Future Experiments with HADES at FAIR

Pavel Tlustý, NPI Řež

• “near future”

- experiments on SIS18 in 2010-2015?

- upgrade of the HADES spectrometer • experiments with HADES on SIS100 at FAIR in 2016-

CHIRAL 2010 workshop, Valencia, June 21-24, 2010 June 24, 2010

2

2.2 GeV (2004)

„Anomalous” excess of e+e- pairsat intermediate masses verify DLS data

NN bremsstrahlungand Dalitz decays

vector mesons / in-medium

p+p

Resonance (,N*) production, formfactors and studies of / Dalitz decays (helicity angles)

C+C

2.0 AGeV (2002)

1.0 AGeV (2004)

1.

p+p

1.25 GeV (2006)

d+p

1.25 GeV (2007)

2.

Ar+KCl

1.76 GeV (2005)

Evolution of e+e- yieldStrangeness: , K±,0,

3.

3.5 GeV (2007)

p+Nb

3.5 GeV (2008)

p+p 4.

Completed physics program

3

Yield/Apart

Ar+KClCa+Ca

Observed systematics of “excess"

Scales with Ebeam like production Scales with Apart stronger than

linear:

≈ <Apart>1.4

“Excess” vs. beam energy and system size

Vector mesons

• larger system – better precision needed for differential studies• reference spectrum (NN)- peripheral reactions, d+p, ?• can one see in-medium effects on vector meson?

5

Ar+KCl data compared to IQMD

K0 - N potential

Data compared to the IQMD. Version with potential preferred.Consistent with KN-potential with a strength of U=39 MeV @ =0

extrapolation from high density to 0 (IQMD)

+A & p+A data (FOPI & ANKE)

consistent with U = 205 MeV at =0 extrapolation from low density to 0 (HSD)

Kaon flow

2cos2cos21 21 vvddN

sideward out-of plane(eliptic)

Y. Shin et. al. (KAOS)PRL 81 (1998) 1576

W. Cassing et al., NPA 727 (2003) 59, E. Bratkovskaya, priv. com.Coupled channel G-Matrix approach (K- spectral functions): L. Tolos et al., NPA 690 (2001) 547

K+

Kaon flow

2cos2cos21 21 vvddN

sideward out-of plane(eliptic)

W. Cassing et al., NPA 727 (2003) 59, E. Bratkovskaya, priv. com.Coupled channel G-Matrix approach (K- spectral functions): L. Tolos et al., NPA 690 (2001) 547

M. Płoskon, PhD Thesis, Univ. Frankfurt 2005

Physics Program on SIS18 – Heavy Ions

combined measurement of dielectron and strangeness production

in heavy systems

• Dielectrons: Studies of properties of the low-mass, i.e. 0.14 < Me+e− < 0.5

GeV/c2 dielectron excess Vector meson (ρ/ω/φ) spectroscopy in the dielectron channel

• Strangeness: φ meson production via the K+K− decay channel K0, K+ and K− production characteristics by means of transverse

momentum, rapidity and flow measurements Studies of strange baryon production: Λ(1115),Σ(1385) and Ξ−(1321) Search for kaonic clusters Studies of HBT correlations

9

Hades Upgrade ProjectAim: heavy systems at SIS18 and SIS100

RPC performance (beam test) Efficiency above 95 % Time res. 50-80ps Negligible crosstalk < 1%

List of HADES upgrade subprojects:

RPC - Resistive Plate Chamber FINISHED Time res. 50-80ps, high granularity

Forward Wall FINISHED range 0.2 – 7 degrees, reaction plane

DAQ-Upgrade (RICH, MDC, FWALL, TOF, SHOWER) goal 20kHz for Au+Au LVL1 ON GOING MDC I rebuild system stability FINISHED

End of 2010: HADES ready for heavier systems

Multipurpose Trigger Readout Board TRB:4 TDC – 128 channels (HPTDC), 4x512Mb SDRAM, FPGA – Virtex4LX40,

ETRAX, FS – 4 processors, 100Mb/s,TCP/IP, 2,5 Gb/s optical link, DSP TigerSharc, DC/DC converters,

10

Simulations – tracking study

Tracking ready to be used in high multiplicity environment

Secondary vertex reconstruction not ready

Tracking optimization on-going

to be verified with HI beam

11

A Large excess (~8) expected from Ar+KCl excess scaling above the NN reference

Differential studies of excess possible: centrality, dN/dmt , angular distributions…

Triggers for peripheral and central reactions. Use peripheral reactions for a

comparison with the NN reference.

