Strangeness Production and Aggregation in Nuclear Matter ...
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Strangeness Production and Aggregation in Nuclear Matter Searching for Kaonic Clusters Our Experimental Strategy Present and Future Strangeness Production in heavy ion collisions Perspectives Laura Fabbietti Die seltsame Welt von Hieronymus Bosch Laura Fabbietti
Transcript of Strangeness Production and Aggregation in Nuclear Matter ...
Strangeness Production andAggregation in Nuclear Matter
Searching for Kaonic ClustersOur Experimental Strategy
Present and FutureStrangeness Production in heavy
ion collisionsPerspectives
Laura Fabbietti
Die seltsame Welt von Hieronymus Bosch
Laura Fabbietti
Our Research
Search for Kaon-Nucleon bound states (Kaonic Clusters) in p+p@3GeVreactions
* p+p --> ppK- + K+
* Construction of a Trigger made of Silicon Dectors p+p --> ppK- + K+ --> + p +K+
* Construction of a GEM-TPC Detector as a Vertex Tracker
Study of Strangeness production in heavy ion and elementary reactions
* K+ K- Production below threshold in heavy ionreactions (1-4AGeV) to study the interaction ofstrange particles with dense and hot nuclear matter
* Recoiless Production in -induced reactionsto study in-Medium properties K+K-
K+
Does such a Strange object exist?
Physics Motivation
p p p pKaon
Do Kaon-Nucleon (deeply)-bound systems exist?
If yes, which density, binding energy and width do they have?
Phasendiagramm der Kernmaterie
Tc ~ 170 MeV
~ 5-10 0
Quark-Gluon Plasma
Kernmaterie Neutronsterne
Urknall
Dichte
Tempe
ratu
r
LHC
FAIR
(1405)= ?K-p
p+p: short range interaction (r<0.3fm)
R( *-p)~1.45 fm assisted by a large momentum transfer
T. Yamazaki et T. Akahishi, Phys. Rev. C 76 (2007) 045201
ppK- production in p+p reactions
p+p ' (1405)‘+p+K+
ppK-+K+
+p +p
- + p + +p
Missing Mass &
Invariant Mass
(1405)
p+p ‚ (1405)‘+p+K+
+p+K+
0 n + - p 0 -
p - 0
Missing Mass>M 0
: Sig = 194 S/B = 3.7 FWHM= 11 MeV P = 4.6*10-4
Trigger Concept
Trigger: Online Comparison of theMultiplicity on si Vio A and si Vio B.
silicon Vertexing and identification online
si Vio A si Vio B
CDC
Annular:1 Detector32 Segments
Patchwork:8 Detectors 40x60 Strips
Trigger Concept
Trigger Electronics
Signals N-Side PreamplifierShaper &Multiplicity Trigger
si Vio TriggerData
Acquisition
Data
Signale
APV25Amplifier
+ Multiplexer
Signals P-Side
FOPI Level 1Trigger
Common Trigger
Requirements:Fast Trigger which can select a chosen hit multiplicity on the silicons Mesytec shaper with ‚fast‘ trigger output (150 nsec after physics)
E12: TUM M Böhmer L Maier
Testing Si Vio
FOPI TRIGGER
FOPI TRIGGER + Si ViO
Si ViO A : 1-2Si ViO B : 2-4
Reduction: >14
Trigger on MIPs with a Threshold of 220 keV
Goal: Discard the events without a decayAnalysis of the real content in the data is in progress.
# H
its o
n s
iV
io A
# Hits on si Vio B# H
its o
n s
iV
io A
# Hits on si Vio B
M. Berger et al. (NIM) in preparation
Main Experiment
3 GeV Proton BeamLiquid H2 TargetBeam Intensity: 5x106 Hz3 weeks beam in October 2009
LH2
TargetVetocounter
Startcounter
Beammonitor Silvio
Status:All Detectors are readyPlan of a third Silicon layer to improve the tracking: Si Vio C 10 Silicons, only APV25 readout.
Expected Signal
Background
p+p @ 3 GeV with FOPI
Simulation of the ppK- Signal and Background.
Probability of the Signal 1/10.000!
p p
ppK- Signal
Spectra expected after 3 weeks of measurements.
Final Signal/Background Ratio: 3/100!
DISTO Results
P. Kienle and T. YamazakiarXiv:0810.5182v1 nucl-ex
p+p (2.4eV)--> K++p+ +...
GEM-TPC for elementary reactions
What? Where?
Why? How and When?
