Answer:
The lifetime of the particle is  [tex]\Delta t = 2.6*10^{-25} \ s[/tex]
Explanation:
From the question we are told that
  The average rest energy is [tex]E = 91.19 \ GeV = 91.19GeV * \frac{1.60 *10^{-10} J }{1GeV} = 1.46 *10^{-8}J[/tex]
  The intrinsic width is  [tex]\Delta E =2.5eV = 2.5GeV * \frac{1.60 *10^{-10}J }{1GeV} = 4*10^{-10} J[/tex]
The lifetime is mathematically represented as
   [tex]\Delta t = \frac{h}{\Delta E}[/tex]
Where h is the Planck's constant with a value of  [tex]1.055*10^{-34} \ J\cdot s[/tex] Â
substituting values
  [tex]\Delta t = \frac{1.055*10^{-34}}{4 *10^{-10}}[/tex]
   [tex]\Delta t = 2.6*10^{-25} \ s[/tex]
