2015 Nobel Prize in Physics announcement

[Orodruin]

Today we will learn who wins the 2015 Nobel Prize in physics. The announcement will be available online at 11.45 CET at the earliest (depending on whether or not they have taken a decision and been able to inform the laureates).

Link to announcement: http://www.kva.se/en/Events-List/2015/Announcement-of-the-Nobel-Prize-in-Physics-2015/

 

[Borg]

It would be interesting to attend one of those.

 

[Orodruin]

You need a registration, a press ID, and to travel to Stockholm. I only have the last part covered - the Academy is order 1 km away from where I am sitting.
Later today we have a colloquium presentation of the Prize here at the AlbaNova University center.

 

[Orodruin]

Neutrino oscillations!

 

[Orodruin]

I think I know some experts on this subject ...

 

[Orodruin]

Here is the press release: http://www.nobelprize.org/nobel_prizes/physics/laureates/2015/press.html

 

[jtbell]

I think I know some experts on this subject ...

Well, I (and the rest of my grad school research group) would have been astonished if I had actually found neutrino oscillations in my dissertation project 33 years ago.

I figured that experiment would get the prize eventually. Congratulations to them!

 

[Greg Bernhardt]

Congrats to the winners!

 

[Greg Bernhardt]

@robphy time to get them to UWLAX!

 

[Ygggdrasil]

@mfb wrote a nice Insights article on the topic a few months ago: https://www.physicsforums.com/insights/neutrino-masses-speed

Somewhat disappointed that it didn't go to Vera Rubin and others for their work on dark matter. Hopefully, she'll still be around when the committee gets around to awarding the next astronomy-related prize.

[edit: thanks to robphy for pointing out the spelling mistake]

 

[robphy]

That probably should be Vera Rubin.

 

[atyy]

Well, I (and the rest of my grad school research group) would have been astonished if I had actually found neutrino oscillations in my dissertation project 33 years ago.

I figured that experiment would get the prize eventually. Congratulations to them!

Gosh, I was certain neutrino oscillations wouldn't get the prize this year - I had assumed they had already gotten it!

 

[Andrew Mason]

I think congratulations are owed to a lot of people who worked on the Neutrino project, including Dr. McDonald and Dr. Kajita.

I did my undergraduate degree at Queen's and spent many hours in Stirling Hall. During my 4 years at Queen's I got to know many of the professors who eventually worked on the neutrino mass project with Dr. McDonald, including Dr. Hugh Evans, Dr. George Ewan and Dr. Hay Boon Mak,. During the summer of 1974 I had the pleasure of working there under Dr. Mak, then a research fellow. He was at that time part of the team at the Chalk River nuclear facility and he later went to the Sudbury Neutrino Observatory when it was started in the 1980s. While my time at Queens was well before Dr. McDonald arrived, it is quite apparent that he was able to work with a very highly qualified group that worked very well together. I think they all deserve recognition in this.

AM

 

[Orodruin]

Art McDonald once asked me back in 2006 or so if I would consider taking up an experimental post-doc with SNO. I guess that is how close I will ever get to work with a Nobel laureate.

Edit: Also, given my experimental skills, this was probably in the best interest of the collaboration

 

[dlgoff]

I guess that is how close I will ever get to work with a Nobel laureate.

Close enough for me.

 

[PWiz]

Wow! So does this now mean that there is a greater probability of the 3 neutrino flavors being massive (and having different invariant masses)? What does the scientific community think about Lorentz-violating neutrino oscillations after this?

 

[Orodruin]

Wow! So does this now mean that there is a greater probability of the 3 neutrino flavors being massive (and having different invariant masses)? What does the scientific community think about Lorentz-violating neutrino oscillations after this?

The results they were awarded the prize for are over a decade old so they are not really news to the scientific community. The results were (and still are) of great importance for the development of the experimental neutrino physics programme as well as for the theoretical developments.

The flavours themselves do not have specific masses. Instead, they are linear combinations of the different mass eigenstates - much in the same way as a quantum state in a superposition of states with different energy does not have a definite energy, but is a superposition of different energy eigenstates.

As for Lorentz invariance, neutrino oscillations are working perfectly fine in a Lorentz invariant framework.

 

[mfb]

At least two mass eigenstates have to be massive. The third could be massless, but there is no special reason to expect this.

