Physics goals NA49-future Experimental landscape

Transcription

1 New ion program at the CERN SPS M. Gazdzicki for NA49-future Frankfurt, Kielce Physics goals NA49-future Experimental landscape Based on Letter of Intent of NA49-future Collaboration: ''Study of Hadron Production in Collisions of Protons and Nuclei at the CERN SPS'', CERN-SPSC

2 Two main events in nucleus-nucleus collisions T Onset of Deconfinement: an early stage hits transition line, observed signals: kink, horn, step T Onset of Criticality: a freeze-out at critical point/line, expected signals: hill/dyke in fluctuations A en er gy µb E(OoD) 30A GeV 2 µb E(OoC)

3 Physics goals of the new SPS program Study the properties of the onset of deconfinement precision measurements Search for the onset of criticality a discovery potential 3

4 Study the properties of the onset of deconfinement AGS SPS(NA49) RHIC HORN Recent results on central heavy ion collisions suggest that the onset of deconfinement is located at snn 7 GeV STEP new questions 4 Data: NA49, RHIC, AGS Predictions: M.G., Gorenstein

5 AGS SPS RHIC new questions: -is it possible to observe the predicted signals of deconfinement in fluctuations and anisotropic flow? -what is the nature of transition from the anomalous energy dependence measured in heavy ion collisions to the smooth dependence seen in p+p interactions? experimental data needed to answer these questions are missing or are of insufficient precision! 5

6 Examples: fluctuations flow high precision data are needed to detect possible anomalies 6

7 the horn SMES predicts that the horn should be independent of the system size from central Pb+Pb to S+S collisions Is this prediction correct? 7

8 Search for the onset of criticality Freeze-out points of central heavy ion collisions at SPS are close to the phase boundary Its structure (1st order PT, 2nd order PT,..., a cross-over) can be studied experimentally HG fits: Becattini et al., Cleymans, Redlich et al. 8 CP: Fodor, Katz

9 p+p C+C Si+Si Pb+Pb at 158A GeV Freeze-out parameters depend on energy and system size ( s, A) (T,µB) An exciting possibility 9

10 Exciting possibility: Systematic scan in energy and system size may uncover the structure of the transition line (T,µB) domain accessible at SPS In particular, it may answer the question: does the critical point of SIM exist in nature and, if it does, where is it located? 10

11 Search for the critical point of strongly interacting matter Search for a maximum in fluctuations (n, pt), anisotropic flow,..., in the two-dimensional space, energy system size (A) A en er gy 11

12 Detecting the critical point (2nd order PT) hill of fluctuations t -ou e z ree f e lat O cr nse iti t o ca lit f y s as m r be m nu 12 gy r e en n o i t va r se n co gy r e n e ) V e G (A needed experimental data are missing!

13 The critical line (2nd and higher order PT) quark gluon plasma 3rd 2nd 1st hadrons 13 CL: Gorenstein, MG, Greiner

14 Detecting the critical line (2nd and higher order PT) t -ou e z ree f e lat O cr nse iti t o ca lit f y s as m r be m nu 14 of s e k dy ation ctu u l f gy r e en n o i t va r se n co gy r e en V) e (G needed experimental data are missing!

15 A+A at 158A GeV Data: NA49 PRC The hill? The dyke? Where is the onset? 15 needed detailed data are missing!

16 NA49-future today NA49-future = a proto-collaboration which intends to use the upgraded NA49 detector at the CERN SPS for: -measurements of hadron production in A+A collisions, in particular fluctuations and long range correlations, with the aim to identify the properties of the onset of deconfinement and search for the critical point of SIM -measurements of hadron production in p+p and p+a interactions needed as a reference data for better understanding of A+A reactions, in particular correlations, fluctuations and high transverse momenta will be the focus of this study -measurements of hadron production in hadron-nucleus interactions needed for neutrino and cosmic ray experiments 16

17 A+A data statistics NA49 NA49-future Pb+Pb In+In Si+Si C+C energy (A GeV) energy (A GeV) = registered collisions (area is proportional to the event number)

18 Beam requirements: beam energy (A GeV) #days 2006: protons : protons : hadrons : indium : silicon : carbon Ions for fixed target program at SPS possible only after the first, 2008, ion run at LHC 18

19 LHC NA49-future SPS 19

20 Existing NA49 facility: A large acceptance: 50% A high momentum resolution: 2 4 p / p 10 1 GeV / c A good particle identification: TOF 60 ps, de / dx / de / dx 0.04, minv 5 MeV 20

