References - Bogoliubov Laboratory of Theoretical Physics - JINR

of photons). This polarization dependence provides the opportunity to determine spin of
produced particle P in the experiments with longitudinally polarized photons.
Figure 3: σ(γγ → P + P − )
πα2 /M 2 , nonpolarized photons, and
P
σ(e+ e− → γ∗ → P + P − )
πα2 /M 2 P
The polarization of produced fermion or vector P depends on the initial photon helicity.
At the P decay this polarization is transformed into the momentum distribution of decay
products. E.g., for the SM processes like γγ → μ + μ − + neutrals (obtained from muon
decay modes of γγ → WW, γγ → τ + τ − , etc.) muons should exhibit charge asymmetry
linked to the polarization of initial photons – see [7]. These studies can help to understand
the nature of candidates for Dark Matter particles.
The possible CP violation in the Pγ interaction can be seen as a variation of cross
section with changing the sign of both photon helicities (like in fig. 1).
This paper was supported by grants RFBR 08-02-00334-a, NSh-1027.2008.2 and Program
of Dept. of Phys. Sc. RAS ”Experimental and theoretical studies of fundamental
interactions related to LHC.”
References
[1] I.F. Ginzburg, G.L. Kotkin, V.G. Serbo, V.I. Telnov. Nucl. Instr. Meth. 205 (1983)
47–68; I.F. Ginzburg, G.L. Kotkin, S.L. Panfil, V.G. Serbo, V.I. Telnov. Nucl. Instr.
Meth. 219 (1983) 5; V. Telnov. hep-ex/0012047
[2] I.F. Ginzburg, G.L. Kotkin, V.G. Serbo, in preparation
[3] B. Badelek et al. TESLA TDR hep-ex/0108012
[4] E. Witten, Nucl. Phys. B120 (1977) 189.
[5] I.F.Ginzburg, I.P. Ivanov, Eur. Phys. J. C22(2001) 411-421)
[6] I.F. Ginzburg, V.G. Serbo. Phys. Lett. B96(1980) 68-70
[7] D. A. Anipko, I. F. Ginzburg, K.A. Kanishev, A. V. Pak, M. Cannoni, O. Panella.
Phys. Rev. D78(2008) 093009; ArXive: hep-ph/0806.1760
[8] I.F.Ginzburg, Proc. 9th Int. Workshop on Photon-Photon Collisions, San Diego (1992)
474; I.F. Ginzburg, K.A. Kanishev, hep-ph/0507336
68