28th Symposium on Astroparticle Physics in the Netherlands, 27/28 June 2024

27 Jun 2024, 09:00 → 28 Jun 2024, 14:10 Europe/Amsterdam

Manuela Vecchi (University of Groningen), Harm Schoorlemmer (Radboud University Nijmegen)

The 28th CAN Symposium will be held on June 27th/28th  in Soesterberg at the hotel Kontakt der Kontinenten. This is the annual meeting of the Dutch astroparticle physics community and it will be organized by the Committee of Astroparticle Physics in the Netherlands - CAN.

There is no conference fee for this event, which is kindly funded by NIKHEF and the Dutch Astronomy Council. 

You can request your accommodation at the conference hotel during the registration process.  

 

Thursday, 27 June

coffee: Coffee and Registration

Pillar Talks

1 CAN Symposium Welcome

Speaker: Dorothea Samtleben

Welcome-APP_2024.pdf

2 Pillar Talk: Cosmic Rays

Speaker: Joerg Hoerandel (Radboud University Nijmegen)

jrh-cosmic-rays.pdf

3 Pillar Talk: Neutrinos

Speaker: Aart Heijboer

4 Pillar Talk: Dark Matter

Speaker: Auke-Pieter Colijn

5 Pillar Talk: Gravitational Waves

Speaker: Maria Haney

6 Pillar Talk: Gamma rays

Speaker: Manuela Vecchi (University of Groningen)

MVecchi@CAN2024.finalfinal.pdf

Lunch

CAN PhD Thesis prize

Contributed talks

7 Dark matter searches with the KM3NeT neutrino telescope

KM3NeT is an underwater neutrino telescope located at two sites in the Mediterranean sea. Neutrinos are indirectly detected from the products of their interactions, which produce Cherenkov radiation. The ORCA detector is designed to measure atmospheric neutrino oscillations, and the ARCA detector is designed to search for neutrinos from astrophysical sources. In tandem with the primary scientific goals of both detectors, observations also allow to address other major questions, like the indirect search for dark matter. Different cosmological observations require the introduction of dark matter as the dominant matter component of the Universe, while vaguely constraining its nature. WIMPs (Weakly Interacting Massive Particles) constitute one of the possible particle dark matter theories. They not only emerge naturally in many extensions of the Standard Model and have the correct cosmological properties, but also they have many and diverse implications for observable phenomena. The main observable for neutrino telescopes is the neutrino flux created either directly by the annihilation of dark matter particles, or by the decay or interaction of the products of their annihilation. In this contribution, the capability of the KM3NeT neutrino telescope to contribute to the long-standing question of the nature of dark matter will be discussed. Limits and sensitivities to the WIMP dark matter thermally-averaged annihilation cross-section will be presented, searching for a neutrino signal created by dark matter annihilations. The search focuses on annihilation signals coming from the Galactic Centre and the Sun, where an over-density of dark matter is believed to be present.

Speaker: Clara Gatius Oliver (PhD student)

DMsearchesKM3NeT_CANsymposium_June24.pdf

8 Measuring atmospheric neutrino oscillation with KM3NeT/ORCA

The KM3NeT Collaboration is constructing the KM3NeT/ORCA detector at the bottom of the Mediterranean Sea, off the coast of Toulon, France. This neutrino telescope is optimized for GeV neutrino detection, with primary goals of determining the neutrino mass ordering and measuring oscillation parameters in the atmospheric neutrino sector. Data collected with intermediate configurations of 6, 10, and 11 detection units have been analyzed. This contribution will present the results of the oscillation parameter measurements and the sensitivity of the ORCA detector to the neutrino mass ordering, demonstrating competitive results with only 10% of the total detector. Additionally, first results and prospects for probing BSM (beyond-the-Standard-Model) scenarios will be discussed.

Speaker: Victor Carretero Cuenca (Nikhef)

KM3NeT_ORCA_Talk_VCarretero.pdf

9 Towards the Deep Underground Neutrino Experiment

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment under construction in the US. In this talk we will describe the physics of DUNE, also outside the oscillations realm, and the Dutch participation in the experiment.

