eunhee kim 1,2 for hyphi collaboration 2 1 seoul national university, 2 gsi, germany
DESCRIPTION
Hyp ernuclear Spectroscopy with H eavy I on Collisions (HypHI) The HypHI Phase 0 experiment at GSI. Eunhee Kim 1,2 for HypHI collaboration 2 1 Seoul National University, 2 GSI, Germany. ND2010 29April2010. L 0. S -. d. s. X -. d. u. s. s. d. d. s. s. s. s. W -. - PowerPoint PPT PresentationTRANSCRIPT
Hypernuclear Spectroscopy with Heavy Ion Collisions (HypHI)
The HypHI Phase 0 experiment at GSI
Eunhee Kim1,2
for HypHI collaboration2
1 Seoul National University,2 GSI, Germany
1 ND2010 29April2010
Hypernuclei: Laboratory for baryon-baryon interaction with hyperon
In order to understand baryon-baryon interaction under flavor SU(3), we need to investigate interactions involving nucleons and hyperons. Information of NN(nucleon-nucleon) interactions mainly
obtained from NN scattering experiments. Lack of information on YN(hyperon-nucleon) and YY(hyperon-
hyperon) interactions
Difficulties to study YN and YY interactions by reaction experiments No hyperon target available due to short lifetime (Y ~ 10-10 s) Impractical to produce hyperon beams with proper energy
Hypernuclei are bound nuclear system with hyperon. Hypernuclei can be used as a micro-laboratory to study YN and YY
interactions.
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Interests in hypernuclear physics Structure and decay of hypernuclei at extreme isospin
Isospin dependence of YN and YY interactions Hypernuclear magnetic moments
Property of hyperons in nuclear medium
Hypernuclear radii Stability of hypernuclei
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Not possible with conventional hypernuclear spectroscopy
via the (K-, -), (+, K+) and (e, e’K+) reactions.
A project of hypernuclear spectroscopy
with heavy ion induced reactions on a stable target nucleus,
the HypHI project.
Reachable with heavy ion collisions.
HypHI project
Projectile
Target
Hot participant zone
Projectile fragment
Hypernucleus
Hypernuclear production in the HypHI project
Energy threshold ~ 1.6 GeV for production (NN → ΛKN)
- Stable heavy ion beams and RI beams with up to 2 AGeV can be achieved at GSI.
The produced hypernucleus has as large velocity as the projectile fragment.
Large Lorentz factor ( > 3) → longer lifetime → Hypernucleus in flight A new doorway for hypernuclear spectroscopy
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HypHI at GSI/FAIR: Concept of experiments
Time-of-Flight detectorsTrackersN-detectorK+ counter
Magnet
n
Residues
p,
K
-Hypernucleus
Mesonic weak decay : → -pNon-mesonic weak-decay: p → np
Produced hypernucleus close to projectile velocity Large Lorents factor > 3 c ~ 20 cm at 2 A GeV
target
Magnet
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Present hypernuclear landscape
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Known hypernuclei
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Phase 1 (2009-2017) at GSIProton rich hypernuclei
Known hypernuclei104 /week103 /week
Hypernuclear landscape with HypHI
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Phase 1 (2009-2014) at GSIProton rich hypernnuclei
Hypernuclear landscape with HypHI
Known hypernuclei104 /week103 /week
Phase 1 (2009-2017) at GSIProton rich hypernuclei
Phase 2 (2017-) at R3B/FAIRNeutron rich hypernuclei
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Hypernuclear landscape with HypHIPhase 1 (2009-2014) at GSIProton rich hypernnuclei
Phase 1 (2009-2017) at GSIProton rich hypernuclei
Phase 3 (201X-) at FAIRHypernuclear separator
Known hypernuclei104 /week103 /weekWith hypernuclear separatorMagnetic moments
Phase 2 (2017-) at R3B/FAIRNeutron rich hypernuclei
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Hypernuclear landscape with HypHI
Known hypernuclei104 /week103 /weekWith hypernuclear separatorMagnetic moments
Phase 0 experiment in 2009: Demonstrate the feasibility of precise hypernuclear spectroscopy with heavy ion beams (6Li beam at 2 A GeV on 12C target) Known hypernuclei
104 /week103 /weekWith hypernuclear separatorMagnetic moments
Phase 1 (2009-2014) at GSIProton rich hypernnuclei
Phase 1 (2009-2017) at GSIProton rich hypernuclei
Phase 3 (201X-) at FAIRHypernuclear separator
Phase 2 (2017-) at R3B/FAIRNeutron rich hypernuclei
Phase 0 experiment To demonstrate the feasibility of the experimental methods of the HypHI project
