Baryon CF paper at 3 GeV
Updated on Thu, 2024-06-27 12:17. Originally created by fuchuan on 2022-07-26 06:54.
Figures
Fig. 4: Left panel: Mid-rapidity (-0.5 < y < 0) source size parameter, shown as a function of collision centrality, for p-p and p−Λ pairs
from = 3.0 GeV Au+Au collisions. Solid and open symbols represent the results extracted from the LL fitting to experimental data and the UrQMD
calculations, respectively. A Gaussian type single particle space distribution is assumed in the LL fit. All source-size parameters are extracted as the
RMS of pair space distribution in the pair rest frame. For data, both statistical and systematic uncertainties are included in the plot but not visible.
Table 2: Scattering parameters (f0, d0) extracted with combined statistical and systematic uncertainties, from individual
and simultaneous fitting for p-p (left) and p−Λ (right) pairs. Individual fitting to data for different collision centralities from
three rapidity windows for p-p pairs, while only two rapidity windows for p−Λ (right) pairs due to the limitation in statistics.
Supporting-materials
p-p:
Title: Measurements of Proton-Proton, Proton-Λ and Proton-Ξ- Correlation Functions in √s_NN= 3 GeV Au+Au Collisions at RHIC
PAs: X. Dong, C. Fu, X.F. Luo, K. Mi, Z. Qin, Y.Q. Qi, S.S. Shi, Y.P. Wang, N. Xu, Z.G. Xiao, Y.J. Zhou
Target journal : Physical Review Letters
Paper draft : In preparation
Analysis note : https://drupal.star.bnl.gov/STAR/blog/fuchuan/pppLampXi-analysis-notes
Paper proposal : https://drupal.star.bnl.gov/STAR/system/files/BaryonCF_3GeV_paper_proposal_04_05.pdf
CVS codes on rcf:
Analysis note : https://drupal.star.bnl.gov/STAR/blog/fuchuan/pppLampXi-analysis-notes
Paper proposal : https://drupal.star.bnl.gov/STAR/system/files/BaryonCF_3GeV_paper_proposal_04_05.pdf
CVS codes on rcf:
Outline
- Abstract
- Motivation
- Figures
- Summary
- Supporting-materials
- Questions-in-PWGC-preview
Abstract
Important information on spatiotemporal extension and the final state interaction (FSI) of the source created in high-energy nuclear collisions can be extracted from the measurements
of two-particle correlations. It is well known that the interaction information of nucleon-nucleon, e.g. proton−proton (p-p), and proton-Λ (p-L), are basic ingredients for studying the
inner structure of compact stars.
of two-particle correlations. It is well known that the interaction information of nucleon-nucleon, e.g. proton−proton (p-p), and proton-Λ (p-L), are basic ingredients for studying the
inner structure of compact stars.
In this paper, we report the first results of baryon correlation functions (CF) for the pairs of p-p, p-Λ and p−Ξ- from 3.0 GeV Au+Au collisions at RHIC. The data was taken with the
fixed-target mode by the STAR experiment.
fixed-target mode by the STAR experiment.
With the Lednický-Lyuboshitz (LL) approach, scattering length f0 and effective range d0 for p-p and p-Λ pairs (spin-averaged) are extracted in different collision centrality and rapidity bins.
While the source parameters change according to collision centrality and rapidity bins, the scattering parameters of (f0, d0) are independent of either centrality nor rapidity within uncertainties.
In case of the p-p correlation function, the extracted scattering length f0 is in good agreement with the previously reported value.
A hadronic transport model UrQMD plus baryon interaction potentials calculations reproduce these correlation functions reasonably well.
A hadronic transport model UrQMD plus baryon interaction potentials calculations reproduce these correlation functions reasonably well.
Motivation
1, Measurements of p-p, p−Λ and p−Ξ- correlation functions in high baryon density region
2, Extraction of strong interaction parameters for p-p and p−Λ pairs
3, Source size extraction and the study on baryon dynamic information
Figures
Fig. 1: The density distributions in transverse momentum (pT) and particle rapidity (y) for proton (a), Λ (b) and Ξ- (c) in 3.0 GeV Au+Au collisions.
A momentum cut with p < 2 GeV/c is applied in proton selection by TPC. Correlation functions are measured within the pT-y regions shown by the box.
A momentum cut with p < 2 GeV/c is applied in proton selection by TPC. Correlation functions are measured within the pT-y regions shown by the box.
