Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes ...
-
Upload
lilian-moore -
Category
Documents
-
view
225 -
download
0
description
Transcript of Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes ...
![Page 1: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/1.jpg)
Oct23-2008論文セミナー
![Page 2: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/2.jpg)
Abstract
![Page 3: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/3.jpg)
Abstract
Au+Au √sNN=62.4GeV
mid-rapidity, 7 centrality classes mT spectra dN/dy
energy dependence (SPS, AGS data) yield (anti-Λ)/Λ ratio
![Page 4: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/4.jpg)
Introduction
strange particle production →collision でできた matter の情報
Why 62.4GeV? ->energy scan b/w SPS & RHIC 130,200GeV SPS : baryon dominated RHIC : net-baryon free
hope excitation function の情報 constrains to the thermal model predictions
![Page 5: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/5.jpg)
STAR experiment TPC (|y|<1.8):charged track SVT (|y|<1.) ,SSD (|y|<1.) :primary/secondary vertex SVT ,TPC : dE/dx を使用して PID
![Page 6: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/6.jpg)
experimental setup
Au+Au √sNN=62.4GeV (Run4)
mid-rapidity STAR detector(|y|<0.5) 6.5×106 events 7 different centrality classes
# of primary tracks(0-5% ~ 60-80%)
charged particle track : TPC -> PID
![Page 7: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/7.jpg)
reconstruction
neutral particle reconstruction : V0 decay topology method
K0(s)->π++π-
(anti-)Λ->(anti-)proton+(π+)π-
S/N improvement dE/dx information (daughter tracks) distance of closest approach (b/w daughter
tracks) some topological cuts
![Page 8: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/8.jpg)
vertex
ex a<0.5cm b>2.85cm c>0.90cm d>5cm
Λ
π
p
b
c
a d
![Page 9: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/9.jpg)
mT spectra & integrated yield
mT distribution
corrections geometrical acceptance detector inefficiency anti-proton absorption NOT contained weak decays of multi-strange
particles
fitting assuming flat rapidity distribution (|y|<0.5)
![Page 10: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/10.jpg)
mT spectra & integrated yield
![Page 11: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/11.jpg)
integrated yield integrated yield
〈 Npart 〉 ← Glauber model
integrated yield / 〈 Npart 〉 enhancement of strangeness
production as a function of centrality
normalized @ most peripheral bin
same enhancement pattern with SPS experiment
earlier saturation point
![Page 12: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/12.jpg)
Energy dependence of yield & ratio
yield of mid-rapidity anti-Λ : monotonic increase Λ : constant Λ : different b/w SPS & RHIC
anti-Λ/Λ ratio @RHIC energy ratio~1
![Page 13: Oct23-2008 論文セミナー. Abstract Au+Au √s NN =62.4GeV mid-rapidity, 7 centrality classes m T spectra dN/dy energy dependence (SPS, AGS data) yield.](https://reader033.fdocuments.net/reader033/viewer/2022051008/5a4d1b657f8b9ab0599af861/html5/thumbnails/13.jpg)
conclusions
strange hyperon production @62.4GeV new point in excitation function
integrated yield / ratio relatively smooth behavior with energy non-identical particle ratio に重要 (Λ/π, K/π)
typical strangeness enhancement