Wednesday, February 11, 2015

Val Fitch, co-discoverer of CP-violation: 1923-2015

Val Logsdon Fitch was born on a cattle ranch in Nebraska, a mile from the ranch where Penny came from, in 1923. His dad was badly injured thanks to a horse riding accident. Val himself went to insurance business and then became a soldier in WW2 before he joined the Manhattan Project. That's where the young man was turned to an experimental physicist.

He went through Columbia and McGill before he became a professor at Princeton where he peacefully died on February 5th, aged 91. His Nobel prize in 1980 was won along with James Watson Cronin for their 1964 discovery of the CP-violation. René Turlay could have shared the prize but he wasn't chosen.

The discovery came from their careful observation of K-mesons or kaons.

Particle physicists have been used to CP-violation for half a century and they're told about this feature of Nature when they're rather young. But the fact that this symmetry is broken may be surprising a priori. I got used to it rather quickly but I am pretty sure that as a kid, I would have guessed that Nature had to obey P, C, as well as PC.

Well, Nature doesn't satisfy PC. The society unfortunately does, most of the time, but Nature doesn't.

First, the P-violation was found in the 1950s. Our bodies are slightly asymmetric, the heart is on the left side, but you may believe that it's just a fancy design chosen by Nature and the mirror images of us with the heart on the right side would work identically. But that's not the case.

The most obvious reason why the parity symmetry is violated is the existence of 2-component (Weyl) spinors – which are needed for fields to describe neutrinos. If one neglects the tiny mass (only observed rather recently, and a fact that makes it better to use Majorana and not Weyl spinors for neutrinos), it just seems that the neutrinos always move by the speed of light and they are left-handed when it comes to their spin (rotation around the axis in the direction of motion). They are spinning in one specific way. The mirror situation is neutrinos that are right-handed but they just aren't allowed at all. If you visualize moving and spinning neutrinos as screws, Nature only allows left-handed screws and the right-handed ones are just forbidden.

This is not the only effect of P-violation but it's the most visible one, at least from a theorist's viewpoint.

However, every particle has an antiparticle and the antineutrinos have the opposite handedness – they are right-handed. So for a decade, it could have looked like that there was a more complicated symmetry, one that combines the mirror reflection P and the replacement of particles by their antiparticles C, that remains a symmetry of Nature. The spectrum of neutrinos is symmetric under this CP-symmetry.

Nevertheless, even this CP-symmetry is broken, as found by the 1964 experiment by the two and a half men. The right theoretical explanation was found in the 1970s. The spectrum of the particle may be CP-symmetric but it is still possible to design CP-violating interactions. So far, all the known experiments violating CP are explained by the CP-violating phase in the CKM matrix, a unitary transformation relating the upper-type quark mass eigenstates and the \(SU(2)\) partners of the lower-type quark mass eigenstates.

The Standard Model has the potential for another source of CP-violation, the \(\theta\) angle, the coefficient in front of \({\rm Tr}\,F\wedge F\) of the \(SU(3)_{QCD}\) gauge group, but all experiments so far seem to indicate that this coefficient is zero within the experimental error margin. That's surprising because this number could be of order one, or \(2\pi\), but it's zero. The Peccei-Quinn theory involving axions remains the most viable natural explanation of the "strong CP-problem" i.e. the tiny value of \(\theta\).

The experiment by Van Fitch and pals looked at decays of the neutral K-mesons. The quark composition may be \(d\bar s\), that's \(K^0\), and \(s\bar d\), that's the antiparticle \(\overline{K^0}\). These two particles are not really mass (or energy) eigenstates, however. One may define their sum, \(K^0_L\), which is long-lived and \(K^0_S\) which is short-lived which are closer to energy eigenstates.

When the CP-violation is neglected, \(K^0_S\) may be seen to have the CP-parity equal to \(CP=+1\) while \(K^0_L\) has \(CP=-1\). However, they did observe that \(K^0_L\) may decay to two pions which have \(CP=+1\) which violates CP because \(+1\neq -1\). A more accurate explanation is that the \(K^0_L\) particle isn't really an eigenstate of CP. It has "mostly" \(CP=-1\) but it has a small part of the wave function with \(CP=+1\).

