Stars as Laboratories for Fundamental Physics - MPP Theory Group

Symbols 647
X j Peccei-Quinn charge of a fermion j
Y mass fraction of helium
Y j number of fermions j per baryon
Y e mass fraction of helium in stellar envelope
Y L lepton number per baryon
z up/down quark mass ratio, z-coordinate
Z mass fraction of “metals,” nuclear charge
Z, Z ◦ Z-boson
Greek Symbols
α fine-structure constant (e 2 /4π = 1/137), asymmetry parameter
in angular distribution of decay photons
α ′ fine-structure constant for general bosons, α ′ = g 2 /4π with the
Yukawa coupling g
α a,χ fine-structure constant for axions, majorons
α s strong fine-structure constant
α π pionic fine-structure constant, α π = (f2m N /m π ) 2 /4π ≈ 15 with
f ≈ 1.0
β velocity of a particle, parameter of axion models, parameter in
nucleon-nucleon-axion bremsstrahlung rate
γ photon, Dirac matrix, adiabatic index, dimensionless fluctuation
rate γ = Γ/T
Γ rate for decay or fluctuations, plasma coupling parameter
Γ σ spin-fluctuation rate in a nuclear medium
δ δ function, Kronecker δ, differential quantity
ϵ energy loss or generation rate per unit mass, electric dipole moment,
polarization vector
ϵ ij neutrino transition electric moment
η degeneracy parameter, η = (µ − m)/T
θ mixing angle, scattering angle
Θ Θ parameter of QCD
Θ W weak mixing angle (sin 2 Θ W = 0.2325)
κ opacity, dimensionless screening or momentum scale
κ ∗ reduced opacity
λ wave length, mean free path
µ magnetic moment, chemical potential, muon, Lorentz index,
mean molecular weight
ˆµ nonrelativistic chemical potential, ˆµ = µ − m
µ ij neutrino transition magnetic moment