Introduction

Shedding light on the nature of dark matter and studying the properties of neutrinos are among the main priorities of modern particle and astroparticle physics today.
Worldwide, more than a dozen direct detection experiments are prepared to observe rare signals induced by dark matter candidates and neutrinos in ultra-sensitive, low-background detectors. One of the leading technologies today are the dual-phase liquid xenon Time Projection Chambers (TPCs). This is a well-established technology, proven to be scalable from a few tens of kg of target mass to the current multi-ton detectors LZ (7t target mass, in US) and XENONnT (6t target mass, in Europe). These detectors have recently achieved the most stringent limits on dark matter searches and demonstrated their exceptional capabilities for additional rare event detections. Despite the exciting prospects for the current running experiments, there is broad consensus in the community of the need for a larger detector, able to further increase the sensitivity to rare events searches. Should the current generation of instruments provide evidence of signals, a large detector will be essential as the nature of dark matter and neutrinos become open to exploration.

Main objectives of research

In this context, the proposed IRP is developed as a natural continuation of the International Emerging Action (IEA) intitled “XEnon Time Projection Chambers: R&D for Future Generation Experiments, searching for Dark Matter and Neutrinoless Double Beta decay (0vbb)” (XERD-DM-0vbb 2023-2024). With the XERD-DM-0vbb IEA the members of the SUBATECH laboratory and the School of Physics at the University of Melbourne (UoM), joined their efforts to prepare the playground for the next generation liquid xenon DARWIN detector [1]. In that respect, the two groups are contributing to R&D activities as well as to analysis via the search for dark matter candidates and investigation of the nature of neutrinos using the data of the current running XENONnT experiment [2,3].

In the context of the evolution of these ongoing activities, two additional institutions are planning to join the network: the CNRS/in2p3 LPNHE laboratory in Paris and the University of Sydney (UoS).  The program is to reinforce the French and Australian joint contributions in preparation for the ultimate observatory for dark matter and neutrino physics [4].

In that regard, the three world leading collaborations in this field of research (XENON, LZ and DARWIN) recently unite forces in the XLZD Consortium aiming at designing and building a single, common and ultimate multi-ton (between 40 and 80 tonnes target mass) experiment for rare events searches, expected to start operating by the start of the next decade. Current detectors LZ and XENONnT have the same science goals but differ in many technical details. Building this collaboration, will allow us to explore and select the best option from both worlds, strengthening our R&D efforts by combining ideas and resources.

References including participants to this IRP proposal

[1] M. Adrover et al., Cosmogenic background simulations for the DARWIN observatory at different underground locations, arXiv:2306.16340

[2] E. Aprile et al., First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment, arXiv:2303.14729
[3] E. Aprile et al., Double-Weak Decays of 124Xe and 136Xe in the XENON1T and XENONnT Experiments, Phys.Rev.C 106 (2022) 2, 024328, arXiv:2205.04158

[4] J. Aalbers et al., A next-generation liquid xenon observatory for dark matter and neutrino physics, J.Phys.G 50 (2023) 1, 013001, arXiv:2203.02309

Expected results

This program will provide France and Australia with an outstanding opportunity to participate in an exciting project of international significance in fundamental physics. The collaboration will result in a better understanding of our Universe notably via the search for dark matter candidates and neutrino properties. The results will be published in international physics journals. Additionally, the project will lay the foundation for a common infrastructure and effective network of knowledge focused on common interests on astrophysics rare-events search and Xe-based detector R&D.

Institutions and laboratories involved

France

• SUBATECH – UMR6457 

   Laboratoire physique nucléaire et des hautes énergies LPNHE Paris UMR7585, IMT Atlantique Nantes

Australia

• The University of Melbourne

   The University of Sydney

   

The science channels of a next-generation liquid xenon observatory (figure taken from https://arxiv.org/pdf/2203.02309.pdf)