B-> rho pi, rho rho, pi pi: hunting for alpha

We determine the domains of the values of unitarity triangle angle alpha, allowed by the charmless strangeless B_d (\bar B_d) decays.Comment: 16 pages. Recent Belle results on CP asymmetries in B_d(\bar{B}_d)-->rho^+ rho^- decays are taken into account. Version to be published in Yad.Fi

QCD factorizations in gamma* gamma* -> rho rho

We calculate the lowest order QCD amplitude, i.e. the quark exchange contribution, to the forward production amplitude of a pair of longitudinally polarized $\rho$ mesons in the scattering of two virtual photons $\gamma^*(Q_1) \gamma^*(Q_2) \to \rho^0_L \rho^0_L$. We show that the scattering amplitude simultaneously factorizes in two quite different ways: the part with transverse photons is described by the QCD factorization formula involving the generalized distribution amplitude of two final $\rho$ mesons, whereas the part with longitudinally polarized photons takes the QCD factorized form with the $\gamma^*_L \to \rho^0_L$ transition distribution amplitude. Perturbative expressions for these, in general, non-perturbative functions are obtained in terms of the $\rho-$meson distribution amplitude

The Changes in Properties of Hadrons in Nuclei and Nuclear Matter

The changes of hadron properties in dense and/or hot matter are discussed in terms of effective chiral Lagrangians with the parameters of the theory scaled in a simple way. The phenomenologically successful Walecka model is identified as a mean field chiral Lagrangian with the scaled parameters. Kaon condensation and chiral restoration transitions can be described within the same mean field framework.Comment: 14 pages, LATEX, 3 figures uuencoded; invited talk at INPC'95, Beijing, China; SNUTP-95-08

Effective Field Theory For Nuclei, Dense Matter And The Cheshire Cat

In this talk I discuss three related topics based on some of the recent developments in hadron and nuclear physics: one, effective field theory approach to two-nucleon systems; two, an explanation of the flavor singlet axial charge in the proton (i.e., "proton spin problem") in terms of a Cheshire Cat phenomenon; and three, the quark-hadron duality in hadronic matter at high density and "qualitons" at high density ("superqualitons"). The principal common theme in these discussions will be the emergence of the generic feature of the Cheshire Cat Principle.Comment: 10 pages, Latex with 1 figure: Talk given at the 12th Nuclear Physics Summer School and Symposium and the 11th International Light-Cone Workshop "New Directions in QCD" 21-25 June 1999, Kyungju, Kore