arXiv subjects

Balma Duch

Publications and source records attributed to Balma Duch.

4 recordsLinked to original sources

arXiv2026

The $γZ$-box correction and its impact on parity-violating deep-inelastic scattering

The $γZ$-box correction is an important electroweak contribution to precision parity-violation measurements, but its conventional low-energy treatment relies on an ambiguous effective quark-mass prescription. We revisit this correction using a finite-mass calculation that provides a well-defined perturbative contribution without introducing such an auxiliary scale. Applying the result to the Jefferson Lab PVDIS measurement shifts the extracted electron-quark couplings at the $10^{-3}$ level. We discuss the implications of this shift for precision electroweak tests and the need for a consistent separation of perturbative and non-perturbative hadronic contributions.

hep-ph↗

arXiv2026

Analytically Consistent Reconstruction of Finite Data Using Padé Sequences

Reconstructing the analytic structure of a function from finite datasets is a fundamental problem across theoretical, numerical, and experimental physics. While Padé approximants provide a natural framework, finite-information effects, as well as statistical and systematic uncertainties, may obscure the underlying analytic structure and limit reconstruction reliability. In this work, we reinterpret the appearance of Froissart doublets not merely as numerical artifacts but as \textit{diagnostic objects} carrying information about the analytic consistency of the input data. Accordingly, we develop a general Padé-based algorithm that exploits the dynamics of Froissart doublets along Padé sequences to identify localized inconsistencies and iteratively reconstruct the analytic structure most compatible with the data. The method requires no model for the origin of the inconsistencies and distinguishes genuine analytic features from spurious structures induced by finite-information effects. We validate it using Stieltjes functions, realistic pseudo-experimental datasets with statistical and systematic uncertainties, and general holomorphic functions. The complete algorithm is provided as a supplementary Mathematica notebook in an open GitLab repository.

physics.data-an↗

arXiv2026

Assessing the role of threshold conditions in the determination of uncertainties in pole extractions using Padé approximants

In this letter, we discuss the determination of the $f_0(500)$ resonance by analytic continuation through Padé approximants of the $ππ$-scattering amplitude from the physical region to the pole in the complex energy plane. Using as input a class of admissible parametrizations of the scalar-isoscalar $ππ$ partial wave and imposing now the correct threshold behavior of the partial amplitude, we improve on the determinations of pole positions obtained in Ref. [1], thus empowering the Padé method as a simple and precise tool for extracting resonance poles from amplitudes.

hep-ph↗

arXiv2026

$\mathbf{γZ}$ Box at Low Energy

We calculate the 1-loop $γZ$ box-graph correction to electron-quark scattering at low energy and low momentum transfer. Both electron and quark masses are kept non-zero. From our result, we extract coupling constants for the low-energy effective Lagrangian with parity-violating 4-fermion interaction terms. We study the zero-mass limits and show that a non-zero electron mass is sufficient to obtain finite, well-defined couplings which are insensitive to a hadronic mass cutoff. We finally discuss the impact of our results on the determination of the weak charge of the proton from polarized electron-proton scattering.

hep-ph↗