Speaker: Paul de Jong

Towards_DUNE_PdJ.pdf

10 The Radar Echo Telescope

The Radar Echo Telescope is currently deployed and taking data for 2024 at the summit station at Greenland. The ultimate objective of the Radar Echo Telescope is to detect high-energy cosmic neutrinos with the Radar Echo Telescope for Neutrinos (RET-N). We have observed radar reflections from particle cascades in a lab setting at SLAC National Accelerator Laboratory. The extensive air shower (EAS) of a high energy cosmic ray (primary energy > 10PeV) deposits around 10% of its primary energy close to the shower core at a high altitude ice sheet producing a much denser in-ice secondary cascade. This in-ice cascade is dense enough to be detected via radar reflections. The Radar Echo Telescope for Cosmic Rays (RET-CR) is a predecessor to RET-N, enabling a validation of the radar method in-nature. The surface stations of the RET-CR triggers on an incoming air shower. It consists of 6 stations with SKALA (50 - 350 MHz) radio antennas and scintillator panels. The parameters reconstructed by the surface station would be validated against those obtained by the in ice radar system. My talk would discuss on the reconstructions for the surface stations, galactic calibrations for the surface station SKALA antennas and insight into the data.

Speaker: Krishna Nivedita Gopinath (Radboud University, Nijmegen)

CAN_symposium-krishna.pdf

coffee

Contributed talks

11 Search for UHE neutrinos in the background of cosmic rays

The main challenge in detecting ultra-high energy (UHE) neutrinos is discriminating a neutrino-induced shower in the background of showers initiated by ultra-high energy nuclei. The resulting shower development from neutrinos exhibits different characteristics from hadron-induced showers because neutrinos penetrate the atmosphere more deeply than hadrons. This study focuses on simulations of highly inclined neutrino-induced showers, exploring an extensive energy range from 1EeV to 120EeV. These simulated showers have different ranges of interaction depths corresponding to each zenith angle, presenting diverse detection challenges. Our methodology utilises timing data from radio antennas for the shower front calculation for extensive air showers induced by neutrinos and nuclei. Furthermore, we incorporate signals obtained from the Water Cherenkov detectors and the spatial distribution of stations registering signals in both Water Cherenkov detectors and radio antennas. We aim to classify neutrino-induced showers and background events stemming from nuclei by harnessing a decision tree classifier employing the Gini impurity method. Our framework yields excellent accuracy for separating the neutrinos from the background. The findings of this study offer significant advancements in the domain of UHE neutrino detection, shedding light on astrophysical phenomena associated with these elusive particles amidst the complex background of UHE nuclei.

Speaker: Abha Khakurdikar (Radboud University)

APPSymposium2024_AbhaK.pdf

12 The potential role of second order Fermi acceleration in Galactic PeVatron candidates

The Galactic origin of multi-PeV cosmic rays is still a mystery, but recent LHAASO results indicate that regions of PeV gamma-ray emission are often associated with starforming regions. The question is then whether there are in these starforming regions there are single PeVatrons sources, such as a power (past) supernova remnant, a powerful pulsar, or one or multiple strong stellar wind shocks, or whether the starforming region is collectively a PeVatron. The latter could be the case if for example there is combined wind from the starforming region creating a collective outer termination shock. However, here I intent to focus on the prospects of second order Fermi acceleration as a source of PeV cosmic rays. I show that for a given relevant velocity (Alfven velocity) second order Fermi acceleration can be just as efficient as first order Fermi acceleration. However, the Alfven velocities are at best a few hundred km/s whereas shock velocities can be much higher. Nevertheless, I will show that even with Alfven speeds of a few hundred km/s one can accelerate protons to PeV energies within the lifetime of a cluster, provided the magnetic field turbulence level is high enough, and the density in the inner regions are diluted. I will show that both conditions are likely met based on observational data and hydrodynamical modeling.

