TY - JOUR

T1 - Precise Measurement of the Chromoelectric Dipole Moment of the Charm Quark

AU - BESIII Collaboration

AU - Ачасов, Михаил Николаевич

AU - Мучной, Николай Юрьевич

AU - Николаев, Иван Борисович

N1 - The BESIII Collaboration thanks the staff of BEPCII [51] and the IHEP computing center for their strong support. This work is supported in part by National Key R&D Program of China under Contracts No. 2023YFA1606000, No. 2023YFA1606704; the Fundamental Research Funds for the Central Universities No. lzujbky-2025-ytA05, No. lzujbky-2025-it06, No. lzujbky-2024-jdzx06; National Natural Science Foundation of China (NSFC) under Contracts No. 12247101, No. 11635010, No. 11935015, No. 11935016, No. 11935018, No. 12025502, No. 12035009, No. 12035013, No. 12061131003, No. 12192260, No. 12192261, No. 12192262, No. 12192263, No. 12192264, No. 12192265, No. 12221005, No. 12225509, No. 12235017, No. 12361141819; the Natural Science Foundation of Gansu Province No. 22JR5RA389, No. 25JRRA799; the “111 Center” under Grant No. B20063; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; CAS under Contract No. YSBR-101; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG under Contract No. FOR5327; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation under Contracts No. 2021.0174, No. 2021.0299; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Research Foundation of Korea under Contract No. NRF-2022R1A2C1092335; National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand under Contract No. B50G670107; Polish National Science Centre under Contract No. 2024/53/B/ST2/00975; Swedish Research Council under Contract No. 2019.04595; U.S. Department of Energy under Contract No. DE-FG02-05ER41374.

PY - 2026/6/11

Y1 - 2026/6/11

N2 - The combined symmetry of charge conjugation and parity (CP) is tested in the hadronic transition ψð3686Þ → πþπ−J=ψ, using a dataset of ð2712.4 14.3Þ × 106 ψð3686Þ events collected by the BESIII detector at the BEPCII collider. The resulting asymmetry observable is ACP ¼ð0.6 1.8 0.1Þ × 10−4, which is determined by combining the two channels J=ψ → eþe− and J=ψ → μþμ−. Additionally, by considering the relationship between the chromoelectric dipole moment (CEDM) and the ACP observable derived from the quantum chromodynamics multipole expansion theory based on the Chen-Kuang modeland the Cornell potential model, we obtain the results of charm quark’s CEDM with d0 c ¼ð2.6 7.8 0.4 0.6Þ × 10−16 e cm, and d0 c ¼ð3.5 10.5 0.6 0.5Þ × 10−16 e cm, respectively. The uncertainties are statistical, systematic, and theoretical, respectively. These results correspond to an upper limit of jd0 cj < 2.1 × 10−15 e cm at 90% confidence level, representing an order of magnitude improvement in sensitivity compared to the previous direct bound using the same decay process.

AB - The combined symmetry of charge conjugation and parity (CP) is tested in the hadronic transition ψð3686Þ → πþπ−J=ψ, using a dataset of ð2712.4 14.3Þ × 106 ψð3686Þ events collected by the BESIII detector at the BEPCII collider. The resulting asymmetry observable is ACP ¼ð0.6 1.8 0.1Þ × 10−4, which is determined by combining the two channels J=ψ → eþe− and J=ψ → μþμ−. Additionally, by considering the relationship between the chromoelectric dipole moment (CEDM) and the ACP observable derived from the quantum chromodynamics multipole expansion theory based on the Chen-Kuang modeland the Cornell potential model, we obtain the results of charm quark’s CEDM with d0 c ¼ð2.6 7.8 0.4 0.6Þ × 10−16 e cm, and d0 c ¼ð3.5 10.5 0.6 0.5Þ × 10−16 e cm, respectively. The uncertainties are statistical, systematic, and theoretical, respectively. These results correspond to an upper limit of jd0 cj < 2.1 × 10−15 e cm at 90% confidence level, representing an order of magnitude improvement in sensitivity compared to the previous direct bound using the same decay process.

KW - Electric dipole-dipole interactions

KW - Particle decays

KW - Strong interaction

KW - Charm quark

KW - Mesons

KW - CP violation

UR - https://www.scopus.com/pages/publications/105043836525

U2 - 10.1103/ycwh-3gy8

DO - 10.1103/ycwh-3gy8

M3 - Article

C2 - 42360932

VL - 136

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 23

M1 - 231903

ER -