The discussion centers on the concept of mass fluctuations in particles, particularly focusing on unstable particles in Quantum Field Theory (QFT). It highlights the significance of "decay width," which is defined as the imaginary part of the complex pole of a particle's Green's function in momentum space. The invariant mass of particles, such as photons from Higgs boson decay, is described as a distribution peaking around the Higgs mass, illustrating the concept of mass width. The participants also reference the notion of "unparticles" and their fluctuating mass, supported by external literature.
PREREQUISITESPhysicists, graduate students in particle physics, and researchers interested in Quantum Field Theory and the behavior of unstable particles.
It is actually called "decay width".maximdogger said:thanks ..I will look up mass width.
The mass of an "unstable particle" (or more accurately a resonance) is a well-defined number. It's given by the complex pole of its Green's function in (four-)momentum space, i.e., the real part of this pole is the mass and the imaginary part is its decay width, i.e., the inverse mean lifetime.malawi_glenn said:No idea what "when viewed" means.
There is however a concept of mass width in QFT for unstable particles.
Yup.vanhees71 said:The mass of an "unstable particle" (or more accurately a resonance) is a well-defined number. It's given by the complex pole of its Green's function in (four-)momentum space, i.e., the real part of this pole is the mass and the imaginary part is its decay width, i.e., the inverse mean lifetime.
I used that paper when I was starting my phd heheDemystifier said:No, but the mass of "unparticle" fluctuates.
https://arxiv.org/abs/0801.4471