arXiv subjects

Lilly Pyras

Publications and source records attributed to Lilly Pyras.

6 recordsLinked to original sources

arXiv2025

Probing hadronic interactions with high-energy and low-energy muons in extensive air showers

High-energy cosmic rays are observed indirectly by detecting the extensive air showers initiated in Earth's atmosphere. The interpretation of experimental data relies on accurate modeling of the air shower development. Simulations based on current hadronic interaction models show significant discrepancies with measurements of the muon content in air showers, commonly referred to as the Muon Puzzle, indicating severe shortcomings in the understanding of particle physics. A hybrid detector design with a surface array and deep underground detector, such as the IceCube Neutrino Observatory, allows simultaneous measurements of muons at two vastly different energies: at GeV energies and above a few 100GeV. We present phenomenological studies of low-energy and high-energy muons in simulated air showers, and discuss how hybrid measurements can provide constraints on multi-particle production in hadronic interaction models.

astro-ph.HE↗

arXiv2025

Road map for the tuning of hadronic interaction models with accelerator-based and astroparticle data

In high-energy and astroparticle physics, event generators play an essential role, even in the simplest data analyses. As analysis techniques become more sophisticated, e.g. based on deep neural networks, their correct description of the observed event characteristics becomes even more important. Physical processes occurring in hadronic collisions are simulated within a Monte Carlo framework. A major challenge is the modeling of hadron dynamics at low momentum transfer, which includes the initial and final phases of every hadronic collision. QCD-inspired phenomenological models used for these phases cannot guarantee completeness or correctness over the full phase space. These models usually include parameters which must be tuned to suitable experimental data. Until now, event generators have been developed and tuned mainly on the basis of data from high-energy physics experiments at accelerators. The wealth of data available from the latest generation of astroparticle experiments has not yet been fully exploited, and in many cases is not satisfactorily described. Both kinds of data sets are complementary as astroparticle experiments provide sensitivity especially to hadrons produced nearly parallel to the collision axis and cover center-of-mass energies up to several hundred TeV, well beyond those reached at colliders so far. In this report, we provide an overview of state-of-the-art event generators and their tuning, including the most relevant inputs from high-energy accelerator and astroparticle experiments. We present a road map that shows, for the first time, how the unified tuning of event generators with accelerator-based and astroparticle data can be performed.

astro-ph.HE↗

arXiv2025

Comparing Calculations of Seasonal Variations of Atmospheric Muons in Deep Underground Detectors

Cosmic rays interact with nuclei in the Earth's atmosphere to produce extensive air showers, which give rise to the atmospheric muon flux. Temperature fluctuations in the atmosphere influence the rate of muons measured in deep underground experiments. This contribution presents predictions of the daily muon flux at a depth of 2000 m.w.e., calculated using MUTE, a software tool which combines MCEq, a numerical solver of the matrix cascade equations in the atmosphere, with PROPOSAL, a propagation code for leptons in matter. The flux estimates are obtained assuming different cosmic-ray flux and hadronic interaction models. The results are compared to previous approaches, based on different methods, to calculate seasonal variations of atmospheric muons in deep underground detectors.

hep-ph↗

arXiv2025

Advances in reconstructing the cosmic-ray energy spectrum with IceTop

The IceTop array at the surface of the IceCube Neutrino Observatory measures extensive air showers produced by cosmic-ray particles with energies from PeV up to EeV, covering the transition region from galactic to extragalactic sources. This contribution presents significant improvements that will enhance the measurement of the cosmic-ray energy spectrum. (I) To analyze more than a decade of data with increasing snow overburdens on the detector, an improved method to handle the time-dependent attenuation of the detector signals was developed. (II) New analysis cuts have been developed to increase the measured event rate while improving the reconstruction quality. (III)~A~new reconstruction method that separately fits the electromagnetic and muonic components, while incorporating data from the deep in-ice detector, enables the reconstruction of air showers with cores outside the IceTop array, up to zenith angles of 50{\deg}. These improvements will significantly increase the event statistics and extend the IceTop spectrum towards higher energies.

astro-ph.HE↗

arXiv2023

Atmospheric muons at PeV energies in radio neutrino detectors

Experiments seeking to detect radio emission stemming from neutrino interactions will soon reach sensitivities that bring a detection within reach. Since experiments like RNO-G or the future IceCube-Gen2 target more than an order of magnitude more effective volume than existing experiments, the renewed and detailed study of rare backgrounds is needed. In this paper, we study the potential background from energy losses of highly energetic atmospheric muons. Due to both limited experimental measurements and limited modeling in hadronic interaction models, the expected event rate is subject to large uncertainties. Here, we estimate rate predictions and their uncertainties for different models and instrumental parameters. We also study possible routes towards mitigation of the muon background, such as parent air shower detection, and illustrate what is needed to make the first measurement of the prompt muon flux at energies above 10 PeV.

astro-ph.HE↗

arXiv2022

TAROGE-M: Radio Antenna Array on Antarctic High Mountain for Detecting Near-Horizontal Ultra-High Energy Air Showers

TAROGE-M is a self-triggered radio antenna array atop the 2700 m high Mt. Melbourne in Antarctica, designed to detect impulsive geomagnetic emission from extensive air showers induced by ultra-high energy (UHE) particles beyond 0.1 EeV, including cosmic rays (CRs), Earth-skimming tau neutrinos, and particularly, the "ANITA anomalous events" (AAEs) from near and below the horizon, which origin remains uncertain and requires more experimental inputs for clarification. The detection concept of TAROGE-M takes advantage of a high altitude with synoptic view toward the horizon as an efficient signal collector, and the radio quietness as well as strong and near vertical geomagnetic field in Antarctica. This approach has a low energy threshold, high duty cycle, and is easy to extend for quickly enlarging statistics. Here we report experimental results from the first TAROGE-M station deployed in 2020, corresponding to $25.3$-days of livetime. The station consists of six receiving antennas operating at 180-450 MHz, and can reconstruct source directions with $\sim0.3^\circ$ angular resolution. To demonstrate its ability to detect UHE air showers, a search for CR signals in the data was conducted, resulting in seven identified events. These events have a mean reconstructed energy of $0.95_{-0.31}^{+0.46}$ EeV and zenith angles between $25^\circ-82^\circ$, with both distributions agreeing with simulations. The estimated CR flux is also consistent with results of other experiments. The TAROGE-M sensitivity to AAEs is approximated by the tau neutrino exposure with simulations, suggesting comparable sensitivity as ANITA's at $~1$ EeV energy with a few station-years of operation. These first results verified the station design and performance in a polar and high-altitude environment, and are promising for further discovery of tau neutrinos and AAEs after an extension in the near future.

astro-ph.HE↗