Solving the Solar Neutrino Problem

In summary, there were deficits in the observed solar neutrino flux compared to theoretical values in the solar neutrino experiments. Focusing on the Cl-37 and Ga-71 reactions, the ratio of observed flux to expected flux was 0.29 and 0.55-0.60 respectively. The reason for the discrepancy is still unknown, but it may have to do with neutrinos changing flavors and the energy-dependent flavor fluctuation. However, taking into account experimental error, the two experiments are consistent with each other. The reference for these results is J.N.Abdurash_itov et al., in Results from SAGE (The Russian American Gallium Experiment), Phys
  • #1
tnho
31
0
In the solar neutrino experiments, there were deficits in the observed solar neutrino flux when compared with the theoretical values. If i just focus on the Cl-37 and Ga-71 reactions to detect solar neutrinos, there is a question confuses me a lot.
That is,

from the result of experiment done by Davis (using Cl-37), the ratio of the observed flux to the expected flux was about 0.29. However, from the result of SAGE and GALLEX (using Ga-71) at later time, the ratio were about 0.55-0.60, which were much different from the previous case. Does anyone know the reason behind??

Thank you very much!

Reference:
J.N.Abdura****ov et al., in Results from SAGE (The Russian American Gallium Experiment), Phys. Lett. B328 (1994) 223-248

P.S. the name cannot be displayed...
it should be "J.N. Abdurash_itov" without "_"..
 
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  • #2
Might it have something to do with Neurtinos coming in three flavours?

As I understand it the current theory is that neutrinos change between three states, it may be that one of the expriments detects only one state of nuetrino whereas the second experiment (using different detectors) might be able to detect two types.
 
  • #3
max_emerso said:
Might it have something to do with Neurtinos coming in three flavours?

As I understand it the current theory is that neutrinos change between three states, it may be that one of the expriments detects only one state of nuetrino whereas the second experiment (using different detectors) might be able to detect two types.

You are right. Neutrinos DO change their flavors (or states).
However, all experiments mentioned above were all observing the electron neutrinos with the same length traveled.
 
  • #4
One argument I heard to explain the GALLEX results was that the capture rate for low energy neutrinos was closer to the theoretical result. This hinged on a energy dependent flavor fluctuation.

But, I think if you take into account the all the experimental error, the two experiments are consistent with each other. This is only from memory, so I may be wrong.
 
  • #5
tnho said:
In the solar neutrino experiments, there were deficits in the observed solar neutrino flux when compared with the theoretical values. If i just focus on the Cl-37 and Ga-71 reactions to detect solar neutrinos, there is a question confuses me a lot.
That is,

from the result of experiment done by Davis (using Cl-37), the ratio of the observed flux to the expected flux was about 0.29. However, from the result of SAGE and GALLEX (using Ga-71) at later time, the ratio were about 0.55-0.60, which were much different from the previous case. Does anyone know the reason behind??

Thank you very much!

Reference:
J.N.Abdura****ov et al., in Results from SAGE (The Russian American Gallium Experiment), Phys. Lett. B328 (1994) 223-248

P.S. the name cannot be displayed...
it should be "J.N. Abdurash_itov" without "_"..

The reason for they got higher observed flux was that they now could measure muon neutrinos as well (if I remember right, did a course in neutrino astrophysics last semster and have a lot of pdf's if you want )
 
  • #6
Norman said:
One argument I heard to explain the GALLEX results was that the capture rate for low energy neutrinos was closer to the theoretical result. This hinged on a energy dependent flavor fluctuation.

But, I think if you take into account the all the experimental error, the two experiments are consistent with each other. This is only from memory, so I may be wrong.

I have thought that before but not quite sure. It is true that oscillation angles do depend on energy.


malawi_glenn said:
The reason for they got higher observed flux was that they now could measure muon neutrinos as well (if I remember right, did a course in neutrino astrophysics last semster and have a lot of pdf's if you want )

um..i don't think so as those experiments only measured the electron neutrinos but no other flavors.
 
  • #7
tnho said:
I have thought that before but not quite sure. It is true that oscillation angles do depend on energy.




um..i don't think so as those experiments only measured the electron neutrinos but no other flavors.


Then I must have rememberd wrong, altough there was one experiment later that also measured the flux of muon neutrinos
 

Related to Solving the Solar Neutrino Problem

1. What is the Solar Neutrino Problem?

The Solar Neutrino Problem refers to the discrepancy between the predicted number of neutrinos from the Sun's nuclear reactions and the number actually observed on Earth. This problem was first identified in the 1960s and has since been a major topic of research in astrophysics.

2. Why is solving the Solar Neutrino Problem important?

Solving the Solar Neutrino Problem is crucial because it provides valuable insights into the inner workings of the Sun and helps us better understand the fundamental properties of neutrinos. It also has implications for our understanding of other astrophysical processes, such as supernovae.

3. How has the Solar Neutrino Problem been addressed by scientists?

Scientists have approached the Solar Neutrino Problem through a combination of theoretical modeling, experimental measurements, and technological advancements. This has led to the development of various neutrino detectors, such as the Sudbury Neutrino Observatory and the Super-Kamiokande, which have helped shed light on the problem.

4. What are some proposed solutions to the Solar Neutrino Problem?

One proposed solution to the Solar Neutrino Problem is the idea of neutrino oscillation, where neutrinos can change between different types (flavors) as they travel through space. Other proposed solutions include modifications to our understanding of the Sun's nuclear reactions or the properties of neutrinos themselves.

5. Has the Solar Neutrino Problem been completely solved?

While significant progress has been made in solving the Solar Neutrino Problem, it is still an ongoing area of research. The discovery of neutrino oscillation in the early 2000s has provided a partial solution, but there are still unanswered questions and areas of uncertainty. Further advancements in technology and experimental techniques will continue to help us better understand this complex problem.

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