(pp+pn)/2

Dalitz

o

baryonic radiation

Collision systems for HI runs:Highest possible energy

high VM and strangeness production

Largest possible colliding systems

increase compression and medium effects

Au(71+) - 1.25 AGeV - similar to pp, np data

Ag(46+) – 1.65 AGeV - comparable with Ar+KCl

(1.75 AGeV)

Medium effects for intermediate masses

12

Sensitivity to medium effects for VM

VM in HI coll. : regeneration and absorption - Ne+e- ~ e+e- Tfireball

HSD + Dropping mass & mass broadenning

AGeVAGeV

AGeV

trigger (25% ot total cross section) with 10 KHz

• Ag+Ag : maximal density VM production rate• direct comparison to Ar+KCl possible

Strangeness : count rate estimates

• counts/day for semicentral LVL1 assuming efficiencies & production rates from ArKcl• 20-100 more than in ArKcl ~ ! ! ! - acc(RPC) x trigger rate (no LVL2 )

Simulations: strangeness K- identification

acceptance purity (no dE/dx used)

• large acceptance: mid rap. coverage• very good K- purity up to pt < 800 MeV/c

Beam/target and Trigger setting, Shift request

• Two beam/target combinations 197Au + 197Au at 1.25 A GeV

107Ag + 107Ag at 1.65 A GeV

• Beam intenisty ~2*107/spill(5s)

• 1% interaction target (12 segments)• LVL1 trigger settings (~20 kHz total): minimum-bias semicentral (25% total cross section) • Shift request:

Au + Au 35 + 5 days (120 shifts)

Ag + Ag 45+ 5 days (150 shifts)

16

FAIR facility at GSISIS100 beam energies: ions up to 14 A GeV (Au79+ – 11.2 AGeV) protons up to 29 GeV

Module Construction time (months)

Ready for installation

0 72 2015 / 16 1 28 2015 / 16 2 60 2016 3 60 2016

B. Sharkov+1 year+1 year

17

HADES/CBM cave design

W. Niebur

18

Di-electrons at SIS100 (2-10 AGeV), motivation

No di-electron data exist in this energy range Extension of the HADES physics program Enhance production of Vector Mesons:

SIS18 SIS 100 subthreshold production above threshold better signal, precise line shape determination reference data for SIIS300

S. Vogel et al.Phys. Rev. C78 044909 (2008)

2AGeV

11AGeV

30AGeV

HADES at SIS100: - running experiment, well understood performance - currently conducted upgrade will improve stability, DAQ and time resolution of the Spectrometer - easy transfer to FAIR, experienced crew - can deliver high quality data

19

Di-electrons at SIS 100 e+e− acceptance

Acceptance for di-electrons from ω->e+e− (2 AGeV and 8 AGeV)

Direct ω decay: PLUTO, ω from thermal model Single leptons filtered with HADES acceptance 90 opening angle cut was applied

Acceptance:2 AGeV 33 %8 AGeV 21 %

Number of 's in acceptance increase by a factor of ~50

20

Di-electrons at SIS 100 – invariant mass

Di-electron invariant mass for various systems:( C+C 2 AGeV and 8 AGeV, Au+Au 1 AGeV and 8 AGeV )

All dilepton sources generated by PLUTO, hadronic and electromagnetic decays Single leptons filtered with HADES acceptance Lepton momentums smeared 90 opening angle cut was applied

1.0 AGeV

Realistic simulationin preparation

21

Hadrons at SIS 100 – acceptanceURQMD and PLUTO events filtered with HADES acceptance

midrapidity covered at both 2.0 and 8.0 AGeV 15 % reduction at 8 AGeV for π 40 % reduction at 8 AGeV for K

8 A GeV

2 A GeV

22

Occupancy estimation at 8 AGeV

Simulated events Central Au+Au at 1.5 AGeV and 8 AGeV, C+C at 2.0 AGeV and 8 AGeV HGeant used for a realistic detector modeling

Main outcome From C+C at 2.0 AGeV Au+Au at 1.5 AGeV (SIS18) - factor of 14 At Au+Au at 1.5 AGeV expected 20% double hit probability !!!

corresponds to Ni+Ni at 8 AGeV - heaviest system at SIS 100

23

Calorimeter project For pair excess determination a precise knowledge of the hadronic cocktail is needed (particle yields at chemical freeze-out)

At 2-40 AGeV mainly dominated by η-Dalitz Normalization to π0 (at SIS18 – TAPS data)

Calorimeter for HADES π0, η measurement improved pion suppression

Side View

START

Electromagnetic calorimeter for HADES (2011- ...) substitute for Pre-Shower (18º<Θ<45º, 8 m2;18 tons) el/ separation, º and η Dalitz, ...

