  TGD predicts the existence of color octet excitations of ordinary leptons
forming 'leptohadrons' as their color singlet bound states. There is some
evidence on the existence of leptohadrons: the production of anomalous $e^+e^-$
pairs in heavy ion collisions, Karmen anomaly, the anomalously high decay rate
of ortopositronium (Op) and anomalous production of low energy $e^+e^-$ pairs
in hadronic collisions. PCAC makes it possible to predict the couplings of
leptopion to leptons. The new contribution to Op decay rate is of correct order
of magnitude and the anomaly allows to determine the precise value of the
parameter $f_{\pi_L}$. Sigma model realization of PCAC makes it possible to
construct a model for the production of leptohadrons in the electromagnetic
fields of the colliding nuclei. $\pi_L$ develops vacuum expectation value
proportional to the 'instanton density' $E\cdot B$ and it is possible to relate
leptohadron production rates to the Fourier transform of $E\cdot B$. Anomalous
$e^+e^-$ pairs must originate from $\sigma_L \pi_L$ pairs via
$\sigma_L\rightarrow e^+e^-$ decay. The peculiar production characteristics of
leptomesons are reproduced, the order of magnitude for the production cross
section is correct and various decay rates are within experimental bounds. A
resonance in photon photon scattering at cm energy equal to leptopion mass is
predicted and leptobaryon pair production in heavy ion collisions is in
principle possible. Leptopion contribution to the $\nu-e$ and $\bar{\nu}-e$
scattering should dominate at low energies.