Speaker: Jacco Vink (University of Amsterdam)

vink_app_symposium_2024.pdf

13 Multi-Messenger Moldeling of the Monogem Pulsar Halo

The High-Altitude Water Cherenkov Telescope (HAWC) has detected TeV halos associated with two nearby pulsars/pulsar wind nebulae (PWN) - Geminga and B0656+14 (Monogem). These TeV halos extend up to tens of parsecs from the central accelerators, indicating that the diffusion of electrons and positrons in the interstellar medium has been suppressed by two orders of magnitude. Although Geminga and Monogem are at similar distances and in the same field of view, they have distinct histories. Notably, Monogem probably still resides within its parent supernova remnant, the Monogem Ring, which can be observed in X-rays. In this work, we perform high-resolution simulations of the propagation and emission of relativistic lepton pairs around B0656+14 using a two-zone diffusion model within the GALPROP framework. We compared the predicted inverse-Compton spectrum to the observations made by HAWC and Fermi-LAT and found physically plausible model parameters that resulted in a good fit to the data. Additionally, we estimated the contribution of this TeV halo to the positron flux observed on Earth. We conclude that future observations of the TeV halo and its synchrotron emission counterpart in radio frequencies and X- rays will be crucial to distinguish between various possible model parameter configurations.

Speaker: Youyou Li (GRAPPA)

Monogem_halo_Youyou.pdf

14 The QCD Axion Mass

Axions are hypothetical particles that may explain the observed dark matter (DM) density and the non-observation of a neutron electric dipole moment. An increasing number of axion laboratory searches are underway worldwide, but these efforts are made difficult by the fact that the axion mass is largely unconstrained. If the axion is generated after inflation there is a unique mass that gives rise to the observed DM abundance; due to nonlinearities and topological defects known as axion strings, computing this mass accurately has been a challenge for four decades. Recent works, making use of large static lattice simulations, have led to largely disparate predictions for the axion mass, spanning the range from 25 microelectronvolts to over 500 microelectronvolts. In this talk, I will show that adaptive mesh refinement (AMR) simulations are better suited for axion cosmology than the previously used static lattice simulations. Using dedicated AMR simulations we obtain a several orders of magnitude leap in dynamic range and provide evidence that axion strings radiate their energy with a scale-invariant spectrum, to within ∼5% precision.

Speaker: Malte buschmann

15 The NOVA SKIES Programme - A training on entrepreneurial competences for young scientists

The NOVA-SKIES (Skilled, Innovative and Entrepreneurial Scientists) programme started in July 2023 and will run till the end of 2028, supported by NOVA funding. The programme provides training on innovation, entrepreneurship, and development of soft and hard skills of PhDs and PDs, and creates career opportunities for PhD candidates and early-career researchers in the field of astronomy in the Netherlands. The NOVA-SKIES programme aims to support the recognition of the competences of young astronomers, and help them to be aware of their skills and of the constructive way in which these skills can be transferred to any career-path they decide to pursue. Once outside academia, thanks to the strong awareness of their values, our PhDs and post-docs become active STEM ambassadors in the society, and this represents an important goal of the astronomical field as a whole. In this talk, I will provide an overview of the programme and share with the audience the importance of supporting the skill transferring between astro-particle physicists and the private sector.

Speaker: Giovanna Pugliese

Afternoon session: Strategy

Borrel and dinner

Friday, 28 June

Morning session: Keynote Talk

16 Keynote Talk: High-energy Neutrinos from Blazars

Speaker: Prof. Sara Buson (DESY, Univ. of Wurzburg)

Highlight talks

17 Highlight: Can we find relic neutrino’s?

Speaker: Auke-Pieter Colijn

18 Highlight: Probing the Most Extreme Environments through Very High Resolution Radio Observations

Speaker: Dr Benito Marcote (Joint Institute for VLBI ERIC (JIVE))

Marcote_talk_astroparticle.pdf

coffee

Contributed talks

19 Methods for antideuteron identification with the AMS-02 detector

Cosmic ray (CR) antideuterons, although yet to be detected in space, represent a highly sensitive channel for probing new physics, including models related to Dark Matter. The identification of CR antideuterons poses significant challenges due to their limited abundance, with an expected flux approximately $10^{-9}$ times lower than that of protons. The AMS-02 experiment, after 11 years of data collection, holds the potential for cosmic-ray antideuterons identification. However, the accurate characterisation and rejection of various backgrounds are crucial to achieve a good isotopic mass separation over a wide range of energies. Machine Learning methods, particularly Boosted Decision Trees, are well suited for this classification task, but their performance relies on the choice of the features needed for their training phase. While physics-driven feature selection methods based on the knowledge of the detector are often used, Machine Learning algorithms for automated feature selection can provide a helpful alternative that optimises the classification method's performance. In the talk, I will review the principal challenges in the search for antideuterons and show how to improve isotope identification with AMS-02 using Machine Learning feature selection algorithms.

