arXiv subjects

Giuseppe Messineo

Publications and source records attributed to Giuseppe Messineo.

5 recordsLinked to original sources

arXiv2026

Any Light Particle Searches with ALPS II: Description of the first science campaign

From February to May of 2024 the Any Light Particle Search II (ALPS II) conducted its first science campaign using the `light-shining-through-a-wall' technique to search for pseudo-Goldstone bosons that lie beyond the Standard Model of particle physics and which are inaccessible by accelerator-based experiments. The experimental setup consists of two strings of superconducting dipole magnets, each more than 100 m long, that are separated by a wall. Laser light is directed through the first magnet string and a heterodyne detection system is used to measure the electromagnetic power that traverses a wall via the conversion to and then from a bosonic field. After the wall, a high-finesse optical cavity resonantly enhances the signal power. Two searches were carried out, one with the laser polarized perpendicular to the magnetic field direction and another with its polarization state aligned parallel to the magnetic field. No evidence for the existence of new bosons was found. In its first science campaign, ALPS II reached photon-boson conversion probability sensitivities of a few $10^{-13}$. The ongoing upgrade of the optical system aims to increase this sensitivity by about four orders of magnitude.

hep-ex↗

arXiv2025

Any Light Particle Searches with ALPS II: first science results

The light-shining-through-a-wall experiment ALPS II at DESY in Hamburg searched for axions and similar lightweight particles in its first science campaign from February to May 2024. No evidence for the existence of such particles was found. For pseudoscalar bosons like the axion, with masses below about 0.1 meV, we achieved a limit for the di-photon coupling strength of 1.5e-9 1/GeV at a 95% confidence level. This is more than a factor of 20 improvement compared to all previous similar experiments. We also provide limits on photon interactions for scalar, vector and tensor bosons. An achievement of this first science campaign is the demonstration of stable operation and robust calibration of the complex experiment. Currently, the optical system of ALPS II is being upgraded aiming for another two orders of magnitude sensitivity increase.

hep-ex↗

arXiv2025

Neutral Barium in Solid Neon: Optical Spectroscopy and First Excited State Lifetime

Matrix isolation spectroscopy enables probing atomic properties in controlled cryogenic environments. We present a spectroscopic study on neutral barium atoms embedded in a neon cryogenic crystal at 6.8 K, extending previous investigations performed in other noble gas hosts. The visible and near-infrared emission spectra were recorded under two different laser excitation schemes. First, 10-ns laser pulses at 355 nm were used to directly excite high-lying energy levels of barium, enabling the observation of fluorescence cascades. Second, a tunable continuous-wave laser operating between 700 nm and 900 nm allowed us to determine the matrix-induced shifts of barium energy levels relative to their vacuum values, as well as the inhomogeneous linewidths of the observed transitions and to perform lifetime measurements. Our results confirm multiple radiative pathways and matrix-induced relaxation channels affecting the 5d6s and 6s6p barium manifolds. Furthermore, we present the first lifetime measurement of the barium 5d6s 3D1 state in a neon crystal, yielding 0.39 \pm 0.02 s, with a predicted increase of about 10% at 2 K. The study of fluorescence and spectroscopic properties of barium isolated in neon represents an important step toward future searches for the electron electric dipole moment using barium monofluoride in neon matrices, where neutral barium atoms may act as unavoidable impurities and potential sources of background and systematic limitations.

physics.atom-ph↗

arXiv2021

The heterodyne sensing system for the ALPS II search for sub-eV weakly interacting particles

ALPS II, the Any Light Particle Search, is a second-generation Light Shining through a Wall experiment that hunts for axion-like particles. The experiment is currently transitioning from the design and construction phase to the commissioning phase, with science runs expected to start in 2021. ALPS II plans to use two different sensing schemes to confirm the potential detection of axion-like particles or to verify an upper limit on their coupling strength to two photons of $g_{aγγ}\leq2\times10^{-11}\text{GeV}^{-1}$. This paper discusses a heterodyne sensing scheme (HET) which will be the first scheme deployed to detect the regenerated light. It presents critical details of the optical layout, the length and alignment sensing scheme, design features to minimize spurious signals from stray light, as well as several control and veto channels specific to HET which are needed to commission and operate the instrument and to calibrate the detector sensitivity.

physics.ins-det↗

arXiv2018

Coherent Detection of Ultra-weak Electromagnetic Fields

We explore the application of heterodyne interferometry for a weak-field coherent detection scheme. The methods detailed here will be used in ALPS II, an experiment designed to search for weakly-interacting, sub-eV particles. For ALPS II to reach its design sensitivity this detection system must be capable of accurately measuring fields with equivalent amplitudes on the order of 10$^{-5}$ photons per second or greater. We present initial results of an equivalent dark count rate on the order of $10^{-5}$ photons per second as well as successful generation and detection of a signal with a field strength equivalent to $10^{-2}$ photons per second.

physics.ins-det↗