dominance of the short distance effect on the KL-KS mass difference will be checked by the Dalitz decays of KL in a way consistent with the K → ππ and KL → γγ decays.

We look at methods to determine the weak phases φ2 and φ3 from B → ππ and Kπ decays within the perturbative QCD approach. We obtain quite interesting bounds on φ2 and φ3 from experimental measurement in B-factory: 55 ≤ φ2 ≤ 100 and 51 ≤ φ3 ≤ 129. Specially we predict the possibility of large direct CP violation effect in B → ππ (23± 7%) decay. DPNU-02-28 hep-ph/0209002

Assuming the QCD multipole expansion is applicable to hadronic transitions of Υ(3S) into lower level bottomonia, we consider the possibility that Υ(3S) has a D−wave component. This assumption leads to a natural explanation of the ππ spectrum in Υ(3S) → Υ(1S) ππ. Consequences of this assumption on other hadronic and radiative transitions of Υ(3S) are also discussed in the same context. PACS numb...

Recently, by reanalyzing the phase shift data of I = 0 ππ and of I = 1/2 Kπ scatterings, we showed the evidences for existence of light scalar mesons, σ(600) and κ(900), respectively, which had been sought but missing for a long time. The σ(600) and κ(900) together with the established resonances, a0(980) and f0(980), are shown to be consistently classified as the members of a single scalar σ-n...

Strong final-state interactions create a pronounced cusp in η → ηππ decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of ππ scattering lengths from K → 3π decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the ππ threshold. PACS. 11.30.Rd Chiral symmetries – 13.25.Jx Dec...

A new study is reported of a lattice QCD calculation of the K → ππ decay amplitude with the Wilson quark action in the quenched approximation at β = 6.1. The amplitude is extracted from the K → ππ Green function, and a conversion to the continuum value is made employing a recent one-loop calculation of chiral perturbation theory. The result is consistent with the experimental value if extrapola...

In benzophenone, intersystem crossing occurs efficiently between the S1(nπ*) state and the T1 state of dominant nπ* character, leading to excited triplet states after photoexcitation. The transition mechanism between S1(nπ*) and T1 is still a matter of debate, despite several experimental studies. Quantum mechanical calculations have been performed in order to assess the relative efficiencies o...