- #1
binbagsss
- 1,265
- 11
As far as I understand, ##I_{3}##, the component of isospin in a certain direction is additive,
but ##I## is to be treated as a vector sum, is this correct?
So, ##I_{3}=1/2## for ##u## quark,
##I_{3}=-1/2 ## for ##d## quark.
Adding ##I_{3}## then for a proton we find ##I_{3}=1/2##
and for a neutron ##I_{3}=-1/2##
Is it from this that we conclude both the proton and neutron form a isospin doublet with ##I=1/2##?
What is the formulae for ##I##? I read somewhere that ##I## is greater than or equal to ##I_{3}##,
So is ##I= |I_{3}| + |I_{2}| + |I_{1}|## ? But if this is the reasoning for the doublet, what about ##I_{2}, I_{1}##?
On instead should the approach be a vector sum of the isospin of the quarks. So both the down and up quarks have ##I=1/2##,
So doing a vector sum of the three quarks gives the three possible values: ##3/2,1/2,1/2##,
So why then, for the doublet would you take the ##1/2## and not ##3/2##. Is there an observation side to this?Thanks in advance.
but ##I## is to be treated as a vector sum, is this correct?
So, ##I_{3}=1/2## for ##u## quark,
##I_{3}=-1/2 ## for ##d## quark.
Adding ##I_{3}## then for a proton we find ##I_{3}=1/2##
and for a neutron ##I_{3}=-1/2##
Is it from this that we conclude both the proton and neutron form a isospin doublet with ##I=1/2##?
What is the formulae for ##I##? I read somewhere that ##I## is greater than or equal to ##I_{3}##,
So is ##I= |I_{3}| + |I_{2}| + |I_{1}|## ? But if this is the reasoning for the doublet, what about ##I_{2}, I_{1}##?
On instead should the approach be a vector sum of the isospin of the quarks. So both the down and up quarks have ##I=1/2##,
So doing a vector sum of the three quarks gives the three possible values: ##3/2,1/2,1/2##,
So why then, for the doublet would you take the ##1/2## and not ##3/2##. Is there an observation side to this?Thanks in advance.