Experimental signals for a second resonance of the Higgs field

Abstract

In the region of invariant mass 620$÷$740 GeV, we have analyzed the ATLAS sample of 4-lepton events that could indicate a new scalar resonance produced mainly via gluon-gluon fusion. These data suggest the existence of a new heavy state $H$ whose mass $660÷680$ GeV would fit well with the theoretical range $M_H=690\pm 10(\mathrm{stat})\pm 20(\mathrm{sys})\mathrm{GeV}$ for the hypothetical second resonance of the Higgs field that has been recently proposed and which would couple to longitudinal W's with the same typical strength of the low-mass state at $125$ GeV. Since the total width ${\Gamma }_H$ is very poorly determined, to sharpen the analysis of the precious ATLAS data, we have considered a particular correlation between resonating peak cross section ${\sigma }_R(pp\to H\to 4l)$ and the ratio ${\gamma }_H={\Gamma }_H/M_H$. This correlation should be nearly insensitive to the precise value of ${\Gamma }_H$ and mainly determined by the lower mass $m_h=$ 125 GeV. Equivalently, if this correlation holds true, one could also fit $m_h$ from the 4-lepton data in the high-mass range 620$÷$740 GeV. The result $(m_h{)}^{\mathrm{fit}}\sim (125\pm 13)$ GeV reproduces the direct measurement of the Higgs particle mass and thus supports the idea that $m_h$ and $M_H$ are the masses of two different excitations of the same field. Therefore, if we combine with the excess at 680 GeV in the ATLAS $\gamma \gamma$ distribution, there are now two signals for a new resonance in the same mass region. Even though, quantitatively, the global statistical significance of each effect is modest, still the sharp correlation ${\gamma }_H-{\sigma }_R$ in the 4-lepton channel should induce to consider seriously these indications.

Accepted for publication on International Journal of Modern Physics A, 15 pages, 3 tables,4 figures

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• An alternative heavy Higgs mass limit
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Cited by in corpus (6)

• Asymmetric di-Higgs signals of the next-to-minimal 2HDM with a $U(1)$ symmetry
• Restricting the parameter space of Type-II Two Higgs Doublet Models with CP violation
• Explaining excesses in four-leptons at the LHC with a double peak from a CP violating Two Higgs Doublet Model
• Higgs boson origin from a gauge symmetric theory of massive composite particles and massless $W^{\pm }$ and $Z^0$ bosons at the TeV scale
• The 690 GeV scalar resonance
• Second resonance of the Higgs field: motivations, experimental signals, unitarity constraints