arXiv subjects

Alessio Carmelo Alvaro

Publications and source records attributed to Alessio Carmelo Alvaro.

4 recordsLinked to original sources

arXiv2026

Matching relations for gluon TMDs up to one-loop accuracy

We present new results on the matching relations for gluon transverse momentum dependent parton distribution functions up to one-loop accuracy. At tree-level, employing the spinor formalism, we obtain these relations up to twist 3 accuracy for both T-even and T-odd distributions, including the hadron-mass corrections. At one-loop order, we extend the parton-in-parton approach to include higher-twist operators in the small-$b$ expansion. As a result, we derive for the first time the Wandzura-Wilczek relation for the worm-gear T distributions and establish a systematic method to include mass corrections at one-loop and twist-2 accuracies.

hep-ph↗

arXiv2026

Collinear matching for leading power gluon transverse momentum distributions

We compute the tree-level and one-loop matching relations for leading power gluon transverse momentum dependent parton distribution functions. At tree level, working within the spinor formalism, we focus on twist-2 and twist-3 contributions, deriving the complete series of mass corrections for both T-even and T-odd distributions. At one-loop accuracy, we extend the parton-in-parton framework to include contributions beyond the leading term in the small-b expansion. Applying this methodology to the gluon sector, we obtain for the first time the Wandzura-Wilczek approximation for the gluon worm-gear T distribution. Furthermore, we develop a method to include the mass corrections in one-loop results and provide a closed-form expression for the mass series suitable for numerical implementations.

hep-ph↗

arXiv2025

Perturbative results for the matrix elements of the vector current and the role of different infrared regulators

We investigate the twist-2 unpolarized generalized parton distributions (GPDs) of quarks for an on-shell gluon target in quantum chromodynamics. These GPDs parametrize the leading-twist matrix elements of the nonlocal light-like flavor-singlet vector current. We compute them at one-loop accuracy in perturbation theory using a quark mass and dimensional regularization as infrared regulators. In particular, we discuss the limit of vanishing momentum transfer. The present work extends our previous related study on the axial current.

hep-ph↗

arXiv2023

Collinear matching for next-to-leading power transverse-momentum distributions

Phenomenological studies of transverse momentum dependent (TMD) parton distributions rely on the expansion in small values of the transverse separation of fields, where TMD parton distributions match onto collinear parton distribution functions. In this work, we derive this expansion at tree-level for the genuine next-to-leading power quark-gluon-quark TMDs, taking into account all the target mass corrections. We find that only a limited number of TMD parton distributions exhibit matching to twist-three collinear distributions, leading to a significant simplification in the analysis of the structure functions of semi-inclusive deep inelastic scattering.

hep-ph↗