Recent BABAR Results on Two-photon Physics
Abstract
Recent BABAR results on two-photon processes are presented. A high statistics study of the two-photon production of the charmonium states etac and etac(2S) is performed. The mass and width of etac and etac(2S) are measured; the ratio of the decay probabilities to KS K+pi- and K+K-pi+pi-pi0 are determined. The latter mode is studied for the first time. The reactions e+e- --> e+e- gamma* gamma* --> e+e- + pseudoscalar meson are studied in the single-tag mode for pi0, eta, eta', and etac. From the measured differential cross sections the Q2 dependencies of the photon-meson transition form factors are extracted. From these measurements we conclude that the pion distribution amplitude strongly differs from the distribution amplitudes of eta and eta' mesons.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.