Longitudinal Short-Distance Constraints on Hadronic Light-by-Light Scattering and Tensor-Meson Contributions to the...

Area of Science:

• Quantum Chromodynamics (QCD)
• Hadronic Light-by-Light Scattering
• Muon Anomalous Magnetic Moment

Background:

• Short-distance constraints in QCD are crucial for calculating the hadronic light-by-light scattering contribution to the muon's anomalous magnetic moment (g-2).
• Holographic QCD models incorporate the Melnikov-Vainshtein constraint but struggle to fully match the symmetric longitudinal short-distance constraint.

Purpose of the Study:

• To investigate the role of tensor mesons in holographic QCD for the muon g-2 calculation.
• To address the 81% matching discrepancy in the symmetric longitudinal short-distance constraint.

Main Methods:

• Utilizing holographic QCD framework.
• Analyzing the contribution of infinite towers of excited tensor mesons.
• Evaluating contributions in different energy regions (low, mixed, high).

Main Results:

• Tensor mesons contribute significantly to the symmetric longitudinal short-distance constraint, filling the gap left by axial vector mesons.
• They provide a sizeable positive contribution in the low-energy region (< 1.5 GeV).
• Contributions from mixed and high-energy regions are small to negligible.

Conclusions:

• Tensor mesons are essential for accurately calculating the muon g-2 within holographic QCD.
• Their inclusion helps reconcile theoretical predictions with experimental and lattice results for the hadronic light-by-light contribution.