The third piece added to a composition of neutral cosmic rays.

We present here a third component in neutral cosmic ray (CR) in addition to known neutrinos and gamma-rays. It is a solar neutral particle (Mp) detected by its influence on free-vibrating piezoelectric micro-crystal excited by an external radiofrequency (F) voltage of 9 – 13 Mhz. The milli-gram crystal sensor was in a housing to block possible charged particles and EMW. Experimental data of the frequency dependencies of vibrational amplitude (A), power (P), and resonance frequency (Fr) of maxima in A and P are sensitive to an orientation of the crystal's main piezoelectric axis in space. The measured P(F) and Fr are distorted under certain space orientations of the axis. In the experiments, the space orientation of the crystal piezoelectric axis was variable. Mp particles were detected when this axis was oriented toward the Sun demonstrating a largely anisotropic distribution. The acoustoelectric measurements of the P(F) dependencies taken under solar influence from free-vibrating micro-crystals yield a rest mass of Mp ~ (5.3 ± 1.7)E-21 kg, which falls in the known knee in the energetic spectrum of CR near ~ PeV mass-energy. Theoretical calculations of measured A, P, and Fr in free-vibrating piezoelectric crystals are compared to the experimental data. A theoretical model of vibrating atoms under the presence of gravitating massive particles, such as Mp, is considered. The Mp particles propagate in space between the Sun and Earth at a speed near 249 km/s.