Speaker: Marta Borchiellini

CAN_dbar2024.pdf

20 Detection of ultra-high-energy particles with the new Radio Detector of the Pierre Auger Observatory

The new Radio Detector (RD) is part of the ongoing AugerPrime upgrade of the Pierre Auger Observatory. It consists of short aperiodic loaded loop antennas designed to measure radio signals from extensive air showers in the 30-80 MHz band. These antennas, with polarisations both parallel and perpendicular to the earth magnetic field, are currently being installed on each of the 1,660 surface detector stations. Several hundred of them are already taking data and the array is expected to be completed in 2024. The RD will be sensitive to the electromagnetic component of inclined showers with zenith angles above 65 degrees. This will increase the sky coverage of mass-sensitive measurements and the sensitivity of the Observatory to neutral particles such as ultra-high-energy photons and neutrinos. In this contribution we report on the current status and future prospects of the RD.

Speaker: Cristina Galea

CAN_RD_status_28jun2024.pdf

21 Ultra High Energy Cosmic Ray Composition Estimation using the AugerPrime Radio Detector

The ongoing inclusion of the Radio Detector (RD) in the AugerPrime Observatory marks a significant advancement in the observatory's capabilities. The Pierre Auger observatory has enhanced our understanding of ultra-high energy cosmic rays (UHECR) for the past two decades. By equipping each of the 1660 detector stations and spanning an area of 3000 km2 with radio antennas, the observatory will be the world's largest radio array dedicated to studying Extensive Air Shower (EAS) physics. This talk will be on the radio detection of cosmic rays and the exciting prospects of radio interferometry being applied to the detection of air showers.

Speaker: Anthony Bwembya (Radboud University)

CAN_sympos_Anthony.pptx

22 AugerPrime and Radio Trigger

The AugerPrime upgrade at the Pierre Auger Observatory marks a pivotal development in ultra-high-energy cosmic ray (UHECR) research. This enhancement equips the observatory with advanced detection capabilities, aimed at providing deeper insights into the properties and origins of cosmic rays with energies above 1 EeV. The presentation will covers the potential implementation of a self-Radio Trigger system, which is proposed but not yet realized. The importance of such a system lies in its ability to autonomously detect radio signals from cosmic ray air showers, significantly boosting detection efficiency, especially for neutral high-energy cosmic rays.

Speaker: Mohamed Ismaiel (Radboud University)

CAN2024V1.pdf

23 Simulation based inference for the next generation of gravitational wave data

As we move towards the next generation of gravitational wave (GW) detections, data analysis techniques pertaining to detection, denoising and parameter inference need to be highly specialised. Ever increasing duty cycles result in a signal dominated era of GWs which brings about its own host of challenges for science interpretation from such data. Is there a way to go about using simulation-based inference? I discuss this in the context of problems such as the LISA global fit and approaches to solve such complex data analysis tasks in a block-by-block basis.

Speaker: Mr Uddipta Bhardwaj (GRAPPA, University of Amsterdam)

24 Holding mirrors still for future gravitational wave detectors

The Einstein Telescope, the future European gravitational wave detector, aims to observe collisions of heavier objects, events deep in cosmological time, and provide early warning for multi-messenger astronomy. To do this it must be sensitive at low frequencies down to 3Hz. However, the current LIGO detectors are limited below 20Hz by sensing and actuation noise from controlling the interferometer. For the Einstein Telescope to reach its design sensitivity from 3Hz onwards a factor of 1 million improvement is needed in the suppression of noises. In this talk I will talk about the necessity for new suspension mechanics and control co-design to leverage and fully account for the strengths and weaknesses of both elements. I will then show how new tools can help us explore the design space to find a solution viable for the Einstein Telescope.

Speaker: Jesse van Dongen

CAN_Jesse_28-06-2024.pdf

Closing remarks

Lunch