A new constraint on cosmological variability of the proton-to-electron mass ratio

Exotic cosmologies predict variability of the fundamental physical constants over the cosmic time. Using the VLT/UVES high resolution spectra of the quasar Q0347-3819 and unblended electronic - vibrational - rotational lines of the H2 molecule identified at z = 3.025 we test possible changes in the proton - to - electron mass ratio mu_0 = m_p/m_e over the period of 11 Gyr. We obtained a new constraint on the time - averaged variation rate of mu_0 of |d mu /d t /mu_0| < 5 10^{-15} yr^{-1} (1 sigma c.l.). The estimated 1 sigma uncertainty interval of the |Delta mu/mu_0| ratio of about 0.004% implies that since the time when the H2 spectrum was formed at z = 3.025, mu_0 has not changed by more than a few thousands of a percent.