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Int. Conference on Low Energy Antiproton Physics , Yokohama, Japan, March 3-7, 2003

Int. Conference on Low Energy Antiproton Physics , Yokohama, Japan, March 3-7, 2003 Positron Storage Ring for Positronium and Antihydrogen Generation in-flight. LEPTA Project. G. Trubnikov, JINR, Dubna. Introduction : Why Ps is so interesting?

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Int. Conference on Low Energy Antiproton Physics , Yokohama, Japan, March 3-7, 2003

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  1. Int. Conference on Low Energy Antiproton Physics, Yokohama, Japan, March 3-7, 2003 Positron Storage Ring for Positronium and Antihydrogen Generation in-flight. LEPTA Project. G. Trubnikov, JINR, Dubna

  2. Introduction: Why Ps is so interesting? 1. Ps is a simple quantum system - “Bohr atom in QED” 2. One can use Ps as a test particle for several experiments of fundamental character 3. There are some puzzles in Ps physics from previous experiments (o-Ps life time, for instance)

  3. Introduction: Why Ps is so interesting? 1. Electron cooling of positrons and Positronium generation 2.Test of CPT theorem, CP and P conservation 2.1. e+ / e- charge difference => the first and foremost experiment 2.2. Rare and forbidden decay channels of o-Ps and p-Ps 2.3. p-Ps => , search for circularly polarized photons 2.4. p-Ps => ~ 3. QED test , P-violation (?) 3.1. Positronium spectroscopy 3.2. p-Ps life time 3.3. o-Ps life time 4. Search for a light, neutral, short-lived boson 5. Hypothesis of "Mirror Universe" 6.Antihydrogen generation in-flight => => CPT theorem test (future development)

  4. W h e r e i s P o s i t r o n i u m f r o m ? ==> ==> L E P T A R i n g L o w E n e r g y P a r t i c l e T o r o i d a l A c c u m u l a t o r

  5. LEPTA scheme Septum e+ trap Collector e-gun e+ source Quadrupole Cooling section Detector B

  6. General parameters of the LEPTA Circumference, m 18.12 Positron energy, keV 10.0 Solenoid magnetic field, G 400 Quad field gradient, G/cm 10.0 Positron beam radius, cm 0.5 Number of positrons 110 Residual gas pressure, Тоrr 110 Electron cooling system Cooling section length, m 4.53 Beam current, A 0.5 Beam radius, cm 1.0 Electron density, cm-3 1.66108 Orthopositronium beam parameters Intensity, atom/sec 110 Angular spread, mrad 1 Velocity spread 1104 Flux diameter at the ring exit, cm 1.1 Decay length, m 8.52

  7. 2.Test of CPT theorem, CP and P conservation

  8. Directcomparison of the e- and e+ electric charges. The experiment concept: Detection of a displacement x of "neutral" atoms, when they travel in a transverse magnetic field B: The method resolution: If x~0.1 mm, BLm, one can obtain e/e < 410-10 The experiment scheme: decay = 8.5 m at vo-Ps=6 m/s

  9. Scheme of the detector based on MCP amplifier  CsI o-Ps CsI o-Ps  CsI Wedge and strip anode MCP Amplifier

  10. The scheme of the position sensitive silicon strip detector Silicon& strips 75 mm Scintillators o-Ps Strip dimensions: 40 mm length, 25 or 40 mcm width, space between strips 69 or 54 mcm

  11. 2.2. The search for forbidden and rare decay channels of o-Ps and p-Ps a) The forbidden and rare o-Ps annihilation channels o-Ps => 2n , n > 2, where n is an integer annihilation probability Theory Experiment o-Ps  2  0 < 1.4x10-3 o-Ps  4 < 10-27 < 0.8 x10-5 b) The forbidden and rare p-Ps annihilation channels p-Ps =>n , n > 2 ; n = 3 - «forbidden» , n = 4 - «allowed» annihilation probability Theory Experiment p-Ps  3  < 10-27 < 2.8x10-6 p-Ps  4 1.48x10-6 (1.50.07stat  0.09syst.)x10-6

  12.  The view in transverse plane tgphoton = 1/ o-Ps  ??? Co-ordinate detector  The search for “forbidden” and rare o-Ps annihilation channels o-Ps => 2n , n > 2, where n is an integer

  13.  ?? p-Ps The view in transverse plane tgphoton = 1/   ?? Magnet yoke Magnet coils Co-ordinate -detector p-Ps generation and decay in magnetic field The search for “forbidden” and rare p-Ps annihilation channels p-Ps =>n , n > 2

  14. B The view in transverse plane tgphoton = 1/  ?? p-Ps  ?? B Co-ordinate -detector Magnet coils Magnet yoke p-Ps generation and decay in magnetic field CPT violation search:p-Ps => , search forcircularly polarized photons with analysis by scattering in magnetized iron (iron = 14 mm for photons of 0.51 MeV energy)

  15.  M 1 e-e+  E1 PPs = (-1) x (+1) = -1 Pphotons= (-1)E1 x (+1)M1 = -1  if linear polarisation Pphotons= (-1)(E1+M1) x (-1)(M1+E1) = +1   if circular polarisation Parity violation CPT violation !

