NBIA Summer School on Neutrinos: Here, There & Everywhere

17 Jul 2023, 09:00 → 21 Jul 2023, 14:30 Europe/Copenhagen

Auditorium A (Niels Bohr Institute)

Markus Ahlers (NBI), Mauricio Bustamante (Niels Bohr Institute, University of Copenhagen)

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Online participation (22/05/2022): In-person registration is closed, but online participation is possible. If you would like to participate of the school online, please complete the Registration form

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The Niels Bohr International Academy (NBIA) invites PhD students and advanced Master students to the International PhD Summer School on Neutrinos: Here, There & Everywhere. This one-week school aims to bring the participants up to date with the latest developments in neutrino physics, from theoretical issues to experimental results, including astrophysical and cosmological aspects.

The deadline for in-person registration is April 30, 2023.  There is no participation fee.

Students will be given topical introductions, along with an overview of the current state of the field and the open questions that confront it. The invited lecturers are internationally renowned experts in their fields. The school participants will gain a broad understanding of current theoretical problems in neutrino physics, state-of-the-art neutrino experiments, and applications of neutrinos in cosmology and astrophysics.

Guest Lectures & Lecturers

Neutrino Theory & Phenomenology
Gabriela Barenboim
Instituto de Física Corpuscular (IFIC), Universidad de Valencia

Neutrino Cosmology
Steen Hannestad
Institut for Fysik og Astronomi, Aarhus Universitet

Neutrino Astrophysics & Astronomy
Walter Winter
Deutsches Elektronen-Synchrotron (DESY), Zeuthen

Local Organizers

Mauricio Bustamante
Markus Ahlers

General instructions

To participate:

• Register as a participant
• Registering is solely an expression of interest; you will later be informed about your admittance to the School by the organizers
• The participation is free of charge and includes catering during coffee and lunch breaks. Students are expected to cover their travel and local expenses.

Participation mode:

• The main form of participation of the School will be in person
• In-person participation is limited to 50 students
• Depending on resources available, we might provide options to participate remotely; you may indicate your preference in the registration form, but please be aware that, at this stage, remote participation is not guaranteed
• Priority will be given to in-person participants

COVID-19 and health:

• Please be aware of the health rules regarding COVID-19 to enter Denmark
• These rules may change over time, so please be sure to revisit them close to your travel dates
• The School will be carried out following the health guidelines of the Danish Health Authority
• We ask our participants to follow best health practices at all times

Visa:

• See here for the list of countries with a visa requirement and visa-free countries to enter Denmark
• If you require an invitation letter to apply for a visa, please contact our administrator Gosia Dekempe.

Credit:

• Students who wish to receive credit (2.5 ECTS) for the course are required to give a short presentation on their current research project, to attend lectures and discussion sessions, as well as to participate actively in problem classes
• Only in-person participants may receive ECTS (unless there are exceptional circumstances)

Questions: 

      Please contact the local organizers, Markus Ahlers and Mauricio Bustamante

Sponsors

Poster_Here_There_Everywhere_2023.pdf

Monday, 17 July

1 Welcome

PhD_School_welcome.pdf

Neutrino Theory & Phenomenology

2 Lecture I

Speaker: Gabriela Barenboim (University of Valencia & IFIC (UV-CSIC))

Gabriela_Barenboim_Lecture_I.pdf

Video lecture I

10:30 Coffee

Neutrino Astrophysics & Astronomy

3 Lecture I

Speaker: Walter Winter (Deutsches Elektronen-Synchrotron (DESY))

2307_NBIA_SummerSchool.pdf

Video on YouTube

12:00 Lunch

Topical Seminar

4 Exploring the dark Universe with gravitational waves

Speaker: Jose Maria Ezquiaga (Niels Bohr Institute)

ezquiaga_neutrino_school23.pdf

Video on YouTube

Student Talks

5 Hunt for Intermediate Black Holes with Gravitational Waves and Neutrinos

Intermediate mass black holes (IMBHs) have been theorized as an intermediate state between stellar and supermassive black holes (SMBHs), but not observations have confirmed their existence yet. We propose a method to search for them using Tidal Distruption Events (TDEs). In particular we focus on the disruption of white dwarfs (WDs) by IMBHs, as they are expected to produce both gravitational waves (GWs) and high energy neutrinos. This is particularly, interesting because WDs cannot be disrupted by a SMBH. We present an introductory study on this method and future prospects.

