22 September 2025 – We present a new paper with the title ‘Constraining gamma-ray burst parameters with the first ultra-high-energy neutrino KM3-230213A‘.
In this paper, we used the best-fit diffuse ultra-high-energy neutrino flux associated with the detection of KM3-230213A to constrain the parameters of gamma-ray bursts.
Gamma ray bursts (GRBs) are the most energetic transient events observed in the Universe in electromagnetic wavebands and are potential sources of ultra-high-energy cosmic rays. Interactions of cosmic-ray protons with photons within the fireball of the gamma ray burst or interactions of particles in the outgoing blastwave with matter and radiation with surrounding matter may also produce cosmic neutrinos.
KM3-230213A is the most energetic cosmic neutrino observed to date. Using the information of this event, we derived constraints on the baryon loading and density of the surrounding medium for long-duration gamma-ray bursts.
We calculated the diffuse flux contribution from a population of GRBs using a continuous range of model parameters and found the best-fit values of baryon loading and matter density through Bayesian inference. With a normal value of the density of matter in the surrounding medium of 1 particle cm-3, we constrain the baryon loading to be less than 392 at 90% confidence.
This is the first time the baryon loading and density parameters have been constrained through the detection of an ultra-high-energy neutrino flux.
The paper has been submitted to Astronomy & Astrophysics and is available as a preprint at arXiv: 2509.14985.
In the figure: Our predicted value of the diffuse astrophysical neutrino flux compared to the predictions of theoretical models and the estimates by IceCube.
