- #1
Murtuza Tipu
- 47
- 2
[mod edit] This question was originally asked at https://physics.stackexchange.com/questions/115053/whats-a-lepto-diquark
This questions refers to Slansky's Group theory for unified model building, page 106 of chapter 7.
He assigns the weight (1)(01), which is stepwise projected from E6 to SU(2)×SU(3), to a state which he calls a 4/3-charged antilepto-diquark.
I assume that the diquark comes from the 2×2/3 for the charge and the lepton from the fact that it will probably be contained in a multiplet together with the leptons...
What I don't understand:
Where does the charge assignement 4/3 comes from?
On the basis of the weight I would have called it a anti-up quark, since it is the upper component of the doublet, the 1 in the first brackets, and transforms as a 3¯ under SU(3) (since (01) is the corresponding fundamental weight). Hence I would assign it a charge 1/3, which later on will be used to determined the charges of the other particles. How does he comes to the conclusion that it must be a diquark?
He comments that it mediates the proton decay. I thought that usually a force is mediated by a boson... Does he means that since the quarks will be together with the leptons in a multiplet, the baryon number does not need to be conserved. Which unable the proton to decay?
Is this diquark something realistic or is it an out-dated object, i.e. ruled out by experiments? When and why was it postulated?
This questions refers to Slansky's Group theory for unified model building, page 106 of chapter 7.
He assigns the weight (1)(01), which is stepwise projected from E6 to SU(2)×SU(3), to a state which he calls a 4/3-charged antilepto-diquark.
I assume that the diquark comes from the 2×2/3 for the charge and the lepton from the fact that it will probably be contained in a multiplet together with the leptons...
What I don't understand:
Where does the charge assignement 4/3 comes from?
On the basis of the weight I would have called it a anti-up quark, since it is the upper component of the doublet, the 1 in the first brackets, and transforms as a 3¯ under SU(3) (since (01) is the corresponding fundamental weight). Hence I would assign it a charge 1/3, which later on will be used to determined the charges of the other particles. How does he comes to the conclusion that it must be a diquark?
He comments that it mediates the proton decay. I thought that usually a force is mediated by a boson... Does he means that since the quarks will be together with the leptons in a multiplet, the baryon number does not need to be conserved. Which unable the proton to decay?
Is this diquark something realistic or is it an out-dated object, i.e. ruled out by experiments? When and why was it postulated?
Last edited by a moderator:
