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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
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SEQUENCE:1
UID:UW-Physics-Event-8720
DTSTART:20240430T160000Z
DTEND:20240430T180000Z
DTSTAMP:20260413T223459Z
LAST-MODIFIED:20240403T192448Z
LOCATION:5280 Chamberlin\; https://uwmadison.zoom.us/u/aeEccgd7y
SUMMARY:Modeling Solar Neutrino Flavor Evolution with Data Assimilatio
 n\, Preliminary Exam\, Caroline Laber-Smith
DESCRIPTION:This talk will cover the application of statistical data a
 ssimilation (SDA) techniques to solar neutrinos in two cases. Statisti
 cal data assimilation is an inference method that incorporates system 
 dynamics from theory to supplement sparse measurements. Solutions are 
 found by minimizing deviation from both measurements and model dynamic
 s and tested based on their predicted results outside of the measured 
 region. We used this technique to model neutrino flavor evolution thro
 ughout the sun\, starting from pure electron flavor at the center and 
 undergoing Mikheyev-Smirnov-Wolfenstein (MSW) resonance as it travels 
 outwards.<br>
\n<br>
\nThis is the first application of SDA to solar n
 eutrinos using real data - measurements of Boron-8 solar neutrino flav
 or recorded by the Borexino and Sudbury Neutrino Observation (SNO) exp
 eriments were used to constrain neutrino flavor towards the edge of th
 e sun. In the first case\, we used this data as a test of the techniqu
 e. We performed this optimization procedure with multiple energy bins 
 matching the observations from the Borexino and SNO experiments separa
 tely. With both sets of measurements\, we found that incorporating MSW
  resonance into the flavor evolution dynamics produces results consist
 ent with the observations.<br>
\n<br>
\nIn the second case\, we introd
 uced parameter estimation by allowing the procedure to vary the matter
  potential inside the sun. As a test of adiabaticity\, we used two dif
 ferent monotonically decreasing models of the matter potential as a fu
 nction of radius. For each model\, the potential was held fixed at the
  edge of our zone of inference to match the standard solar model\, whi
 le the value at the core of the sun was used as a varying parameter. F
 or both models\, we found that a core potential between 0.025 and 0.03
 0 per kilometer produces results most consistent with observed neutrin
 o fluxes.
URL:https://www.physics.wisc.edu/events/?id=8720
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