Parity violation of electroweak force in phase transitions of single crystals of D- and L-alanine and valine

Three kinds of experiments have been designed in attempting to observe the parity violation of electroweak force at the phase transition of single crystals of D- and L-alanine and valine. (1) An obvious lambda phase transition at 270 +/- 1 K was shown in the specific heat measurement of alanine and valine enantiomers by differential scanning calorimetry. The biologically dominant L-enantiomer was found to have lower energy. (2) Magnetization of single crystals of D- and L-alanine and D-valine were measured as a function of temperature using the SQUID magnetometer. The difference of the mass susceptibility chi(rho) similar to T curve between the D-alanine and L-alanine is attributable to the variation of intramolecular geometry of chirality density, which is related to the parity violation energy shift of a chiral molecule and is a consequence of the short range of the weak interaction between the nuclei and electrons. (3) Laser Raman spectra of D- and L-alanine at different low temperatures (100 K, 250 K, 260 K, 270 K, 280 K and 290 K) showed that the second order C alpha-H deformation modes at 2606 cm(-1), 2724 cm(-1) of D-alanine vanished at 270 K but reappeared at 100 K. In the same method, L-alanine has no such phenomenon. An obvious decrease in the scattering intensity of the methyne group C(alpha)-H stretching mode at 2964 cm(-1) in D-alanine occurs at the lambda transition temperature. We present our experiments involving the possible relevance of Z(0) force with Salam's putative phase transition in the origin of homochirality.BiophysicsSCI(E)PubMed50ARTICLE151-652