Observation of Excess $\Lambda(\bar{\Lambda})$ Production in Two-Photon Processes at TRISTAN

TL;DR

This study measures $ ext{Lambda}(ar{ ext{Lambda}})$ production in two-photon processes at TRISTAN, finding cross sections twice as large as leading-order predictions, indicating the need for more advanced theoretical models.

Contribution

First inclusive measurement of $ ext{Lambda}(ar{ ext{Lambda}})$ production in two-photon processes at TRISTAN, highlighting discrepancies with leading-order theory.

Findings

Measured cross sections are twice as large as theoretical predictions.

Data suggests the importance of next-to-leading-order calculations.

Results provide new insights into baryon production in two-photon interactions.

Abstract

We have carried out inclusive measurements of $\Lambda(\bar{\Lambda})$ production in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV and the integrated luminosity was 265 pb$^{-1}$. Inclusive $\Lambda (\bar{\Lambda})$ samples were obtained under such conditions as no-electron, anti-electron, and remnant-jet tags. The data were compared with theoretical calculations. The measured cross sections are two-times larger than the leading-order theoretical predictions, suggesting the necessity of next-to-leading-order Monte-Carlo generator.