Why does mass behave differently when combining quarks and antimatter?

[talanum52]

Homework Statement

Why does mass behave differently?

Relevant Equations

N/A

Mass behaves opposite that of other quantum numbers when combining matter (quarks) and antimatter. Why?

 

[DrClaude]

Is this really a homework question? In any case, the question is not clear.

What does "opposite" mean here? And mass is not a quantum number...

 

[talanum52]

Is this really a homework question? In any case, the question is not clear.

What does "opposite" mean here? And mass is not a quantum number...

It adds together, rather than cancel.

 

[jbriggs444]

It adds together, rather than cancel.

Anti-particles have positive mass, not negative mass.

 

[talanum52]

Anti-particles have positive mass, not negative mass.

Why?

 

[jbriggs444]

Why?

Because "mass" is the magnitude of the energy-momentum four-vector which is always positive.

In simpler but almost completely equivalent terms, because $E=mc^2$ (in a particle's rest frame) and energy is always positive.

And because the notion of particles that speed up when you apply a retarding force is not very sensible.

And because experiment shows that they have positive mass.

 

[talanum52]

O.K. Thank you.

 

[malawi_glenn]

Is this really a homework question?

No, the OP has the recent days posted several of their questions in the HW forum which actually belongs in the technical forums (some threads got deleted because of OP is working on their own model of particles.)