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, Baldini Ferroli R, 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, Chen Y B, Chen Z J, Cheng W S, Cibinetto G, Cossio F, Cui X F, Dai H L, Dai X C, Dbeyssi A, de Boer R E, 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, Dong X, Du S X, Fan Y L, Fang J, Fang S S, Fang Y, Farinelli R, Fava L, Feldbauer F, Felici G, Feng C Q, Feng J H, Fritsch M, Fu C D, Gao Y, Gao Y, Gao Y, Gao Y G, Garzia I, Ge P T, Geng C, Gersabeck E M, Gilman A, Goetzen K, Gong L, Gong W X, Gradl W, Greco M, Gu L M, Gu M H, Gu S, Gu Y T, Guan C Y, Guo A Q, Guo L B, Guo R P, Guo Y P, Guskov A, Han T T, Han W Y, Hao X Q, Harris F A, He K L, Heinsius F H, Heinz C H, Held T, Heng Y K, Herold C, Himmelreich M, Holtmann T, Hou G Y, Hou Y R, Hou Z L, Hu H M, Hu J F, Hu T, Hu Y, Huang G S, Huang L Q, Huang X T, Huang Y P, Huang Z, Hussain T, Hüsken N, Ikegami Andersson W, Imoehl W, Irshad M, Jaeger S, Janchiv S, Ji Q, Ji Q P, Ji X B, Ji X L, Ji Y Y, Jiang H B, Jiang X S, Jiao J B, Jiao Z, Jin S, Jin Y, Jing M Q, Johansson T, Kalantar-Nayestanaki N, Kang X S, Kappert R, Kavatsyuk M, Ke B C, Keshk I K, Khoukaz A, Kiese P, Kiuchi R, Kliemt R, Koch L, Kolcu O B, Kopf B, Kuemmel M, Kuessner M, Kupsc A, Kurth M G, Kühn W, Lane J J, Lange J S, Larin P, Lavania A, Lavezzi L, Lei Z H, Leithoff H, Lellmann M, Lenz T, Li C, Li C H, Li Cheng, Li D M, Li F, Li G, Li H, Li H, Li H B, Li H J, Li J L, Li J Q, Li J S, Li Ke, Li L K, Li Lei, Li P R, Li S Y, Li W D, Li W G, Li X H, Li X L, Li Xiaoyu, Li Z Y, Liang H, Liang H, Liang H, Liang Y F, Liang Y T, Liao G R, Liao L Z, Libby J, Lin C X, Liu B J, Liu C X, Liu D, Liu F H, Liu Fang, Liu Feng, Liu H B, Liu H M, Liu Huanhuan, Liu Huihui, Liu J B, Liu J L, Liu J Y, Liu K, Liu K Y, Liu L, Liu M H, Liu P L, Liu Q, Liu Q, Liu S B, Liu Shuai, Liu T, Liu W M, Liu X, Liu Y, Liu Y B, Liu Z A, Liu Z Q, Lou X C, Lu F X, Lu H J, Lu J D, Lu J G, Lu X L, Lu Y, Lu Y P, Luo C L, Luo M X, Luo P W, Luo T, Luo X L, Lyu X R, Ma F C, Ma H L, Ma L L, Ma M M, Ma Q M, Ma R Q, Ma R T, Ma X X, Ma X Y, Maas F E, Maggiora M, Maldaner S, Malde S, Mangoni A, Mao Y J, Mao Z P, Marcello S, Meng Z X, Messchendorp J G, Mezzadri G, Min T J, Mitchell R E, Mo X H, Mo Y J, Muchnoi N Yu, Muramatsu H, Nakhoul S, Nefedov Y, Nerling F, Nikolaev I B, Ning Z, Nisar S, Olsen S L, Ouyang Q, Pacetti S, Pan X, Pan Y, Pathak A, Patteri P, Pelizaeus M, Peng H P, Peters K, Pettersson J, Ping J L, Ping R G, Poling R, Prasad V, Qi H, Qi H R, Qi K H, Qi M, Qi T Y, Qian S, Qian W B, Qian Z, Qiao C F, Qin L Q, Qin X P, Qin X S, Qin Z H, Qiu J F, Qu S Q, Rashid K H, Ravindran K, Redmer C F, Rivetti A, Rodin V, Rolo M, Rong G, Rosner Ch, Rump M, Sang H S, Sarantsev A, Schelhaas Y, Schnier C, Schoenning K, Scodeggio M, Shan D C, Shan