TY - JOUR

T1 - Underlying-event studies with strange hadrons in pp collisions at $$\sqrt{s} = 13$$ TeV with the ATLAS detector

AU - The ATLAS collaboration

AU - Ali, Hanadi

AU - Alsolami, Zainab

AU - Barton, A.E.

AU - Borissov, G.

AU - Bouhova-Thacker, E.V.

AU - Ferguson, Ruby

AU - Ferrando, James

AU - Fox, H.

AU - Hagan, Alina

AU - Henderson, R.C.W.

AU - Jones, R.W.L.

AU - Kartvelishvili, V.

AU - Love, P.A.

AU - Marshall, E.J.

AU - Meng, L.

AU - Muenstermann, D.

AU - Ribaric, N.

AU - Sampson, Elliot

AU - Smizanska, M.

AU - Spinali, S.

AU - Wharton, A.M.

PY - 2024/12/29

Y1 - 2024/12/29

N2 - Properties of the underlying-event in pp interactions are investigated primarily via the strange hadrons $$K_{S}^{0}$$ K S 0 , $$\Lambda $$ Λ and $$\bar{\Lambda }$$ Λ ¯ , as reconstructed using the ATLAS detector at the LHC in minimum-bias pp collision data at $$\sqrt{s} = 13$$ s = 13 TeV. The hadrons are reconstructed via the identification of the displaced two-particle vertices corresponding to the decay modes "Equation missing", $$\Lambda \rightarrow \pi ^-p$$ Λ → π - p and $$\bar{\Lambda }\rightarrow \pi ^+\bar{p}$$ Λ ¯ → π + p ¯ . These are used in the construction of underlying-event observables in azimuthal regions computed relative to the leading charged-particle jet in the event. None of the hadronisation and underlying-event physics models considered can describe the data over the full kinematic range considered. Events with a leading charged-particle jet in the range of $$10 < p_T \le 40$$ 10 < p T ≤ 40 GeV are studied using the number of prompt charged particles in the transverse region. The ratio $$N(\Lambda + \bar{\Lambda })/N(K_{S}^{0})$$ N ( Λ + Λ ¯ ) / N ( K S 0 ) as a function of the number of such charged particles varies only slightly over this range. This disagrees with the expectations of some of the considered Monte Carlo models.

AB - Properties of the underlying-event in pp interactions are investigated primarily via the strange hadrons $$K_{S}^{0}$$ K S 0 , $$\Lambda $$ Λ and $$\bar{\Lambda }$$ Λ ¯ , as reconstructed using the ATLAS detector at the LHC in minimum-bias pp collision data at $$\sqrt{s} = 13$$ s = 13 TeV. The hadrons are reconstructed via the identification of the displaced two-particle vertices corresponding to the decay modes "Equation missing", $$\Lambda \rightarrow \pi ^-p$$ Λ → π - p and $$\bar{\Lambda }\rightarrow \pi ^+\bar{p}$$ Λ ¯ → π + p ¯ . These are used in the construction of underlying-event observables in azimuthal regions computed relative to the leading charged-particle jet in the event. None of the hadronisation and underlying-event physics models considered can describe the data over the full kinematic range considered. Events with a leading charged-particle jet in the range of $$10 < p_T \le 40$$ 10 < p T ≤ 40 GeV are studied using the number of prompt charged particles in the transverse region. The ratio $$N(\Lambda + \bar{\Lambda })/N(K_{S}^{0})$$ N ( Λ + Λ ¯ ) / N ( K S 0 ) as a function of the number of such charged particles varies only slightly over this range. This disagrees with the expectations of some of the considered Monte Carlo models.

U2 - 10.1140/epjc/s10052-024-13243-1

DO - 10.1140/epjc/s10052-024-13243-1

M3 - Journal article

VL - 84

JO - European Physical Journal C: Particles and Fields

JF - European Physical Journal C: Particles and Fields

SN - 1434-6044

IS - 12

M1 - 1335

ER -