Speakers: Alberto Gálvez Ureña (Ceico at the Institute of Physics of the Czech Academy of Sciences), Pavel Kůs (CEICO, Institute of Physics of the Czech Academy of Sciences)

IMBHs with GWs and Neutrinos.pdf

Video on YouTube

6 Towards xenon-doped liquid argon for LEGEND

The LEGEND collaboration is searching for neutrinoless double beta decay of Ge-76. To this end, high-purity Ge detectors are operated in an instrumented liquid argon volume, shielding them from external background radiation passively and actively via the emission of scintillation light upon interaction with ionizing radiation. While liquid argon scintillation detectors are an established and well-performing technology, they suffer from short emission wavelengths, long scintillation times, and only moderate attenuation lengths. Adding small amounts of xenon can enormously improve the scintillation properties.
Xenon-doped liquid argon features a higher photo-electron yield, a faster scintillation time profile, and a longer attenuation length than pure liquid argon. In this talk, I will present the current knowledge on xenon-doped liquid argon scintillation, its advantages and disadvantages, and its potential future impact on LEGEND.

Speaker: Christoph Vogl (TU-Munich)

Towards xenon-doped liquid argon for LEGEND

Towards xenon-doped liquid argon for LEGEND.pdf

Video on YouTube

7 Intrinsic Resolution Limits in Low-Energy Neutrino Event Reconstruction with IceCube

The IceCube Observatory is a cubic-kilometer neutrino telescope built into the deep glacial ice at the South Pole. Low energy extensions to the detector include the existing DeepCore subarray and the upcoming IceCube Upgrade. These focus on neutrino oscillation physics using atmospheric neutrinos and are characterized by a denser instrumentation. These elusive particles are indirectly detected by collecting Cherenkov photons emitted by secondary charged particles produced as a result of neutrino-nucleon interactions inside the detector. The reconstruction of event information, in particular direction and energy of an incoming neutrino, is a crucial ingredient to the oscillation analyses. The accuracy of reconstruction is therefore affected by statistical fluctuations in the particle shower development as well as by photon propagation and detection efficiencies of sensors. My current research is focussed towards identifying the theoretically achievable resolution in the absence of modeling inaccuracies and computational limitations. The study aims to analyze the factors that limit reconstruction performance, which include algorithmic deficiencies such as minimizer performance and the available information contained in the events.

Speaker: Kaustav Dutta (Universität Mainz)

NBI Summer School 2023_kadutta.pdf

Video on YouTube

8 Neutrino Decay scenarios on the Cosmic Neutrino Background

In this work, we explore the consequences of neutrino decay facilitated by a neutral scalar on possible cosmic neutrino background (CνB) detection in the future, especially in the PTOLEMY experiment. We analyze the distortion of the expected event spectrum as a function of the singlet mass and Yukawa couplings, and we consider both a three-neutrino scenario and a scenario with an extra sterile neutrino.

Speaker: Leonardo Ferreira Leite (State University of Campinas (Unicamp) / CERN)

Copenhagen-Leonardo.pdf

Video on YouTube

15:00 Coffee

Exercises

neutrino_astrophysics_astronomy

• Effa_gfugold.txt
• exercises_neutrino_astrophysics_astronomy.ipynb
• exercises_neutrino_astrophysics_astronomy.pdf
• Online Jupyter notebook

neutrino_cosmology exercises_neutrino_cosmology.pdf

neutrino_theory_phenomenology exercises_neutrino_theory_phenomenology.pdf

Discussion

Reception

Tuesday, 18 July

Neutrino Astrophysics & Astronomy

9 Lecture II

Speaker: Walter Winter (Deutsches Elektronen-Synchrotron (DESY))

2307_NBIA_SummerSchool.pdf

Video on YouTube

10:30 Coffee

Neutrino Theory & Phenomenology

10 Lecture II

Speaker: Gabriela Barenboim (University of Valencia & IFIC (UV-CSIC))

Gabriela_Barenboim_Lecture_II.pdf

Video on YouTube

12:00 Lunch

Topical Seminar

11 Diffusive shock acceleration and multi-messenger radiation from wind bubbles

Speaker: Enrico Peretti (Niels Bohr Institute, University of Copenhagen)

Topical_Seminar_Peretti.pdf

Video on YouTube

Student Talks

12 Modeling neutrino emission from Active Galactic Nuclei

The IceCube Neutrino Observatory is a cubic kilometer detector located at the South Pole that detects high-energy neutrinos by the Cherenkov radiation produced by secondary particles when they interact in the ice. With a decade of data, the IceCube Collaboration has started to identify active galactic nuclei (AGN) as neutrino sources. These had been theorized to be potential sites to accelerate cosmic rays and produce neutrinos. The sources are gamma-ray obscured sources, confirming evidence that they should be based on the diffuse extragalactic neutrino flux. In this talk, we present simple dimensional arguments that cosmic neutrinos are produced in AGN within less than 100 Schwarzschild radii from their central black hole.