Fig. 2: Collision centrality dependence of the correlation functions for mid-rapidity (−0.5 < y < 0) pairs of p−p (left panel)
and p−Λ (middle panel) from 3 GeV Au+Au collisions. For p−Ξ- (right panel) correlation function, only 0-60% result is available
due to the limitation in statistics. Symbols, solid lines and dashed lines represent the results from experiment, fitting results of
Lednický-Lyuboshitz (LL) model and UrQMD model calculation, respectively. Vertical bar and band on data points represent statistical and
systematic uncertainty, respectively.
and p−Λ (middle panel) from 3 GeV Au+Au collisions. For p−Ξ- (right panel) correlation function, only 0-60% result is available
due to the limitation in statistics. Symbols, solid lines and dashed lines represent the results from experiment, fitting results of
Lednický-Lyuboshitz (LL) model and UrQMD model calculation, respectively. Vertical bar and band on data points represent statistical and
systematic uncertainty, respectively.
Fig. 3: Extracted strong interaction parameters (f0, d0) from p-p and p−Λ correlation functions in 3.0 GeV Au+Au collisions.
For p-p pairs, the resulting 3-σ contour-lines for 0-10% (dot-dashed line), 10-20% (short-dashed line), 20-40% (solid line) and
40-60% (dotted line) centrality bins and rapidity windows of [-0.5, 0] (blue), [-0.75, -0.5] (red) and [-1.0, -0.75] (gray) are shown
in the right and insert. For p−Λ pairs, due to limited statistics, only 1-σ contours from three centrality bins 0-10 % (dot-dashed line),
10-20% (short-dashed line), 20-60% (long dashed line) and two rapidity windows [-0.5, 0] (blue) and [-0.75, -0.5] (red) are shown.
Black stars and solid lines represent the results of combined fits: while the size parameters vary as a function of collision centrality and
different rapidity windows, only one set of the strong interaction parameter (f0, d0) is extracted for given sets of correlation functions.
For p-p pairs, the resulting 3-σ contour-lines for 0-10% (dot-dashed line), 10-20% (short-dashed line), 20-40% (solid line) and
40-60% (dotted line) centrality bins and rapidity windows of [-0.5, 0] (blue), [-0.75, -0.5] (red) and [-1.0, -0.75] (gray) are shown
in the right and insert. For p−Λ pairs, due to limited statistics, only 1-σ contours from three centrality bins 0-10 % (dot-dashed line),
10-20% (short-dashed line), 20-60% (long dashed line) and two rapidity windows [-0.5, 0] (blue) and [-0.75, -0.5] (red) are shown.
Black stars and solid lines represent the results of combined fits: while the size parameters vary as a function of collision centrality and
different rapidity windows, only one set of the strong interaction parameter (f0, d0) is extracted for given sets of correlation functions.
Fig. 4: Left panel: Mid-rapidity (-0.5 < y < 0) source size parameter, shown as a function of collision centrality, for p-p and p−Λ pairs
from = 3.0 GeV Au+Au collisions. Solid and open symbols represent the results extracted from the LL fitting to experimental data and the UrQMD
calculations, respectively. A Gaussian type single particle space distribution is assumed in the LL fit. All source-size parameters are extracted as the
RMS of pair space distribution in the pair rest frame. For data, both statistical and systematic uncertainties are included in the plot but not visible.
Right panel: Solid circles represent the final state strong interaction parameters (f0, d0) extracted from p-p and p−Λ correlation functions.
Open triangles represent the predictions from model calculations. Brown square denotes the value from low energy scattering experiment.
Open triangles represent the predictions from model calculations. Brown square denotes the value from low energy scattering experiment.
1-σ contours are shown for both p-p and p−Λ pairs.
Table 1: Source-size parameters, with combined statistical and systematic uncertainties, extracted from data and UrQMD calculations
for p-p (left) and p−Λ (right) pairs from different centrality and rapidity bins. The R_G is the assumed single particle Gaussian source size
parameter, and RMS_G is the corresponding RMS value from the pair rest frame.
for p-p (left) and p−Λ (right) pairs from different centrality and rapidity bins. The R_G is the assumed single particle Gaussian source size
parameter, and RMS_G is the corresponding RMS value from the pair rest frame.
Table 2: Scattering parameters (f0, d0) extracted with combined statistical and systematic uncertainties, from individual and simultaneous fitting for p-p (left) and p−Λ (right) pairs. Individual fitting to data for different collision centralities from
three rapidity windows for p-p pairs, while only two rapidity windows for p−Λ (right) pairs due to the limitation in statistics.
