Prof Subir Sarkar

Abstract:

High-energy neutrinos, being neutral and weakly interacting particles, are powerful probes of the sites of production and acceleration of cosmic rays. The challenging discovery of cosmic neutrinos by the IceCube Collaboration has moved the field closer to realizing the potential of neutrino astronomy. Meanwhile, ground-based cosmic ray detectors like the Pierre Auger Observatory and the Telescope Array have reached an unprecedented accuracy in the determination of the features of the cosmic rays at the highest energies. We report on a collaborative effort between IceCube, the Pierre Auger Observatory and Telescope Array to identify directional correlations between the arrival directions of the highest-energy cosmic rays from both hemispheres and of the most probable cosmic neutrino events detected by IceCube. We describe the updated results of two independent searches using seven years of IceCube neutrino data and the most energetic cosmicray events detected by the Pierre Auger Observatory and the Telescope Array. The directional correlation found between UHECRs and neutrinos is reported with a significance of ~ 2σ.

Abstract:

During the past two decades, experiments in both the northern and southern hemispheres have observed a small but measurable energy-dependent sidereal anisotropy in the arrival direction distribution of Galactic cosmic rays with relative intensities at the level of one per mille. Individually, these measurements are restricted by limited sky coverage, and so the power spectrum of the anisotropy obtained from any one measurement displays a systematic correlation between different multipole modes $C_\ell$. We present the results of a joint analysis of the anisotropy on all angular scales using cosmic-ray data collected during 336 days of operation of the High-Altitude Water Cherenkov (HAWC) Observatory (located at 19$^\circ$ N) and 5 years of data taking from the IceCube Neutrino Observatory (located at 90$^\circ$ S) The results include a combined sky map and an all-sky power spectrum in the overlapping energy range of the two experiments at around 10 TeV. We describe the methods used to combine the IceCube and HAWC data, address the individual detector systematics, and study the region of overlapping field of view between the two observatories.

Abstract:

Contents:

1 IceCube-Gen2: the next-generation neutrino observatory for the South Pole

2 IceAct: Imaging Air Cherenkov Telescopes with SiPMs at the South Pole for IceCube-Gen2

3 Overview and performance of the D-Egg optical sensor for IceCube-Gen2

4 Muon track reconstruction and veto performance with D-Egg sensor for IceCube-Gen2

5 In-ice self-veto techniques for IceCube-Gen2

6 A camera system for IceCube-Gen21

7 The mDOM – A multi-PMT Digital Optical Module for the IceCube-Gen2 neutrino telescope

8 The IceTop Scintillator Upgrade

9 Overview and Performance of the Wavelength-shifting Optical Module (WOM)

10 The Precision Optical CAlibration Module for IceCube-Gen2: First Prototype

Abstract:

Contents:

1 Search for GeV neutrinos associated with solar flares with IceCube

2 Estimating the Sensitivity of IceCube to Signatures of Axion Production in a Galactic Supernova

3 Searching for Arbitrary Low-Energy Neutrino Transients with IceCube

4 Deep Learning in Physics exemplified by the Reconstruction of Muon-Neutrino Events in IceCube

5 Connecting Beyond the Research Community: IceCube Education, Outreach, and Communication Efforts