At any rate, we can't define a \(CP\) parity operator that would commute with the Hamiltonian so the symmetry is violated. I should perhaps remind you that \(CP\) is a normal linear operator, not an antilinear one. Only those parity-like operators with "T" in them – e.g. \(T\) or \(CPT\) – are antilinear because the complex conjugation is needed to revert the flow of time.

Fitch was a member of the Board of Sponsors of The Bulletin of the Atomic Scientists, the organization that is currently notorious for its annoying periodic warnings that the Earth is gonna explode in three or five minutes (I forgot the exact timing because I immediately refocus my eyes and ears whenever I am exposed to this garbage).

RIP, Dr Fitch.


  1. It's always gratifying to see that there are people in this world who are capable of intellectually outgrowing their origins. To be sure, he wasn't the first and won't be the last, but it's good to see every such case all the same.

  2. I realized that I have a question of my own. :)

    If NATO were to be dissolved, do you think the EU would need to built up its armed forces further, or would the existing force levels be adequate to provide security to all the members?

  3. I don't think it is fair to blame the results of short sighted, feckless leadership on public opinion. I don't remember getting out of Korea at all. Please don't tell the Norks.

  4. A fine fellow this Putin. Still, if he were to offer me a cup of tea, I would politely decline (unless I have my geiger counter at hand).

  5. The low oil prices complicated Russia's situation further, making the current standoff all the more dangerous.

    As to what it was all about, I see it in many ways the way you do. The last "normal" elections in Ukraine were generally recognized as free and fair, at least as far as I remember, so a coup that was not of entirely internal origin was a legitimate cause for Russia's interference.

    However, where we may differ somewhat is that I don't see Russia as an entirely benign entity, so now that it got to flex its muscle, even if due to our own silliness, there's a chance it will do more flexing unless it is somehow discouraged from letting this spread beyond Ukraine. So, a not entirely perfunctory show of disapproval was still needed after the Crimea annexation. I'd prefer to see NATO dissolved, of course, and the US entirely out of the picture, but so long as we still have some responsibilities in the European defense arrangements, there was no way to just say, oops, we messed up, so let's just call it a day. They seem to be looking for an arrangement that will allow all sides make their point and save their face; let's hope it succeeds.

  6. Theory says reality is exactly mirror symmetric, or curve fit (parity violations, symmetry breakings, chiralanomalies, baryogenesis, dark matter, Chern-Simons repair of Einstein-Hilbert). CP-violation is a failure of the universe, not of theory.

    Phys. Rev. 104(1) 254 (1956)
    Phys. Rev.. 105(4) 1413 (1957)
    Nobel Laureates - two pages!
    PNAS 14(7) 544 (1928)
    Forced to recant. Reality must be mirror symmetric
    Phys. Rev.. 105(4) 1413 (1957)
    Parity-violation is trivially observed. Nobody did it before the fact, for it was Officially impossible.

  7. Except that socialists and fascists are competing for the same collectivist/statist turf, and have long memories and hold grudges. to you and me there may not be any difference between the Bloods and the Crips, but to them there's a world of difference. A lot of "intellectual" Americans still take the loss of Russia hard (whether to capitalists or "fascists" does not matter to them, and is in fact the same thing). A case can be made that the "nation building" in the region is an effort to bring Russia back into the larger socialist fold.

  8. I don't really want to impugn anyone's character or actions, but I've wondered sometimes if the anti-nuke stance of people who worked on the Manhattan Project was due to a real change in conscience (which would be hard enough to understand) or just consistent sympathy for socialist USSR during WW2 (for nukes) and the Cold War (anti-nuke). I believe the Bulletin of Atomic Scientists has signed on to global warming.

  9. Yes, I do. Anywhere the US is in an armed conflict the rest of the world is at war because you are like an elephant in a porcelain shop.

  10. kashyap vasavadaFeb 11, 2015, 5:53:00 PM

    What is the current experimental status of TCP symmetry ? I understand, if a violation of TCP symmetry is found, it would be a major, major revolution, since it is a consequence of local field theory.

