Using QCD Counting rules to Identify the Production of Gluonium

Abstract

The empirical identification of bound states of gluons has remained a central goal of hadron spectroscopy. We suggest an experimentally challenging, but model--independent way to assess which zero charge, isospin-zero mesons have a large gluonium light-front wavefunction component in the quark and gluon Fock space of QCD. Our method exploits QCD counting rules which relate the power-law fall-off of production amplitudes at high momentum transfer to the meson's twist (dimension minus spin of its minimum interpolating operators). Scalar $0^{+}$ glueballs composed of two valence gluons with zero internal orbital angular momentum have twist $\tau =2$. In contrast, quark-antiquark $|q\bar{q}⟩$ scalar mesons have twist $\tau \ge 3$ since they have nonzero orbital angular momentum, and multi-quark states such as $|qq\bar{q}\bar{q}⟩$ tetraquarks yield twist $\tau \ge 4$. Thus, the production cross section for both $|q\bar{q}⟩$ and $|qq\bar{q}\bar{q}⟩$ mesons will be suppressed by at least one power of momentum transfer relative to glueball production. For example, in single inclusive particle hadroproduction $AB\to CX$, the cross section for glueball production at high transverse momentum $p_T$ and fixed $x_T=2\frac{p_T}{\sqrt{s}}$ will dominate higher twist mesons by at least two powers of $p_T$. Similarly, in exclusive production processes at large CM energy and fixed CM angle, the glueball rate dominates by a power of $s$: we illustrate the method with a simple reaction, $e^{-}{e}^{+}\to \varphi f_0$ where the $f_0$ can be tested to be a glueball versus another type of scalar meson.

7 pages, 4 plots

References in corpus (14)

• Identification of a Scalar Glueball
• Is f0(1710) a glueball?
• Scalar Glueball, Scalar Quarkonia, and their Mixing
• Superconformal Baryon-Meson Symmetry and Light-Front Holographic QCD
• Hadronic Superpartners from Superconformal and Supersymmetric Algebra
• Non-ordinary light meson couplings and the $1/N_c$ expansion
• Supersymmetry in the Double-Heavy Hadronic Spectrum
• Comment on "Chiral Suppression of Scalar Glueball Decay"
• Glueball phenomenology and the relativistic flux tube model
• Hadron physics potential of future high-luminosity B-factories at the Upsilon(5S) and above
• Reply to Comment on "Chiral suppression of scalar glueball decay"
• QCD Compositeness as Revealed in Exclusive Vector Boson Reactions through Double-Photon Annihilation: $e^{+}{e}^{-}\to \gamma {\gamma }^{\ast }\to \gamma V^0$ and $e^{+}{e}^{-}\to {\gamma }^{\ast }{\gamma }^{\ast }\to V^0{V}^0$
• QCD Constituent Counting Rules for Neutral Vector Mesons
• Production of a tensor glueball in the reaction $\gamma \gamma \to G_2{\pi }^0$ at large momentum transfer

Cited by in corpus (3)

• Coupled-channel approach in hadron-hadron scattering
• Glueball scattering cross section in lattice SU(2) Yang-Mills theory
• Glueballs as the Ithaca of meson spectroscopy