Observation and Properties of the 𝑋⁡(3872) Decaying to 𝐽/𝜓⁢𝜋+⁢𝜋− in 𝑝⁢ ‾ 𝑝 Collisions at √𝑠=1.96  T⁢e⁢V

V. M. Abazov, H. Castilla-Valdez, E. De La Cruz-Burelo, A. Sánchez-Hernández et al. (D0 Collaboration)

Abstract 

We report the observation of the 𝑋⁡(3872) in the 𝐽/𝜓⁢𝜋+⁢𝜋− channel, with 𝐽/𝜓 decaying to 𝜇+⁢𝜇−, in 𝑝⁢‾𝑝 collisions at √𝑠=1.96  T⁢e⁢V. Using approximately 230  p⁢b−1 of data collected with the Run II D0 detector, we observe 522±100 𝑋⁡(3872) candidates. The mass difference between the 𝑋⁡(3872) state and the 𝐽/𝜓 is measured to be 774.9±3.1⁢(s⁢t⁢a⁢t)±3.0⁢(s⁢y⁢s⁢t)  M⁢e⁢V/𝑐2. We have investigated the production and decay characteristics of the 𝑋⁡(3872) and find them to be similar to those of the 𝜓⁡(2⁢𝑆) state.

DOI: 10.1103/PhysRevLett.93.162002