Adam Brown contributed with a poster on the XENONnT upgrades and status and Ricardo Peres on the software for the supernova early warning system:
Giovanni Volta, Michelle Galloway and Chiara Capelli contributed with talks on the general XENON1T results, the ongoing search for dark absorption and the analysis on high energy events respectively. The full talks are linked. Below a key slide from each talk is shown: the spin-independent elastic WIMP-nucleon scattering limit at 90% CL still are the most sensitive limits on WIMP dark matter. The motivation for light dark matter searches is becoming more and more pressing. And our reconstruction of single-site and multiple-site interactions for the neutrinoless double beta decay search significantly improves our capability to contribute to this exciting science channel.
A talk on the measurement of the double electron capture half-life of xenon-124 with the XENON1T experiment was given at the Lepton Photon 2019 conference in Toronto in August 2019. Ethan Brown from Rensselaer Polytechnic Institute presented this exciting result, demonstrating the power of the ultra-low background in XENON1T. This yielded the measurement of the longest process ever directly observed at 1.8×10^22 years, a trillion times longer than the age of the Universe.
Some of the dark matter search results were also presented in this talk, advertising the incredible success of the XENON program and the science reach of the XENON1T experiment in rare event detection.
A talk on the XENON project was given at the 15th Patras Workshop on Axions, WIMPs and WISPs, which was held in Freiburg (Germany) in the first week of June. Andrea Molinario from the Gran Sasso Science Institute and Laboratori Nazionali del Gran Sasso presented the most recent results from the data analysis of XENON1T, in particular the search for WIMP-nucleon spin-dependent and spin-independent interactions. The sensitivity of this search will be much-improved upon by the upcoming XENONnT phase of the experiment.
The first observation of 124Xe double electron capture and the measurement of the half-life of the process were also shown (this topic had a dedicated talk by Sebastian Lindemann). In the second part of his talk, Andrea gave an update on the status of XENONnT. The presentation is available here.
Our latest XENON1T paper on details of our analysis was presented at the Low Radioactivity Techniques, a conference focused on low background experiments. In the talk (that you can find here), the response model of the detector, the challenges of background modeling, as well as the used techniques were described. In a low background experiment is often hard to asses the expected distribution of events due to lack of statistics and to many subtle effects. In the talk a novel technique was described to introduce a well-motivated systematic uncertainty to the background model based on a calibration sample, which can be relevant to other low background experiments.
XENON was present at the ALPS conference in Austria. Chiara Capelli from University of Zurich gave a talk on behalf of the XENON collaboration. The talk focused on the latest XENON1T results on spin-independent and spin-dependent WIMPs, and on the newest results on two-neutrinos double electron capture, with a final status on the XENONnT upgrade. The talk is available here.
On March 8, 2019, Shigetaka Moriyama presented the status of the XENONnT experiment at the international symposium on “Revealing the history of the Universe with underground particle and nuclear research” in Sendai, Japan. The symposium is held by a Japanese research community working on underground experiments and developing low background techniques. Its members are interested in the physics goals of XENONnT as well as its radon reduction technique and will enhance the experiment with Super-Kamiokande’s water Cherenkov technology developed in Kamioka, Japan, for the SK-Gd project. Super-Kamiokande developed this technology to measure the diffuse relic neutrino flux from past supernovae.
At the Sendai meeting, this community is summarizing its achievements over last five years and aims to secure new funding for the next five years by expanding its activity through internationalization and the inclusion of new physics topics such as history of stars, galaxies, and the origin of the heavy elements in the Universe.
Oslo welcomed all 66 participants of the second Rucio Community Workshop with pleasant weather and a venue which offered an astonishing view about the capital of Norway. The opensource and contribution model of the Rucio data management tool captures more and moreattention from numerous fields. Therefore, 21 communitiesreported this year about the implementation of Rucio in their current data workflows, discussed with the Rucio developing team possible improvements and chatted among each other during the coffee breaks to learn from others experiences. Among the various communities were presentationsgiven by the DUNE experiment, Belle-2 and LSST. The XENON Dark Matter Collaboration presented the computing scheme of the upcoming XENONnT experiment. Two keynote talks from Richard Hughes-Jones(University of Maryland) and GundmundHøst(NeIC) highlighted the concepts of the upcoming generation of academic networks and the Nordic e-Infrastructure Collaboration.