Speaker: Ms Arifa Khatee Zathul (University of Wisconsin-Madison)

Modeling nu emission from AGN.pdf

Video on YouTube

13 Studying the physical properties of the engines of neutrino-emitter blazars.

High-energy neutrinos detected by the IceCube Observatory provide an exclusive opportunity to study the origin of cosmic rays and the nature of the sources producing them. Blazars are among the proposed birthplaces for the astrophysical high-energy neutrinos. We focus on a small set of blazars that are likely counterparts to IceCube neutrinos.

In this contribution, we aim to inspect this sub-population of neutrino-emitter blazars to study the observational and physical properties that govern the physics of these objects and likely make them capable of accelerating cosmic rays. We will discuss our analysis approach and the general context of the properties displayed by the overall blazar population.

Speaker: Alessandra Azzollini (Julius-Maximilians Universität Würzburg)

Azzollini_Properties of likely neutrino-emitter blazars.pdf

Video on YouTube

14 Investigating high-energy neutrinos from blazars with an analysis of the IceCube observatory data

In the past decade, the IceCube observatory has established the presence of a diffuse flux of high-energy neutrinos (≥100 TeV to 10 PeV) that is consistent with an astrophysical origin. However, the population of sources responsible for this flux remains largely unknown.
Among the candidate sources of neutrinos, blazars have been suggested as promising emitters of the high-energy events detected by IceCube. A recent study has provided evidence of a statistically significant spatial correlation between blazars from the 5th Roma-BZCat catalog (5BZCat) and the IceCube data. In this contribution, we explore the findings from a complementary approach.

Speaker: Eleonora Barbano (Julius-Maximilians-Universität Würzburg, Fakultät für Physik und Astronomie, Emil-Fischer-Str. 31, D-97074 Würzburg, Germany)

Barbano_Investigating high-energy neutrinos from blazars with the IceCube data.pdf

Video on YouTube

15 Jet contribution to the 𝛾-ray Flux in NGC 1068

NGC1068 is a Seyfert II starburst galaxy emitting in a very broad range of frequencies, from radio up until
gamma-ray energies. Since the observed high-energy neutrinos and gamma-rays fluxes are different by at
least 2 orders of magnitude, it becomes necessary to account for a multi-component model to describe the
multimessenger emission by NGC1068. The neutrinos signal can be explained through hadronic processes in
the corona of the AGN and the gamma-rays observed by Fermi-LAT can originate from the circumnuclear
starburst ring.
In this presentation, the pc-to-kpc scale radio jet of NGC1068 is investigated in terms of its potential gamma-
ray contribution via hadronic or leptonic processes. Moreover, the radio data provided by VLBA and ALMA
observations at different distances from the central engine is taken into account. So, it can be clearly shown
that it is very unlikely that these gamma-rays can be explained by this radio jet.

Speaker: Silvia Salvatore

SalvatorePresentation.pdf

Video on YouTube

15:00 Coffee

Exercises

neutrino_astrophysics_astronomy

• Effa_gfugold.txt
• exercises_neutrino_astrophysics_astronomy.ipynb
• exercises_neutrino_astrophysics_astronomy.pdf
• Online Jupyter notebook

neutrino_cosmology exercises_neutrino_cosmology.pdf

neutrino_theory_phenomenology exercises_neutrino_theory_phenomenology.pdf

Discussion

Wednesday, 19 July

Neutrino Theory & Phenomenology

16 Lecture III

Speaker: Gabriela Barenboim (University of Valencia & IFIC (UV-CSIC))

Gabriela_Barenboim_Lecture_III.pdf

Video on YouTube

10:30 Coffee

Neutrino Cosmology

17 Lecture I

Speaker: Steen Hannestad (Aarhus University)

nbi2023-1.pdf

Video on YouTube

12:00 Lunch

Topical Seminar

18 Neutrino constraints from gamma-ray bursts

Speaker: Annika Rudolph (Niels Bohr Institute, University of Copenhagen)

NU_from_GRBs_summer_school_AR.pdf

Video on YouTube

Student Talks

19 Multi-messenger observations with the KM3NeT telescope: search for high energy neutrinos coinciding with fast radio bursts

