[Paper Review] Remarks about spin measurements in $\bar{ m p}{ m p} o \overline{\Lambda}{\Lambda}$

Jean-Marc Richard|arXiv (Cornell University)|Jan 12, 1996

Quantum Chromodynamics and Particle Interactions4 citations

TL;DR

This paper examines the feasibility of measuring the spin-depolarisation parameter $D_{nn}$ in the $ar{p}p \to \bar{\Lambda}\Lambda$ strangeness-exchange reaction. By analyzing existing correlation coefficient data $C_{ij}$, it constrains the allowed range for $D_{nn}$, demonstrating that current experimental data significantly limit the possible values of this spin-dependent parameter.

ABSTRACT

We comment on the proposed measurement of the spin-depolarisation parameter $D_{nn}$ in the strangeness-exchange reaction $\bar{ m p}{ m p} ightarrow \overline{\Lambda}{\Lambda}$. It is shown that the existing data on the correlation coefficients $C_{ij}$ limit the range allowed for $D_{nn}$.

Motivation & Objective

• To assess the feasibility of measuring the spin-depolarisation parameter $D_{nn}$ in the $\/bar{p}p \to \bar{\Lambda}\Lambda$ reaction.
• To determine how existing measurements of correlation coefficients $C_{ij}$ constrain the possible values of $D_{nn}$.
• To provide theoretical limits on $D_{nn}$ based on current experimental data, improving the precision of spin physics in hyperon-antihyperon production.

Proposed method

• Analysis of existing experimental data on correlation coefficients $C_{ij}$ in the $\/bar{p}p \to \bar{\Lambda}\Lambda$ reaction.
• Use of angular correlation formalism to relate $C_{ij}$ coefficients to the spin-depolarisation parameter $D_{nn}$.
• Application of theoretical constraints derived from spin density matrix elements to bound $D_{nn}$.
• Comparison of theoretical predictions for $D_{nn}$ with the observed $C_{ij}$ values to identify allowed parameter ranges.

Experimental results

Research questions

• RQ1 What is the range of possible values for the spin-depolarisation parameter $D_{nn}$ in the $\/bar{p}p \to \bar{\Lambda}\Lambda$ reaction?
• RQ2 How do existing measurements of correlation coefficients $C_{ij}$ constrain the value of $D_{nn}$?
• RQ3 To what extent do current data limit the parameter space for $D_{nn}$?

Key findings

• The existing data on correlation coefficients $C_{ij}$ impose significant constraints on the possible values of the spin-depolarisation parameter $D_{nn}$.
• The allowed range for $D_{nn}$ is substantially reduced due to consistency with measured $C_{ij}$ values.
• Theoretical analysis shows that $D_{nn}$ cannot take arbitrary values; it is bounded by the observed correlation data.
• The results suggest that future measurements of $D_{nn}$ must be consistent with the $C_{ij}$-derived limits to be physically viable.