Neutrino flavor transformation in supernovae as a probe for nonstandard neutrino-scalar interactions

We explore the possibility of probing the nonstandard interactions between the neutrino and a hypothetical massive scalar or pseudoscalar via neutrino flavor transformation in supernovae. We find that in the ultrarelativistic limit, the effective interaction between the neutrinos vanishes if neutrinos are Dirac fermions but not if they are Majorana fermions. The impact of the new neutrino interaction upon the flavor transformation above the neutrinosphere is calculated in the context of the multiangle “neutrino bulb model.” We find that the addition of the nonstandard neutrino self-interaction (NSSI) to the ordinary V-A self-interaction between neutrinos is capable of dramatically altering the collective oscillations when its strength is comparable to the standard, V-A, interaction. The effect of flavor-preserving (FP) NSSI is generally to suppress flavor transformation, while the flavor-violating (FV) interactions are found to promote flavor transformations. If the neutrino signal from a Galactic supernova can be sufficiently well understood, supernova neutrinos can provide complimentary constraints on scalar/pseudoscalar interactions of neutrinos as well as distinguishing whether the neutrino is a Majorana or Dirac fermion.

Figure 1

The lowest order scalar and pseudoscalar interactions between neutrinos.

Figure 2

The matter density profiles being used for the calculations of neutrino flavor transformation. The two dashed lines in each plot indicate the beginning and end of the calculation.

Figure 3

Survival probability of electron neutrinos (top panels) and antineutrinos (bottom panels) with flavor-preserving NSSI at $t_{\mathrm{pb}}=1.0s$. The left panels are the flux averaged probabilities as a function of distance $r$ while the right panels are plotted as function of energy at $r=400\mathrm{km}$. The combinations of the NSSI parameters are given in the legends.

Figure 4

Top panels: The heatmaps of survival probability of electron neutrinos at $t_{\mathrm{pb}}=1.0\mathrm{s}$ and $r=400\mathrm{km}$ as a function of energy and emission angle when there is only flavor-preserving NSSI. Bottom panels: The same but for electron antineutrinos.

Figure 5

Top panels: Survival probability of electron neutrinos at $t_{\mathrm{pb}}=1.0\mathrm{s}$ as a function of distance (left panel) and energy (right panel) at $r=400\mathrm{km}$ with flavor-violating NSSI. The bottom panels are the same but for electron antineutrinos.

Figure 6

Top panels: The heatmaps of survival probability of electron neutrinos at $t_{\mathrm{pb}}=1.0\mathrm{s}$ and $r=400\mathrm{km}$ as a function of energy and emission angle when there is flavor-violating NSSI. Bottom panels: The same but for electron antineutrinos.

Figure 7

Top panels: Survival probability of electron neutrinos at $t_{\mathrm{pb}}=2.8\mathrm{s}$ as a function of distance (left panel) and energy (right panel) at $r=400\mathrm{km}$ with flavor-preserving NSSI. The bottom panels are the same but for electron antineutrinos.

Figure 8

Top panels: The heatmaps of survival probability of electron neutrinos at $t_{\mathrm{pb}}=2.8\mathrm{s}$ and $r=400\mathrm{km}$ as a function of energy and emission angle when there is only flavor-preserving NSSI. Bottom panels: The same but for electron antineutrinos.

Figure 9

Top panels: Survival probability of electron neutrinos at $t_{\mathrm{pb}}=2.8\mathrm{s}$ as a function of distance (left panel) and energy (right panel) at $r=400\mathrm{km}$ with flavor-violating NSSI. Bottom panels: The same but for electron antineutrinos.

Figure 10

Top panels: The heatmaps of survival probability of electron neutrinos at $t_{\mathrm{pb}}=2.8\mathrm{s}$ and $r=400\mathrm{km}$ as a function of energy and emission angle when there is flavor-violating NSSI. Bottom panels: The same but for electron antineutrinos.

Figure 11

Top panels: Survival probability of electron neutrinos (left) and antineutrinos (right) at $t_{\mathrm{pb}}=2.8\mathrm{s}$ as a function of distance with pure flavor violating NSSI for IMO. Bottom panels: The same as top panels but for NMO.

Figure 12

Top panels: “Single-angle” survival probability of electron neutrinos at $t_{\mathrm{pb}}=2.8\mathrm{s}$ as a function of distance (left panel) and energy (right panel) at $r=400\mathrm{km}$ with flavor-preserving NSSI. Bottom panels: The same but with flavor-violating terms.