Yukawa potential

In particle and atomic physics, a Yukawa potential (also called a screened Coulomb potential) is a potential of the form

where g is a magnitude scaling constant, i.e. is the amplitude of potential, m is the mass of the affected particle, r is the radial distance to the particle, and k is another scaling constant, which finally the product of km is the range. The radial derivative is positive, implying that the potential is monotone increasing in r, and implying the force is always attractive.