Ablikim M, Achasov M N, Ahmed S, Albrecht M, Alekseev M, Amoroso A, An F F, An Q, Bai J Z, Bai Y, Bakina O, Baldini Ferroli R, Ban Y, Begzsuren K, Bennett D W, Bennett J V, Berger N, Bertani M, Bettoni D, Bianchi F, Boger E, Boyko I, Briere R A, Cai H, Cai X, Cakir O, Calcaterra A, Cao G F, Cetin S A, Chai J, Chang J F, Chelkov G, Chen G, Chen H S, Chen J C, Chen M L, Chen P L, Chen S J, Chen X R, Chen Y B, Cheng W, Chu X K, Cibinetto G, Cossio F, Dai H L, Dai J P, Dbeyssi A, Dedovich D, Deng Z Y, Denig A, Denysenko I, Destefanis M, De Mori F, Ding Y, Dong C, Dong J, Dong L Y, Dong M Y, Dou Z L, Du S X, Duan P F, Fang J, Fang S S, Fang Y, Farinelli R, Fava L, Fegan S, Feldbauer F, Felici G, Feng C Q, Fioravanti E, Fritsch M, Fu C D, Gao Q, Gao X L, Gao Y, Gao Y G, Gao Z, Garillon B, Garzia I, Gilman A, Goetzen K, Gong L, Gong W X, Gradl W, Greco M, Gu M H, Gu Y T, Guo A Q, Guo R P, Guo Y P, Guskov A, Haddadi Z, Han S, Hao X Q, Harris F A, He K L, He X Q, Heinsius F H, Held T, Heng Y K, Holtmann T, Hou Z L, Hu H M, Hu J F, Hu T, Hu Y, Huang G S, Huang J S, Huang X T, Huang X Z, Huang Z L, Hussain T, Ikegami Andersson W, Irshad M, Ji Q, Ji Q P, Ji X B, Ji X L, Jiang X S, Jiang X Y, Jiao J B, Jiao Z, Jin D P, Jin S, Jin Y, Johansson T, Julin A, Kalantar-Nayestanaki N, Kang X S, Kavatsyuk M, Ke B C, Khan T, Khoukaz A, Kiese P, Kiuchi R, Kliemt R, Koch L, Kolcu O B, Kopf B, Kornicer M, Kuemmel M, Kuessner M, Kupsc A, Kurth M, Kühn W, Lange J S, Lara M, Larin P, Lavezzi L, Leithoff H, Li C, Li Cheng, Li D M, Li F, Li F Y, Li G, Li H B, Li H J, Li J C, Li J W, Li Jin, Li K J, Li Kang, Li Ke, Li Lei, Li P L, Li P R, Li Q Y, Li W D, Li W G, Li X L, Li X N, Li X Q, Li Z B, Liang H, Liang Y F, Liang Y T, Liao G R, Liao L Z, Libby J, Lin C X, Lin D X, Liu B, Liu B J, Liu C X, Liu D, Liu D Y, Liu F H, Liu Fang, Liu Feng, Liu H B, Liu H L, Liu H M, Liu Huanhuan, Liu Huihui, Liu J B, Liu J Y, Liu K, Liu K Y, Liu Ke, Liu L D, Liu Q, Liu S B, Liu X, Liu Y B, Liu Z A, Liu Zhiqing, Long Y F, Lou X C, Lu H J, Lu J G, Lu Y, Lu Y P, Luo C L, Luo M X, Luo X L, Lusso S, Lyu X R, Ma F C, Ma H L, Ma L L, Ma M M, Ma Q M, Ma T, Ma X N, Ma X Y, Ma Y M, Maas F E, Maggiora M, Malik Q A, Mangoni A, Mao Y J, Mao Z P, Marcello S, Meng Z X, Messchendorp J G, Mezzadri G, Min J, Mitchell R E, Mo X H, Mo Y J, Morales Morales C, Muchnoi N Yu, Muramatsu H, Mustafa A, Nefedov Y, Nerling F, Nikolaev I B, Ning Z, Nisar S, Niu S L, Niu X Y, Olsen S L, Ouyang Q, Pacetti S, Pan Y, Papenbrock M, Patteri P, Pelizaeus M, Pellegrino J, Peng H P, Peng Z Y, Peters K, Pettersson J, Ping J L, Ping R G, Pitka A, Poling R, Prasad V, Qi H R, Qi M, Qi T Y, Qian S, Qiao C F, Qin N, Qin X S, Qin Z H, Qiu J F, Rashid K H, Redmer C F, Richter M, Ripka M, Rivetti A, Rolo M, Rong G, Rosner Ch, Sarantsev A, Savrié M, Schnier C, Schoenning K, Shan W, Shan X Y, Shao M, Shen C P, Shen P X, Shen X Y, Sheng H Y, Shi X, Song J J, Song W M, Song X Y, Sosio S, Sowa C, Spataro S, Sun G X, Sun J F, Sun L, Sun S S, Sun X H, Sun Y J, Sun Y K, Sun Y Z, Sun Z J, Sun Z T, Tan Y T, Tang C J, Tang G Y, Tang X, Tapan I, Tiemens M, Tsednee B, Uman I, Varner G