Measurement of the doubly Cabibbo-suppressed decay D+ → K+π+π-π0 with semileptonic tags

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Amoroso, A.; An, M. R.; An, Q.; Bai, X. H.; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I; Ban, Y.; Begzsuren, K.; Berger, N.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bloms, J.; Bortone, A.; Boyko, I; Briere, R. A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chang, J. F.; Chang, W. L.; Chelkov, G.; Chen, D. Y.; Chen, G.; Chen, H. S.; Chen, M. L.; Chen, S. J.; Chen, X. R.

来源：Physical Review D, 2021, 104(7): 072005.

DOI：10.1103/PhysRevD.104.072005

• CHARM

We propose a new semileptonic tag method to study the doubly Cabibbo-suppressed D decay in psi(3770) -> D (D) over bar reaction. Utilizing the dataset corresponding to an integrated luminosity of 2.93 fb(-1) at a center-of-mass energy of 3.773 GeV collected by the BESIII detector, we determine the branching fraction for D+ -> K+pi(+)pi(-)pi(0) to be (1.03 +/- 0.12(stat) +/- 0.06(syst)) x 10(-3), in which the contributions from narrow intermediate resonances, D+ -> K+eta, D+ -> K+omega, and D+ -> K+phi have been excluded. Combining the world average of the branching fraction of D+ -> K+pi(+)pi(-)pi(0), we determine B(D+ -> K+pi(+)pi(-)pi(0))/B(D+ -> K+pi(+)pi(-)pi(0)) = (1.65 +/- 0.21)%, corresponding to (5.73 +/- 0.73) tan(4)theta(c), where theta(c) is the Cabibbo mixing angle. These results are consistent with our previous measurement with hadronic tags but are significantly larger than other doubly Cabibbo-suppressed decays in the charm sector.