B.Pontecorvo: life and ideas

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B.Pontecorvo life and ideas

• M.G. Sapozhnikov
• Joint Institute for Nuclear Research, Dubna
• Pontecorvo Selected Scientific Works.
  Recollections on B.Pontecorvo.
• Edited by S.M.Bilenky, T.D.Blokhintseva,
  I.G.Pokrovskaya and M.G.Sapozhnikov. Societa
  Italiana di Fisica, 1997.
• Russian edition, two volumes, series "Classics of
  Science" of Russian Academy of Science, 1998.
• htttp//pontecorvo.jinr.ru
• Film Bruno Pontecorvo, Science-Video, 2003

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• Born at 22.08.1913 in Pisa
• Grandfather Pellegrino Pontecorvo
• Textile bisness
• strada P.Pontecorvo in Pisa

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• Father Massimo Pontecorvo
• Mother Maria Maroni
• Guido - biologist, FRS, Prof. in University of
  Glasgow
• Giuliana - politics, Italy
• Giovanni David - agriculturist, England
• Anna - teacher, England
• Laura - nurse, Italy
• Paolo - radar research work, USA
• Gilberto - register and producer, Italy

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The Fermi school

• Entering Facolta di Ingegneria dell'Universita di
  Pisa at 16 years
• Facolta di Fisica e Matematica dell'Universita di
  Roma at 18 years
• Degree of laurea at 20 years.
• "Influence of hydrogeneous substances on the
  radioactivity produced by neutrons"
• E.Fermi, E.Amaldi, B.Pontecorvo, F.Rasetti,
  E.Segre
• October 22, 1934.
• Patent on slow neutrons, October 26, 1934

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The work with F.Joliot-Curie

• Fellowship of Ministero dell'Educazione Nazionale
  for studies with neutrons.
• February 1936, Paris, F.Joliot-Curie.
• ... Working with Joliot it is impossible not to
  be his friend...He has clear mind, broad
  scientific erudition, deep understanding of the
  scientific problems, huge working abilities and
  assureness in himself...There are two
  distinctions of Joliot powerful scientific
  fantasy and what italians calls
  "spregiudicatezza" - an ability to accept any,
  even seemingly "impossible" or "strange" fact.
• Curie-Carnegie prize for study of nuclear
  isomerism

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• Institute of Radium, Paris

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• Mussolinis racist law of 1938

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The communist

• Joint Communist Party
• Bruno became a Communist because he believed
  Communism would create a New Man people that
  were better than they were before, and better
  than the people that exist today. And many
  Italian intellectuals believed in that. For
  example, I too was a Communist
• Gillo Pontecorvo, Interview from the film Bruno
  Pontecorvo.
• He had a very passionate belief in the Soviet
  Union, perhaps a very childish and naive belief.
  I remember when the radio broadcasts the Kremlin
  chimes Bruno would come up to the radio
  especially to listen to those Kremlin chimes.
  Those were the sounds the chimes of his
  dreams
• Gillo Pontecorvo, Interview from the film Bruno
  Pontecorvo.

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Paris, 1936-1940

• Hotel Grand Hommes

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• Married Marianna Nordblom.
• Gil (30.07.38).
• June 1940, escaped from Paris.
• August 1940, departure from Portugal to USA
• with Duccio and Giuliana Tabets

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USA, 1940-1943

• Work on oil logging at Wells Survey, Inc. Tulsa
  Oklahoma
• (with help of E.Segre)
• Invention of neutron oil-logging.
• All patents were properties of the Wells Servey,
  Inc

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Chalk River (1943-1949)

• 1943 Join Anglo-Canadian Research Reactor
  Project. Montreal and Chalk River.
• First method of neutrino registration (Cl-Ar
  method),1946.
• (trying to perform that in a track).
• Unification of weak interactions,1947.
• Muon decays into 3 particles. No ??e?, 1948.
• High multiplication proportional counters, 1949.
• First limit on neutrino mass (mlt500 eV) from
  spectrum of 3H, 1949.

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Harwell, 1949-1950

• February 1948, British citizenship.
• January 1949. Family set at Harwell.
• May 1949. Lecturing in Paris.
• Looking for work
• Anglo-Iranian Oil Company
• University chair in Pisa
• University chair in Liverpool -- accepted
• 1 September 1950 start of the new work

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• First Brunos
• logbook in Dubna

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• First entry of the 1950 logbook.

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• Working at
• Ustanovka M
• best world accelerator of that time (480 MeV)
• no war applications,

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?e ? ??

• Proposal for 500 A proton cyclotron on 800 MeV,
  1958.
• Rochester conference in Kiev, 1959.
• Are the electron and muon neutrinos identical?
• .... for people working on muons in the old
  times, the question about different types of
  neutrinos has always been present.
• B.P."The infancy and youth of neutrino physics"

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• B.Pontecorvo, "Electron and muon neutrinos", 1959
  
• Models of new accelerators are being discussed
  now in which
• the intensity of the accelerated protons may be
  increased as much as by
• three orders of magnitude.
• The neutrino beam from decays of stopped muons
  with E? 35 MeV.
• ? ?e ??? ?e
• ??? p ? ? n
• ??? p ? e n
• M.Schwartz, L.Lederman, J.Steinberger, 1959
• T? measure high-energy neutrinos to study ?(?p)
  for unitarity crisis in weak interactions
• AGS exp N11, "Study of neutrino interactions,
  search for intermediate boson
• The neutrino beam from decays of ? (1GeV) E?
  ?220 MeV
• "The net result is that in 1959 Pontecorvo
  proposes to address the right question but with
  hopeless technique and Schwartz addresses a
  problem that doesn't solved until the 1982
  discovery of the W but his proposal is the right
  experiment to solve ????e problem."