What does the scientific community think about Lorentz-violating neutrino oscillations after this?

There have never been Lorentz-violating observations of anything. There was a measurement error from OPERA four years ago that got fixed three years ago.

 

[mjsd]

so glad to see this has finally happened. I was in my final years at high school when Super-K announced their results...
and somehow I moved into the topic of neutrino models at uni

 

[Vanadium 50]

greater probability of the 3 neutrino flavors being massive (and having different invariant masses)

The probability is the same as it was before the prize was awarded, no? Prizes don't influence nature.

At least two mass eigenstates have to be massive. The third could be massless

Does that work? I don't think it's as simple as looking at the DeltaM terms. I think that derivation is done under the assumption of three non-zero masses.

 

[Orodruin]

Does that work? I don't think it's as simple as looking at the DeltaM terms. I think that derivation is done under the assumption of three non-zero masses.

It works perfectly fine. The approximation made in the usual heuristic derivation is $\sqrt{p^2 + m_i^2} \simeq p + m_i^2/2p$, which remains true even for $m_i = 0$ (in fact, for $m_i = 0$, it is no longer an approximation).

 

[PWiz]

The probability is the same as it was before the prize was awarded, no? Prizes don't influence nature.

The fact that the nobel prize is being awarded for results obtained 10 years ago makes me feel that some other recent measurements have pointed in the same direction as the original results, lending credibility to the original experimental data. A nobel prize looks like a gesture of acknowledgment from the scientific community IMO, because I'm pretty sure the Royal Swedish Academy of Sciences won't award it to someone for findings which some scientists find inconclusive.

 

[lisab]

I guess that is how close I will ever get to work with a Nobel laureate.

Work with a laureate? No, not me, but I almost tripped Hans Dehmelt in the hallway when I was a student at UW.

 

[Orodruin]

Work with a laureate? No, not me, but I almost tripped Hans Dehmelt in the hallway when I was a student at UW.

In my first international physics conference, my supervisor told me I had just cut the line to the coffee break just in front of Lincoln Wolfenstein. Of course, I had no idea what he looked like at the time.

 

[robphy]

When I was a grad student, I found Chandrasekhar's wallet in the library.
He was browsing the stacks earlier... and I guess his wallet fell out.

 

[martinbn]

When I was a grad student, I found Chandrasekhar's wallet in the library.
He was browsing the stacks earlier... and I guess his wallet fell out.

Did you give it back?

 

[Vanadium 50]

It works perfectly fine.

I was actually thinking about something else. Usually the derivation uses the Schroedinger equation, justified because you can always find a frame near the rest frame of the neutrino. That doesn't work if one of the eigenstates is massless. The derivation may still give the right answer, but the argument is a little shakier.

 

[Orodruin]

I was actually thinking about something else. Usually the derivation uses the Schroedinger equation, justified because you can always find a frame near the rest frame of the neutrino. That doesn't work if one of the eigenstates is massless. The derivation may still give the right answer, but the argument is a little shakier.

The normal heuristic derivation is very shaky at best not only for this reason but also because it is usually assumed that all mass eigenstates carry the same momentum. If you really want to do it properly, you need to look at it from a QFT viewpoint including the reactions in which the neutrinos are created and destroyed. A slightly more rigorous option yet still not as rigorous as the QFT approach is using a wave-packet approach. For relatively reasonable assumptions and approximations, these both give the same result as the heuristic derivation.

Edit: You also typically do not go to the rest frame of the neutrino in the heuristic approach. You just make the approximation I quoted for the energies.

 

[TheAnt]

Neutrino oscillations!

When I heard about it!

 

[Davephaelon]

Congratulations to the recipients, and to everyone involved in neutrino oscillation physics over the years!

Of great interest is that the MicroBooNE collaboration has seen its first cosmic muons: http://www.fnal.gov/pub/today/archive/archive_2015/today15-08-12.html This project was started to investigate an excess of low energy electron neutrinos seen in the MiniBooNE Project, which itself was designed to investigate an anomaly in the LSND experiment, which suggested the existence of a fourth, sterile neutrino species: http://www.aps.org/publications/apsnews/200706/miniboone.cfm

The MicroBooNE project is planned to take data for three years.