zfit_physics.pdf.Argus(*args[, obs])	ARGUS shape describing the invariant mass of a particle in a continuous background.
zfit_physics.pdf.RelativisticBreitWigner(*args)	Relativistic Breit-Wigner distribution.
zfit_physics.pdf.CMSShape(m, beta, gamma, obs, *)	CMSShape PDF.
zfit_physics.pdf.Cruijff(mu, sigmal, alphal, ...)	Cruijff PDF, a Gaussian with two width, left and right, and non-Gaussian tails.
zfit_physics.pdf.ErfExp(mu, beta, gamma, n, ...)	ErfExp PDF, the product of a complementary error function and an exponential function.
zfit_physics.pdf.Novosibirsk(mu, sigma, ...)	Novosibirsk PDF.
zfit_physics.pdf.Tsallis(m, t, n, obs, *[, ...])	Tsallis-Hagedorn PDF.