Understanding Muon and Tau Antineutrinos: Common Questions and Misconceptions

[spideyinspace]

i have many doubts about muon anti neutrino and tau anti neutrino...some are
1. is it so tough to detect them...anyone detected them ?
2. do they decay?
3. do they react with other particles like electrons,protons etc?
can anyone give some information about them?

 

[jtbell]

1. is it so tough to detect them...anyone detected them ?

Yes, they've been detected, the muon neutrino as far back as the 1960s, and the tau neutrino was first detected directly in 2000.

2. do they decay?

No, there's nothing lighter for them to decay into.

3. do they react with other particles like electrons,protons etc?

Yes, that's how we detect them!

can anyone give some information about them?

http://www.google.com/search?hl=en&q=muon+neutrinos

http://www.google.com/search?hl=en&q=tau+neutrinos

 

[spideyinspace]

yes i can understand the discovery of muon and tau neutrino would confirm that there should be anti neutrinos of that kind... but i asked about anti neutrinos of moun and tau types..

 

[jtbell]

Oops, I missed the "anti".

I know for muon antineutrinos what I said still works, except maybe the year they were first detected. I don't remember whether those experiments specifically found neutrinos or antineutrinos. When I was a graduate student in the late 1970s and early 1980s I worked on an experiment at Fermilab that used a beam of muon antineutrinos. There was nothing special about producing them versus producing muon neutrinos. They're produced by letting negative versus positive pions or kaons decay.

According to the Web site of the experiment that first detected tau neutrinos, their apparatus produced both tau neutrinos and antineutrinos:

http://www-donut.fnal.gov/web_pages/DONUT/Design/Design.html

I don't see (yet) any specific reference to tau antineutrinos in their results. However, I don't see any reason why their detector would find only neutrinos and not antineutrinos. In order to distinguish them, you have to find out whether they produced a negative or postive tau lepton. I can't figure out yet whether they were able to distinguish between the two kinds of taus.

 

[spideyinspace]

Oops, I missed the "anti".

I know for muon antineutrinos what I said still works, except maybe the year they were first detected. I don't remember whether those experiments specifically found neutrinos or antineutrinos. When I was a graduate student in the late 1970s and early 1980s I worked on an experiment at Fermilab that used a beam of muon antineutrinos. There was nothing special about producing them versus producing muon neutrinos. They're produced by letting negative versus positive pions or kaons decay.

According to the Web site of the experiment that first detected tau neutrinos, their apparatus produced both tau neutrinos and antineutrinos:

http://www-donut.fnal.gov/web_pages/DONUT/Design/Design.html

I don't see (yet) any specific reference to tau antineutrinos in their results. However, I don't see any reason why their detector would find only neutrinos and not antineutrinos. In order to distinguish them, you have to find out whether they produced a negative or postive tau lepton. I can't figure out yet whether they were able to distinguish between the two kinds of taus.

Thank you for the reply..Does this mean detecting muon,tau antineutrino is tough than detecting muon,tau neutrino?...
Do they(muon,tau antineutrino) easily react with other particles(like electrons,protons,neutrons) or they don't interact with other particles?you also said that they don't decay...
putting it all together shall i assume if muon,tau antineutrinos are once produced then they don't change their identity i.e they remain as they are..provided they don't interact with other particles..

 

[malawi_glenn]

all neutrinos oscillate when they propagete freeley.

All neutrinos has been dected, last one was the tau-anti neutrino.

Anti neutrinos interact with matter just as neutrinos do, i.e via the weak interaction. Infact, you can't detect something if it don't react with anything.. and yes, they interact very weakly in comparison with other elementary particles. And no, neutrinos don't decay, at least not in the standard model of elementary particles ;)

You seem to be a very curious guy spideyinspace, many of the quesions you have asked the last week is covered in intro books in particle physics, have you ever read one of those? We can give you good tips.

 

[spideyinspace]

all neutrinos oscillate when they propagete freeley.

All neutrinos has been dected, last one was the tau-anti neutrino.

Anti neutrinos interact with matter just as neutrinos do, i.e via the weak interaction. Infact, you can't detect something if it don't react with anything.. and yes, they interact very weakly in comparison with other elementary particles. And no, neutrinos don't decay, at least not in the standard model of elementary particles ;)

You seem to be a very curious guy spideyinspace, many of the quesions you have asked the last week is covered in intro books in particle physics, have you ever read one of those? We can give you good tips.

Thank you...if you have any pdf's related to neutrino and antineutrino, please post the link..am not physics student but interested in physics...

 

[spideyinspace]

all neutrinos oscillate when they propagete freeley.

All neutrinos has been dected, last one was the tau-anti neutrino.

Anti neutrinos interact with matter just as neutrinos do, i.e via the weak interaction. Infact, you can't detect something if it don't react with anything.. and yes, they interact very weakly in comparison with other elementary particles. And no, neutrinos don't decay, at least not in the standard model of elementary particles ;)

You seem to be a very curious guy spideyinspace, many of the quesions you have asked the last week is covered in intro books in particle physics, have you ever read one of those? We can give you good tips.

Thank you...if you have any pdf's related to neutrino and antineutrino, please post the link..yes,am not physics student but interested in physics...

 

[malawi_glenn]

I have many pdf's but don't have links. Write PM to me and I give you my mail and I'll attach them.

It is a must to have knowledge in quantum mechanics to fully apprechiate particle physics.