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arXiv · 2609.34644

Radial Excitation Spectra of Light Pseudoscalar and Vector Mesons in Light-Front Holographic QCD

Abhisth Srivastava
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Abstract

The non-perturbative regime of Quantum Chromodynamics (QCD) poses significant challenges for analytical treatment. Light-Front Holographic QCD (LFHQCD) offers an effective semiclassical framework for exploring hadronic structure through a holographic dual description of confinement. While the standard soft-wall model, along with the Brodsky-de Téramond (BdT) longitudinal prescription, provides satisfactory results for meson ground states, it shows deviations of around 17 to $18\%$ for radial excitations of the pion family. In this work, we extend the transverse confining potential by adding Coulombic and logarithmic contributions beyond the standard soft-wall framework. We solve the resulting light-front Schrödinger equation numerically, and we combine the transverse mass spectrum with the BdT longitudinal prescription to obtain the complete meson mass spectrum. We compute the radial excitation spectra of the $π$, $ρ$, and $K^{*}$ meson families and analyze their Regge trajectories. The modified framework reduces the overall average deviation from experimental data from about $7.6\%$ to $5.2\%$ compared to the standard soft-wall model, representing a $\sim 32\%$ improvement for the fitted nine-state dataset in describing radially excited states. The results show that short-range Coulombic and intermediate-range logarithmic contributions are important for refining the radial meson spectrum within the light-front holographic approach.

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Abhisth Srivastava. 2026-09-28. Radial Excitation Spectra of Light Pseudoscalar and Vector Mesons in Light-Front Holographic QCD. https://arxiv.org/abs/2609.34644

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