- #1
ehrenfest
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Homework Statement
Can someone explain to me why in the world Zwiebach sets M^2 = -p^2 in this equation? Even in natural units, that doesn't seem right.
In quantum field theory, the mass of a particle is related to its energy and momentum through the equation E^2 = m^2c^4 + p^2c^2. This equation can be rewritten as M^2 = -p^2, where M is the mass of the particle and p is its momentum. The negative sign in front of p^2 is a convention used in theoretical physics to simplify calculations and maintain consistency with other equations.
No, the negative sign in front of p^2 does not indicate that the particle has a negative mass. This equation applies to all particles, including those with positive mass. The negative sign is simply a mathematical convention and does not have a physical interpretation.
This equation, M^2 = -p^2, is a relativistic version of the equation E=mc^2. In special relativity, energy and momentum are related through the equation E^2 = m^2c^4 + p^2c^2. By setting E=pc (for a massless particle), we get M^2 = -p^2, which is equivalent to E=mc^2 for a particle at rest.
Yes, this equation can be applied to all types of particles, including those with spin. The equation M^2 = -p^2 is a fundamental equation in quantum field theory and can be used to describe the behavior of all particles, regardless of their spin value.
This equation has both theoretical and practical applications. In theoretical physics, it is used to study the behavior of particles in quantum field theory. In practical applications, it is used in high energy physics experiments, such as particle accelerators, to calculate the mass of particles based on their energy and momentum.