Silvia Pascoli

A bstract: The nanohertz gravitational waves (GW) observed by pulsar timing arrays may originate from a cosmological first-order phase transition (PT) at ~ 100 MeV. Taking this possibility seriously motivates the question: why 100 MeV? We point out that a PT at exactly those scales is predicted by the generation of the baryon asymmetry from a dark asymmetry via resonant neutron-dark matter oscillations, and we show that this PT can induce an observable GW signal compatibly with all experimental constraints. This proposal predicts dark matter self-interactions close to their observational upper limits and lowers the maximal expected mass of neutron stars. Independently of GW, this baryogenesis mechanism is tested by searches for missing-energy at the LHC and for neutron decays. We keep the model consistent with big-bang nucleosynthesis by adding heavy neutral leptons below 100 MeV, which generate neutrino masses and can induce further experimental tests.

DUNE (Deep Underground Neutrino Experiment) is a long-baseline neutrino oscillation experiment currently under construction, whose far detectors will be the largest liquid argon time projection chambers ever built. This detector design calls for custom-built cryogenic front-end electronics to meet its performance requirements. This paper describes the charge readout electronics that will be used in the DUNE horizontal drift (HD) far detector and presents performance results using data from the ProtoDUNE-HD detector, a 770 ton liquid argon time projection chamber operated at the CERN Neutrino Platform in 2024 that served as the final prototype of the DUNE HD design.

We present (EvaLuator of tunnElliNg Actions), an open-source Python package designed to compute the full evolution of first-order phase transitions in the early Universe generated by particle physics models, taking into account several refinements that go beyond commonly assumed simplifications. The core of is based on a vectorized implementation of the tunnelling potential formalism, making it the first and only public code to compute finite-temperature tunnelling actions within this framework. This allows for a fast computation of the finite-temperature tunnelling action. This, in turn, enables the sampling of the full range of temperatures where two phases coexist and the use of integral expressions that track the complete evolution of the transition, providing a comprehensive picture of it. In addition, provides all the tools to compute the resulting stochastic gravitational waves spectrum, allowing for the full chain of computations – from the Lagrangian parameter inputs to the final gravitational waves spectrum – in a fast and self-contained implementation.

Motivated by the recent evidence of a stochastic gravitational wave background found by pulsar timing array experiments, we focus on one of the prime cosmological explanations, i.e., a supercooled first order phase transition. If confirmed, it would offer a unique opportunity to probe early Universe dynamics and the related physics beyond the Standard Model of particles and interactions. However, the prediction of the gravitational wave spectrum from a given particle physics scenario requires theoretically and computationally demanding methods. While several tools have been put forward to reduce uncertainties and automatize these computations, we study here the possibility to perform the full pipeline of computations semi-analytically in the 4D theory for a U(1)′ conformal extension of the Standard Model, thus avoiding computationally intensive simulations. Our approach yields accurate results that can be used in phenomenological studies and allow for an efficient exploration of the connection between the particle physics models and their cosmological predictions.

We present the measurement of π + -argon inelastic cross sections using the ProtoDUNE single-phase liquid argon time projection chamber in the incident π + kinetic energy range of 500–800 MeV in multiple exclusive channels (absorption, charge exchange, and the remaining inelastic interactions). The results of this analysis are important inputs to simulations of liquid argon neutrino experiments such as the Deep Underground Neutrino Experiment and the Short Baseline Neutrino program at Fermi National Accelerator Laboratory. They will be employed to improve the modeling of final state interactions within neutrino event generators used by these experiments, as well as the modeling of π + -argon secondary interactions within the liquid argon. This is the first measurement of π + -argon absorption at this kinetic energy range as well as the first ever measurement of π + -argon charge exchange.

We present MicroBooNE’s first search for dark sector e + e − explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible e + e − pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of 6.87 × 10 20 protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced e + e − events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of 69.7 ± 17.3 . This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.

We present ELENA (EvaLuator of tunnElliNg Actions), an open-source Python package designed to compute the full evolution of first-order phase transitions in the early Universe generated by particle physics models, taking into account several refinements that go beyond commonly assumed simplifications. The core of ELENA is based on a vectorized implementation of the tunnelling potential formalism, which allows for a fast computation of the finite-temperature tunnelling action. This, in turn, enables the sampling of the full range of temperatures where two phases coexist and the use of integral expressions that track the complete evolution of the transition, providing a comprehensive picture of it. In addition, ELENA provides all the tools to compute the resulting stochastic gravitational waves spectrum, allowing for the full chain of computations - from the Lagrangian parameter inputs to the final gravitational waves spectrum - in a fast and self-contained implementation.