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We suggest a few particle physics processes in which excited 2p pionium$\mathrm{A}^\prime_{2\pi}$ may be observed. They include the$e^+e^-\to\pi^+\pi^-$ annihilation, the $V^0\to\pi^0\ell^+\ell^-$ and$K^\pm\to\pi^\pm\ell^+\ell^-$ ($\ell=e,\mu$) decays, and the photoproduction oftwo neutral pions from nucleons. We analyze available experimental data andfind that they, in some cases, indicate the presence of 2p pionium, but do notprovide definite proof.

Possible manifestation of the 2p pionium in particle physics processes