Transverse spin correlation of back-to-back dihadrons in unpolarized collisions
Lei Yang, Yu-Kun Song, Shuyi Wei
Abstract
The spin correlation of back-to-back dihadrons emerges in unpolarized high-energy collision, empowering unpolarized experiments to shed light on the spin-dependent fragmentation functions. This work investigates the transverse spin correlation of back-to-back dihadrons in unpolarized <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:msup> <a:mrow> <a:mi>e</a:mi> </a:mrow> <a:mrow> <a:mo>+</a:mo> </a:mrow> </a:msup> <a:msup> <a:mrow> <a:mi>e</a:mi> </a:mrow> <a:mrow> <a:mo>−</a:mo> </a:mrow> </a:msup> </a:mrow> </a:math> , <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mi>p</c:mi> <c:mi>p</c:mi> </c:math> , and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mi>γ</e:mi> <e:mi>p</e:mi> </e:math> collisions, which serves as a novel probe of the chiral-odd fragmentation function <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:msub> <g:mi>H</g:mi> <g:mrow> <g:mn>1</g:mn> <g:mi>T</g:mi> </g:mrow> </g:msub> <g:mo stretchy="false">(</g:mo> <g:mi>z</g:mi> <g:mo stretchy="false">)</g:mo> </g:math> . We compute the transverse spin correlation at the partonic level and establish a connection with helicity amplitudes. Measuring this observable in future experiments can reveal valuable information on the hadronization of transversely polarized quarks.