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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-9750
DTSTART:20260804T160000Z
DTEND:20260804T180000Z
DTSTAMP:20260713T203844Z
LAST-MODIFIED:20260710T151850Z
LOCATION:5280 Chamberlin
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>\nFi
 rst\, we take an SDA-based approach to modeling flavor evolution of so
 lar neutrinos undergoing dynamics described by the Mikheyev-Smirnov-Wo
 lfenstein (MSW) effect. We incorporate measurements of solar neutrino 
 flavor composition from the Borexino and Sudbury Neutrino Observatory 
 experiments as a constraint for our model. This serves as a test case 
 to establish the efficacy of SDA for neutrino oscillations. We find th
 at this approach can reproduce the expected behavior from a typical fo
 rward integration method when the MSW effect is included in model dyna
 mics. After verifying SDA can match established results\, we use SDA t
 o derive estimates of the solar neutrino mixing angle. Additionally\, 
 we constrain electron density inside the Sun and find a result consist
 ent with the standard solar model.<br>\n<br>\nWe then turn to neutrino
 s in a core-collapse supernova (CCSN)\, where high neutrino density al
 lows for complex behavior from neutrino-neutrino interactions. Despite
  their important role in CCSN dynamics\, this complex nonlinear behavi
 or makes collective CCSN neutrino oscillations difficult to model. We 
 apply SDA to the task of modeling flavor evolution within the CCSN env
 elope\, using a matter density profile and simulated measurements of n
 eutrino flavor external to the CCSN. We demonstrate that SDA could be 
 used with neutrino measurements to distinguish between multiple possib
 le matter profiles\, and to place a limit on fluctuations in matter de
 nsity.
URL:https://www.physics.wisc.edu/events/?id=9750
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