A possible interpretation for $X(6900)$ observed in four-muon final state by LHCb -- A light Higgs-like boson?

Abstract

A peak structure of $J/\psi$ pair production around $6.9\mathrm{GeV}$ was observed and analyzed by the LHCb collaboration using the Run I and II data of LHC. How to understand this peak arouses enthusiastic discussions among both theorists and experimentalists of high energy physics, because this discovery might hint something new. Overwhelming works on this topic tend to attribute the peak as a four-quark state: tetraquark or molecule. Instead, we suggest that this peak is corresponding to a fundamental Higgs-like boson with mass about $6.9\mathrm{GeV}$ which is advocated by a BSM effective theory. We present a detailed analysis on both signal and SM background, including integrated cross sections and invariant mass distributions of the final-state $J/\psi$ pair. Our numerical results are well in coincidence with the experimental data, as postulating the resonance observed by LHCb to be a BSM $0^{++}$ scalar. Therefore, the peak at $M_{\text{di-}J/\psi }\sim 6.9\mathrm{GeV}$ might be a hint of new physics beyond the SM whose scale is not as large as mostly expected by high energy physicists. More further works are urgently needed in both experimental and theoretical aspects to validate or negate this assumption.

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References in corpus (2)

• Fully-charm tetraquarks: $cc\bar{c}\bar{c}$
• About the $J/\psi J/\psi$ peak of LHCb: fully-charmed tetraquark?

Cited by in corpus (6)

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• Pseudoscalar charmonium pair interactions via the Pomeron exchange mechanism
• Mass spectra for the $cc\bar{b}\bar{b}$/$bb\bar{c}\bar{c}$ tetraquark states
• Searching for fully-heavy tetraquark states in QCD moment sum rules