arXiv subjects

Jeffrey M. Hyde

Publications and source records attributed to Jeffrey M. Hyde.

7 recordsLinked to original sources

arXiv2023

Constraints on Neutrino Self-Interactions from IceCube Observation of NGC 1068

The active galaxy NGC 1068 was recently identified by the IceCube neutrino observatory as the first known steady-state, extragalactic neutrino point source, associated with about 79 events over ten years. We use the IceCube data to place limits on possible neutrino self-interactions mediated by scalar particles with mass between 1 - 10 MeV. We find that constraints on flavor-specific $ν_τ$ self-interactions with low mediator masses are comparable to constraints derived from the diffuse high-energy neutrino flux at low energies, while constraints on flavor-universal self-interactions are less restrictive than current bounds.

hep-ph↗

arXiv2020

Exploring Hubble Constant Data in an Introductory Course

Popular accounts of exciting discoveries often draw students to physics and astronomy, but at the introductory level it is challenging to connect with these in a meaningful way. The use of real astronomical data in the classroom can help bridge this gap and build valuable quantitative and scientific reasoning skills. This paper presents a strategy for studying Hubble's Law and the accelerating expansion of the universe using actual data. Along with understanding the physical concepts, an explicit goal is to develop skills for analyzing data in terms of a model.

physics.ed-ph↗

arXiv2019

Biprobability approach to CP phase degeneracy from non-standard neutrino interactions

Non-standard interactions (NSI) between neutrinos and matter at long-baseline experiments could make determination of the CP-violating phase $δ_{13}$ ambiguous due to interference with additional complex phases. Such degeneracies are often studied in the context of specific experiments and a few parameter choices, leaving it unclear how to extract a general understanding of when two sets of parameters may be degenerate or how different types of experiments in principle combine to lift such a degeneracy. This work complements detailed simulations of individual experiments by showing how underlying parameters relate to degeneracies as represented on a biprobability plot. We show how a range of energies near the oscillation maximum $Δ_{31} = π/2$ separates some degenerate probabilities along the CP-conserving direction of biprobability space according to $δ_{+} \equiv δ_{13} + δ_{eτ}$, while near $Δ_{31} = 3π/2$ degenerate probabilities are separated along the CP-violating direction according to $δ_{eτ}$. We apply this to the experimental hints that suggest $δ_{13} \sim -π/2$ to see that this could also be consistent with $δ_{13}, δ_{eτ} = 0$ or $π$. The baseline and energy range characteristic of DUNE provides some resolution, but a further improvement comes from beams a few degrees off-axis at $\gtrsim 1000$ km baselines, including some proposed sites for T2HKK.

hep-ph↗

arXiv2018

Detecting CP Violation in the Presence of Non-Standard Neutrino Interactions

New physics beyond the Standard Model could appear at long baseline oscillation experiments as non-standard interactions (NSI) between neutrinos and matter. If so, determination of the CP-violating phase $δ_{13}$ is ambiguous due to interference with additional complex phases. I'll present my work using both numerical solutions and a perturbative approach to study oscillation probabilities in the presence of NSI. I'll show how the CP phase degeneracies are visualized on biprobability plots, and the extent to which the energy spectrum for a given baseline length can help resolve them. In particular, this shows how the broad range of energies at DUNE would help distinguish between maximal, standard CP violation and the absence of CP violation with large $ε_{eτ}$.

hep-ph↗

arXiv2015

Sensitivity of gravitational waves from preheating to a scalar field's interactions

After inflation, a period of preheating may have produced a stochastic background of high frequency gravitational waves (GWs) that would persist until today. The nature of the inflaton's coupling to Standard Model or other fields is unknown, so it is useful to ask what features such fields may typically have, and how these affect predictions for the GW's produced. Here we consider the inflaton to be coupled to a light scalar field, and show that even a very small quartic self-interaction term will reduce the amplitude of the GW spectrum. For self-coupling $λ_χ \gtrsim g^2$, where $g^2$ is the inflaton-scalar coupling, the peak energy density goes as $Ω_{\rm gw}^{(λ_χ)} / Ω_{\rm gw}^{(λ_χ=0)} \sim (g^2/λ_χ)^{2}$. A consequence is that if the universe reheats through an inflaton-Higgs coupling then the spectrum would be suppressed but the dynamics would be sensitive to the Higgs potential near the energy scale of inflation.

hep-ph↗

arXiv2014

Cosmic Strings in Hidden Sectors: 1. Radiation of Standard Model Particles

In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant cosmic strings to Standard Model particles. We calculate the spectrum of radiation emitted by these "dark strings" in the form of Higgs bosons, Z bosons, and Standard Model fermions assuming that string tension is above the TeV scale. We also calculate the scattering cross sections of Standard Model fermions on dark strings due to the Aharonov-Bohm interaction. These radiation and scattering calculations will be applied in a subsequent paper to study the cosmological evolution and observational signatures of dark strings.

hep-ph↗

arXiv2013

Dark Strings and their Couplings to the Standard Model

We consider the Standard Model extended by a hidden sector U(1)_X symmetry that is spontaneously broken at the TeV scale by the vacuum expectation value of an additional scalar field. We study "dark string" solutions in this model and their properties due to the Higgs portal and gauge kinetic mixing operators. We find that dark strings effectively interact with Higgs and Z bosons by linear couplings, and with leptons and baryons via Aharonov-Bohm couplings, thus possibly leading to new cosmological constraints on dark matter models with spontaneously broken extra U(1) symmetry factors.

hep-ph↗