21 Planed basic upgrades: A. Replacement of the TPC read-out by an ALICE-like system: an increase of the event rate by a factor of about 20 to a time average 30 Hz B. Replacement of the VETO Calorimeter by a Projectile Spectator Detector: an increase of the resolution in the measurement of the number of projectile spectators by a factor 5 to E/E 50%/E, a possible determination of the reaction plane C. Reduction of the gap between left and right TPC chambers from 25 cm to 9 cm: an increase of the acceptance for vertex pions by 20% - 50% (depending on energy) to about 75% and 90% at 20A and 158A GeV, respectively 21

22 The NA49-future Collaboration: 80 physicists from 20 institutes and 14 countries: University of Athens, Athens, Greece University of Bergen, Bergen, Norway KFKI IPNP, Budapest, Hungary Cape Town University, Cape Town, South Africa Jagellionian University, Cracow, Poland Joint Institute for Nuclear Research, Dubna, Russia University of Frankfurt, Frankfurt, Germany Cern, Geneva, Switzerland Forschungszentrum Karlsruhe, Karlsruhe, Germany Swietokrzyska Academy, Kielce, Poland Institute for Nuclear Research, Moscow, Russia LPNHE, Universites de Paris VI et VII, Paris, France Pusan Natinal University, Pusan, Republic of Korea Faculty of Physics, University of Sofia, Sofia, Bulgaria St. Petersburg State University, St. Petersburg, Russia State University of New York, Stony Brook, USA IFC, IFIC, CSIC and Universidad de Valencia, Valencia, Spain Warsaw University of Technology, Warsaw, Poland University of Warsaw, Warsaw, Poland Rudjer Boskovic Institute, Zagreb, Croatia 22

23 Project status: Letter of Intent ''Study of Hadron Production in Collisions of Protons and Nuclei at the CERN SPS'', CERN-SPSC , submitted to the SPSC in January 2006 A one week long test run (p-beam) scheduled for August 2006 Submission of the proposal planed for November 2006 Two running R&D projects: -a high resolution Projectile Spectator Detector (INR Moscow, together with CBM), -semi-cylindrical GEM detectors (Gas Detector Development Group, CERN) 23

24 Experimental landscape 24

25 AGS SPS SIS RHIC RHIC-CP Onset of deconfinement at snn 7 GeV 25

26 Search for the critical point LHC RHIC SPS RHIC-CP 26 SIS NT

27 Physics of strongly interacting matter vs accelerators RHIC-CP 27

28 Physics comparison: SPS vs RHIC-SP SPS (NA49-future) RHIC-SP (STAR+...) energy (?)-200 acceptance 4π (inclusive) limited (e-by-e) mid-rapidity (inclusive) 2π mid-rapidity (e-by-e) event rate 30 Hz 1(?) Hz at low E centrality control a full measurement of Nprojspec (PSD) 28 (?)

29 NA49-future: -perfect for a fast energy-system size scan, -ideal to study fluctuations of extensive quantities, -unique possibility to measure total multiplicities RHIC-SP -very broad energy range, -full azimuthal coverage and forward-backward symmetry at mid-rapidity, -excellent for a study of anisotropic flow and other azimuthal correlations (e.g. at high transverse momentum) We need both NA49-future and RHIC-SP running soon 29

30 Summary Key questions concerning: properties of the onset of deconfinement precision measurements existence/location of the onset of criticality a discovery potential can be soon studied experimentally in a low cost and low manpower program: NA49-future at the CERN SPS This program is complementary to the other future ion projects at LHC, RHIC and SIS

31 l a n o i t i d d A 31 s e d i l s

32 Projectile Spectator Detector : 3 e l cm u od 20 m x1 D 0 PS 0x1 1 PSD 200 modules: E/E 50% / E(GeV), transverse non-uniformity < 5%, full functionality in the range GeV 32

33 Projectile Spectator Detector Centrality dependence of the scaled variance of multiplicity distribution in Pb+Pb at 158A GeV NA49 Veto limit NA49-future PSD limit 33

34 Projectile Spectator Detector transparency mixing reflection 0 target 34 y projectile

35 Semi-cylindrical GEM detector 35

36 Semi-cylindrical GEM detector The frame set used for the assembly: 36

37 Semi-cylindrical GEM detector Mechanical prototype in construction, using a precision temporary mandrel; electrodes are glued and assembled in sequence: 37

38 Semi-cylindrical GEM detector Completely assembled Triple-GEM cylindrical detector, with emulated readout connectors on its long side. Radius and length of the module are, respectively, ~10 cm and 30 cm, determined by the size of the GEMs used: 38

39 DAQ-a high event rate 39

40 TPC: Schematic view of the Vertex TPCs construction Decrease of the gap between left and right modules from 25 cm to 9 cm leads to a significant increase of acceptance 40

41 Acceptance for vertex pions of the modified TPCs 160A GeV 41 20A GeV

42 Acceptance for vertex pions of the modified TPCs 160A GeV 42 20A GeV

43 Needed improved measurements of flow will be possible Pb+Pb collisions at 40A GeV 43