Multiplicity dependence of (multi-)strange hadron production in proton-proton collisions at $$\sqrt{s}$$ = 13 TeV

Abstract

Abstract The production rates and the transverse momentum distribution of strange hadrons at mid-rapidity ( $$\left| y\right| &lt; 0.5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mfenced><mml:mi>y</mml:mi></mml:mfenced><mml:mo>&lt;</mml:mo><mml:mn>0.5</mml:mn></mml:mrow></mml:math> ) are measured in proton-proton collisions at $$\sqrt{s}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 13 TeV as a function of the charged particle multiplicity, using the ALICE detector at the LHC. The production rates of $$\mathrm{K}^{0}_{S}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup></mml:math> , $$\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Λ</mml:mi></mml:math> , $$\Xi $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Ξ</mml:mi></mml:math> , and $$\Omega $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Ω</mml:mi></mml:math> increase with the multiplicity faster than what is reported for inclusive charged particles. The increase is found to be more pronounced for hadrons with a larger strangeness content. Possible auto-correlations between the charged particles and the strange hadrons are evaluated by measuring the event-activity with charged particle multiplicity estimators covering different pseudorapidity regions. When comparing to lower energy results, the yields of strange hadrons are found to depend only on the mid-rapidity charged particle multiplicity. Several features of the data are reproduced qualitatively by general purpose QCD Monte Carlo models that take into account the effect of densely-packed QCD strings in high multiplicity collisions. However, none of the tested models reproduce the data quantitatively. This work corroborates and extends the ALICE findings on strangeness production in proton-proton collisions at 7 TeV.