title: Determining gamma from B --> pi(pi) decays without the CP-asymmetry Cpi(0)pi(0).
abstract: Factorization based on the soft-collinear effective theory (SCET) can be used to reduce the number of hadronic parameters in an isospin analysis of B --> pi(pi) decays by one. This gives a theoretically precise method for determining the CP violating phase gamma by fitting to the B --> pi(pi) data without Cpi(0)pi(0). SCET predicts that gamma lies close to the isospin bounds. With the current world averages we find gamma = 75 degrees +/- 2 degrees(+9 degrees)(-13 degrees), where the uncertainties are theoretical, then experimental.
authors.affiliation: California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Bauer
authors.forename: Ira Z
authors.initials: IZ
authors.lastname: Rothstein
authors.forename: Iain W
authors.initials: IW
authors.lastname: Stewart