Production of $\nu_\tau$ neutrinos and $\overline{\nu}_tau$ antineutrinos -- elaborate calculation for a fixed target experiment SHiP

TL;DR

This paper provides detailed calculations of tau neutrino and antineutrino production cross sections in proton-Mo collisions at 400 GeV, including various charm and strange quark fragmentation processes, to estimate tau neutrino yields for the SHiP experiment.

Contribution

It offers an elaborate, comprehensive calculation of tau neutrino production mechanisms in fixed target experiments, incorporating multiple fragmentation channels and decay chains, which was not thoroughly addressed before.

Findings

Quantitative cross sections for tau neutrino production are provided.

Estimated tau neutrino yields for the SHiP experiment are presented.

Different production contributions are explicitly compared.

Abstract

We discuss cross sections for $\nu_{\tau}$ and ${\overline \nu}_{\tau}$ production from the direct $D_s^{\pm} \to \nu_{\tau}/{\overline \nu}_{\tau}$ and chain $D_s^{\pm} \to \tau^+/\tau^- \to \nu_{\tau}/{\overline \nu}_{\tau}$ decays in $p\!+^{96}\!\mathrm{Mo}$ scattering with proton beam $E_{\mathrm{lab}}$ = 400 GeV \textit{i.e.} at $\sqrt{s}_{NN}$ = 27.4 GeV. In our calculations we include $D_s^{\pm}$ from charm fragmentation $c \to D_s^{+}$ and $\bar c \to D_s^-$ as well as those from subleading fragmentation of strange quarks/antiquarks $s \to D_s^-$ and $\bar s \to D_s^+$. The different contributions to $D_s^{\pm}$ and $\nu_{\tau} / {\overline \nu}_{\tau}$ production rates are shown explicitly. Estimates of a number of observed $\nu_{\tau} / \overline{\nu}_{\tau}$ in the $\nu_{\tau} / \overline{\nu}_{\tau} +^{208}\!\mathrm{Pb}$ reaction, with 2m long target are given.