Cosmic Gall

1. Cosmic Gall Neutrinos they are very small.They have no charge and have no massAnd do not interact at all.The earth is just a silly ballTo them, through which they simply pass,Like dustmaids down a drafty hallOr photons through a sheet of glass.They snub the most exquisite gas,Ignore the most substantial wall,Cold-shoulder steel and sounding brass,Insult the stallion in his stall,And, scorning barriers of class,Infiltrate you and me! Like tallAnd painless guillotines, they fallDown through our heads into the grass.At night, they enter at NepalAnd pierce the lover and his lassFrom underneath the bed – you callIt wonderful; I call it crass. John Updike (1960)

2. Wat vooraf ging … ,The History before the history (1896-1930) • Before the neutrino comes, the beta decay problem had to appear. And in order for that problem to appear, radioactivity had to be discovered. Henri Becquerel in the year 1896, then Pierre and Marie Curie were the first actors of this time. While Henri Becquerel discovered some strange radiation coming from uranium salts, Pierre and Marie Curie isolated radium, a material much more radioactive than uranium. • In 1899, Rutherford shows that two types of radiation exist, that he calls alpha and beta. In 1900, Villard gives evidence for a third type of radiation coming from radium, that he calls gamma radiation. In 1902, Pierre and Marie Curie show that beta radiation was nothing else than electrons, while F. Soddy and E. Rutherford estimate that alpha, beta and gamma radiation are different types of radioactivity. • A crazy race begins to study in details those radiations coming from radioactive materials. Around 1904, Rutherford shows that alpha radiation is made of something like helium atoms. Finally, three types of radioactivity are definitely asserted: • alpha radioactivity: an Helium 4 nucleus (two protons and two neutrons) comes out of the radioactive nucleus. • gamma radioactivity: a photon of great energy (few MeV) comes out of the radioactive nucleus. • beta radioactivity: an electron comes out of the radioactive nucleus. • The beta radiation (electron), the presumed only particle emitted, should have had a well fixed energy. But, after different studies of this radiation made by Lise Meitner, Otto Hahn, Wilson and von Baeyer, James Chadwick shows in 1914 that this is not the case: the electron energy spectrum is continuous. • Do we have to throw away the energy conservation principle, the sacred principle of scientists always verified by experiment ?... Niels Bohr, among others, dares to believe it. We must wait the year 1930 and Wolfgang Pauli in order the see an other solution. (Uit : ‘History of the neutrinos’ http://wwwlapp.in2p3.fr/neutrinos/aneut.html)

3. Probleempje ? Beta-verval : Energieverdeling elektronen :

4. Voorstel : Pauli (1930)

5. Pauli's letter of the 4th of December 1930 Dear Radioactive Ladies and Gentlemen, As the bearer of these lines, to whom I graciously ask you to listen, will explain to you in more detail, how because of the "wrong" statistics of the N and Li6 nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the "exchange theorem" of statistics and the law of conservation of energy. Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have spin 1/2 and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass and in any event not larger than 0.01 proton masses. The continuous beta spectrum would then become understandable by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and the electron is constant... I agree that my remedy could seem incredible because one should have seen those neutrons much earlier if they really exist. But only the one who dare can win and the difficult situation, due to the continuous structure of the beta spectrum, is lighted by a remark of my honoured predecessor, Mr Debye, who told me recently in Bruxelles: "Oh, It's well better not to think to this at all, like new taxes". From now on, every solution to the issue must be discussed. Thus, dear radioactive people, look and judge. Unfortunately, I cannot appear in Tubingen personally since I am indispensable here in Zurich because of a ball on the night of 6/7 December. With my best regards to you, and also to Mr Back. Your humble servant . W. Pauli, December 1930

6. Solvay conferentie, Brussel, oktober 1933 At Solvay conference in Bruxelles, in October 1933, Pauli says, speaking about his particles: "... their mass can not be very much more than the electron mass. In order to distinguish them from heavy neutrons, mister Fermi has proposed to name them "neutrinos". It is possible that the proper mass of neutrinos be zero... It seems to me plausible that neutrinos have a spin 1/2... We know nothing about the interaction of neutrinos with the other particles of matter and with photons: the hypothesis that they have a magnetic moment seems to me not funded at all."

