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ATLAS measurement of the two-particle correlation sensitivity to jets in $pp$ collisions

Measurements of two-particle correlations in $pp$ collisions show the presence of long-range correlations along $\Delta\eta$ that are strikingly similar to those seen in heavy-ion collisions. In larger systems, the long-range correlations are known to arise from the collective dynamics of the produc...

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Detalles Bibliográficos
Autor principal: Yin, Pengqi
Lenguaje:eng
Publicado: 2022
Materias:
Acceso en línea:http://cds.cern.ch/record/2806544
Descripción
Sumario:Measurements of two-particle correlations in $pp$ collisions show the presence of long-range correlations along $\Delta\eta$ that are strikingly similar to those seen in heavy-ion collisions. In larger systems, the long-range correlations are known to arise from the collective dynamics of the produced quark-gluon plasma (QGP). The similarity between the $pp$ and heavy-ion measurements raises the possibility that a tiny droplet of the QGP is produced even in $pp$. However, models that attribute the correlation in $pp$ collisions to semi-hard processes can qualitatively reproduce the measurements. Thus performing the $pp$ measurements with distinguishing particles associated with semi-hard processes, such as low-$p_{\mathrm{T}}$ jets, can further elucidate the origin of the long-range correlations. This talk presents new measurements of two-particle correlations in $pp$ collisions at $\sqrt{s}=13$~TeV with two different particle pair selections. In the first case, tracks associated with jets are excluded from the correlation analysis. This case results in a minor influence on the magnitude of the long-range correlation. In the second case, the two-particle correlations are measured between jet constituents and the underlying-event tracks. In this case, the correlations show no ridge-like structure.