On the observability of free quarks near their production thresholds

TL;DR

The paper proposes experimental methods to detect free quarks near their production thresholds, focusing on conditions where quarks might not hadronize and could be observable directly.

Contribution

It introduces the idea of searching for free quarks near production thresholds and suggests experimental approaches involving irradiation of samples at specific energies.

Findings

Free quarks may be observable if produced below the pion threshold.

Production near threshold could result in hadronization probability less than one.

Searching for fractional charges in stable matter could be promising.

Abstract

It is proposed to search for free quarks near their production thresholds. If the current-quark masses for u, d quarks are smaller than the pion mass, $u\bar{u}$ and $d\bar{d}$ pairs produced below the pion pair threshold, would not have sufficient energy to hadronize and could be observable. In the case of large u,d quark masses and also for the heavy quarks, production near threshold may show hadronization probability $<1$, and lead to free quarks. Searches for fractional charges in stable matter could be more promising, through irradiation of samples at energies near the quark pair production thresholds.