hep-ph digest · Sep 25, 2026

Spectral shaping of Gaussian white noise for synthetic axion signal generation in microwave cavity haloscopes

D. Vattolo · D. Ahn · G. Carugno · R. Di Vora · D. Maiello · A. Ortolan · G. Ruoso · G. Sardo Infirri · C. Braggio

Microwave cavity haloscopes search for dark-matter axions through the weak electromagnetic field generated by axion-photon conversion in a static magnetic field. Realistic synthetic signals are essential for end-to-end calibration of the receiver, validation of the analysis pipeline, measurement of signal recovery efficiency, and blind-injection studies. Here, we present a general method for producing stochastic synthetic axion waveforms by shaping Gaussian white noise in the frequency domain. The target axion power spectral density is imposed directly on the Fourier coefficients, and arbitrarily long continuous time streams are generated efficiently using an overlap-save implementation. The method reproduces both the ensemble-averaged spectral line shape and the time-domain fluctuations expected for a classical axion field, while providing direct control of the total injected power. Because the spectral model enters only through a replaceable transfer function, the routine can accommodate the Standard Halo Model as well as nonstandard velocity distributions and narrow substructure.

hep-phphysics.ins-det

Hyperfine Structure of

B

and

D

Mesons in a QCD-Inspired Potential Model

Krishna Kingkar Pathak

We investigate the hyperfine structure of

B

and

D

mesons within a QCD-inspired potential model based on the Cornell ansatz. The conventional contact spin--spin term is regularized with a Gaussian smearing to remove the short-distance singularity, and analytic wavefunctions are obtained using the Dalgarno--Lewis perturbative method with the Coulomb part as parent. The numerical study has been extended to include explicit 2S hyperfine predictions and results for the

B_{c}

system; these additions probe the stability of the potential parameter space (effective

α_{s}

, confinement strength and smearing width) for unequal-mass systems and radial excitations. We also present a short sensitivity study of the fixed effective coupling

α_{s}

and discuss the physical interpretation of the smearing parameter

σ

. The combined analytic and phenomenological framework provides compact, testable benchmarks for upcoming spectroscopy measurements.

hep-phpublished in Eur. Phys. J. Plus (2025) 14…