Ways to detect neutrinos

[Heis3nberg]

How scientist could detect "undetectable particles"? In the case of neutrinos this question is very common. In fact neutrinos reply to weak and gravitational interactions, so when they go across a beam of matter, they can't interact with its atoms ( On electromagnetic or strong interactions)  .There are some indirect ways to find them, thank to Beta decay.

-Electron neutrinos

Electron neutrinos are the easiest to reveal; in neutrinos detectors there is a great amount of CCl4 (Carbonium tetrachloride); when neutrinos from the Sun or deep space impact with Clorium (Cl N=17), they convert it in Argon gas (Ag N=18) and there is also an emission of an electron.

ν e + 37 C l → 37 A r + e − {\displaystyle \nu _{e}+^{37}Cl\to ^{37}Ar+e^{-}}

 

There are also some Gallium detectors: They detect low energy neutrinos

 

ν e + 71 G a → 71 G e + e − {\displaystyle \nu _{e}+^{71}Ga\to ^{71}Ge+e^{-}

 

Then, scientists check the amount of  gas Argon produced and the emission of electron to decree the number of neutrinos detected.

N.B only electron ones can be found by this method.

 

-Muon and Tau neutrinos

In OPERA experiment scientists have proved the oscillation between muon and tau neutrinos.

Muon neutrinos are generated in the high atmosphere thank to the decay of Pions and kaons:

 

π + → μ + + ν μ ,       π − → μ − + ν ¯ μ . {\displaystyle \pi ^{+}\to \mu ^{+}+\nu _{\mu },~~~\pi ^{-}\to \mu ^{-}+{\bar {\nu }}_{\mu }.}

 

kaons decay emitting pions and bosons, which decay in muons and neutrinos..

In OPERA a beam of protons are accelerated against a Carbon target (C, N=6), it creates pions and kaons which decay in muons and muon neutrinos; There are other targets created by piles of lead in a tunnel made of plastic scintillators. In this tunnel muon neutrinos travel and due to "neutrinos oscillation" ( phenomena described in solar neutrinos problem) they can change their "flavor charge " to become tau neutrinos. Tau neutrinos impact with lead atoms, it generates tauons which decay in muons and some neutrinos. This decay leaves a print in photographic plates of the detector, so we have the proof of tau neutrinos and his oscillation of the flavor charge.

 

This principle was very similar to that one adopted in DONUT experiment, which proofs the existence of tau neutrinos.

 

 

π + → μ + + ν μ ,       π − → μ − + ν ¯ μ . {\displaystyle \pi ^{+}\to \mu ^{+}+\nu _{\mu },~~~\pi ^{-}\to \mu ^{-}+{\bar {\nu }}_{\mu }

 

 

 

[swansont]

19 minutes ago, Heis3nberg said:

There are some indirect ways to find them, thank to Beta decay.

Also the Cherenkov radiation detectors as mentioned in your other thread.

Ad, as with that thread, can you point to what you want to discuss here?

[Kartazion]

33 minutes ago, Heis3nberg said:

 

kaons decay emitting pions and bosons, which decay in muons and neutrinos..

 

I don't see where the neutrinos are.

[swansont]

51 minutes ago, Heis3nberg said:

kaons decay emitting pions and bosons

pions are bosons (they are spin 0)

[Heis3nberg]

6 hours ago, Kartazion said:

I don't see where the neutrinos are.

Kaons decay in pions and then pions decay in neutrinos and muons.

6 hours ago, swansont said:

pions are bosons (they are spin 0)

yes sorry, for bosons I mean also W bosons, which take part in the kaons decay