Photoproduction of doubly heavy baryon at the ILC

TL;DR

This paper investigates the production of doubly heavy baryons at the ILC, providing detailed cross section calculations and predicting large event numbers for future experiments.

Contribution

It presents a comprehensive calculation of doubly heavy baryon photoproduction at the ILC, including multiple diquark configurations and improved computational methods.

Findings

Approximately 2 million $\\Xi_{cc}$ baryons can be produced annually.

Predicted event numbers for $\\Xi_{bc}$ and $\\Xi_{bb}$ baryons are 220,000 and 3,000 respectively.

The study demonstrates the feasibility of observing these baryons at the ILC.

Abstract

In the present paper, we make a detailed study on the doubly heavy baryon photoproduction in the future $e^+e^-$ International Linear Collider (ILC). The baryons $\Xi_{cc}$, $\Xi_{bc}$, and $\Xi_{bb}$ are produced via the channel $\gamma \gamma \to \Xi_{QQ'} +\bar{Q'} +\bar{Q}$, where $Q$ and $Q'$ stand for heavy $c$ or $b$ quark, respectively. As for the $\Xi_{QQ'}$-baryon production, it shall first generate a $(QQ')[n]$-diquark and then form the final baryon via fragmentation, where $[n]$ stands for the color- and spin- configurations for the $(QQ')$-diquark states. According to the non-relativistic QCD theory, four diquark configurations shall provide sizable contributions to the baryon production, e.g., $[n]$ equals $[^3S_1]_{\bar{\textbf{3}}}$, $[^1S_0]_{\textbf{6}}$, $[^3S_1]_{\textbf{6}}$, or $[^1S_0]_{\bar{\textbf{3}}}$, respectively. We adopt the improved helicity amplitude approach for the hard scattering amplitude to improve the calculation efficiency. Total and differential cross sections of those channels, as well as the theoretical uncertainties, are presented. We show that sizable amounts of baryon events can be generated at the ILC, i.e., about $2.0\times 10^{6}$ $\Xi_{cc}$, $2.2\times 10^{5}$ $\Xi_{bc}$, as well as $3.0\times 10^{3}\;\Xi_{bb}$ events are to be generated in one operation year for $\sqrt{S}=500$ GeV and ${\cal L}\simeq 10^{36}$cm$^{-2}$s$^{-1}$.