COHERENT recently presented the full statistics analysis of the COHERENT CsI target at the Magnificent CEvNS Workshop in November and the “wine and cheese” seminar at Fermilab earlier this month. This result not only included a factor of two increase in exposure beyond COHERENT’s first observation of coherent elastic neutrino nuclear scattering (CEvNS) in 2017, but also a dramatic reduction in the experiment’s largest systematic uncertainty stemming from calibrations of the detector response.
The simultaneous measurement of multiple neutrino flavors at the Spallation Neutron Source provides the best probe to date of a set of non-standard lepton quark couplings that, unconstrained, complicate our understanding of the neutrino oscillation picture. The large mixing angle interpretation of the global neutrino oscillation data has proven quite robust for the last 20 years, but there is one notable exception. In 2006, Omar Miranda and coauthors [1]showed that if we allow these unmeasured or poorly constrained quark lepton couplings to vary, there is also a “dark side” solution to the neutrino oscillation picture that fits the data equally well. Pilar Coloma and coauthors[2] revisited this in 2017 with the latest oscillation data and showed that the DUNE neutrino mass ordering program which relies on the assumption that these couplings do not exists, would have a similar ambiguity. MEPhI graduate student, Alexey Konovolov, and Duke University postdoc, Dan Pershey, led the analysis of the data and the interpretation of the results respectively[3].
[1] Omar G. Miranda, Maria Amparo Tortola, and Jose W. F. Valle. Are solar neutrino oscillations robust? JHEP, 2006(10):008–008, 2006.
[2] Pilar Coloma, M. C. Gonzalez-Garcia, Michele Maltoni, Thomas Schwetz. COHERENT Enlightenment of the Neutrino Dark Side. Phys.Rev.D 96 (2017) 11, 115007.
[3] https://indico.cern.ch/event/943069/timetable/#20201116.detailed
