Half-string oscillator approach to string field theory

In this letter we present an operator formalism for Closed String Field Theory based on closed half-strings. Our results indicate that the restricted polyhedra of the classical non-polynomial string field theory, can be represented as traces of infinite matrices, with operator insertions that reparametrise the half-strings.

Asimetría de carga en la colisión de Leptones Positivos y Negativos con Núcleos : Efecto del intercambio de dos Fotones

B meson decay constants f(Bc), f(Bs) and f(B) from QCD sum rules

Finite energy QCD sum rules with Legendre polynomial integration kernels are used to determine the heavy meson decay constant f(Bc), and revisit f(B) and f(Bs). Results exhibit excellent stability in a wide range of values of the integration radius in the complex squared energy plane, and of the order of the Legendre polynomial. Results are f(Bc) = 528 +/- 19 MeV, f(B) = 186 +/- 14 MeV, and f(Bs) = 222 +/- 12 MeV.