The KM3NeT experiment is a next-generation neutrino telescope, consisting of two separate detection structures, organised as arrays of light sensors, and immersed in the depths of the Mediterranean Sea. The two detectors are the Oscillation Research with Cosmics in the Abyss (ORCA detector), located off the coast of France and the Astrophysics Research with Cosmics in the Abyss (ARCA detector), off the coast of Sicily. Identical in the design but differing by scale, these two detectors observe neutrino interactions in the sea water through Cherenkov light produced by the interaction products at different energy ranges. Specifically, ORCA aims at detecting atmospheric neutrinos to study their oscillation parameters, while ARCA will focus at higher energies on astrophysical neutrinos and the characterisation of their sources. Among the latter topic, Fast Radio Bursts (FRB) are good candidates for multi-messenger emissions due to the huge energy involved in their burst. I will present the method and criteria of a multi-messenger analysis intended to search for spatial and temporal coincidences of astrophysical neutrino signals from KM3NeT with a FRB catalogue of around 800 sources among which 14 have been observed in this period, ranging from January 2020 to March 2021, and were visible from the KM3NeT site.

Speaker: Mr Felix Bretaudeau (on behalf of the KM3NeT Collaboration)

NBIA_Neutrino_2023_Felix_Bretaudeau.pdf

Video on YouTube

20 Light dark matter around 100 GeV from the inert doublet model

We made global fits of the inert Higgs doublet model (IDM) in the light of collider
and dark matter search limits and the requirement for a strongly first-order elec-
troweak phase transition (EWPT). These show that there are still IDM parameter
spaces compatible with the observational constraints considered. In particular, the
data and theoretical requirements imposed favour the hypothesis for the existence
of a scalar dark matter candidate around 100 GeV. This is mostly due to the pull
towards lower masses by the EWPT constraint. The impact of electroweak precision
measurements, the dark matter direct detection limits, and the condition for obtain-
ing a strongly enough first-order EWPT, all have strong dependence, sometimes in
opposing directions, on the mass splittings between the IDM scalars.

Speaker: Leila Kalhor (Shahid Beheshti University)

NBI2023.pdf

Video on YouTube

21 Improving CP Measurement with THEIA and Muon Decay at Rest

We explore the possibility of using the recently proposed THEIA detector to measure the $\bar \nu_\mu \rightarrow \bar \nu_e$ oscillation with neutrinos from a muon decay at rest ($\mu$DAR) source to improve the leptonic CP phase measurement. Due to its intrinsic low-energy beam, this $\mu$THEIA configuration ($\mu$DAR neutrinos at THEIA) is only sensitive to the genuine leptonic CP phase $\delta_D$ and not contaminated by the matter effect. With detailed study of neutrino energy reconstruction and backgrounds at the THEIA detector, we find that the combination with the high-energy DUNE can significantly reduce the CP uncertainty, especially around the maximal CP violation cases $\delta_D = \pm 90^\circ$. Both the $\mu$THEIA-25 with 17 kt and $\mu$THEIA-100 with 70 kt fiducial volumes are considered. For DUNE + $\mu$THEIA-100, the CP uncertainty can be better than $8^\circ$.

Speaker: Chui-Fan Kong (Tsung-Dao Lee Institute)

NBIA_KONG.pdf

Video on YouTube

15:00 Coffee

15:30 Free Afternoon

19:00 School Dinner

Thursday, 20 July

Neutrino Cosmology

22 Lecture II

Speaker: Steen Hannestad (Aarhus University)

mnu.avi

nbi2023-2.pptx

Video on YouTube

10:30 Coffee

Neutrino Astrophysics & Astronomy

23 Lecture III

Speaker: Walter Winter (Deutsches Elektronen-Synchrotron (DESY))

2307_NBIA_SummerSchool.pdf

Video on YouTube

12:00 Lunch

Topical Seminar

24 Near-future discovery of point sources of ultra-high-energy neutrinos

Speaker: Damiano Fiorillo (Niels Bohr Institute, University of Copenhagen)

SlidesNBISchool.pdf

Video on YouTube

Student Talks

25 A First Look at Sky Anisotropies of High-Energy Neutrino Flavours

High-energy astrophysical neutrinos, with TeV–PeV energies and cosmological-scale baselines, provide us with a unique opportunity to study fundemental physics. By looking for the differences in the distribution of arrival directions of neutrinos of different flavours, we can probe physics beyond the Standard Model that predicts directionally-varying flavour ratios under the reasonable assumption of directionally isotropic flavour ratios in astrophysical neutrino production. Using 7.5 years of IceCube High Energy Starting Events, we model a flavour-dependent spherical harmonic expansion of the neutrino flux and ground our predictions in realistic detector simulations. Further, we forecast the near-future reach of current and upcoming neutrino telescopes to constrain and detect these flavour anisotropies. We discuss the application of these predictions to constrain anisotropy-generating parameters, including those arising from Lorentz invarience violation, as well as flavour-dependant couplings of neutrinos to dark matter.