24

Calorimeter project

Millstones achieved: Test at MAMI, lead glass modules from OPAL

energy resolution for photons K. Lapidus, Eliane Epple, simulation the parameterization lookup table almost ready, detailed, fast simulation will be possible Mechanical construction – general concept ready, approved by HADES construction engineer, U. Kopf

5.4% / sqrt(E)

25

Calorimeter projectMillstones achieved: Measure the pion rejection and compare

this to the simulation HADES ECM test in CERN T10 (F.Guber), HADES – NA61 collaboration May 24 - 31.

Millstones to be achieved: FE electronics pi0 reconstruction in beam test

26

Summary and outlook Di-electron radiation from the HI collision at SIS 18 is being investigated in a very systematic, model independent way.

No medium effects observed for light systems (C+C) The "reference spectrum" based on elementary reactions established

for heavier systems (Ar+KCl) First VM signal measured at SIS 18 in Ar+KCl collisions Modification of the meson properties in-medium (p+Nb) under investigation

Interesting physics program for future proposals of HADES at SIS 18( Au+Au, Ag+Ag, − beam )

SIS100 – a natural way of the physics programme extension The device is ready to take high quality data Easy installation at SIS 100 VM produced above the production thresholds High acceptance for direct decays of VM over whole energy

regions of SIS 18 and SIS100 (from 33 % at SIS 18 to 22 % at SIS100) Waiting for FAIR . . . 2016-2017 ....

27

The HADES CollaborationCyprus:Department of Physics, University of Cyprus

Czech Republic:Nuclear Physics Institute, Academy of Sciences of Czech Republic

France:IPN (UMR 8608), Université Paris Sud

Germany:GSI, DarmstadtFZ Dresden-RossendorfIKF, Goethe-Universität FrankfurtII.PI, Justus Liebig Universität GiessenPD E12, Technische Universität München

Italy:Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del SudIstituto Nazionale di Fisica Nucleare, Sezione di Milano

Poland:Smoluchowski Institute of Physics, Jagiellonian University of Cracow

Portugal:LIP-Laboratório de Instrumentação e Física Experimental de Partículas

17 institutions120members

Russia:INR, Russian Academy of ScienceJoint Institute of Nuclear ResearchITEP

Spain:Departamento de Física de Partículas, University of Santiago de CompostelaInstituto de Física Corpuscular, Universidad de Valencia-CSIC

28

Backup slides

Kaonic Nuclear clustersStat. model predictions for cluster formation in Au-Au collisions

promising candidate ?: K- pp system

• predictions from theory : 20-70 MeV binding

energy , hadronic decay into p• experimental evidences : FINUDA K- absorption on nucleus M (p) = 2255±7 MeV/c2 , = 67 ± 14 MeV/c2

M. Agnello et al., PRL 94, 212303 (2005).

DISTO p + p -> K+ + X X-> p

MX = 2265 ± 2 (stat) ± 5 (syst) MeV/c2 X = 118 ± 8 (stat) ± 10 (syst) MeV/c2

RMS radius of (p) < 1.7 fm !

Y. Yamazaki et al..arXiv:1002.3526

  

• R. Kotte : (p) source in ArKcl

but no sensitivity to p potential and ..no signal in p inv. mass visible

30

Experiments with pion beamsThe GSI secondary pion beam

line

Mom. det. of the beam particles with precision 0.3% for exclusive reconstruction Tracking in the beam line needed: silicon strip detector

31

Pion beam project - beam detectors

Beam tracking Si detectors (TU Munich) Two 10cm x 10 cm sensors (P-Type) arrived,

Radiation hard 1 Megarad level – to be verified !!! Electronics designed by W.Koenig, partially produced,

2 versions will be tested at Munich:- discreet version, TRB based system Robert Münzer - nXyter version: Rafal Lalik

32

Di-electrons from π− induced reactions at SIS18

M.E

ffen

berg

er e

t al.

nucl

-th/9

9010

39

π−+ A – inclusive ω measurement

-p boundn e+e-n;

pe+e-< 300 MeV/c; „at rest”

Exclusive measurement • large cross-section

off-shell ρ/ω coupling to S11(1535) and D13(1550) M.Soyeur et al., nucl-th/0003013

- p (ω/ρ)n e+ e- n − selection of ρ and ω − η-> e+ e-, π0π0, ... suppression by missing mass technique.

Beam particle tracking is essential, in preparation

cGeVpmbnptot /3.1@5.2 =

cGeVpmbXpp ptot /5.3@4.0

cut on missing mass of e+ e- (nutron ); e+e- suppressed!