Event calendar file
State of the Universe
Propagation of decaying neutrinos in matter: an analytic treatment
by Mr. Dibya Sankar Chattopadhyay (TIFR, Mumbai)
Friday, May 20, 2022
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(Asia/Kolkata)
at A369 and Zoom https://us02web.zoom.us/j/82512956967?pwd=angyQ0ZDdHZUdzFUbjkybmxsWFNFUT09 Meeting ID: 825 1295 6967 Passcode: 384194
at A369 and Zoom https://us02web.zoom.us/j/82512956967?pwd=angyQ0ZDdHZUdzFUbjkybmxsWFNFUT09 Meeting ID: 825 1295 6967 Passcode: 384194
| Description |
We present compact analytic expressions for neutrino propagation probabilities in matter, with effects from invisible decay of neutrinos included. These will be directly relevant for long-baseline, reactor and atmospheric neutrino experiments. The inclusion of decay leads to the effective Hamiltonian being non- Hermitian, with the Hermitian component representing oscillation, and the anti-Hermitian component corresponding to invisible decay. Due to a possible mismatch between the effective mass and the decay eigenstates of neutrinos, these two components need not commute. In fact, in the presence of matter, these two components will invariably become non-commuting. We overcome this by employing the techniques of inverse Baker-Campbell-Hausdorff (BCH) expansion, and the Cayley-Hamilton theorem applied in the 3-flavor framework. We also derive the probabilities in the One Mass Scale Dominance (OMSD) approximation. The analytic results obtained provide physical understanding into possible effects of neutrino decay as it propagates through Earth matter. We show that the non-intuitive feature of decay increasing the value of $P_{\mu\mu}$ at its first and second oscillation dip may be explained by our analytic expression. (Based on arXiv:2111.13128 [hep-ph] and arXiv:2204.05803 [hep-ph]) |