  11. Wouldn't that question be equivalent to "How constrained is Lorentz violation currently"?

  12. kashyap vasavadaFeb 11, 2015, 8:57:00 PM

    Yes. That is true if you start from the field theory result. But in view of the importance of the subject for the fundamental physics,it may be desirable to have direct experiments on TCP violation. I sort of recall that there were T violation experiments in the same system as CP violation. But I have forgotten the details and will have to look up.

  13. Solzhenitsyn opined in Izvestia that 1930s famine on the Ukraine was no different from the Russian famine of 1921 as both were caused by the ruthless robbery of peasants by Bolshevik grain procurements. According to him, the lie of the Holodomor being genocide was invented decades later after the event, and Ukrainian effort to have the famine recognized as genocide is an act of historical revisionism that has now surpassed the level of Bolshevik agitprop. The writer cautioned that the genocidal claim has its chances to be accepted by the West due to the general western ignorance of Russian and Ukrainian history. Looks like Medvedev is still depending on Putin about Ukraine

  14. Who's to blame for these inaccurate forecasts? - it seems the IMF, who wanted greek leaders to accept their program, would have pushed optimistic forecasts, but also that the greek leaders would have accepted or perpetrated such lies in order to get bailed out.

  15. Just recently Obama has suggested switching 50% of the defense budget to foreign aid.

  16. Obama is pro-Europe, but he is also pro-Soviet, so he is confused as to the proper action in Europe. Previously, he tried to reverse a coup in Honduras when a Communist was exiled.

  17. Republicans might object, but I suspect nothing much would happen. Billions have been spent bailing out other countries through the IMF in the past. Right now Republicans are just trying to avoid government shutdowns, and not doing much about reversing anything he has done to increase bureaucracy. Even the rebates for solar panels are still alive.

  18. War happens for many reasons. Here is some history for you.

  19. Item 12 demands autonomy of some Donbass regions. What that means exactly is open to interpretation.

  20. You are not the only one.

    "Landau vigorously rejected the possibility of parity non-conservation, saying “space cannot be asymmetric!"


    After that I reported our results to Pomeranchuk. Pomeranchuk decided that we had to tell them to Dau — immediately, next Wednesday. On Wednesday, Dau’s first reaction was to refuse to listen. “I do not want to hear anything about parity nonconservation. This is nonsense!” Chuk persuaded him: “Dau, have patience for about 15 minutes, listen to what young people have to say.” With heavy heart Dau agreed. I spoke not for long, perhaps, for half an hour. Dau kept silent, and then went away. Next day in the morning
    Pomeranchuk called me: Dau solved the parity non-conservation problem! We were supposed to come to him immediately. By that time both of Landau’s papers — on the conservation of the combined (CP) parity and on two-component neutrinos, with all formulations, were already ready.
    Landau considered the CP conservation to be the exact law of nature; he did not admit the possibility of its violation. Concerning CP, Landau would say exactly the same words on the space asymmetry as he used to say previously with regards to P violation. I constructed an example of the Lagrangian in which CP was violated, and nothing bad happened to the vacuum, and tried to change Landau’s mind, but he did not want to listen"

    I think you might want to read all article it is interesting :

    Landau’s Theoretical Minimum, Landau’s Seminar, ITEP
    in the Beginning of the 1950’s :

  21. kashyap vasavadaFeb 12, 2015, 2:14:00 AM

    Thanks for the historical reference. One sentence which made me belly laugh is
    "The professors of the Physics Department were strong in the Marxist philosophy, but almost all were weak in physics."!!

  22. Have you ever philosopized that this universe might be one of the least failed possible fabrications that the multiverse is capable of?😈😉

  23. Insightful and amusing texts, John!

  24. Dear Orson, at the end, the average of the trends from the rural stations and urban stations is very close to one another.

    But even if it were not, what's the problem? It will just mean that the stations with an increasing UHI effect will contribute some increase to the temperatures, and a part of the observed warming trend will be due to UHI.

  25. But even if it were not, what's the problem? It will just mean that the stations with an increasing UHI effect will contribute some increase to the temperatures, and a part of the observed warming trend will be due to UHI.

    The difference is that less of the warming could be attributed to GHGs. Isn't this obvious?

  26. Right, that was my point, right? So it's a trade-off and as long as one is rational, one doesn't "gain" any propaganda edge anyway.

