Indications of electron-to-proton mass ratio variations in the Galaxy. II. 3 mm methanol lines toward Sgr B2(N) and (M)

J. S. Vorotyntseva, S. A. Levshakov, C. Henkel

Differential measurements of the fundamental constant mu = m_e/m_p (the electron-to-proton mass ratio) for two sources near the Galactic Center - the Sgr B2(N) and B2(M) molecular…