W, Shan X Y, Shangguan J F, Shao M, Shen C P, Shen H F, Shen P X, Shen X Y, Shi H C, Shi R S, Shi X, Shi X D, Song J J, Song W M, Song Y X, Sosio S, Spataro S, Su K X, Su P P, Sui F F, Sun G X, Sun H K, Sun J F, Sun L, Sun S S, Sun T, Sun W Y, Sun W Y, Sun X, Sun Y J, Sun Y K, Sun Y Z, Sun Z T, Tan Y H, Tan Y X, Tang C J, Tang G Y, Tang J, Teng J X, Thoren V, Tian W H, Tian Y T, Uman I, Wang B, Wang C W, Wang D Y, Wang H J, Wang H P, Wang K, Wang L L, Wang M, Wang M Z, Wang Meng, Wang W, Wang W H, Wang W P, Wang X, Wang X F, Wang X L, Wang Y, Wang Y, Wang Y D, Wang Y F, Wang Y Q, Wang Y Y, Wang Z, Wang Z Y, Wang Ziyi, Wang Zongyuan, Wei D H, Weidner F, Wen S P, White D J, Wiedner U, Wilkinson G, Wolke M, Wollenberg L, Wu J F, Wu L H, Wu L J, Wu X, Wu Z, Xia L, Xiao H, Xiao S Y, Xiao Z J, Xie X H, Xie Y G, Xie Y H, Xing T Y, Xu G F, Xu Q J, Xu W, Xu X P, Xu Y C, Yan F, Yan L, Yan W B, Yan W C, Yan Xu, Yang H J, Yang H X, Yang L, Yang S L, Yang Y X, Yang Yifan, Yang Zhi, Ye M, Ye M H, Yin J H, You Z Y, Yu B X, Yu C X, Yu G, Yu J S, Yu T, Yuan C Z, Yuan L, Yuan X Q, Yuan Y, Yuan Z Y, Yue C X, Yuncu A, Zafar A A, Zeng Y, Zeng Y, Zhang A Q, Zhang B X, Zhang Guangyi, Zhang H, Zhang H H, Zhang H H, Zhang H Y, Zhang J J, Zhang J L, Zhang J Q, Zhang J W, Zhang J Y, Zhang J Z, Zhang Jianyu, Zhang Jiawei, Zhang L M, Zhang L Q, Zhang Lei, Zhang S, Zhang S F, Zhang Shulei, Zhang X D, Zhang X Y, Zhang Y, Zhang Y H, Zhang Y T, Zhang Yan, Zhang Yao, Zhang Yi, Zhang Z H, Zhang Z Y, Zhao G, Zhao J, Zhao J Y, Zhao J Z, Zhao Lei, Zhao Ling, Zhao M G, Zhao Q, Zhao S J, Zhao Y B, Zhao Y X, Zhao Z G, Zhemchugov A, Zheng B, Zheng J P, Zheng Y, Zheng Y H, Zhong B, Zhong C, Zhou L P, Zhou Q, Zhou X, Zhou X K, Zhou X R, Zhou X Y, Zhu A N, Zhu J, Zhu K, Zhu K J, Zhu S H, Zhu T J, Zhu W J, Zhu W J, Zhu Y C, Zhu Z A, 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. 2021 Oct 22;127(17):171801. doi: 10.1103/PhysRevLett.127.171801.
Using a dataset of 6.32 fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]{τ}, and find B{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0) MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→μ^{+}ν_{μ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→μ^{+}ν_{μ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.
利用北京谱仪III（BESIII）探测器在质心能量为4178至4226兆电子伏特之间收集的6.32飞靶^{-1}的正负电子对撞数据，我们通过τ^{+}→e^{+}ν_{e}ν[上划线]{τ}测量了轻子衰变D{s}^{+}→τ^{+}ν_{τ} 的绝对分支比，结果为B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}，其中第一个不确定度为统计不确定度，第二个为系统不确定度。与之前的最佳测量结果相比，精度提高了一倍。结合格点量子色动力学计算得到的f_{D_{s}^{+}}或CKMfitter组得到的|V_{cs}|，我们分别提取出|V_{cs}|=0.978±0.009±0.012和f_{D_{s}^{+}}=(251.1±2.4±3.0)兆电子伏特。将我们的结果与D_{s}^{+}→τ^{+}ν_{τ}和D_{s}^{+}→μ^{+}ν_{μ}的世界平均值相结合，我们得到分支比的比值B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→μ^{+}ν_{μ}}=9.72±0.37，这与轻子味普适性的标准模型预测一致。
