Anti-Nuclei in Relativistic Nuclear Collisions: Results and Expectations

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1 Makutsi-Symposium, Nov. 20 Anti-Nuclei in Relativistic Nuclear Collisions: Results and Expectations Reinhard Stock, Goethe University Frankfurt

2 Content Nuclei and Anti-Nuclei in A+A collisions - - Early observations of Coalescence at Bevalac Deuteron & Anti-Deuteron at SPS, NA49 - Anti-3 He and - 4 He at RHIC, STAR - Strange Nuclei: 3 He and 3 He at RHIC, STAR Λ Λ Formation of Nuclei: From primordial p, n, p, n nuclei The statistical model Coalescence ratios Outlook: beyond Anti-4 He?!

3 Early Data Bevalac , LBL-GSI-Collaboration a) 20 Ne + U p, d, t, 3 He, 4 He at 0.4 GeV/nucleon b) 20 Ne + U d... to 2 C, 4 N at 0.4 and 2.0 GeV/nucleon Coalescence Mechanism: Butler-Pearson 96 in p+p@ps, CERN Mechanism: primordial p and n in phase-space internal wave-functions of light nuclei About 20-40% of primordial nucleon yield coalesces to light nuclei Much lower fraction at higher energies

4 s VOLUME $7, NUMBER 3 SEPTEMBER 976 Final-State Interactions in the Production of Hydrogen and Helium Isotopes by Relativistic Heavy Ions on Uranium* H. H. Gutbrod Geseltschagt gr Schteerionenforschung, Dannstadt, Germany, and Lanrence Berkeley Laboratory, Berkeley, California A,. Sandoval I'aehbexeieIE I'hysN, Vnivexsitat Maxbuwg, Maxbmg, Germany, and Lasexenee Berkeley Laboratory, Berkeley, California P. J. Johansen, g A. M. Poskanzer, J. Gosset, t W. G. Meyer, and G. D. Westfall Lan+ence Bet'keley Laboratory, Berkeley, California R. Stock Eachbezeieh J%;ysik, Univewsitat Maxbuwg, Marbuxg, Germany (geceived 3 July 976) r r [ ~ f I I i i r I (j t He He. 30' 60' 90' 400 MeV/nucl. 3Qo 60 30' 90' QO I I I.. I I I.. I b 0 I\ Id = 0. 30' 60' 90' 20' 00 Qo 'He 30' 60' 4He -: 250 MeV/nucl EI~b (MeV/nucl. )

5 PH YSICAL REVIE% C VOLUME 6, N UMBER 2 AUG UST 977 Central co&casions of relativistic heavy iona* J. Gosset, ' H. H. Gutbrod, %. G. Meyer, A. M. Poskanzer, A. Sandoval, R. Stock, and G. D. %estfa La~rence Berkeley Laboratory, Berkeley, California 94720, Gesellschaft fiir Schwerionenforschung, Darmstadt, Germany, and Fachbereich Physik, Universitat Marburg, Marburg, Germany (Received 3 May 977) The energy spectra of protons and light nuclei produced by the interaction of 'He and ' Ne projectiles with Al and U targets have been investigated at incident energies ranging from 0.25 to 2. GeV per nucleon. Single fragxnent inclusive spectra have been obtained at angles between 25' and 50', in the energy range from 30 to 50 MeV/nucleon. The multiplicity of intermediate and high energy charged particles was determined in coincidence with the measured fragments. In a separate study, fragment spectra were obtained in the evaporation energy range from "C and ' Ne bombardment of uranium. We observe structureless, exponentially decaying spectra throughout the range of studied fragment masses. There is evidence for two major classes of fragments; one with emission at intermediate temperature from a system moving slowly in the lab frame, and the other with high temperature emission from a system propagating at a velocity intermediate between target and projectile. The high energy proton spectra are fairly well reproduced by a nuclear fireball model based on simple geometrical, kinematical, and statistical assumptions. Light cluster emission is also discussed in the framework of statistical models. I IO'= Ucl. IO 2 b cl IO~= 4J CL Io-6= IO 7= G~ I l l p (MeV/c) 3500

6 Deuterons and Anti-Deuterons at the SPS, NA49 Central Pb+Pb d or d + X s = 7.3 GeV FT Principle: Combination of TOF with specific ionization, de/dx, in Time Projection Chamber de/dx (a.u.) a) 3 2 d d b) p d m 2 (GeV 2 /c 4 ) 2 4 m 2 (GeV 2 /c 4 )

