Thu·Nov 25, 2021Thursday·November 25, 2021

1. 01*

   First results from the HENSA/ANAIS collaboration at the Canfranc Underground Laboratory

   N Mont-Geli🇪🇸 · A Tarifeño-Saldivia🇪🇸 · S E A Orrigo🇪🇸 · J L Tain🇪🇸 · M Grieger🇩🇪 · J Agramunt🇪🇸 · A Algora🇪🇸 · J Amaré🇪🇸 · D Bemmerer🇩🇪 · F Calviño🇪🇸 · S Cebrián🇪🇸 · I Coarasa🇪🇸 and 15 other authors

   The HENSA/ANAIS collaboration aims for the precise determination of the neutron flux that could affect ANAIS-112, an experiment looking for the dark matter annual modulation using NaI(Tl) scintillators. In this work, the first measurements of the neutron flux and Monte Carlo simulations of the neutron spectrum are reported.

   nucl-exJ.Phys.Conf.Ser.(2021)·4 citations
2. 02*

   Statistical significance of the sterile-neutrino hypothesis in the context of reactor and gallium data

   Jeffrey M. Berryman🇺🇸 · Pilar Coloma🇪🇸 · Patrick Huber🇺🇸 · Thomas Schwetz🇩🇪 · Albert Zhou🇩🇪

   We evaluate the statistical significance of the 3+1 sterile-neutrino hypothesis using ${\nu }_e$ and ${\bar{\nu }}_e$ disappearance data from reactor, solar and gallium radioactive source experiments. Concerning the latter, we investigate the implications of the recent BEST results. For reactor data we focus on relative measurements independent of flux predictions. For the problem at hand, the usual ${\chi }^2$-approximation to hypothesis testing based on Wilks' theorem has been shown in the literature to be inaccurate. We therefore present results based on Monte Carlo simulations, and find that this typically reduces the significance by roughly $1\sigma$ with respect to the naïve expectation. We find no significant indication in favor of sterile-neutrino oscillations from reactor data. On the other hand, gallium data (dominated by the BEST result) show more than $5\sigma$ of evidence supporting the sterile-neutrino hypothesis, favoring oscillation parameters in agreement with constraints from reactor data. This explanation is, however, in significant tension ($\sim 3\sigma$) with solar neutrino experiments. In order to assess the robustness of the signal for gallium experiments we present a discussion of the impact of cross-section uncertainties on the results.

   ↳ hep-phhep-exnucl-exJHEP(2022)·71 citations
3. 03*

   Mounting Evidence for the Violation of Lepton Flavor Universality

   Andreas Crivellin🇨🇭 · Martin Hoferichter🇨🇭

   The Standard Model (SM) of particle physics was finalized in its current form in the mid-1970s, and has been extensively tested and confirmed ever since, with the discovery of the Higgs boson in 2012 being the last missing piece. While no new particles have been directly discovered at the Large Hadron Collider (LHC) at CERN so far, precision observables sensitive to quantum effects of new particles have accumulated intriguing hints for physics beyond the SM. All these anomalies can be interpreted from the point of view of lepton flavor universality, i.e., as hints that electrons, muons, and tau leptons differ much more than predicted by the SM. These tensions can be explained by postulating the existence of new exotic particles. Future measurements will be able to conclusively test this hypothesis, potentially providing long-awaited evidence how the SM needs to be extended at high energies.

   ↳ hep-phhep-exhep-latnucl-ex+1Science(2021)·47 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.