Using a 13.7 fb-1 data sample collected with the CLEO II and II.V detectors, we report new branching fraction measurements for two Cabibbo-suppressed decay modes of the D+ meson: B(D+→ π+π0) = (1.31±0.17±0.09±0.09) ×10-3 and B(D+→ K+K̄ 0) = (5.24±0.43±0.20±0.34)×10-3 which are significant improvements over past measurements. The errors reflect statistical and systematical uncertainties as well as the uncertainty in the absolute D+ branching fraction scale. We also set the first 90% confidence level upper limit on the branching fraction of the doubly Cabibbo-suppressed decay mode B(D+ → K+π 0)<4.2×10-4.
Bibliographical noteFunding Information:
This work was financially supported by the program from National Natural Science Foundation of China (No. 41977332 , 41773117 , 91644102 , 91543116 ), the Key Research and Development Program of Shaanxi Province ( 2018-ZDXM3-01 ), and Research Grant Council of The Hong Kong Special Administrative Region China, Theme-Based Research Scheme ( T24-504/17-N ). Jianjun Li also acknowledged the support of the Youth Innovation Promotion Association CAS (No. 2020407 ).