Neutrino-nucleus cross sections for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi></mml:math>-boson and trident production
B. Zhou, J. F. Beacom
Abstract
The physics of neutrino-nucleus cross sections is a critical probe of the Standard Model and beyond. A precise understanding is also needed to accurately deduce astrophysical neutrino spectra. At energies above $\ensuremath{\sim}5\text{ }\text{ }\mathrm{GeV}$, the cross section is dominated by deep inelastic scattering, mediated by weak bosons. In addition, there are subdominant processes where the hadronic coupling is through virtual photons, ${\ensuremath{\gamma}}^{*}$: (on-shell) $W$-boson production (e.g., where the underlying interaction is ${\ensuremath{\nu}}_{\ensuremath{\ell}}+{\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{\ensuremath{-}}+{W}^{+}$) and trident production (e.g., where it is $\ensuremath{\nu}+{\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}\ensuremath{\nu}+{\ensuremath{\ell}}_{1}^{\ensuremath{-}}+{\ensuremath{\ell}}_{2}^{+}$). These processes become increasingly relevant at TeV--PeV energies. We undertake the first systematic approach to these processes (and those with hadronic couplings through virtual $W$ and $Z$ bosons), treating them together, avoiding common approximations, considering all neutrino flavors and final states, and covering the energy range 10--${10}^{8}\text{ }\text{ }\mathrm{GeV}$. In particular, we present the first complete calculation of $W$-boson production and the first calculation of trident production at TeV--PeV energies. When we use the same assumptions as in prior work, we recover all of their major results. In a companion paper [this issue, Phys. Rev. D 101, 036010 (2020)], we show that these processes should be taken into account for IceCube-Gen2.