Journal Article

FZJ-2021-01580

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Coupled-Channel Interpretation of the LHCb Double- J / ψ Spectrum and Hints of a New State Near the J / ψ J / ψ Threshold

Dong, X.-K. (Corresponding author) ; Baru, V. ; Guo, F.-K. (Corresponding author) ; Hanhart, C.FZJ* ; Nefediev, A.FZJ*

2021
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/27647  doi:10.1103/PhysRevLett.126.132001

Abstract: Recently, the LHCb Collaboration reported pronounced structures in the invariant mass spectrum of J/ψ pairs produced in proton-proton collisions at the Large Hadron Collider. In this Letter, we argue that the data can be very well described within two variants of a coupled-channel approach employing T matrices consistent with unitarity: (i) with just two channels, J/ψJ/ψ and ψ(2S)J/ψ, as long as energy-dependent interactions in these channels are allowed, or (ii) with three channels J/ψJ/ψ, ψ(2S)J/ψ, and ψ(3770)J/ψ with just constant contact interactions. Both formulations hint at the existence of a near-threshold state in the J/ψJ/ψ system with the quantum numbers JPC=0++ or 2++, which we refer to as X(6200). We suggest experimental tests to check the existence of this state and discuss what additional channels need to be studied experimentally to allow for distinctive tests between the two mechanisms proposed. If the molecular nature of X(6200), as hinted by the three-channel approach, is confirmed, many other double-quarkonium states should exist driven by the same binding mechanism. In particular, there should be an ηcηc molecule with a similar binding energy.

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Contributing Institute(s):

1. Theorie der Starken Wechselwirkung (IAS-4)
2. Theorie der starken Wechselwirkung (IKP-3)

Research Program(s):

1. 511 - Enabling Computational- Data-Intensive Science and Engineering (POF4-511) (POF4-511)
2. DFG project 196253076 - TRR 110: Symmetrien und Strukturbildung in der Quantenchromodynamik (196253076) (196253076)

Appears in the scientific report 2021

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Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOAP3 sponsored Journal ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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