Time variation of the fine structure constant and of the Higgs vacuum expectation value on cosmological time scales

Abstract

Aims. We study the time variation of both the fine structure constant, α, and the Higgs vacuum expectation value, v, during Big Bang nucleosynthesis (BBN). Methods. We calculate the primordial abundances of D, 4 He, and 7 Li by modifying Kawano's code, and by using observational data we set constraints on the joint variation of α and v. To perform the calculations we considered the dependence of the deuteriumbinding energy, D , upon v, obtained from the treatment of different proton-neutron interactions. Results. Results are consistent with variation on v (even at the level of 6σ) and null variation of α (within 2σ) if the 7 Li data are used in the analysis. However, if data on these nuclei are not considered in the statistical analysis, we found null variation on both fundamental constants within 2σ. Conclusions. We found that the best-fit values of the variation of v and α are sensible to the dependence of the deuterium binding energy upon the Higgs vacuum expectation value. We found non-null variation of v within 6σ if all the observational data are used in the analysis. If data on the primordial abundance of 7 Li are taken at face value, the discrepancy between BBN and WMAP estimates may be explained by allowing variations of v.

New cosmological constraints on the variation of fundamental constants: the fine structure constant and the Higgs vacuum expectation value

“…In a previous work (Mosquera & Civitarese 2011) it was found that the variation of the fine structure constant was null within 2σ, the variation of the Higgs vacuum expectation value was not null within 6σ, and the value of the baryon-to-photon ratio agreed well with the WMAP estimations.…”

“…For details see Landau et al (2006Landau et al ( , 2008; Scóccola et al (2008) and Mosquera & Civitarese (2011).…”

“…Mosquera et al (2008) have studied the variation of the fine structure constant in the early Universe and set constraints on the free parameters of the Bekenstein model (Bekenstein 1982), and in Scóccola et al (2008) the variation of v in the early Universe (BBN and CMB) has been studied. In Mosquera & Civitarese (2011) and Landau et al (2008) the variation of α and v during BBN have been studied without assuming any theoretical model for the variations.…”

Time variation of fundamental constants in nonstandard cosmological models

“…The lithium abundance is reduced, in the context of non-null variation of fundamental constants, by a factor 2 compared to the results obtained in the context of the standard model (4.7 × 10 −10 ). This result is in agreement with the results of other works [19,26,34,35] which have reported that the variation of some fundamental constants, i.e., quark masses, the fine structure constant, and the Higgs vacuum expectation value, improves the agreement between the observed primordial abundances and the corresponding theoretical values.…”

“…The theoretical abundances computed by using the baryon density determined by the CMB data are consistent with the observed abundances of deuterium and helium, but not with the lithium data. This problem, called the lithium problem, was studied by several authors and by several different points of view, such as the turbulent transport in radiative zones of the stars [3], the existence of lithium depletion [4,5], the inclusion of resonant cross sections [6][7][8][9], sterile neutrinos [10][11][12][13][14][15][16][17][18][19][20][21][22], variation of fundamental constants [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37], and the inclusion of cosmological scalar fields and brane cosmology [33].…”