We revisit, scrutinize, improve, confirm and complete our previous results [1-3] from the scalar di-gluonium sum rules within the standard SVZ-expansion at N2LO without instantons and beyond the minimal duality ansatz : "one resonance + QCD continuum" parametrization of the spectral function which is necessary for a better understanding of the complex spectra of the $I=0$ scalar mesons. We select different (un)subtracted sum rules (USR) moments of degree $\leq$ 4 for extracting the two lowest gluonia masses and couplings. We obtain: $[M_{σ_B},f_{σ_B}]=[1.07(13),0.46(16)],~[M_{G_1},f_{G_1}][1.55(12),0.37(11)]$ GeV and the corresponding masses of the radial excitations : $M_{σ'_B}$= 1.11(12) and $M_{G'_1}=1.56(14)$ GeV which are (unexpectedly) almost degenerated with the ground states. The 2nd radial excitation is found to have a much heavier mass: $M_{G_2}\simeq$ 2.99(22) GeV. Combining these results with some Low-Energy Vertex Sum Rules (LEV-SR), we predict some hadronic widths and classify them into two groups : -- The $σ$-like ($σ_B,σ'_B$) which decay copiously to $ππ$ from OZI-violating process and the $σ'_B$ to $2(ππ)S$ through $σσ$. -- The $G$-like $(G_1,~G'_1$ and eventually $G_2$) which decay into $η'η, ~ηη$ through the $U(1)_A$ gluonic vertex. Besides some eventual mixings with quarkonia states, we may expect that the observed $σ/f_0(500)$ and $f_0(137)$ are $σ$-like while the $f_0(1.5)$ and $f_0(1.7)$ are $G$-like gluonia. The high mass $G_2(2.99)$ can also mix with the $G_1,~G'_1$ to bring the gluon component of the gluonia candidates above 2 GeV. We also estimate the conformal charge $ψ_G(0)=2.09(29)$ GeV$^4$ and its slope $10^2ψ'_G(0)=-22(29)$ GeV$^2$. Our results are summarized in Table 1.
Non-Abelian and Type-A Conformal Anomalies from Euler Descent
Racah Institute of Physics, Hebrew University of Jerusalem(雷哈物理学研究所,希伯来大学);Department of Physics, LEPP, Cornell University(康奈尔大学物理系);The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University(特拉维夫大学雷蒙德和贝弗利萨克勒物理与天文学学院)
Adler function and Bjorken polarized sum rule: Perturbation expansions in powers of $SU(N_c)$ conformal anomaly and studies of the conformal symmetry limit
Anomaly-mediated Scalar Gravitational Interactions and the Coupling of Conformal Sectors
Dipartimento di Matematica e Fisica, Università del Salento(萨伦托大学数学与物理系);INFN Sezione di Lecce(意大利国家核物理研究所莱切分部);National Center for HPC, Big Data and Quantum Computing(高性能计算、大数据与量子计算国家中心);CNR-nanotec, Lecce(国家研究委员会纳米技术研究所莱切分部)