New limit on magnetic monopole flux from catalysis of proton decay in white dwarfs

Abstract

We propose a question that why no late type M and much later type N white dwarfs (WDs) with surface temperatures less than 3000 K have ever been observed? On the basis of proton decay catalyzed by magnetic monopoles(MMs), we have presented four new energy-source models associated with MMs to discuss the cooling of WDs by some observations from seven red giant stars with LAMOST. It is found that the number of MMs captured by a WD can reach the maximum value of [Formula: see text] when the MMs flux [Formula: see text]. The good agreement of our luminosities calculated for WDs with the observations shows that our models are rational due to the Rubakov Callan (RC) effect by MMs. It is concluded that the energy source of WDs is the proton decay catalyzed by MMs. We obtain a new limit of the MMs flux of [Formula: see text] for WDs when the number density of nucleons [Formula: see text] and asteroseismic correction factor [Formula: see text] due to the RC effect by MMs.

The Influence of Velocity-dependent Correction Factor on Proton Decay Reactions in Massive White Dwarfs

“…Recently, we discussed the energy source problem for WDs. First, we discussed the numbers of MMs captured in space at the surface of stars, which is given by (Peng et al 1985;Peng & Liu 2023;Liu et al 2023aLiu et al , 2023bLiu & Liu 2023c, 2023d g m = 3hc/2e and m B , which are the magnetic charge of MMs and the baryon number mass, respectively. The MM mass is about m m ∼ 10 16 m p (Polyakov 1974), where m p is the mass of a proton.…”

“…The reactions pM → e + π 0 M + debris(85%), and pM → e + μ ± M + debris(15%) are named proton decay reactions catalyzed by MMs, which were proposed by the RC effect. The luminosity due to the RC effect is (Peng et al 1985;Peng & Liu 2023;Liu et al 2023aLiu et al , 2023bLiu & Liu 2023c, 2023d)…”

“…where R g = 2.96 × 10 5 M * is the Schwarzschild radius, and M 12 = M * /10 12 , M * = M/M e and R * = R/R e (Peng et al 1985;Peng & Liu 2023;Liu et al 2023aLiu et al , 2023bLiu & Liu 2023c, 2023d. As a general rule, the values of reaction cross-section are distributed between 10 −26 and 10 −24 cm 2 .…”

“…Their researches provide a database for further exploration of the evolution of WDs. Recently, the energy source problem for WDs has been discussed by Peng & Liu (2023); Liu et al (2023aLiu et al ( , 2023b; Liu & Liu (2023c) and Liu & Liu 2023d). However, the influence of the velocity-dependent correction factor on the cross-sections in the Rubakov process is ignored in the above works.…”