Speaker: Bernanda Telalovic (Niels Bohr Institute, University of Copenhagen)

NBI_sschool_2023_presentation.pdf

Video on YouTube

26 Anomalies in the Radio Neutrino Observatory Greenland

After two seasons of deployment, 7 stations built and many lessons learned, the Radio Neutrino Observatory Greenland (RNO-G) is now operational. In the coming years, the construction of another 28+ stations will bring the array to full capacity as an instrument with an eye towards the ultra-high energy neutrino (>10 PeV) regime, creating another link in the fast paced and rapidly changing landscape of multi-messenger astronomy. Until now, the data volume of our two initial seasons has remained manageable. However, as the array continues to grow, we need to develop more and more clever processes regarding how to filter our data; we must throw away the noise and identify the most promising events. Data reduction tools become crucial for anthropogenic, environmental and local noise identification/removal in order to test and monitor our instrument as we scale up. We present a convolutional encoder-decoder network that assigns an anomaly ranking to events, helping to classify different categories of background and signal.

Speaker: Zachary Meyers (DESY Zeuthen)

Copenhagen-2.pdf

Video on YouTube

27 The Role of Electromagnetic Cascades in High-Energy Neutrino Astrophysics

High-energy gamma-rays do not travel freely across our Universe. Above the pair production threshold, they interact with background photon fields, giving rise to eletromagnetic cascades that take place over cosmological distances, and producing sub-TeV gamma-ray fluxes at the Earth. In this talk, we will demonstrate how one can use such cascades in a multimessenger context to infer properties of the IceCube astrophysical neutrino sources. We also explore the role of muon pair production in producing neutrinos along the development of ultra-high energy cascades, opening a potential window to probe cosmic accelerators at large redshifts.

Speaker: Antonio Capanema (Pontifícia Universidade Católica do Rio de Janeiro)

Here, There & Everywhere.key

Here, There & Everywhere.pdf

Video on YouTube

28 Stochastic modelling of cosmic ray sources for diffuse high-energy gamma-rays and neutrinos

Cosmic rays of energies up to a few PeV are believed to be of Galactic origin, yet individual sources have still not been firmly identified. Due to inelastic collisions with the interstellar gas, cosmic-ray nuclei produce a diffuse flux of high-energy gamma-rays and neutrinos. Fermi-LAT has provided maps of galactic gamma-rays at GeV energies which can be produced by both hadronic and leptonic processes. Neutrinos, on the other hand, are exclusively produced by the sought-after hadronic processes, yet they can be detected above backgrounds only at hundreds of TeV. Oftentimes, diffuse emission maps are extrapolated from GeV to PeV energies, but the sources contributing at either energies likely differ. We have modelled the production of diffuse emission from GeV through PeV energies in a Monte Carlo approach, taking into consideration the discrete nature of sources. We can generate realisations of the diffuse sky in a matter of seconds, thus allowing for characterising correlations in direction and energy. At hundreds of TeV, relevant for observations with LHAASO, Tibet AS-gamma, IceCube and the upcoming SWGO, variations between different realisations are sizeable. Specifically, we show that extrapolations of diffuse emission from GeV to PeV energies must fail and apply our results on the recent experimental findings.

Speaker: Anton Stall (Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University)

Copenhagen_Anton Stall.pdf

Video on YouTube

15:00 Coffee

Exercises

neutrino_astrophysics_astronomy

• Effa_gfugold.txt
• exercises_neutrino_astrophysics_astronomy.ipynb
• exercises_neutrino_astrophysics_astronomy.pdf
• Online Jupyter notebook

neutrino_cosmology exercises_neutrino_cosmology.pdf

neutrino_theory_phenomenology exercises_neutrino_theory_phenomenology.pdf

Discussion

Friday, 21 July

Neutrino Cosmology

29 Lecture III

Speaker: Steen Hannestad (Aarhus University)

nbi2023-4.pptx

Video on YouTube

10:30 Coffee

Topical Seminar

30 Coherent forward scattering of neutrinos

TBA

Speaker: Shashank Shalgar (NBIA)

Video on YouTube

31 Farewell & Intro of Niels Bohr Archive

Farewell video on YouTube

NBI history video on YouTube

school_farewell.pdf

Guided Tour by Niels Bohr Archive

12:00 Lunch