Discovering the diffuse flux of UHE neutrinos


Fifty years ago, Berezinsky first predicted ultra-high-energy (UHE) neutrinos, the most energetic ones expected, about a thousand times more so than those seen by IceCube so far. Today, we have yet to discover them, but this may finally change in the near future!

IceCube-Gen2, and other upcoming neutrino telescopes, have a real chance of discovering the long-sought diffuse flux of UHE neutrinos. In a new paper, led by Víctor B. Valera and in collaboration with Christian Glaser, we make detailed, robust, and realistic discovery prospects:

Near-future discovery of the diffuse flux of ultra-high-energy cosmic neutrinos
Victor Branco Valera, Mauricio Bustamante, Christian Glaser

Our results are promising: we find that if we are lucky this can happen within only a handful of years of operation! Figures 1 and 14 are the money plots.  Figure 1, reproduced below, shows that most flux models can be discovered within ten years of Gen2 and most within a handful of years. 

Figure 14, in the paper, shows that, in the event of flux discovery, most models can be distinguished from each other.

This paper is a companion to two earlier papers of ours that use the same computational framework that accounts for theory and experimental nuance to make forecasts:

Discovering UHE neutrino point sources


In the near future, we expect that next-generation neutrino telescopes will provide us with the sensitivity required to discover the first sources of UHE neutrino point sources (> 100 PeV). In a recent paper, led by postdoc Damiano Fiorillo, we provided detailed forecasts for what the radio array of IceCube-Gen2 could achieve by looking for neutrino multiplets:

Read more at:

Near-future discovery of point sources of ultra-high-energy neutrinos
Damiano F.G. Fiorillo, Mauricio Bustamante, Victor B. Valera

Measuring the UHE neutrino-nucleon cross section


Recently, we put out a paper, led by PhD student Victor Valera, where we present the first complete forecasts of how well the planned radio array of IceCube-Gen2 will be able to measure the UHE (> 100 PeV) neutrino-nucleon cross section. The results are encouraging!

Read more at:

The ultra-high-energy neutrino-nucleon cross section: measurement forecasts for an era of cosmic EeV-neutrino discovery
Victor Branco Valera, Mauricio Bustamante, Christian Glaser

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:

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 ( and Mauricio Bustamante (

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