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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:1
UID:UW-Physics-Event-9750
DTSTART:20260804T160000Z
DTEND:20260804T180000Z
DTSTAMP:20260801T032548Z
LAST-MODIFIED:20260730T143833Z
LOCATION:5280 Chamberlin or https://uwmadison.zoom.us/j/97932736917?pw
 d=padQGmMWLAc7XYLrrF71yigFUEXwAY.1
SUMMARY:Applications of Statistical Data Assimilation to Neutrino Flav
 or Oscillations in Solar and CCSN Environments\, Thesis Defense\, Caro
 line Laber-Smith\, Physics PhD Graduate Student
DESCRIPTION:Neutrinos can be a powerful avenue for exploring astrophys
 ical environments\, as their low rate of interaction makes them reliab
 le carriers of information. However\, this same trait makes it difficu
 lt to observe neutrinos\, leading to a lack of data. We explore applic
 ations within neutrino physics of statistical data assimilation (SDA)\
 , a technique well-suited to problems with sparse data. Specifically\,
  we focus on neutrino flavor evolution inside of matter.<br>
\n<br>
\n
 First\, we take an SDA-based approach to modeling flavor evolution of 
 solar neutrinos undergoing dynamics described by the Mikheyev-Smirnov-
 Wolfenstein (MSW) effect. We incorporate measurements of solar neutrin
 o flavor composition from the Borexino and Sudbury Neutrino Observator
 y experiments as a constraint for our model. This serves as a test cas
 e to establish the efficacy of SDA for neutrino oscillations. We find 
 that this approach can reproduce the expected behavior from a typical 
 forward integration method when the MSW effect is included in model dy
 namics. After verifying SDA can match established results\, we use SDA
  to derive estimates of the solar neutrino mixing angle. Additionally\
 , we constrain electron density inside the Sun and find a result consi
 stent with the standard solar model.<br>
\n<br>
\nWe then turn to neut
 rinos in a core-collapse supernova (CCSN)\, where high neutrino densit
 y allows for complex behavior from neutrino-neutrino interactions. Des
 pite their important role in CCSN dynamics\, this complex nonlinear be
 havior makes collective CCSN neutrino oscillations difficult to model.
  We apply SDA to the task of modeling flavor evolution within the CCSN
  envelope\, using a matter density profile and simulated measurements 
 of neutrino flavor external to the CCSN. We demonstrate that SDA could
  be used with neutrino measurements to distinguish between multiple po
 ssible matter profiles\, and to place a limit on fluctuations in matte
 r density.
URL:https://www.physics.wisc.edu/events/?id=9750
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