Weak force carriers, W+, Z°, W- have spin 1
Weak force carriers, W+, Z°, W- have spin 1
Weak force carriers, W+, Z°, W- have spin 1
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
SNO published results: http://www.sno.phy.queensu.ca/sno/publications.html<br />
13<br />
= 1.76<br />
±<br />
0.05 ±<br />
0.09⋅10<br />
6<br />
cm<br />
−2<br />
sec<br />
−1<br />
electron-neutrinos only<br />
Φ NC<br />
=<br />
5.09<br />
Φ CC<br />
1<br />
+ 0.44<br />
− .43<br />
+ 0.46<br />
−0.43<br />
6<br />
−2<br />
0 ⋅10<br />
cm sec<br />
−<br />
all neutrino types<br />
ν<br />
e<br />
Ratio: = 0. 35<br />
ν e + ν μ + ντ<br />
Significance of the SNO<br />
result: first experiment to<br />
“see what happened” by<br />
measuring all neutrino types<br />
Interpretation:<br />
• the total number of neutrinos is consistent with expectations from the solar model.<br />
• only electron-type neutrinos are produced in solar fusion reactions<br />
• 2/3 of these must be turning into other neutrino types (μ, τ) before reaching earth!<br />
Unavoidable conclusion: neutrinos must <strong>have</strong> a small but<br />
finite rest mass! (next question: how big is it?)
Change language