
ASYMMETRY IN EXPERIMENTS TESTING CPT IN ORTHOPS DECAY
Nevenka M. Antović, Sergey K. Andrukhovich
Pages: 177182
DOI: 10.21175/RadJ.2016.03.033
Received: 28 FEB 2016,
Received revised: 24 APR 2016,
Accepted: 29 APR 2016,
Published online: 26 DEC 2016
Abstract 
References 
Full Text (PDF)
Atom of positronium (Ps) – the bound state of an electron and a positron, has two ground states: singlet (paraPs) and triplet (orthoPs). In this paper we consider asymmetry in the CPT test experiments performed using polarized orthoPs decay. OrthoPs annihilates dominantly into three gamma rays with the continuous energy spectrum in the range (0511) keV. In searching for decays of orthoPs which violate CPT symmetry, the correlation was tested , where is the orthoPs spin, and , are the momenta of the two most energetic annihilation photons (E _{g1}E _{g2}E _{g3}). The experimental tests consisted in comparing the number of asymmetric decays of polarized orthoPs in two identical reflectionsymmetric geometries, and the angular correlation coefficient was calculated from the asymmetry (A). Using our previous results, as well as the results of the other researchers, we particularly discuss the tests carried out at the three and sevendetector system (A = 0.0017 ± 0.0017 and A = 0.0008 ± 0.00091, respectively), together with their measuring errors.
 W. Bernreuther, U. Low, J. P. Ma, O. Nachtmann, "How to test CP, T, and CPT invariance in the three photon decay of polarized ^{3}S_{1} positronium," Z. Phys. C, vol. 41, no. 1, pp. 143158, 1988.
DOI: 10.1007/BF01412589
 T. Yamazaki, T. Namba, A. Asai, T. Kobayashi, "Search for CP violation in positronium decay," Phys. Rev. Lett., vol. 104, no. 8, p. 083401, 2010.
DOI: 10.1103/PhysRevLett.104.083401
 P. A. Vetter, S. J. Freedman, "Search for CPTodd decays of positronium," Phys. Rev. Lett., vol. 91, p. 263401, 2003.
DOI: 10.1103/PhysRevLett. 91.263401." target="_blank"> 10.1103/PhysRevLett. 91.263401.
 P. A. Vetter, "Experimental tests of fundamental symmetries in positronium annihilation," Int. J. Mod. Phys. A, vol. 19, no. 23, pp. 38653878, 2004.
DOI: 10.1142/S0217751X04020130
 V. I. Goldanskii, Physical chemistry of positron and positronium, Science, Moscow, 1968 (in Russian).
 A. P. Mills, S. Berko, "Search for C nonconservation in electronpositron annihilation," Phys. Rev. Lett., vol. 18, no 11, p. 420, 1967.
DOI: 10.1103/PhysRevLett.18.420
 P. A. Vetter, S. J. Freedman, "Branchingratio measurements of multiphoton decays of positronium," Phys. Rev. A, vol. 66, no. 5, p. 052505, 2002.
DOI: 10.1103/PhysRevA.66.052505
 B. K. Arbic, S. Hatamian, M. Skalsey, J. Van House, W. Zheng, "Angularcorrelation test of CPT in polarized positronium," Phys. Rev. A, vol. 37, no. 9, pp. 31893194, 1988.
DOI: 10.1142/S0217751X04020130
 S. K. Andrukhovich, N. Antovich, A. V. Berestov, O. N. Metelitsa, "Test CPT in the decay of polarized positronium using multidetector spectrometer," Mater. Sci. Forum, vol. 363365, pp. 591593, 2001.
DOI: 10.4028/www.scientific.net/MSF.363365.591
 D. Kaminska et al., "Searches for discrete symmetries violation in orthopositronium decay using the JPET detector," Nukleonika, vol. 60, no. 4, pp. 729762, 2015.
DOI: 10.1515/nuka20150131
 N. Antović, “Investigation of rare positronium decays on multidetector gammacoincidence spectrometers,” PhD thesis, University of Belgrade, Faculty of Physics, 2000 (in Serbian).
 S. K. Andrukhovich, N. Antovich, A. V. Berestov, "A spectrometer for the study of angular correlations in polarizedorthopositronium decay," Instrum. Exp. Tech. vol. 43, no. 4, pp. 453459, 2000.
DOI: 10.1007/BF02758945
 V. G. Baryshevsky et al., "Observation of time oscillation in 3gannihilation of positronium in a magnetic field", Phys. Lett. A vol. 136, no. 78, pp. 428432, 1989.
DOI: 10.1016/03759601(89)904283
