Determining gamma from B --> pi(pi) decays without the CP-asymmetry Cpi(0)pi(0)

Christian W Bauer; Ira Z Rothstein; Iain W Stewart

doi:10.1103/PhysRevLett.94.231802

Determining gamma from B --> pi(pi) decays without the CP-asymmetry Cpi(0)pi(0)

Phys Rev Lett. 2005 Jun 17;94(23):231802. doi: 10.1103/PhysRevLett.94.231802. Epub 2005 Jun 17.

Authors

Christian W Bauer¹, Ira Z Rothstein, Iain W Stewart

Affiliation

¹ California Institute of Technology, Pasadena, California 91125, USA.

PMID: 16090459
DOI: 10.1103/PhysRevLett.94.231802

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.