7. Fermi-theorie voor neutrino-interacties W±, Z0 : zware ijkbosonen Lage energie processen • Belangrijke benaderingen : • -lage-energie puntinteractie, er worden geen ijkbosonen uitgewisseld • (…. -> Glashow-Weinberg-Salam ’68) • geen pariteitsbreking • ( … ->Feynman & Gell-Mann ’56) ‘Zwakke’ interactie :koppelingsconstante klein GF = 1.16639 10− 5GeV− 2 heelkleine werkzame doorsneden !

8. Neutrino-experimenten in de kinderschoenen 2 neutrino experiment : ontdekking muon neutrino (Lederman, Schwartz, Steinberger (1962) ) ‘From Poltergeist to particle’ : neutrino-detectie : Savannah River, (Cowan&Reines 1956) Homestake (Davis, 1970) : zonneneutrino’s

9. Waar ? • kosmologische neutrino’s • natuurlijke radio-acitiveit • reactorneutrino’s • supernovaneutrino’s • hoog-energetische kosmische neutrino’s • zonneneutrino’s • atmosferische neutrino’s

10. Neutrino-oscillaties – Pontecorvo 1957 Bruno Pontecorvo • Voorwaarden voor oscillaties : • mixing • massaverschillen

11. Neutrino mixing en oscillaties

12. Oscillaties in materie – MSW effect (Mikheyev-Smirnov-Wolfenstein ’78/’85) de curves corresponderen met verschillende waarden van de vacuum mixing hoek θ A/Δm2

13. Neutrino-oscillaties experimenteel bekeken -Kamiokamijn -waterdetector -enkel elektronneutrino’s • Eerste positief signaal : Super-Kamiokande (1998) – atmosferisch neutrino’s http://neutrino.phys.washington.edu/~superk/

14. SK resultaten azimuthale asymmetrie (PRL 811562-1567,1998)

15. Gedetecteerde/verwachte events … maar waar is de rest naartoe ? …

16. …. SNO ! Bevestiging : SNO (Sudbury Neutrino Observatory, Canada) ook gevoelig aan neutrale stroomreacties : neutrino’s van alle flavors ! neutrale stroom – detectie neutronen : ook mu, tauneutrino’s ! geladen stroom elektron scattering – relatief kleine werkzame doorsneden http://www.sno.phy.queensu.ca/

17. 8B zonneutrino’s : dag/nacht asymmetrie

18. Oscillatieparameters • Maki-Nagawa-Sakata matrix ! • oscillatielengte Lν • massakwadraat verschillen Δm2 Experimenteel :