After the successful XENON1T stage with two major science runs, a world-leading limit for spin-indepenent Dark Matter interactions with nucleons and further publications, the XENON1T experiment stopped data taking in December 2018. We aim for two major updates for the successor stage of XENONnT:a larger time projection chamber (TPC) which holds ~8,000 kg of liquid xenon with 496 PMTs for signal readout and an additional neutron veto detector based on Gadolinium doped water in our water tank. That requiresupgrades in our current data management and processing scheme, which was presentedlast year at the first Rucio Community Workshop. Fundamental change is the new data processor STRAX which allows us much faster data processing.Based on the recorded raw data, the final data product will be available at distinct intermediate processing stages which depend on each other. Therefore, we stop using our “classical” data scheme of raw data, processed data and minitrees, and instead aim for a more flexible data structure. Nevertheless, all stages of the data are distributed with Rucio to connected grid computing facilities.STRAX will be able to processdata from the TPC, the MuonVeto and the NeutronVetotogether to allow coincident analysis.
The data flow of the XENONnT experiment. A first set data is processed already at the LNGS. All data kinds are distributed with Rucio to the analysts.
Reprocessing campaigns are planed ahead with HTCondor and DAGManjobs at EGI and OSG similar to the setup of XENON1T.Due to the faster data processor, it becomes necessary to outline a well-established read and writeroutine with Rucio to guarantee quick data access. Another major update in the XENONnT computing scheme becomes the tape backup location. Because of the increased number of disks and tape allocations in the Rucio catalogue, we will abandon the Rucio independent tape backup in Stockholm and use dedicated Rucio storage elements for storing the raw data. The XENON1T experiment collected ~780 TB of (raw)data during its life time which are all managed by Rucio. The XENON Collaboration is looking forward to continuing this success story with XENONnT
Physics meets winter sports at the Lake Louise Winter Institute, a particle physics conference held annually in the beautiful Canadian Rockies. On February 12, 2019, Evan Shockley from University of Chicago presented at the conference on behalf of the XENON collaboration. The talk focused on the latest, world-leading WIMP results, and included a status update on XENON1T and its imminent upgrade, XENONnT. The talk is available here.
XENONnT will feature a larger detector and even lower background than XENON1T, making it ~10 times more sensitive to interactions from dark matter and other rare processes. With installation coming later this year, it’s an exciting time for the XENON collaboration and the field of dark matter research!
Two members of the University of Zurich group gave talks on XENON1T at the annual meeting of the Swiss Physical Society in Lausanne, Switzerland. Chiara Capelli presented the latest news from the experiment and in particular the recently presented limit on spin-independent WIMP-nucleon cross-section, while Adam Brown spoke about the ongoing work searching for the inelastic scattering of WIMPs.
One of the key slides from Chiara’s talk is below. In the top-right you can see the WIMP-search data pre-unblinding, and in the bottom-right the efficiency for detecting nuclear recoils which happen in our fiducial volume. In the full talk, which is available here, she also presented the final limit and then gave a update on the preparations for the detector upgrade to XENONnT which are ongoing at the University of Zurich.
Adam’s talk focussed instead on an alternative possibility of searching for WIMPs via their inelastic scattering off xenon nuclei. During the interaction the nucleus is excited, and so the usual nuclear recoil signal would be observed in coincidence with the 39.6 keV gamma ray from the de-excitation of the nucleus. One of the attractions of this search channel, which is however less sensitive than elastic scattering, is that it distinguishes between spin-dependent and spin-independent WIMP interactions: a spin-dependent interaction is needed to change the nuclear spin state during its excitation. Again, the full talk is available online here.
Featured from left to right: Kelly Odgers, Chloé Therreau, Amanda Depoian, Abigail Kopec, Dr. Ethan Brown, Arianna Rocchetti, Matthew Bernstein, and Leaf Swordy.
They obtained a broader understanding of the current state of Dark Matter research; especially cosmological and astrophysical evidence for Dark Matter; the best-motivated theoretical dark matter particle models; and various detection techniques. It was also an opportunity for them to meet and connect with their colleagues in the field and hone presentation skills. More information and uploaded talk slides can be found at https://indico.cern.ch/event/704938/.