  16. 3. QED test 3.1. Positronium spectroscopy => => structure of Ps spectrum a) Fine structure of the ground state; o-Ps - p-Ps transitions in magnetic field b) Transition energy of different states c) Fine structure of excited states d) e+e- charges and masses from Ps spectrum

  17. 3.2. QED test: p-Pslife time Theory Experiment p-Ps life time, ps 125.16(08) 125.142(27) [2x10-4] A peculiarity: p-Ps decay length  3 cm a) generation of p-Ps by the mixing of o-Ps and p-Ps states in magnetic field B  2 T and direct measurement of p-Ps => => N(x) in a vacuum drift channel  => / 310-5 if x  1 mkm (“the absorption targets”); b) indirect method: - mixing of o-Ps - p-Ps states in B  0.4 T and detection of decays in 2 (p-Ps) and 3 (o-Ps), analysis of No-Ps(x) in magnetic field

  18. 3.2. QED test: o-Pslife time Theory Experiment o-Ps life time, ns 142.038141.880(32) [2x10-4] 142.150(80) [5x10-4] The Experiment Resolution: N(x) = N(0)exp{-x / v }, ln N(x)/N(0) = - kx Fitting with l.s.m gives us: Correspondingly, the  value ismeasured with a precision of : Thus, for  /  110 –5 we need  v / v ~  x / x  110 –5 N(0) ~ 1010 , Ntotal~ nN(0)/k0L ~ 0.6 nN(0) ~ 31010 It means the experiment duration ~ 3106 sec ~ 1.5 months

  19. The measurement of the o-Ps life time with o-Ps in-flight (Re)movable calibrationNa22 source  o-Ps  Annihilation in a target via para-state Reference and movable co-ordinate detectors x Semitransparent wheelImpermeable (re)movable plate

  20. If such a discrepancy does exist what can be a reason? A) Hypothesis of the light, neutral, short-lived boson B) Hypothesis of “The Mirror Universe”

  21. 4. Search for aprobable channel of o-Ps annihilation via a light, neutral, short-lived boson: o-Ps => + A0 , A0 => 2  . If mA0 =<1 MeV/sec2 => Probability (12.8)x10-5 for mA0 < 30 keV/sec2life < 10-13 (mA0c2)keV sec Branching ratio 10-3 10-5 10-7 2 3 1. U. Amaldi et al., Phys. Lett. B 153, 444 (1985) 2. S. Orito et al., Phys. Rev. Lett. v63, 597 (1989) 3. M. Tsuchiaki et al., Phys. Lett. B 236 (1990) 4. Akopyan et al., Phys. Lett. B 272, 443 (1991) 5. S. Asai et al., Phys. Lett. B 323, 90 (1994) 5 4 1 0 200 400 600 800 1000 mA0 (keV) The resultant upper-limits at 90% confidence level on the branching ratio of + A0 decay in comparison with the existing limits

  22. 5. Hypothesis of "Mirror Universe» The Basic Idea: I Kobzarev, L.Okun, I.Pomeranchuk, Yad. Fiz., 3 (1966) CP-violation L- particles (“usual”) R-particles (“mirror”) ( introduced by T.D.Lee and C.N.Yang in 1960) L- and R- particles can interact only by exchange with photons or gravitons . The idea of a test: S.Glashow, Phys. Letters 167B(1986)35 -Positronium as a test system .

  23. Antihydrogen generation in-flight => => CPT theorem test (future development) p~ AD (CERN) e H~ LEPTA e+ e

  24. We plan to obtain H0 flux of intensity of 104-105 atoms/sec Antiproton ring parameters : Experiments with H0 in flight: - Direct comparison of particle electrical charges - Microwave spectroscopy of the 2S-2P states of H0 - The atomic interferometer and Stern-Gerlah method. Spectroscopy of the 1S state - Laser spectroscopy of fast antihydrogen atoms

  25. Accuracies of the experimental values of the fundamental particles parameters

  26. November 2002 Work in progress

  27. The end. http://lepta.jinr.ru

  28. An interaction ofLeft o-Psand Right o-Ps : e e   o-Ps o-Ps e+ e+ What can be observed? One can detect o-Ps (“L-system”), however one can NOT detect o-Ps (“R-system”) The probability of “attendance” of o-Ps is equal to .  =   the o-Ps decay rate in Lab. Ref. Frame. S.Glashow: f, f  87 GHz, ?

  29. Estimations of  : S. Glashow (1986)  E.Carlson and S.Glashow (1987)  S.Gninenko (1994)  The Task for experiment: to measure the distribution The experiment resolution follows from here: Correspondingly, one has to provide at L = 10 m and  =  . Thus, parameters of the experiment #3.3 do fit the requirements!

  30. The data acquisition duration necessary for providing of the desirable resolution hours Detector type o-Ps direct o-Ps and/or annihilation detection -quanta detection Detector with MCP 50 500 Silicon strip detector 16 160

  31. B The view in transverse plane tg = 1/ ~?? p-Ps ?? B • Co-ordinate • -detectors Magnet coils Magnet yoke p-Ps generation and decay in magnetic field 2.4. p-Ps => ~ (???)

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