First Exclusive Reconstruction of the 𝐵^*+, 𝐵^*0, and 𝐵^*0<inf>𝑠</inf> Mesons and Precise Measurement of Their Masses

Abstract

Using proton-proton collision data collected by the CMS experiment at √𝑠 = 13 TeV in 2016–2018, corresponding to an integrated luminosity of 140 fb−1, the first full reconstruction of the three vector 𝐵 meson states, 𝐵^*+, 𝐵^*0, and 𝐵^*0<inf>𝑠</inf>, is performed. The mass differences between the excited mesons and their corresponding ground states are measured to be 𝑚⁡(𝐵*+) − 𝑚⁡(𝐵⁺) = 45.277 ±0.039 ±0.027 MeV, 𝑚⁡(𝐵^*0) − 𝑚⁡(𝐵⁰) = 45.471 ±0.056 ±0.028 MeV, and 𝑚⁡(^𝐵*0<inf>𝑠</inf>) − 𝑚⁡(𝐵⁰<inf>𝑠</inf>) = 49.407 ±0.132 ±0.041 MeV, where the first uncertainties are statistical and the second are systematic. These results improve on the precision of previous measurements by an order of magnitude.