Hyperfine splitting effects in string hadronization
Christian Bierlich, Smita Chakraborty, Gösta Gustafson, Leif Lönnblad
Abstract
Abstract We revisit the recipe for hadron formation in the Lund string hadronization model. Given an incoming quark or quark-diquark pair, weights for hadron formation are updated to take hyperfine splitting effects arising from the mass difference between $$\mathrm {u,d}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>u</mml:mi> <mml:mo>,</mml:mo> <mml:mi>d</mml:mi> </mml:mrow> </mml:math> -type and $$\mathrm {s}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>s</mml:mi> </mml:math> -type quarks. We find that the procedure improves the description of hadron yields in $$\mathrm {e}^+\mathrm {e}^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>e</mml:mi> </mml:mrow> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mrow> <mml:mi>e</mml:mi> </mml:mrow> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> collisions and the $$\phi $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>ϕ</mml:mi> </mml:math> cross section in neutral current DIS. We also show results for proton collisions, and discuss the future use of this study in the context of small system collectivity.