Experimental proposal by B. Ketzer andL.Fabbietti accepted by the GSI PAC03.2008 -->52 parasitic shifts cave B
Gem TPC
Test in Bonn:Elektron beamMomentum: 600 – 800 MeVRate: 500 Hz
Test Prototype read-out with 6x4 T2K Chipswith 64 Channels each.
First Detector Board to test the Read-Outelectronics and study the spatial resolution asa function of the pad geometry.1532 Pads, 2 Sizes:773 Pads with 1.5 mm Radius759 Pads with 1.25 mm Radius
E18-TUM: B. Ketzer, C. Höppner
Gem TPC
50mm
150m
m
Front-End electronics on the Readoutboard.
Readout with 42x4 T2K Chips with 64Chan. each.10417 Pads with 1.5 mm Radius.The Board is currently been developed.
Test des Gem TPC Prototype with FOPI
E18-TUM: B. Ketzer, C. Höppner, I. KonorovGSI: Detector Lab.
Readout
ADC
Input stage
• reads the ADC
• computes average
values
• performs pedestal
subtraction
• writes to
intermediate FIFOs
.
.
.
FIFO
#1
FIFO
#2
FIFO
#16
Output stage
• reads the FIFOs
• performs zero
suppression
• writes to 16
output FIFOs
Pedestals
(block memory)
Clock,
Trigger,
Time
Thresholds
(block memory)
B
U
S
out
out
Hot-Link
Interface
FIFO
(averages)
FIFO
(frame)
T2K Readout Architecture
out
E18-TUM: I. Konorov
T2K based readout
Data ADC cardT
rig
ger
GeSiCA
(ROC)HOT
Link
S-Link
cardFrontend
n-XYTER based readout
DataSysCore
(ROC)Ethernet
Frontend
(self-triggered)
Alternative Readout
E18-TUM: I. Konorov
GSI: Detector Lab.
K- Production in Heavy Ion Collisions
K+
K-
c 10-15 fm/c K- Production via Strangeness Exchange:
Dominant mechanism K- ?,
K- and K+ multiplicity scales similarly
NN YK+N E
th=1.58GeV
Y NK
A. Foerster et al., Phys. Rev. C75 024906 2007
On the other hand we have measured:
Which translates in:
K= 0.37 ± 0.13
18 ± 6% K-stemming from Decay.
This can be considered as a lower limit, since we would not see K± decaying inmedium even if the width would be modified ( in vacuum: )c 46 fm /c
How are K- producted below threshold in heavyion collisions?
A. Agachikiev et al. (PRC) in preparation
Kaon Identification
S/B:
K+: 1.1 - 35.6
K- : 0.5 - 4.1
< mK
± >= 485 MeV /c2
K± = 20 MeV /c
2
TOF
Tofino
M. Lorenz [email protected]
Strangeness Suppresion ?
PRELIMINARY
H. Oeschler, K Redlich
Au+Au:
B. Holzman (E917) Nucl. Phys. A 698 (2002)643-646.
S.V. Afanasiev et al. (NA49) Phys. Lett. B 491(2000) 59.
J.Adams et al. (STAR) Phys. Lett B 612 (2005) 181-189
Decay channels of (1405)
Channel 1:
Channel 2:
Channel 3
Channel 4
+++++ n)1405(
+++++ n)1405(
++++
0)1405( p
(1405)0
+0
+ + + p + + + +
2104
10483
2772
15841
Expected yield of (1405)Channel
(1405) =10μb
TOT (p + p) = 40 mb
Total Statistics collected by HADES: 1.2 * 109 evt
Simulation to estimate the geometrical acceptanceof the exclusive measurement of the decaychannels.
TOF Reconstructor
No Start Detector available for high rate proton beamsCalculation of a new START time via the ‘Leading particle’ Method.Therefore one identified Particle is needed.Using MDC/TOF/TOFINO dE/dx information the PID is set.
Simulation
Missing Mass of each K+p pair.
p + p p + K+
+
p + K+
+0(1193)
p + K+
+0(1385)
p + K+
+0(1385)
p + K+
+ (1405)
Experimental Data
Cut on Kaon Momentum: p>500MeV/c Structure in-between known resonances? Something new?Investigations are going on.
preliminary
Summary
New experimental Method to study the production of ppK- in p+pCollisions
siLVio Trigger working
GEM-TPC being developed
Future Campaigns with FOPI
/K- Ratio measured with HADES
(1405) in the [email protected] HADES Data
ppK- in the HADES data?
Tons of experiments in 2009-2010 :)
The Group
Matthias
Martin RobertEliane
Laura
Olaf
Alex
Johannes
Alexander
