Supplemental material for "A change of direction in pairwise neutrino conversion physics: The effect of collisions" (arXiv:2011.00004)
Authors: Shashank Shalgar and Irene Tamborra
The density matrices of neutrinos and antineutrinos, $\rho$ and $\bar{\rho}$, can be written in terms of polarization vectors in the two-flavor approximation ($P$ and $\bar{P}$):
$$
\rho = \frac{1}{2}\left(1+\vec{P}\cdot\vec{\sigma}\right),
$$
where $\vec{\sigma}$ are the Pauli matrices. We plot the angle-integrated polarization vectors, which are convenient tools for visualization and convey the same information as the density matrices. In the movies below, we show the evolution of the angular distributions of neutrinos and antineutrinos (on the left) and the evolution of the polarization vectors (on the right) for three different scenarios. We have fixed the initial length of the neutrino polarization vector to $1$ and the initial length of the antineutrino polarization vector to $1/2$ for the ease of viewing.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for Case A with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for Case A with $\Delta m^{2} = 2.5\times 10^{-3}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for Case A with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = 2\bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for Case B with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and the polarization vectors for case B with $\Delta m^{2} = 2.5\times 10^{-3}$ eV$^{2}$, $E = 50$ MeV and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions the polarization vectors for Case B with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = 2\bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for Case C with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for case C with $\Delta m^{2} = 2.5\times 10^{-3}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = \bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Evolution of the neutrino and antineutrino angular distributions and polarization vectors for case C with $\Delta m^{2} = 2.5\times 10^{-6}$ eV$^{2}$, $E = 50$ MeV, and $\mathcal{C} = 2\bar{\mathcal{C}} = 1.0$ km$^{-1}$.
Please cite the paper if you use any of these videos in your talks or in any other academic setting.
If you face technical difficulties in accessing the movies or if you wish to discuss the physics behind the simulations, please feel free to contact the authors.
