Publications associées à MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026

Measurement of the K+ → π+γγ decay

Alessandro Mapelli, Radoslav Marchevski, Alina Kleimenova

A sample of 3984 candidates of the K+ -> pi(+)gamma gamma decay, with an estimated background of 291 +/- 14 events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leadin ...

Elsevier2024

Mountaintop Gamma Ray Observations of Three Terrestrial Gamma‐Ray Flashes at the Säntis Tower, Switzerland With Coincident Radio Waveforms

Farhad Rachidi-Haeri, Marcos Rubinstein, Amirhossein Mostajabi, Antonio Sunjerga

We report on the mountain top observation of three terrestrial gamma-ray flashes (TGFs) that occurred during the summer storm season of 2021. To our knowledge, these are the first TGFs observed in a mountaintop environment and the first published European ...

2024

Constraints on the intergalactic magnetic field from Fermi/LAT observations of the 'pair echo' of GRB 221009A

Andrii Neronov

Delayed 'pair-echo' signal from interactions of very-high-energy gamma rays in the intergalactic medium can be used for the detection of the intergalactic magnetic field (IGMF). We used the data of the Fermi/LAT telescope coupled with LHAASO observatory me ...

Edp Sciences S A2024

Gamma-ray Spectroscopy in Low-Power Nuclear Research Reactors

Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immedia ...

MDPI2024

Attaining the PeV frontier of the cosmic ray spectrum in space with HERD

Chiara Perrina

The High Energy cosmic-Radiation Detection facility (HERD) is a calorimetric experiment planned to be launched in 2027. It will be operational for at least 10 years on board the China Space Station. With HERD we will measure the energy flux of cosmic proto ...

E D P SCIENCES2023

Hadronic nature of high-energy emission from the Galactic ridge

Andrii Neronov

We show that the IceCube observation of the Galactic neutrino-flux component confirms the hint of detection of neutrinos from the Galactic ridge (the inner part of the Milky Way disk within the Galactic longitude IlI < 30(degrees)), previously reported by ...

American Physical Society2023

Gamma-Blind Fast Neutron Detection for Spent Nuclear Fuel Characterization

Alexander Wolfertz

In this thesis, the development and testing of a system for measuring the axial distribution of fast neutron emission of spent nuclear fuel rods is presented. Emphasis is placed on the novel fast neutron detector used which can reliably work in extremely h ...

EPFL2023

Power variations in fractional Sobolev spaces for a class of parabolic stochastic PDEs

Robert Dalang, Carsten Hao Ye Chong

We consider a class of parabolic stochastic PDEs on bounded domains D c Rd that includes the stochastic heat equation but with a fractional power gamma of the Laplacian. Viewing the solution as a process with values in a scale of fractional Sobolev spaces ...

INT STATISTICAL INST2023

The formation of the faintest galaxies in cosmological simulations: from the impact of primordial magnetic fields to the metal enrichment of present day dwarfs by first stars

Mahsa Sanati

In the theory of the bottom-up assembly of cosmic structures, one of the main challenges is to connect the smallest, most inconspicuous galaxies we observe today to the building blocks of more massive galaxies such as our own, the Milky Way. Do these so-ca ...

EPFL2023

Reconstruction of decays to merged photons using end-to-end deep learning with domain continuation in the CMS detector

Rakesh Chawla, Arvind Shah, Andrea Rizzi, Matthias Finger, Federica Legger, Sun Hee Kim, Jian Zhao, João Miguel das Neves Duarte, Tagir Aushev, Hua Zhang, Alexis Kalogeropoulos, Yixing Chen, Tian Cheng, Ioannis Papadopoulos, Gabriele Grosso, Valérie Scheurer, Meng Xiao, Maren Tabea Meinhard, Qian Wang, Michele Bianco, Varun Sharma, Jessica Prisciandaro, Joao Varela, Sourav Sen, Ashish Sharma, Seungkyu Ha, David Vannerom, Csaba Hajdu, Sanjeev Kumar, Sebastiana Gianì, Kun Shi, Abhisek Datta, Guido Andreassi, Miao Hu, Siyuan Wang, Muhammad Waqas, Anton Petrov, Jian Wang, Yi Zhang, Lei Zhang, Muhammad Ansar Iqbal, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Brown carbon absorption in the Mediterranean basin from local and long-range transported biomass burning air masses

Athanasios Nenes

This study examines the impact of light absorption from biomass burning (BB) brown carbon (BrC) in the Mediterranean basin from local and distant fire incidents during a typical fire season in August 2019 and under severe fire activity in August 2021. The ...

Elsevier2023

Dynamics of cavitation bubbles near granular boundaries

Mohamed Farhat, Armand Baptiste Sieber, Davide Bernardo Preso

We study the dynamics of a cavitation bubble near beds of sand of different grain sizes. We use high-speed imaging to observe the motion of the bubble and the sand for different values of the stand-off parameter gamma (dimensionless bubble-boundary distanc ...

Cambridge University Press2022

Signatures of anisotropic diffusion around PeVatrons in 100 TeV gamma-ray data

Andrii Neronov

The Tibet AS gamma collaboration has reported a diffuse gamma-ray emission signal from the Galactic Plane. We consider the possibility that the diffuse emission from the outer Galactic Plane at the highest energies is produced by cosmic rays spreading from ...

American Physical Society2022

DARKFLUX: A new tool to analyze indirect-detection spectra of next-generation dark matter models

Emma Elizabeth Tolley

We present DARKFLUX, a software tool designed to analyze indirect-detection signatures for next-generation models of dark matter (DM) with multiple annihilation channels. Version 1.0 of this tool accepts user-generated models with 2 -> 2 tree-level dark ma ...

ELSEVIER2022

Engineering Absorption for Foil Applications

Sebastian Mader

Light matter interactions such as extinction, reflection, and transmission can be described by classical optics. Dur-ing the past decades, research focused on a novel resonant extinction type called plasmonics that allows for en-hancement of both types of ...

EPFL2022

Do the majority of stars form as gravitationally unbound?

Richard Irving Anderson

Context. Some of the youngest stars (age less than or similar to 10 Myr) are clustered, while many others are observed scattered throughout star forming regions or in complete isolation. It has been intensively debated whether such scattered or isolated st ...

2022

High-Performance CMOS SPAD-Based Sensors for Time-of-Flight PET Applications

Francesco Gramuglia

Detecting light, photon by photon, has been possible since the 1930s, with the invention of the photomultiplier tube (PMT). However, it is only since the 1970s, that solid-state single-photon detectors have emerged and only since 2003 that a new technology ...

EPFL2022

Detectability of Large Correlation Length Inflationary Magnetic Field with Cherenkov Telescopes

Andrii Neronov

Magnetic fields occupying the voids of the large scale structure may be a relic from the Early Universe originating from either Inflation or from cosmological phase transitions. We explore the possibility of identifying the inflationary origin of the void ...

2022

Gravitational wave signal from primordial magnetic fields in the Pulsar Timing Array frequency band

Andrii Neronov

The NANOGrav, Parkes, European, and International Pulsar Timing Array (PTA) Collaborations have reported evidence for a common-spectrum process that can potentially correspond to a stochastic gravitational wave background (SGWB) in the 1-100 nHz frequency ...

American Physical Society2022

Modeling the response of a diamond detector in the zero power reactor CROCUS

Pavel Frajtag, Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, DongHyuk Lee

The present manuscript documents the development of a practical calculation scheme to model the response of a diamond detector in the mixed (neutron and gamma) radiation field of the CROCUS experimental reactor at EPFL. The model is shown to perform reason ...

SPRINGER HEIDELBERG2021