Observation of the Doubly Cabibbo-Suppressed Decay D+ -> K+ pi(+) pi(-) pi(0) and Evidence for D+ -> K+ omega

Abstract

Using 2.93 fb(-1) of e(+)e(-) collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the doubly Cabibbo-suppressed decay D+-> K+pi(+)pi(-)pi(0) is reported. After removing decays that contain narrow intermediate resonances, including D+. K+., D+ -> K+ omega, and D+-> K+ phi, the branching fraction of the decay D+ -> K+ pi(+)pi(-)pi(0) is measured to be o1.13 similar to 0.08stat similar to 0.03syst+ x 10(-3). The ratio of branching fractions of D+ -> K+ pi(+)pi(-)pi(0) over D+. K+ pi(+)pi(-)pi(0) is found to be o1.81 similar to 0.15+%, which corresponds to (6.28 +/- 0.52) tan(4)theta(C), where theta(C) is the Cabibbo mixing angle. This ratio is significantly larger than the corresponding ratios for other doubly Cabibbo-suppressed decays. The asymmetry of the branching fractions of charge-conjugated decays D+ -> K+ pi(+)pi(-)pi(0) is also determined, and no evidence for CP violation is found. In addition, the first evidence for the D+ -> K+ -> decay, with a statistical significance of 3.3 sigma, is presented and the branching fraction is measured to be B(D+ -> K+omega) = (5.7(-2.1stat)(+2.5) +/- 0.2(syst)) x 10(-5).