7 AFT d 2 N/(p t dp t dy) (GeV -2 c 2 ) d 2 N/(p t dp t dy) (GeV -2 c 2 ) d a) p x x 0. x 0.0 x c) x 0. x p t (GeV/c) -3 x d b) x 0. x 0.0 p d) x x 0. x p t (GeV/c) AFT dn/dy Gaussian (calculated parameters) Gaussian (antiproton coalescence) cosh(2y) (proton coalescence) d x d y NA49@SPS at the SPS, NA49 Central Pb+Pb p, d, p, d s = 7.3 GeV

8 E A d 3 N A d 3 P FT Coalescence at the SPS = B A ( d 3 N p E p d 3 p ) Z ( d 3 N n E n d 3 p ) A Z B - 2 (GeV2 /c 3 ) -2-3 FT d Central collisions E864 Au+Pb NA49 Pb+Pb NA52 Pb+Pb NA44 Pb+Pb STAR Au+Au BRAHMS Au+Au PHENIX Au+Au 2!s (GeV)

9 Up to Anti- 4 He STAR@RHIC, Au+Au A, A at s = 200 GeV STAR TPC Nature 473:353,20 arxiv:3.332 [nucl-ex]

10 Up to Anti- 4 He with STAR STAR@RHIC, Au+Au A, A at s = 200 GeV Principle: Combination of TOF with specific ionization, de/dx, in Time Projection Chamber

11 Up to Anti- 4 He with STAR STAR@RHIC, Au+Au A, A at s = 200 GeV What is Antimatter? Those who say that antihydrogen is antimatter should realize that we are not made of hydrogen and we drink water, not liquid hydrogen -- Dirac Quoted from A. Zichichi (2008) Antiparticles and antimatter: the basic difference. Annihilate with normal matter! +,! " are each other s antiparticle 2. Nuclear force 3. Relatively long lifetime 3

12 Up to Anti- 4 He with STAR STAR@RHIC, Au+Au A, A at s = 200 GeV

13 A and A Formation in the Statistical Hadronization Model A. Andronic, P. Braun-Munzinger, J. Stachel, H. Stöcker, Phys. Lett. B 697 (20) 203, arxiv:.2995 Assumptions: p, p, n, n are produced at hadronic freeze-out. At RHIC we have T 65 MeV, μb 20 MeV This fixes the total nucleus/anti-nucleus yields Total entropy per baryon is fixed here D. Hahn, H. Stöcker. Nucl. Phys. A 452 (986) 723 All hadronic species multiplicities, including light nuclei, form a Grand Canonical Ensemble the Statistical Model

14 Statistical Model Results I A. Andronic, P. Braun-Munzinger, J. Stachel, H. Stöcker, Phys. Lett. B 697 (20) 203, arxiv:.2995 dn/dy 2 s NN =200 GeV - Data + - " " STAR PHENIX BRAHMS 2 Model,! /N df =3.6/2 3 T=64 MeV, µ b = 24 MeV, V=950 fm + K K - p p # # $ - $ + %& d d K* '* * 3 3 # He/ He

15 Statistical Model Results II Ratio A. Andronic, P. Braun-Munzinger, J. Stachel, H. Stöcker, Phys. Lett. B 697 (20) 203, arxiv: p/p #/# d/d 3 3 He/ He 4 4 He/ He 2 3 s NN (GeV)

16 Statistical Model Results III A. Andronic, P. Braun-Munzinger, J. Stachel, H. Stöcker, Phys. Lett. B 697 (20) 203, arxiv:.2995 events 6 Yield (dn/dy) for He, He 4 4 He, He 3! H 5!! H 6!! He He 7!! " s NN (GeV)

17 Coalescence View Ratios from mass two to four follow very well from p/p ratio

18 Outlook Hypernuclei: Ratio -2 3! ! H/ 5!! H/! 6!! He/!!! " 7He/! Antinuclei: From 3 He to 4 He: each further unit increment in A requires about 500 times more (experiment efficiency) x (accelerator luminosity) Second generation experiments at RHIC and LHC s NN (GeV) Figure 5. Energy dependence of hypernuclei to Λ yield ratios. A Topic for FAIR