Unveiling the effects of multiple soft partonic interactions in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mi>p</mml:mi></mml:math> collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13.6</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:mrow></mml:math> using a new event classifier

Abstract

Event classifiers based either on the charged-particle multiplicity or the event shape have been extensively used in proton-proton ($pp$) collisions by the ALICE Collaboration at the LHC. The use of these tools became very instrumental since the observation of fluidlike behavior in high-multiplicity $pp$ collisions. In particular, the study as a function of the charged-particle multiplicity registered in the forward V0 ALICE detector allowed for the discovery of strangeness enhancement in high-multiplicity $pp$ collisions. However, one drawback of the multiplicity-based event classifiers is that requiring a high charged-particle multiplicity biases the sample towards hard processes like multijet final states. These biases make it difficult to perform jet-quenching searches in high-multiplicity $pp$ collisions. In this context, the present paper explores the use of the new event classifier, flattenicity; which uses the multiplicity calculated in the forward pseudorapidity region. To illustrate how this tool works, pp collisions at $\sqrt{s}=13.6\text{ }\text{ }\mathrm{TeV}$ simulated with pythia 8 are explored. The sensitivity of flattencity to multipartonic interactions as well as to the ``hardness'' of the collision are discussed. pythia 8 predictions for the transverse momentum spectra of light- and heavy-flavored hadrons as a function of flattenicity are presented.

Topics & Concepts