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Borexino: photographing the Sun using neutrinos

Technical: Windows 7,8 64-bit users are definitely recommended to download the stable 64-bit version of Chrome which has twice lower instability rate and is faster, not to mention some new abilities. The installer will automatically update your (now 32-bit) Chrome. Perhaps you have to run it twice, closing Chrome perfectly in between. At the end, "About Chrome" should show "Version 37.0.2062.94 unknown-m (64-bit)".
Physics World and most of other MSM science news sources inform us about the observations by Borexino, an Italian experiment located in Gran Sasso (the word could mean "boring former baby") that observed the \(pp\) neutrinos, the neutrinos created during\[

p + p \to \text{d} + e^{+} + \nu_e

\] i.e. the fusion of proton pairs in the Sun (which produces about 99% of the solar output), for the first time.

A five-minute 2009 video promoting Borexino. Is her accent Italian?

To achieve the goal that wasn't guaranteed from the beginning, they had to use a thousand of tons of water buried 1,400 meters beneath the surface, in order to shield some of the backgrounds.

You should understand that the \(pp\) neutrinos were challenging for the experimenters because even though they represent most of the solar neutrino flux, they have low energies, at most \(0.4\MeV\).

So all the neutrinos that were observed previously – especially those whose "solar neutrino oscillations" were measured – were neutrinos coming from reactions different than the proton-proton fusion, especially the following decay of boron-8 nuclei:\[

{^8}B \to {^8}Be + e^{+} + \nu_e

\] Some of the other reactions have even higher energies, up to \(18\MeV\). I suppose that the original modest plan of Borexino was to look at the neutrinos from the boron-8 reaction above only and that's why it was named "Borexino". If they had known that they would be going to observe the \(pp\) neutrinos, they would have probably named the experiment The Pipino.

All of their observations seem to be consistent with the conventional solar model (of nuclear reactions).

Off-topic from Acapella Science (the author of the Bohemian Gravity): Ice Bucket Quartet

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reader Fer137 said...

The name is because at first they thought to use boron for detecting neutrinos. (BOron Experiment ->BOREX->Borexino)
Later they used another liquid.

reader NikFromNYC said...

Alas the most prolific commenter on the second highest traffic ranked climate skeptical blog by Goddard is a sun physics crackpot who also happens to be widely known in alarmist circles as a registered child rapist. He was also a coauthor of the first edition of the greenhouse effect denying Sky Dragon book with popular skeptic Tim Ball. Given how obscure nuclear physics is to most skeptics, it would be useful if his scientific claims were addressed here, once and for all, rather than ignored since this person alone helps Al Gore and Co. successfully label all skeptics as being lunatics.

reader Luboš Motl said...

If you mean Oliver Manuel, I am getting his e-mails from his e-mail list. Today's rant against the solar model was hilarious. ;-)

reader NikFromNYC said...

Yup, here he is in his daily glory on a skeptic blog that is now second in popularity due to regular DrudgeReport links to it:

“Today about 100 scientists coauthored an article in Nature that confirms the Standard Solar Model of fusion in the core of the Sun against precise, overwhelming experimental evidence the Sun’s neutron-rich pulsar core is the Creator, Destroyer and Sustainer of every atom, life and world in the solar system [1] – like Marduk, the one God of ancient Egypt [2].”

reader Svik said...

So where is the picture in pp neutrinos. Its not on the paper.

They propaply have only observed about 10 neutrinos yet. Can they measure the source direction and reconstruct a picture of the center of the sun??

reader Svik said...

Some Vienna Iqoqis have managed to use entangled photons to take pictures of a cat without the red photons captured ever touching the cat. Pretty eh.

The other touching photons are IR which do touch it.

The camera sees the visible red only.

The invisible camera.

reader Jorginho said...

If Cao-Zhu are as great as you said, why they did not solve the problem by themselves before? Truth be said, Hamilton got years stuck in his proof. Perelman was the man who solved the Poincaré conjecture. Unfortunately, people tried to take that away from him.

reader Luboš Motl said...

I've never said that Cao and Zhu were good enough to be very likely to solve the problem by themselves.

reader Rashmi Pal said...

Very usable post.