QCD Compositeness as Revealed in Exclusive Vector Boson Reactions through Double-Photon Annihilation: $e^{+}{e}^{-}\to \gamma {\gamma }^{\ast }\to \gamma V^0$ and $e^{+}{e}^{-}\to {\gamma }^{\ast }{\gamma }^{\ast }\to V^0{V}^0$

Abstract

We study the exclusive double-photon annihilation processes, $e^{+}{e}^{-}\to \gamma {\gamma }^{\ast }\to \gamma V^0$ and $e^{+}{e}^{-}\to {\gamma }^{\ast }{\gamma }^{\ast }\to V_a^0{V}_b^0,$ where the $V_i^0$ is a neutral vector meson produced in the forward kinematical region: $s\gg -t$ and $-t\gg {\Lambda }_{\mathrm{QCD}}^2$. We show how the differential cross sections $\frac{d\sigma }{dt}$, as predicted by QCD, have additional falloff in the momentum transfer squared $t$ due to the QCD compositeness of the hadrons, consistent with the leading-twist fixed-${\theta }_{\mathrm{CM}}$ scaling laws. However, even though they are exclusive channels and not associated with the conventional electron-positron annihilation process $e^{+}{e}^{-}\to {\gamma }^{\ast }\to q\bar{q},$ these total cross sections $\sigma (e^{+}{e}^{-}\to \gamma V^0)$ and $\sigma (e^{+}{e}^{-}\to V_a^0{V}_b^0),$ integrated over the dominant forward- and backward-${\theta }_{\mathrm{CM}}$ angular domains, scale as $1/s$, and thus contribute to the leading-twist scaling behavior of the ratio $R_{e^{+}{e}^{-}}$. We generalize these results to exclusive double-electroweak vector-boson annihilation processes accompanied by the forward production of hadrons, such as $e^{+}{e}^{-}\to Z^0{V}^0$ and $e^{+}{e}^{-}\to W^{-}{\rho }^{+}$. These results can also be applied to the exclusive production of exotic hadrons such as tetraquarks, where the cross-section scaling behavior can reveal their multiquark nature.

arXiv comment10 pages

References in corpus (11)

• Big-Bang Nucleosynthesis
• Linear Confinement and AdS/QCD
• Light-Front Dynamics and AdS/QCD Correspondence: The Pion Form Factor in the Space- and Time-Like Regions
• Nonperturbative QCD Coupling and its $\beta$ function from Light-Front Holography
• Light and heavy mesons in a soft-wall holographic approach
• Meson Transition Form Factors in Light-Front Holographic QCD
• Light-front quark model consistent with Drell-Yan-West duality and quark counting rules
• Effective confining potentials for QCD
• The QCD Dynamics of Tetraquark Production
• Light-front potential for heavy quarkonia constrained by the holographic soft-wall model
• Constituent counting rule for exclusive production of heavy quarkoniumlike exotic resonance and a light hadron

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• QCD Constituent Counting Rules for Neutral Vector Mesons
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• Experimental review of the ${\rm Y}(1S,2S,3S)$ physics at $e^{+}{e}^{-}$ colliders and the LHC
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• Constituent Counting Rules and Exotic Hadrons
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