new_contents: import math
  import scipy.constants
  
  
  electron_mass_name = 'electron mass energy equivalent in MeV'
  electron_mass_mev, _, _ = scipy.constants.physical_constants[electron_mass_name]
  
  
  def rigidity(energy_mev):
      gamma = energy_mev / electron_mass_mev
      beta = math.sqrt(1 - gamma ** (-2))
      energy_j = energy_mev * 1e6 * scipy.constants.e
      p = beta * energy_j / scipy.constants.c
      return p / scipy.constants.e
  
subject: Copy utils from pml to pytac