    The question still is how much of the effects is due to CO2 and how much is due to UHI etc. In the cities themselves, it's obvious that UHI is the biggest contribution. In the global average, cities are so rare that UHI is nearly negligible.

  27. The onus is on you to show why adjusted data is better than raw data. You are the one who is "assuming" raw data is worse. and that to correct the "biases" inherent in raw data Unbias humans can be relied on to improve the data. Climate Scientists who have bought into Anthropogenic Global Warming can be counted on to make "Unbias" adjustments to the data? If you believe that I have a bridge in Brooklyn to sell you. Again what other that "Unbias" adjustments to raw data by Bias Climate Scientists do you have to prove your point?

  28. I think Lubos is more credible because he is taking sides only with the science.

  29. The temperature data in your graph is from the ocean shows NASA making the ocean look warmer than the raw data shows. Do you have a graphic from NASA on land data that supports your contention that NASA is cooling the past and warming the present. The one have is below.

  30. The proposition that one gets more accurate data when the raw data is adjusted to account for biases and irregularities isn't an assumption, it's a demonstrable fact.

  31. Now you are doing what you accuse Steve Goddard of doing making assumptions based on your belief that adjusted data is better than raw data with no facts to support it.

  32. Thanks, I wasn't sure if I was missing something, good luck with the peace agreement!

  33. one of the reasons there is way is because when the ottoman empire fell, the British created a bunch of fraudulent states, controlled by a small minority, to cut up oil reserves into smaller countries the British could control...States like the UAE, Bahrain, Quatar, and Kuwait...
    oh, Im sorry....does that include the country that supports you? gee.

  34. Dear david, First, that was just one example of how wars come about and it is a point of view for that matter no matter how many people ascribe to it.

    Second,I don't blame you for the lack of knowledge about the history of the ME, but please be careful not to make conclusions about thinks you don't know about. At the time of the fall of the Ottoman empire(1917) oil has not been discovered yet, oil was discovered in the 30's. Also Kuwait was already under the British protection from 1899, and these entities existed in present form in at least past 300 years with same structure for the ruling families although their social function was a bit different. The inter history of Persian gulf states(and Iran) with British and Portugal goes back 400 hundreds of years.

    We deal with all countries of the world, and like any relation if they make mistakes or mistreat we will obviously object and ask for correction. And if they do something good for us we are obliged to do the same.

  35. Sorry Lubos but your argument does not convince.

    Firstly, claiming models as authority to demonstrate a divergence of temperature trends on a multi-decadal basis between lower troposphere and surface temperatures is not convincing. There are just too many things that the models don't get right.

    On the other hand, it is just common sense that at a point on the earth, the temperature at a meter above the earth and the temperature in the troposphere above that point are correlated. I never said that the temperatures were "the same thing". Hence, one would not expect to see a significant multi-decadal divergence between the two temperatures and even less so for a global divergence of average surface temperature vs average tropospheric temperatures.

    Since I generally enjoy and respect your blog and opinions, I will pretend that I did not read your intemperate last paragraph.

  36. The adjustments of concern are not being made by individual weather stations. They are those being made by GISS, NOAA, CRU and various national met bureaus. The results are then being incorporated into purported global trends and presented as high quality peer reviewed science. Surely you can not be arguing that undeclared, unexplained adjustments to data in such circumstances is acceptable practice.

  37. dude your country is an artifact of the British empire...
    it has no legitimacy at all...less than Israel.'
    get over it, get what you wish for...a rewriting of the borders and countries in the mideast...and kiss your annual payments goodbye.
    while hundreds of millions of islamic people suffer in poverty, your leaders live in opulence... deal with it.

  38. Sorry, the chance that we may agree about something is virtually zero.

    It's the *majority* of the work of GISS, NCDC, HadCRUT, BEST, and others to apply the correct adjustments to the raw data.

    Yes, it's better if the adjustments are transparent. But what really decides about the quality of the product is whether the adjustments are *right*.

    There are all reasons to believe that transparency is just a straw man. BEST has been constructed to make all these things transparent - in fact, done automatically according to open-source algorithms you may reproduce at home - and got the same results within tiny deviations, but for some reason, you don't choose to talk about this evidence that the adjustments were right.

