Observation of New Resonances Decaying to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>J</mml:mi><mml:mo stretchy="false">/</mml:mo><mml:mi>ψ</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>J</mml:mi><mml:mo stretchy="false">/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>ϕ</mml:mi></mml:math>

The first observation of exotic states with a new quark content cc¯us¯ decaying to the J/ψK+ final state is reported high significance from an amplitude analysis B+→J/ψϕK+ decay. carried out using proton-proton collision data corresponding total integrated luminosity 9 fb−1 collected by LHCb experiment at center-of-mass energies 7, 8, and 13 TeV. most significant state, Zcs(4000)+, has mass 4003±6−14+4 MeV, width 131±15±26 spin parity JP=1+, where quoted uncertainties are statistical systematic, respectively. A 1+ X(4685) J/ψϕ also observed significance. In addition, four previously confirmed two more states, Zcs(4220)+ X(4630), exceeding 5 standard deviations.Received 2 March 2021Accepted 7 July 2021DOI:https://doi.org/10.1103/PhysRevLett.127.082001Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article’s title, journal citation, DOI. Funded SCOAP3.© 2021 CERN, for CollaborationPhysics Subject Headings (PhySH)Research AreasParticle decaysParticle interactionsParticle mixing & oscillationsParticle productionQuark modelParticles Fields