S, Wang B, Wang B L, Wang D, Wang D Y, Wang Dan, Wang K, Wang L L, Wang L S, Wang M, Wang Meng, Wang P, Wang P L, Wang W P, Wang X F, Wang Y, Wang Y F, Wang Y Q, Wang Z, Wang Z G, Wang Z Y, Wang Zongyuan, Weber T, Wei D H, Weidenkaff P, Wen S P, Wiedner U, Wolke M, Wu L H, Wu L J, Wu Z, Xia L, Xia Y, Xiao D, Xiao Y J, Xiao Z J, Xie Y G, Xie Y H, Xiong X A, Xiu Q L, Xu G F, Xu J J, Xu L, Xu Q J, Xu Q N, Xu X P, Yan F, Yan L, Yan W B, Yan W C, Yan Y H, Yang H J, Yang H X, Yang L, Yang Y H, Yang Y X, Yang Yifan, Yang Z Q, Ye M, Ye M H, Yin J H, You Z Y, Yu B X, Yu C X, Yu J S, Yu J S, Yuan C Z, Yuan Y, Yuncu A, Zafar A A, Zeng Y, Zeng Z, Zhang B X, Zhang B Y, Zhang C C, Zhang D H, Zhang H H, Zhang H Y, Zhang J, Zhang J L, Zhang J Q, Zhang J W, Zhang J Y, Zhang J Z, Zhang K, Zhang L, Zhang S F, Zhang T J, Zhang X Y, Zhang Y, Zhang Y H, Zhang Y T, Zhang Yang, Zhang Yao, Zhang Yu, Zhang Z H, Zhang Z P, Zhang Z Y, Zhao G, Zhao J W, Zhao J Y, Zhao J Z, Zhao Lei, Zhao Ling, Zhao M G, Zhao Q, Zhao S J, Zhao T C, Zhao Y B, Zhao Z G, Zhemchugov A, Zheng B, Zheng J P, Zheng W J, Zheng Y H, Zhong B, Zhou L, Zhou Q, Zhou X, Zhou X K, Zhou X R, Zhou X Y, Zhou Xiaoyu, Zhou Xu, Zhu A N, Zhu J, Zhu J, Zhu K, Zhu K J, Zhu S, Zhu S H, Zhu X L, Zhu Y C, Zhu Y S, Zhu Z A, Zhuang J, Zou B S, Zou J H
Institute of High Energy Physics, Beijing 100049, People's Republic of China.
G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk 630090, Russia.
Phys Rev Lett. 2019 Jan 11;122(1):011804. doi: 10.1103/PhysRevLett.122.011804.
Using e^{+}e^{-} annihilation data of 2.93 fb^{-1} collected at center-of-mass energy sqrt[s]=3.773 GeV with the BESIII detector, we measure the absolute branching fraction of D^{0}→K^{-}μ^{+}ν_{μ} with significantly improved precision: B_{D^{0}→K^{-}μ^{+}ν_{μ}}=(3.413±0.019_{stat}±0.035_{syst})%. Combining with our previous measurement of B_{D^{0}→K^{-}e^{+}ν_{e}}, the ratio of the two branching fractions is determined to be B_{D^{0}→K^{-}μ^{+}ν_{μ}}/B_{D^{0}→K^{-}e^{+}ν_{e}}=0.974±0.007_{stat}±0.012_{syst}, which agrees with the theoretical expectation of lepton flavor universality within the uncertainty. A study of the ratio of the two branching fractions in different four-momentum transfer regions is also performed, and no evidence for lepton flavor universality violation is found with current statistics. Taking inputs from global fit in the standard model and lattice quantum chromodynamics separately, we determine f_{+}^{K}(0)=0.7327±0.0039_{stat}±0.0030_{syst} and |V_{cs}|=0.955±0.005_{stat}±0.004_{syst}±0.024_{LQCD}.
利用北京谱仪III（BESIII）探测器在质心能量(\sqrt{s}=3.773) GeV下收集的(2.93,\mathrm{fb}^{-1})的正负电子湮灭数据，我们以显著提高的精度测量了(D^{0}\to K^{-}\mu^{+}\nu_{\mu})的绝对分支比：(B_{D^{0}\to K^{-}\mu^{+}\nu_{\mu}}=(3.413\pm0.019_{统计}\pm0.035_{系统})%)。结合我们之前对(B_{D^{0}\to K^{-}e^{+}\nu_{e}})的测量，确定两个分支比的比值为(B_{D^{0}\to K^{-}\mu^{+}\nu_{\mu}}/B_{D^{0}\to K^{-}e^{+}\nu_{e}}=0.974\pm0.007_{统计}\pm0.012_{系统})，在不确定性范围内与轻子味普适性的理论预期相符。还对不同四动量转移区域的两个分支比的比值进行了研究，在当前统计数据下未发现轻子味普适性违反的证据。分别采用标准模型全局拟合和格点量子色动力学的输入，我们确定(f_{+}^{K}(0)=0.7327\pm0.0039_{统计}\pm0.0030_{系统})以及(|V_{cs}|=0.955\pm0.005_{统计}\pm0.004_{系统}\pm0.024_{LQCD})。