19. … neutrinos over the world Chooz

20. 07-04 April 11, 2007 Media Contact:Mike Perricone, Fermilab Office of Public Affairs, mikep@fnal.gov, 630-840-3351Kurt Riesselmann, Fermilab Office of Public Affairs, kurtr@fnal.gov, 630-840-3351 Photos and graphics of the MiniBooNE experiment are available at: http://www.fnal.gov/pub/presspass/images/BooNE-images.html For immediate release MiniBooNE opens the boxResults from Fermilab experiment resolve long-standing neutrino question BATAVIA, Illinois-Scientists of the MiniBooNE1 experiment at the Department of Energy's Fermilab2 today (April 11) announced their first findings. The MiniBooNE results resolve questions raised by observations of the LSND3 experiment in the 1990s that appeared to contradict findings of other neutrino experiments worldwide. MiniBooNE researchers showed conclusively that the LSND results could not be due to simple neutrino oscillation, a phenomenon in which one type of neutrino transforms into another type and back again. The announcement significantly clarifies the overall picture of how neutrinos behave. Currently, three types or "flavors" of neutrinos are known to exist: electron neutrinos, muon neutrinos and tau neutrinos. In the last 10 years, several experiments have shown that neutrinos can oscillate from one flavor to another and back. The observations made by the LSND collaboration also suggested the presence of neutrino oscillation, but in a neutrino mass region vastly different from other experiments. Reconciling the LSND observations with the oscillation results of other neutrino experiments would have required the presence of a fourth, or "sterile" type of neutrino, with properties different from the three standard neutrinos. The existence of sterile neutrinos would throw serious doubt on the current structure of particle physics, known as the Standard Model of Particles and Forces. Because of the far-reaching consequences of this interpretation, the LSND findings cried out for independent verification. The MiniBooNE collaboration ruled out the simple LSND oscillation interpretation by looking for signs of muon neutrinos oscillating into electron neutrinos in the region indicated by the LSND observations. The collaboration found no appearance of electron neutrinos as predicted by a simple two-neutrino oscillation scenario. "It was very important to verify or refute the surprising LSND result," said Robin Staffin, DOE Associate Director of Science for High Energy Physics. "We never know what nature has in store for us. The MiniBooNE experiment was an important one to do and is to be complimented for a job well done." The MiniBooNE experiment, approved in 1998, took data for the current analysis from 2002 until the end of 2005 using muon neutrinos produced by the Booster accelerator at Fermilab. The MiniBooNE detector, located about 500 meters from the point at which the muon neutrinos were produced, looked for electron neutrinos created by the muon neutrinos. The experiment's goal was either to confirm or to refute the startling observations reported by the LSND collaboration, thus answering a long-standing question that has troubled the neutrino physics community for more than a decade. "Our results are the culmination of many years of very careful and thorough analysis. This was really an extraordinary team effort," said MiniBooNE cospokesperson Janet Conrad of Columbia University. "We know that scientists everywhere have been eagerly waiting for our results." The MiniBooNE collaboration used a blind-experiment technique to ensure the credibility of their analysis and results. While collecting their neutrino data, the MiniBooNE collaboration did not permit themselves access to data in the region, or "box," where they would expect to see the same signature of oscillations as LSND. When the MiniBooNE collaboration opened the box and "unblinded" its data less than three weeks ago, the telltale oscillation signature was absent. "We are delighted to see that the work of the MiniBooNE team has led to the resolution of this puzzle," said Marv Goldberg, Program Director for Elementary Particle Physics at the National Science Foundation. "We're proud that our support yielded such an important breakthrough for neutrino physics and we look forward to additional results from this team of university and national laboratory scientists." Although the MiniBooNE researchers have decisively ruled out the interpretation of the LSND results as being due to oscillation between two types of neutrinos, the collaboration has more work ahead. "We have been studying the bulk of our data for several years," said Fermilab physicist Steve Brice, analysis coordinator for the MiniBooNE experiment, "but we have had access to these sequestered data for only a short time. There are remaining analyses that we are eager to do next. They include detailed investigation of data we observe at low energy that do not match what we expected to see, along with more exotic neutrino oscillation models and other exciting physics." At this time, the source of the apparent low-energy discrepancy is unknown. "It is great to get the MiniBooNE results out," said Fermilab Director Pier Oddone. "It clears one mystery but it leaves us with a puzzle that is important to understand." The MiniBooNE collaboration will further analyze its data. "As in many particle physics experiments, we have a result that answers some questions and raises others," said MiniBooNE co-spokesperson William Louis, Los Alamos National Laboratory, who also worked on the original LSND experiment. "We live in interesting times." For its observations, MiniBooNE relies on a detector made of a 250,000-gallon tank filled with ultrapure mineral oil, clearer than water from a faucet. A layer of 1280 light-sensitive photomultiplier tubes, mounted inside the tank, detects collisions between neutrinos made by the Booster accelerator and carbon nuclei of oil molecules inside the detector. Since January 2006, the MiniBooNE experiment has been collecting data using beams of antineutrinos instead of neutrinos and expects further results from these new data. Notes for editors: Scientists of the MiniBooNE collaboration will present their results at the meeting of the American Physical Society in Jacksonville, Florida on April 16. Conference organizers have arranged for a press briefing at 1 PM (EDT) on April 16. 1 The MinibooNE experiment, formally known as the Booster Neutrino Experiment, is an international collaboration of scientists involving 77 physicists from 17 institutions in the U.S. and the United Kingdom who conduct the MiniBooNE experiment at Fermilab. MiniBooNE physicists are supported by funding from the U.S. Department of Energy and the U.S. National Science Foundation. 2 Fermi National Accelerator Laboratory is a Department of Energy Office of Science national laboratory operated under contract by the Fermi Research Alliance, LLC. The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States. 3 LSND is the Liquid Scintillator Neutrino Detector experiment at the Department of Energy's Los Alamos National Laboratory.