Prospects for the Detection of the Diffuse Supernova Neutrino Background with the Experiments SK-Gd and JUNO

Abstract

The advent of gadolinium-loaded Super-Kamiokande (SK-Gd) and of the soon-to-start JUNO liquid scintillator detector marks a substantial improvement in global sensitivity for the Diffuse Supernova Neutrino Background (DSNB). The present article reviews the detector properties most relevant for the DSNB searches in both experiments and estimates the expected signal and background levels. Based on these inputs, we evaluate the sensitivity of both experiments individually and combined. Using a simplified statistical approach, we find that both SK-Gd and JUNO have the potential to reach >3σ evidence of the DSNB signal within 10 years of measurement. Combination of their results is likely to enable a 5σ discovery of the DSNB signal within the next decade.

Advancing the Landscape of Multimessenger Science in the Next Decade

“…Furthermore, the discovery prospects of the DSNB in the next decade are promising with the gadolinium enhanced Super-Kamiokande (SK-Gd) detector [644,645] which will have reduced backgrounds and low energy thresholds making the detection of low energy events (¿10 MeV) possible [632,637]. Data taking in the SK-Gd configuration started in late 2020 [646] and a statistical evidence (3σ) of the DSNB signal is expected within 10 years of running time. Other experiments include, Jiangmen Underground Neutrino Observatory [JUNO; 647] and Hyper-Kamiokande [648].…”

Non-Universal Stellar Initial Mass Functions: Large Uncertainties in Star Formation Rates at $z\approx 2-4$ and Other Astrophysical Probes

“…Only in recent years have experiments begun to approach the sensitivity necessary to directly observe the DSNB (Malek et al 2003;Bays et al 2012;Zhang et al 2015;Abe et al 2022Abe et al , 2021Li et al 2022). While no signal has yet been detected, the enrichment of Super-Kamiokande (SK) with gadolinium (Beacom & Vagins 2004;Horiuchi et al 2009) and the future proposed and planned experiments such as Hyper-Kamiokande (HK), JUNO, Jinping, and THEIA (An et al 2016;Beacom et al 2017;Abe et al 2018;Sawatzki et al 2021;Li et al 2022) are expected to have enough sensitivity to make a first detection in the coming years.…”

“…Only in recent years have experiments begun to approach the sensitivity necessary to directly observe the DSNB (Malek et al 2003;Bays et al 2012;Zhang et al 2015;Abe et al 2022Abe et al , 2021Li et al 2022). While no signal has yet been detected, the enrichment of Super-Kamiokande (SK) with gadolinium (Beacom & Vagins 2004;Horiuchi et al 2009) and the future proposed and planned experiments such as Hyper-Kamiokande (HK), JUNO, Jinping, and THEIA (An et al 2016;Beacom et al 2017;Abe et al 2018;Sawatzki et al 2021;Li et al 2022) are expected to have enough sensitivity to make a first detection in the coming years. Once observed, the DSNB will provide a test of astrophysical observables (Lunardini 2009;Keehn & Lunardini 2012;Nakazato 2013;Nakazato et al 2015;Priya & Lunardini 2017;Møller et al 2018;Kresse et al 2021;Singh & Rentala 2021;Horiuchi et al 2021;Libanov & Sharofeev 2022), neutrino flavor physics (Lunardini & Tamborra 2012;Tabrizi & Horiuchi 2021;Suliga et al 2022), and physics beyond the Standard Model (Ando 2003;Fogli et al 2004;Goldberg et al 2006;Baker et al 2007;Farzan & Palomares-Ruiz 2014;Jeong et al 2018;Creque-Sarbinowski et al 2021;de Gouvêa et al 2020;Das & Sen 2021;Suliga et al 2022...…”

Exploring the Fate of Stellar Core Collapse with Supernova Relic Neutrinos

“…Figure 1 shows the latest experimental upper limits from SK (Abe et al 2021) and KamLAND (Abe et al 2022), in comparison to predictions from our models in this paper. Various detectors such as water Cherenkov, liquid scintillators, xenon-based, etc in the next few decades expect the SRN discovery by improving sensitivity dramatically (Li et al 2022;Suliga et al 2022;Sawatzki et al 2021;de Gouvêa et al 2020;Møller et al 2018;Priya & Lunardini 2017). Accordingly there is a higher demand for the preparation to extract physical constraints when SRNs are actually detected.…”

“…The capture rate is ∼50% with 0.01% gadolinium in water and ∼90% with 0.1% according toLi et al (2022).4 The photosensors for HK have a better performance than those for SK, but the neutron tagging performance depends also on the detector size, the water purity, the coverage of sensors, etc.…”