NBIA Neutrino Summer School 2022


Join us in the 2022 edition of the NBIA PhD Summer School on Neutrinos: Here, There & Everywhere. This time it will be mainly an in-person event!


📌 Where? Niels Bohr Institute, Copenhagen, Denmark

📅 When? July 11-15

🙋 For whom? PhD students and advanced MSc students

👥 Participation mode? In person (unless otherwise advisable)

💵 What’s the damage? No participation fee

❓ Questions? E-mail the local organizers (addresses on the school page)

⏳ Registration deadline: March 31 (register early; limited capacity)

NBI Neutrino Summer School 2021


Our week-long online NBI Neutrino Summer School “Here, There & Everwhere” wrapped up today!

Find the slides for all talks and hands-on exercises on Indico.

The video recordings of all of the lectures and topical seminars are in our YouTube channel.

Thanks to our guest lecturers Joachim Kopp, Olga Mena, and Foeteini Oikonomou, to our topical seminar speakers from NBI Jason Koskinen, Tom Stuttard, Tyler Corbett, Oleg Ruchayskiy, Shashank Shalgar, and Rasmus Hansen, and to our eighteen student speakers from around the world.

NBIA International PhD Summer School on Neutrinos: Here, There & Everywhere


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.

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.

School dates: July 5-9, 2021

Registration and information: https://www.nbia.dk/neutrino2021

Registration deadline: March 31, 2021 (please register early)

Format: We are presently planning an in-person meeting, but we want to keep everyone safe, so we may revisit the school format if it becomes necessary or advisable due to travel or health restrictions

Participation fee: None

Questions: Please contact the organizers, Markus Ahlers (markus.ahlers@nbi.ku.dk) and Mauricio Bustamante (mbustamante@nbi.ku.dk)

The Future of High-Energy Astrophysical Neutrino Flavor Measurements


There is a vast potential in using the measurement of the flavor composition of high-energy (TeV-PeV) astrophysical neutrinos to test astrophysics and fundamental physics. But there is also plenty of uncertainty in the prediction of the allowed flavor composition at Earth, due to the uncertainties in the mixing parameters, and in the measurement of flavor composition in neutrino telescopes. In other words, flavor is a powerful tool, but it needs sharpening.

In our latest paper, we show that in the next 20 years, flavor will become the sharp tool it was always meant to be, thanks to new oscillation experiments and new neutrino telescopes:

The Future of High-Energy Astrophysical Neutrino Flavor Measurements
Ningqiang Song, Shirley Weishi Li, Carlos A. Argüelles, Mauricio Bustamante, Aaron C. Vincent

By 2040, we will be able to use flavor composition by itself to identify the production mechanism of high-energy astrophysical neutrinos:

Regions of allowed flavor composition at Earth: 2020 vs. 2040

POEMMA paper


The big POEMMA paper is finally out! It contains the science case, goals, and design of POEMMA, a twin-satellite experiment to detect the fluorescence and Cherenkov emission from extensive air showers triggered by ultra-high-energy cosmic rays and neutrinos in the atmosphere.

The POEMMA (Probe of Extreme Multi-Messenger Astrophysics) Observatory
A.V. Olinto et al.

My own small contribution was mainly on the opportunities for beyond-the-Standard-Model neutrino opportunities at ultra-high energies.

Flavor boundaries with high-energy active-sterile neutrino mixing


If the three active neutrinos mix with a sterile one, i.e., in 3+1 scenarios, they may modify the flavor composition of high-energy astrophysical neutrinos. We analytically derived boundaries in flavor space to avoid having to sample over unknown mixing and help boost searches for new physics (we provided them in nice downloadable data tables, too):

Flavors of Astrophysical Neutrinos with Active-Sterile Mixing
Markus Ahlers, Mauricio Bustamante, Niels Gustav Nortvig Willesen

The solid lines are the new 3+1 boundaries, computed for the three benchmark production scenarios (three different colors), compared to the boundaries that we computed for three-flavor mixing (dashed lines) in our earlier paper (1810.00893):

Neutrinos as cosmic magnetometers


Where are the IceCube high-energy astrophysical neutrinos coming from? We don’t know yet! But if the neutrino sources harbor large magnetic fields, then maybe they will leave imprints (due to synchrotron radiation) on the neutrino flux. We looked for these imprints in public IceCube data:

Using High-Energy Neutrinos As Cosmic Magnetometers
Mauricio Bustamante & Irene Tamborra

We exclude large magnetic fields of 10 kG–10 MG: