# What is natural width in particle physics?

What is the meaning of the term "natural width" in particle physics?

From http://nordberg.web.cern.ch/PAPERS/JINST08.pdf, page 2:

... there is a range of production and decay mechanisms, depending on the mass of the Higgs boson, $$H$$. At low masses ($$m_H < 2m_Z$$), the natural width would only be a few MeV, and so the observed width would be defined by the instrumental resolution.