Simultaneous fitting to data and UrQMD from all centrality and three rapidity windows. Since d0 is not well constrained
for p−Λ pairs, the value is fixed in the simultaneous fit. Fixed d0 is from combined fitting to data from two rapidity windows,
and theoretical prediction value, for simultaneous fitting to data and UrQMD, respectively
for p−Λ pairs, the value is fixed in the simultaneous fit. Fixed d0 is from combined fitting to data from two rapidity windows,
and theoretical prediction value, for simultaneous fitting to data and UrQMD, respectively
Summary
First results of collision centrality and rapidity dependence of baryon correlation functions for p-p, p-Λ and p-Ξ- pairs from 3.0 GeV Au+Au collisions at RHIC are reported.
Using the LL-fitting formula, the parameters of the source size, scattering length f0 and effective range d0 for the pairs of p-p and p-Λ are extracted from different collision
centrality and rapidity bins As expected, the source size parameters vary with centrality and rapidity, showing the characteristic expansion dynamics in such collisions.
On the other hand, both values of (f0, d0) do not show any visible centrality and rapidity dependence.
centrality and rapidity bins As expected, the source size parameters vary with centrality and rapidity, showing the characteristic expansion dynamics in such collisions.
On the other hand, both values of (f0, d0) do not show any visible centrality and rapidity dependence.
For p-p pairs, the extracted spin singlet value of (f0, d0) are (7.02±0.03 fm, 3.41±0.23 fm). These are also found to be consistent within uncertainties with those from low energy
scattering experiment. For p-Λ pairs, the spin-averaged value of f0 is 2.34±0.1 fm. Because of the involvement of the strange quark, the scattering strength for p-Λ is much weaker
than that of p-p pairs. In case of p-Ξ- pairs, one could not determine the interaction parameters due to low statistics.
scattering experiment. For p-Λ pairs, the spin-averaged value of f0 is 2.34±0.1 fm. Because of the involvement of the strange quark, the scattering strength for p-Λ is much weaker
than that of p-p pairs. In case of p-Ξ- pairs, one could not determine the interaction parameters due to low statistics.
Calculations of transport model UrQMD with strong interaction potentials reproduced the measured correlation functions reasonably well.
This is the first time that the baryon interaction parameters are extracted in high-energy nuclear collisions. These new results provide important
information on the properties of the baryon strong interaction which is crucial for understanding the inner structure of compact stars.
information on the properties of the baryon strong interaction which is crucial for understanding the inner structure of compact stars.
Supporting-materials
p-p:
https://drupal.star.bnl.gov/STAR/system/files/Proton_CF_PWG_2020_1217.pdf
https://drupal.star.bnl.gov/STAR/system/files/QPT2021_Chuan_v7.pdf
https://drupal.star.bnl.gov/STAR/system/files/Proton_CF_CollaborationMeeting_Chuan_0916_v2.pdf
https://drupal.star.bnl.gov/STAR/system/files/BaryonCF_3GeV_CollaborationMeeting_Chuan_20220913.pdf
https://drupal.star.bnl.gov/STAR/system/files/Proton_CF_CollaborationMeeting_Chuan_2023_10_17.pdf
https://drupal.star.bnl.gov/STAR/system/files/pXi_CorrelationFunction_qm22poster_v5.pdf
https://drupal.star.bnl.gov/STAR/system/files/LambdaProton_CF_QinZhi_20220714.pdf
https://drupal.star.bnl.gov/STAR/system/files/pLambda_CF_Zhi_PWG20230601.pdf
https://drupal.star.bnl.gov/STAR/system/files/ProtonLambdaCF_LLFit_AuAu3GeV_QinZhi_20230826.pdf
https://drupal.star.bnl.gov/STAR/system/files/PWG_pLambdaCF_3GeV_Update_QinZhi_20240111.pdf
p-Ξ-:
https://drupal.star.bnl.gov/STAR/system/files/yingjie_20220217_3GeV_pXi.pdf
https://drupal.star.bnl.gov/STAR/system/files/yingjie_20220317_3GeV_pXi_v1_0.pdf
https://drupal.star.bnl.gov/STAR/system/files/pXi_CorrelationFunction_qm22poster_v5.pdf
https://drupal.star.bnl.gov/STAR/system/files/yingjie_20231214_pXi_update_0.pdf
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