Crystal Ball Function

The Crystal Ball function, named for the Crystal Ball Collaboration that introduced it, is a probability density function used in high-energy physics to model lossy processes such as bremsstrahlung radiated by electrons. It combines a Gaussian core with a power-law tail below a chosen threshold, and both the function itself and its first derivative are continuous across that threshold, a property that makes it well suited to fitting experimental particle-physics data that shows a Gaussian peak with a skewed low-energy tail. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/