    The main problem is that you don't seem to care whether they are *right*. You only care about inventing bureaucratic hurdles that may be used to spit on someone else's real work.

  39. Could you please stop flooding my blog with this total rubbish?

    I have never used the word "model" in this blog post - your suggestion to otherwise is just a demonstrable lie whose dishonesty may be easily checked by everyone - and climate models are obviously not being used when people measure near-surface temperatures.

  40. Banning Gail Combs is a sign of rationality as far as I'm concerned ...

    This temperature assessment is tricky business, and frankly I found this post refreshing in light of all the shrill alarums being passed around the Web. (And I happen to think that many of the actual adjustments such as those cited for Iceland, Australia and now Paraguay are highly suspicious.)

  41. Lubos,

    Don't worry, you are not disagreeing with anything I stated or implied but only with the straw men of your own creation. I have no objection to data adjustment in itself but do think that proper science requires any such manipulation should be fully disclosed.

    You seem to argue that disclosure is unimportant so long as the adjustment is "right"; but, how can "right" be assessed if what has been done is unknown. As for criminalizing any such adjustment, that is solely your suggestion, not mine.

    You are obviously a very bright person but you can still be wrong too. Need you be reminded of your heartfelt but (fortunately) quite wrong self-diagnosis of a terminal medical condition.

    Lighten up a bit and don't always assume that everyone else is a fool.

  42. David browse this wiki article quickly, there is nothing in it about your claim.

  43. Sorry, Walter, you are confusing science and bureaucracy.

    The scientific method is a collection of clever and functional rules to find the truth about Nature. The scientific method doesn't include any arbitrary bureaucratic regulations about data's being open-source for everyone, or something like that.

    Institutions, journals, parliaments etc. may impose such extra rules but they are a matter of politics, not science, and whether these laws are imposed or not can't decide the question whether a scientific proposition is right.

  44. The US and Europe states must be united in this issue Ukraine issue because it seems that even with the peace treaty obtained at Minsk, the shellings are back in Ukraine and the Russian para troops are still fighting.

    Europe has an issue on arming Ukraine because they receive gas from Russia so they rely on Russia for fossil resources.

    In the meantime Hungary resumed its gas deliveries to Ukraine even if before, Russia was their biggest supplier.

  45. Mosh is right. There is a large problem in the Land Surface record, though: 80% of the USHCN ("crown jewel" of the GHCN) stations has non-compliant microsite (study period 1979 - 2008). To insure an unperturbed set, stations with moves or TOBS flips are dropped, thus eliminating those factors from consideration. MMTS conversion adjustment is applied (which increases the raw trend).

    The well sited stations average a Tmean trend of ~0.195C/decade, while the poorly sited stations trend at ~0.325. This data is homogenized, which process identifies and adjusts outliers to conform with the maximum.

    So which stations do you suppose are identified as outliers? And in which direction do you supposed they are adjusted?

    The adjusted trend is ~0.324.

    All trace of the well sited station signal is obliterated. Non-compliant microsite is a systematic error, and, as a result, homogenization adjusts the stations in exactly the wrong direction.

    Adjustment (or, alternatively, simply dropping poorly sited or perturbed stations) is very important, yes, but it has to be done right, and currently it simply isn't. This bodes very poorly for the overall accuracy of GHCN data, either raw or adjusted. It suggests that the land surface trend is highballed by at least 60%, resulting in an overall spurious exaggeration of the global trend (including oceans) of at least 20%, possibly more.

  46. I have been thinking about the things you have been saying. It is natural for the hyena to envy the lion, but there is something worse going on with you. You are a disgusting Nazi, the only difference being that you are French and not German. We don't have many Nazis like you in America, so I didn't recognize what you are at first.

    The US didn't even have an army to speak of before getting dragged into two European wars. Wars started by nationalist bigots like yourself, each believing that your own native culture is superior to all others.

    The reason we don't have very many Nazis like you is that our fathers were sent over to Europe, Africa, and the Pacific to fight people like you who foment wars on the least provocation.

  47. You are one hell of a clown, Cogniscentum :-D

  48. And you are a Nazi.

  49. nah...shes just the type of woman who would have effed them in exchange for some property that once belonged to a jew.

  50. Lubos, I linked your article in the comments section on ZeroHedge.