# HELP !!! Physics

#1
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#2
But I don't get it !
Can someone please explain me !!
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5 years ago
#3
The charge has to be conserved as well as lepton number I believe
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#4
(Original post by Needchemhlp)
The charge has to be conserved
I have doubt between A and C ??
Why not C ?
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5 years ago
#5
This is to do with the conservation of quantum numbers (charge, baryon number, electron number, muon number, and strangeness). In particular for this example, we're trying to find where lepton numbers are (and are not) conserved.

Interaction A:
Charge: Is conserved - an initial charge of zero is countered by a negative and a positive particle, and a neutral particle.
Baryon Number: Is conserved - none of these particles are baryons;
Electron Number: Is conserved - none of these particles are electrons;
Muon Number: Is conserved - the anti-muon's lepton number of +1 is countered by the muon neutrino's lepton number of -1;
Strangeness: Need not be conserved - this is a weak interaction, in which strangeness can (but won't always) change by 1.

You can repeat this process for the other interactions to determine which are possible and which are not.

Hope that helps!
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#6
(Original post by SummerStrawberry)
This is to do with the conservation of quantum numbers (charge, baryon number, electron number, muon number, and strangeness). In particular for this example, we're trying to find where lepton numbers are (and are not) conserved.

Interaction A:
Charge: Is conserved - an initial charge of zero is countered by a negative and a positive particle, and a neutral particle.
Baryon Number: Is conserved - none of these particles are baryons;
Electron Number: Is conserved - none of these particles are electrons;
Muon Number: Is conserved - the anti-muon's lepton number of +1 is countered by the muon neutrino's lepton number of -1;
Strangeness: Need not be conserved - this is a weak interaction, in which strangeness can (but won't always) change by 1.

You can repeat this process for the other interactions to determine which are possible and which are not.

Hope that helps!
What do you mean by ELECTRON NUMBER ??
I have never heard of it !
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5 years ago
#7
(Original post by NNB_Herath)
What do you mean my ELECTRON NUMBER ??
I have never heard of it !
Im not sure about electron number either but he/she is right but you only need really charge and lepton conservation.
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#8
(Original post by Needchemhlp)
Im not sure about electron number either but he/she is right but you only need really charge and lepton conservation.
You can only ignore B because of charge conservation.
You can ignore D because of lepton number conservation.

But I am having the doubt between A and C because they both have satisfying charge and lepton numbers .

Why not C ?? What is Electron Number ??
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5 years ago
#9
Instead of having a lepton number, each of the leptons have their own quantum numbers that need to be conserved (but only the electron and muon will come up). So both electron number and muon number need to be conserved
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#10
(Original post by AHappyStudent)
Instead of having a lepton number, each of the leptons have their own quantum numbers that need to be conserved (but only the electron and muon will come up). So both electron number and muon number need to be conserved
Hmmmmmm
Quite reasonable......By the way I guess this is it !!
Thanks for the help.

But it would be much more of a help if you can give me a more detailed explanation
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#11
Do you always have to consider individual electron or muon number in interactions ???
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5 years ago
#12
(Original post by NNB_Herath)
Do you always have to consider individual electron or muon number in interactions ???
If there is a single type of lepton (not counting neutrinos as a different type) then you are basically just considering the lepton number. It's the same thing but the different types are independant of each other and all need to be conserved.

It will come up in questions so you may need to use it. When specifying them call them the 'electron lepton number' or the 'muon electron number'.

Electrons have an electron number of +1 and a muon number of 0.
Muons have an electron number of 0 and a muon number of +1.
Neutrinos have the same numbers as their corresponding heavier leptons

Antiparticles have the negative values as usual
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#13
(Original post by AHappyStudent)
If there is a single type of lepton (not counting neutrinos as a different type) then you are basically just considering the lepton number. It's the same thing but the different types are independant of each other and all need to be conserved.

It will come up in questions so you may need to use it. When specifying them call them the 'electron lepton number' or the 'muon electron number'.

Electrons have an electron number of +1 and a muon number of 0.
Muons have an electron number of 0 and a muon number of +1.
Neutrinos have the same numbers as their corresponding heavier leptons

Antiparticles have the negative values as usual
Okk !!
Thanks
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5 years ago
#14
(Original post by NNB_Herath)
Be is not possible because charge isn't conserved. C and D are not possible because the specific lepton numbers for electrons and muons are not conserved

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