Study of the semileptonic decay D 0 → K ¯ 0 π − e + ν e

Journal article

We report an improved study of the semileptonic decay D0→K¯0π−e+νe based on a sample of 7.9 fb−1 of e+e− annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. The branching fraction of this decay is measured to be BD0→K¯0π−e+νe = (1.444 ± 0.022stat ± 0.024syst)%, which is the most precise to date, where the first uncertainty is statistical and the second is systematic. Based on investigation of the decay dynamics, we find that the decay is dominated by the K*(892)− component and present an improved measurement of its branching fraction to be BD0→K∗892−e+νe = (2.039 ± 0.032stat± 0.034syst)%. We also determine the ratios of the hadronic form factors for the K*(892)−e+νe decay to be rV = V(0)/A1(0) = 1.48 ± 0.05stat± 0.02syst and r2 = A2(0)/A1(0) = 0.70 ± 0.04stat± 0.02syst, where V(0) is the vector form factor and A1, 2(0) are the axial form factors. In addition, the K¯0π−S-wave component is found to account for (5.87 ± 0.32stat± 0.16syst)% of the total decay rate, corresponding to a branching fraction of BD0→K¯0π−S−wavee+νe = (0.085 ± 0.005stat± 0.003syst)%.

Authors: Ablikim, M; Achasov, MN; Adlarson, P; Afedulidis, O; Ai, XC

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Journal of High Energy Physics
• Volume: 2025
• Issue: 3
• Article number: 197
• Publication date: 2025-03-26
• Acceptance date: 2025-03-06
• DOI: 10.1007/jhep03(2025)197
• EISSN: 1029-8479
• ISSN: 1126-6708
• Language: English
• Keywords: Charm Physics; e+-e− Experiments