with 6Li beams at 2 A GeV by producing and identifying light hypernuclei
3H → 3He + -
4H → 4He + -
5He → 4He + p +
-
▶ Beam: 6Li at 2 A GeV with an intensity of 5 x106 /s▶ Active Target : 12C with a thickness of 8 g/cm2
⊙ magnet direction
(0.75 T)
3days in Aug. and 11days in Oct. 2009
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ALADiN magnet
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(0.75 T)
TOF start (Time-of-flight start)
▶ For beam particles▶ Plastic fingers + small PMTs
: 1 MHz beam rate per finger▶ Time resolution: ~ 200 ps
5cm
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Scintillating fiber detectors
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▶ 4352 fibers with a diameter of 0.83 mm
▶ HAMAMATSU H7260KS MOD readout
▶ X and Y tracking : Position resolution: 0.46 mm (RMS)
▶ For secondary vertex triggerD. Nakajima, B. Özel-Tashenov et al., Nucl. Instr. and Meth. A 608 (2009) 287
TR0 TR1 TR2
3.8cm
3.8cm 24.5cm
11.3cm
13.2cm
7.6cm
Drift chambers
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24cm 14cm
120cm
90cm
Small DCBig DC
▶ Wire plane: xx’vv’uu’▶ Drift length: 2.5mm▶ Typical resolution(RMS): 0.30
mm
▶ Gas: Ar 70% + CO2 30%
▶ Insensitive in beam region by wrapping seinse wires with teflon
▶ Wire plane: XX’YY’U▶ Drift length: XY 4.5mm, U 9.0mm ▶ Typical resolution(RMS): XY 0.30 mm, U
0.40mm
▶ Gas: Ar 70% + CO2 30%
▶ Insesitive in beam region by connectiing sense and potential wires
ALADiN TOF wall
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▶ For -
▶ Plastic scintillators(96 bars)+ PMTs▶ Time resolution: ~ 200 ps ▶ Y position calculated by the
difference between top and bottom TDCs.
110cm
240cm
Big TOF wall (TFW)
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▶ For -
▶ X and Y layers (18 bars + 14 bars)
▶ Time resolution: ~ 200 ps (RMS)
150cm
188.5cm
TOF + wall
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▶ For and proton▶ Plastic scintillators (16 bars × 2
layers) with a hole for beam + PMTs
▶ Time resolution: 357±3 ps (FWHM)
▶ Energy resolution : 18 % (FWHM)
1m
96cm
hole : 7.5x6.5 cm2
Problems and improvement of Phase 0 Problems of Phase 0 experiment
Low efficiency of - detection
in ALADiN TOF wall Many events for scattering
particles
from TOF+ holding structure
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Phase 0.5 experiment▶ Study of heavier hypernuclei ▶ Beam: 20Ne at 2 A GeV with an intensity of
6 x105 /s ▶ Target : 12C with a thickness of 8 g/cm2
▶ Performed in March 2010
Improvement of setup in March
Movement of ALADiN TOF wall toward behind TOF+ wall- Cross-check positively charged particles with high energy deposition
Movement of Big DC closer to Big TOF - Avoid improper operation from much high multiplicity caused by 20Ne beam- Remove the background events from TOF+ holding structure
Phase 0.5 experiment
14 days in Mar. 2010
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▶ Beam: 20Ne at 2 A GeV with an intensity of 6 x105 /s to study light and heavier hypernuclei together ▶ Active Target : 12C with a thickness of 8 g/cm2
upstream
downstream
Experimental performance Phase 0 with 6Li beams
Multiplicity in TR1
QDC in TOF+
Phase 0.5 with 20Ne beams Multiplicity in TR1
QDC in TOF+
p
Li
CNe
O
p
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People working for HypHI Phase 0/0.5 GSI Helmholtz-University Young
Investigators Group VH-NG-239 S. Bianchin O. Borodina (Mainz Univ.) V. Bozkurt (Nigde Univ.) B.Göküzüm (Nigde Univ.) E. Kim (Seoul Nat. Univ) A. Le Fevre D. Nakajima (Tokyo Univ.) B. Özel C. Rappold (Strasbourg Univ.) T.R. Saito (Spokes person)
Mainz University P. Achenbach, J. Pochodzalla
GSI HP2 and Mainz University F. Maas, Y. Ma
GSI HP1 W. Trautmann
GSI EE department J. Hoffmann, K. Koch, N. Kurz, S. Minami, W.
Ott, S. Voltz
GSI Detector Lab. M. Träger, C. Schmidt
KEK T. Takahashi, Y. Sekimoto
KVI M. Kavatsyuk
Kyoto University T. Nagae
Osaka University S. Ajimura, A. Sakaguchi, K.Yoshida
Osaka Electro-Communication University T. Fukuda, Y. Mizoi
Tohoku University T. Koike, H.Tamura
Seoul National University H.Bhang, K. Tanida, M.Kim, C.Yoon, S.Kim
Nigde University S.Erturk, Z.S.Ketenci
Theoretical support T. Gaitanos (Giessen), E. Hiyama (RIKEN), D.
Lanskoy (Moscow), H. Lenske (Giessen), U. Mosel (Giessen)
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