The IceCube Neutrino Observatory is a unique astrophysical instrument located in the South Pole that operates continuously, detecting high-energy neutrinos from the entire sky. Among its core scientific capabilities is the real-time alert system, which enables rapid follow-up observations across the electromagnetic spectrum. Through the Gamma-ray Follow-Up (GFU) program, IceCube identifies...
The blazar TXS 0506+056 was the first astrophysical source associated with a high-energy astrophysical neutrino detection. Traditionally, this production has been attributed to processes in the powerful relativistic jet, but the recent observation of neutrinos from the AGN NGC 1068 suggests a production also in the core, non-jetted region. I will discuss whether the neutrinos from TXS 0506+056...
The High-Altitude Water Cherenkov Telescope (HAWC) has detected TeV halos associated with two nearby pulsars and their pulsar wind nebulae (PWNe), Geminga and B0656+14, in the 8–40 TeV energy range. These TeV halos extend up to tens of parsecs from their central accelerators, indicating that the diffusion of electrons and positrons in the interstellar medium is suppressed by two orders of...
This Master's Thesis explores the prospects of detecting the neutrino signal associated with a hadron-to-quark matter phase transition during core-collapse supernovae (CCSNe), a process that may lead to the formation of quark stars—compact and exotic objects composed of deconfined quark matter. By using state-of-the-art CCSN simulations that incorporate this first-order phase transition in the...
In order to develop a consistent quantum theory of gravity, we must understand whether spacetime exhibits fluctuations at the Planck scale. If these Planck-scale fluctuations exist, they may cause propagating particles to evolve in an apparently non-unitary manner. Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances....
The PTOLEMY collaboration aims to detect the Cosmic Neutrino Background (C$\nu$B) and measuring the neutrino mass. To do so, PTOLEMY plans to reconstruct the tritium beta decay and the cosmic neutrino capture on tritium: the electrons near the endpoint of the spectrum will be decelerated and then detected using an array of Transition-Edge Sensors (TES). To be sensitive to neutrino mass effects...
The goal of ENUBET is to develop the first monitored neutrino beam for high precision cross section measurements, in which the neutrino flux in the Hyper-Kamiokande and DUNE energy range is inferred from the measurement of charged leptons in an instrumented decay tunnel. The systematic uncertainties that usually afflict the estimate of the neutrino flux are suppressed by measuring in an...
Only left-handed particles and right-handed antiparticles participate in charged-current weak interactions. Because of spin effects, the energy fraction transferred to the target atom, called inelasticity, is on average larger for neutrino interactions than for antineutrinos. This allows a partial statistical separation between neutrinos and antineutrino events in a non-magnetized...
The all-sky very-high energy ($10^4-10^6$ GeV) atmospheric muon flux is most recently measured by IceCube, where in the higher energy range, the spectrum hardens indicating a prompt component. IceCube also measures the atmospheric muon neutrino flux at high energy. Since this is dominated by the astrophysical flux, they are only able to set an upper bound on the prompt atmospheric muon...
Neutrinos, despite their weak interactions, play an important role in core-collapse supernova evolution. In the supernova core, the neutrino number density is so high that the coherent forward scattering among neutrinos leads to flavor conversion, a phenomenon that can alter both the supernova explosion dynamics and nucleosynthesis. A necessary condition for the development of fast neutrino...
Gamma-ray emission from the plane of the Milky Way is understood as partly originating from the interaction of cosmic rays with the interstellar medium. The same interaction is expected to produce a corresponding flux of neutrinos. In 2023, IceCube reported the first observation of this galactic neutrino flux, rejecting the null-hypothesis at 4.5σ. The analysis relied on spatial models – based...
A key question in cosmology is whether massive neutrinos exist on cosmic scales. Current cosmological observations have severely compressed the viable range for neutrino masses and even prefer phenomenologically an effective negative mass. This poses a great challenge to the cosmological search for neutrinos. Based on current background and large scale structure data, taking a full redshift...
Despite robust cosmological and astrophysical evidence for the existence of non-baryonic Dark Matter (DM), its microscopic nature remains a mystery. Among the several possible scenarios, light DM candidates thermally produced in the early Universe are especially interesting, as they are both theoretically motivated and experimentally accessible. In this context, inelastic dark matter (iDM)...
The Sun can efficiently capture leptophilic dark matter that scatters with free electrons. If this dark matter subsequently annihilates into leptonic states, it can produce a detectable neutrino flux. Using 10 years of Super-Kamiokande observations, we set constraints on the dark-matter/electron scattering cross-section that exceed terrestrial direct detection searches by more than an order of...
The CONUS experiment was located 17m from the core of the powerful nuclear power plant in Brokdorf (Germany) with the aim of detecting coherent elastic neutrino nucleus scattering (CE$\nu$NS) from reactor anti-neutrinos. The experiment ended operations in 2022 with the world-best limits on the detection of such events at nuclear reactors making way for the first detection of CE$\nu$NS at a...
KM3NeT is a next-generation neutrino telescope currently under construction in the Mediterranean Sea. The detector comprises two components, ARCA and ORCA, each equipped with optical sensors that detect Cherenkov light emitted by charged particles resulting from neutrino interactions in the surrounding medium. ARCA, sensitive to interactions in the TeV–PeV energy range, is designed to observe...
Heavy Neutral Leptons (HNLs) are hypothetical particles that are able to explain neutrino oscillations. The presence of HNLs induces charged lepton flavor violating (cLFV) processes. Non-observations of these processes puts the strongest limits on parameters of HNL much heavier than the electroweak scale.
We demonstrate that for such HNLs, the branching ratio of cLFV processes is actually...
At extremely high energies (EHE), i.e. from 1 PeV to 10 EeV, one of the main backgrounds in IceCube neutrino analyses comes from atmospheric muon bundles. These consist of several muons produced in the same cosmic-ray air shower that cross the detector simultaneously. Due to their combined energy loss and spatial distribution, bundles can mimic the signature of a single, high-energy muon from...
As the Earth travels across the Milky Way, it passes through the galactic halo of dark matter particles. Occasionally a dark matter particle could interact with the contents of the earth, scattering it to a lower energy, which can lead to it becoming gravitationally trapped inside the Earth. If these dark matter particles are self-annihilating, or decay, one possible final state product will...
Neutrino astronomy has recently begun probing the PeV energy regime, yet observations remain severely limited by low event statistics. Upcoming neutrino telescopes predominantly utilize water Cherenkov and radio detection techniques, each targeting distinct portions of the neutrino spectrum and consequently leaving a critical observational gap from PeV to EeV energies. Trinity, an imaging air...
The Trinity Demonstrator is an imaging atmospheric Cherenkov telescope (IACT) to observe air showers from Earth-skimming tau neutrinos originating from diffuse and point sources. The telescope is stationed on Frisco Peak, Utah. Since its first light on October 3rd, 2023, the telescope has been looking for 10 PeV to 1 EeV neutrinos within its 4° x 4° field of view. The Demonstrator serves as a...
