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Λk femtoscopy in Pb-Pb collisions at sNN =2.76 TeV

Acharya, S ; Stenlund, Evert LU and Zurlo, N (2021) In Physical Review C 103(5).
Abstract
The first measurements of the scattering parameters of ΛK pairs in all three charge combinations (ΛK+, ΛK−, and ΛK0S) are presented. The results are achieved through a femtoscopic analysis of ΛK correlations in Pb-Pb collisions at √sNN=2.76 TeV recorded by ALICE at the Large Hadron Collider. The femtoscopic correlations result from strong final-state interactions and are fit with a parametrization allowing for both the characterization of the pair emission source and the measurement of the scattering parameters for the particle pairs. Extensive studies with the THERMINATOR 2 event generator provide a good description of the nonfemtoscopic background, which results mainly from collective effects, with unprecedented precision. Furthermore,... (More)
The first measurements of the scattering parameters of ΛK pairs in all three charge combinations (ΛK+, ΛK−, and ΛK0S) are presented. The results are achieved through a femtoscopic analysis of ΛK correlations in Pb-Pb collisions at √sNN=2.76 TeV recorded by ALICE at the Large Hadron Collider. The femtoscopic correlations result from strong final-state interactions and are fit with a parametrization allowing for both the characterization of the pair emission source and the measurement of the scattering parameters for the particle pairs. Extensive studies with the THERMINATOR 2 event generator provide a good description of the nonfemtoscopic background, which results mainly from collective effects, with unprecedented precision. Furthermore, together with HIJING simulations, this model is used to account for contributions from residual correlations induced by feed-down from particle decays. The extracted scattering parameters indicate that the strong force is repulsive in the ΛK+ interaction and attractive in the ΛK− interaction. The data hint that the ΛK0S interaction is attractive; however, the uncertainty of the result does not permit such a decisive conclusion. The results suggest an effect arising either from different quark-antiquark interactions between the pairs (s¯s in ΛK+ and u¯u in ΛK−) or from different net strangeness for each system (S=0 for ΛK+, and S=−2 for ΛK−). Finally, the ΛK systems exhibit source radii larger than expected from extrapolation from identical particle femtoscopic studies. This effect is interpreted as resulting from the separation in space-time of the single-particle Λ and K source distributions. (Less)
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author
; and
author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review C
volume
103
issue
5
article number
055201
publisher
American Physical Society
external identifiers
  • scopus:85106384742
ISSN
2469-9985
DOI
10.1103/PhysRevC.103.055201
language
English
LU publication?
yes
id
25dd8408-03c4-4c6a-b55d-155cb0222ab3
date added to LUP
2021-06-09 13:55:18
date last changed
2025-04-04 14:30:27
@article{25dd8408-03c4-4c6a-b55d-155cb0222ab3,
  abstract     = {{The first measurements of the scattering parameters of ΛK pairs in all three charge combinations (ΛK+, ΛK−, and ΛK0S) are presented. The results are achieved through a femtoscopic analysis of ΛK correlations in Pb-Pb collisions at √sNN=2.76 TeV recorded by ALICE at the Large Hadron Collider. The femtoscopic correlations result from strong final-state interactions and are fit with a parametrization allowing for both the characterization of the pair emission source and the measurement of the scattering parameters for the particle pairs. Extensive studies with the THERMINATOR 2 event generator provide a good description of the nonfemtoscopic background, which results mainly from collective effects, with unprecedented precision. Furthermore, together with HIJING simulations, this model is used to account for contributions from residual correlations induced by feed-down from particle decays. The extracted scattering parameters indicate that the strong force is repulsive in the ΛK+ interaction and attractive in the ΛK− interaction. The data hint that the ΛK0S interaction is attractive; however, the uncertainty of the result does not permit such a decisive conclusion. The results suggest an effect arising either from different quark-antiquark interactions between the pairs (s¯s in ΛK+ and u¯u in ΛK−) or from different net strangeness for each system (S=0 for ΛK+, and S=−2 for ΛK−). Finally, the ΛK systems exhibit source radii larger than expected from extrapolation from identical particle femtoscopic studies. This effect is interpreted as resulting from the separation in space-time of the single-particle Λ and K source distributions.}},
  author       = {{Acharya, S and Stenlund, Evert and Zurlo, N}},
  issn         = {{2469-9985}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{5}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review C}},
  title        = {{Λk femtoscopy in Pb-Pb collisions at sNN =2.76 TeV}},
  url          = {{http://dx.doi.org/10.1103/PhysRevC.103.055201}},
  doi          = {{10.1103/PhysRevC.103.055201}},
  volume       = {{103}},
  year         = {{2021}},
}