Observation of New Resonances Decaying to 𝐽/𝜓⁢𝐾+ and 𝐽/𝜓⁢𝜙

The first observation of exotic states with a new quark content 𝑐⁢¯𝑐⁢𝑢⁢¯𝑠 decaying to the 𝐽/𝜓⁢𝐾+ final state is reported with high significance from an amplitude analysis of the 𝐵+→𝐽/𝜓⁢𝜙⁢𝐾+ decay. The analysis is carried out using proton-proton collision data corresponding to a total integrated luminosity of 9  fb−1 collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The most significant state, 𝑍𝑐⁢𝑠⁢(4000)+, has a mass of 4003±6+4−14  MeV, a width of 131±15±26  MeV, and spin parity 𝐽𝑃=1+, where the quoted uncertainties are statistical and systematic, respectively. A new 1+  𝑋⁡(4685) state decaying to the 𝐽/𝜓⁢𝜙 final state is also observed with high significance. In addition, the four previously reported 𝐽/𝜓⁢𝜙 states are confirmed and two more exotic states, 𝑍𝑐⁢𝑠⁢(4220)+ and 𝑋⁡(4630), are observed with significance exceeding 5 standard deviations.