1. Goal: to investigate baryonic matter at low T and large B by means of rear probes
dielectrons penetrating probes
 emissivity, in medium hadron properties
strangeness production : , K , 0 ,  ,  0 ( ) , - (1321) (- ct=4.91cm) ,  - (K- ct=2.46 cm)
neutral mesons , , , 0
Strategy:
Reference measurements in N +N
A+A and p+A at 4-12 AGeV
bridge to CBM at SIS AGeV (FAIR)
L. McLerran, R.D. Pisarski 2007
experiment: chemical freeze-out
RHIC BES
SPS
Begun, Gazdzicki, Gorenstein, arXiv: v2
CBM
Fair
FAIR
HADES

3. AGS: Si+Au (Pb) 14.6 AGeV
neutral mesons ; , , not measured , (large error)
Triple strange baryons : 

4. Data on strangeness
P. Erice 2012

5. Flow data
2-6 GeV flow measured only for protons

6.  meson and flow

7. Double strange - (1321)
data: PRL 103 (2009)
 production significantly larger then transport model (UrQMD) and statistical model predictions
Note that also  is enhanced and  is not suppressed at all  all have ss(bar) content !
SHM: S. Wheaton, J. Cleymans,
Comp. Phys. Comm. 180 (2009) 84
data: EPJA 47 (2011) 21
640 MeV below NN threshold !
P.Salabura

8. Low Mass e+e- Excess in URHiC
Pb-Au(8.8 AGeV)
Calculations:R. Rapp et al..
Au-Au min. bias
QM12
Pb-Au(17.3GeV)
consistent description with “universal” medium effect
around Tpc
excess below VM pole seems to rise as beamenergdecreases

9.  -meson in hot and dense matter
Data : Na60 acceptance corrected : EPJC 59 (2009) 607
Calculations: Hess/Rapp: NPA806(2008)339.
„baryons”
pion loop
direct  - N* /
SPS
rB /r0
0.1
0.7
2.6
 - /N* couplings play dominant role in „rho” melting
Do these effects contribute to e+e- production at low energies?

10. Neutral mesons from pp(A) at 12 GeV/c

11. Summary Cu
QM2005:
KEK PS-E325 measured e+e- and K+K- invariant mass distributions in 12GeV p + A reactions.
Significant enhancement was seen on the e+e- invariant mass distributions at the low-mass side of the f meson peak in the Cu data, in bg < 1.25 region.
This observation is comparable to the model calculation including in-medium mass modification.
We observed the signature of the in-medium mass modification both in f and r / w mesons.
Result of
r/w  e+e- Cu

12. Acceptance vs Ebeam

13. Occupances vs Ebeam