Experimental limits on quarks, tachyons, and massive particles in cosmic rays

A large detector with high redundancy is used to search for various types of anomalous particles in cosmic rays at sea level. The detector is sensitive to zenith angles between 45° and 90°. Previously obtained limits on the fluxes of charge $\frac{1}{3}$ and $\frac{2}{3}$ particles are reduced to 2.9 × ${10}^{-10\mathrm{}}$ and 2.6 × ${10}^{-10\mathrm{}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ ${\sec }^{-1\mathrm{}}$, respectively. The flux of ionizing tachyons is determined to be less than 2.4 × ${10}^{-9\mathrm{}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ ${\sec }^{-1\mathrm{}}$. The massive-particle flux limit we obtain is inconsistent with previous claims of such particles assuming that these particles are isotropic in zenith angle.