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Neutrino oscillations

• S.M.Bilenky "Early years of neutrino
  oscillations", hep-ph/9908335, 1999.
• "Mesonium and antimesonium", 1957. (?e?) ?
  (??e)
• "The possibility of K0 ???K0 transitions induced
  by weak interactions makes it necessary to
  consider neutral K mesons as a mixture of
  particles of different combined parity (K01 and
  K02). We discuss here the problem as to whether
  there exist other "mixed" neutral particles (not
  necessarily "elementary" ones) which are not
  identical to the corresponding antiparticles and
  for which particle ?? antiparticle transitions
  are not strictly forbidden."
• "If the theory of two component neutrino was not
  valid (which is hardly probably at present) and
  if the conservation law for neutrino charge took
  no place, neutrino ?? antineutrino transitions in
  vacuum would be in principle possible.

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Inverse ?- processes and non-conservationof
lepton charge", 1957.

• ... it is assumed that a) the neutrino ? and
  antineutrino ?? emitted in the processes p ? n
  ? ? and n ?p ?- ?? are not identical
  particles b) the neutrino charge is not strictly
  conserved.
• ...It follows from a) and b) that neutrinos in
  vacuum can transform themselves into antineutrino
  and vice versa. This means that neutrino and
  antineutrino are particle mixtures, i.e.
  symmetrical and antisymmetrical combination of
  two truly neutral Majorana particles ?1 and ?2
  having different combined parity.
• ... a beam of neutral leptons from a reactor
  which at first consists mainly of antineutrinos
  will change its composition and at certain
  distance R from the reactor will be composed of
  neutrino and antineutrino in equal quantities.
• ...effect of transformation of neutrino and
  antineutrino and vice versa may be unobservable
  in the laboratory because of large values of R,
  but will certainly occur, at least, on an
  astronomic scale.

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MNS or P mixing?

• MNS neutrino part of nucleon

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• First high-energy neutrino experiment at
  accelerator (V.Veksler, A.Tyapkin, B.Pontecorvo)
  1961
• From 9 runs 8 were OK
• If 10 will be OK we start writing a paper
• No, we will increase the shielding!

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• All main ideas of the modern neutrino physics
  was suggested by Bruno Pontecorvo.
• Val Telegdi

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The role of the leader, 1976

• great care for students and young physicists
• no official pupils
• The leader in the scientific group is a typical
  scientist, slightly older and more experienced,
  but less able to perceive new things.

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• The leader should not demand from his employees
  that they should be similar to him.
• There are people which like to spend day and
  night in the experimental hall (the most typical
  is Yu.D.Prokoshkin). That is nice feature but
  nobody proved that all people must behave like
  that and that is the only way for a successful
  scientist.

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• The leader should use different characters and
  different features of the members of the team.
  The strength of the group is just in
  complementarity of different features

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• The leader should be ready to learn from young
  members of his team as much as they learn from
  him.
• Citation from LeninSometimes old generation
  dont understand the youth, which should come to
  socialism (science B.P.) in other way, in other
  form and in different environment as their
  fathers. Therefore we for full independence of
  the youth. Because without full independence the
  youngsters neither could be good socialists
  (scientists - B.P.), nor be ready to move
  socialism (science B.P.) forward.
• We are for full independence of the youth, but
  also for full freedom of comrade criticism of
  their mistakes. We should not flattened to the
  youth.

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• Agreement between B.Pontecorvo and M.Balandin,
  1970
• 1. M.Balandin obliged from 1 November of 1970 NOT
  to come to work to the laboratory. He should stay
  home and prepare his PhD. As exception, he
  could come to the library.
• 4. The PhD must be practically ready by January
  1971. Meaning of the word practically could be
  judged by B.Pontecorvo and G.Selivanov.
• 5. If these points will not be fulfilled the
  promises of B.Pontecorvo to M.Balandin will be
  invalid.

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• Each member of the team obtained personal quartal
  plan.
• The weekly seminar is by Fridays.

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The teacher

• Professor of Moscow State University 1961-1966
• Head of the chair on elementary particle physics
• 1966-1986

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• Take note that when one saying that this
  experimentalist has clever hands, it means,
  mainly, that he has clever head. More than 70 of
  great experiments was not only done but also
  suggested by the experimentalists themselves.

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Students folklore

• Exams on the table
• Diploma student and cards
• Vertushka and COMPASS
• Rolling the coin

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The writer

• Unfinished manuscript about E.Majorana
• This man could solve the most difficult problems
  of Nature, but could not find the sense of its
  own life.

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• Dont loose the precious time!
• Yunost, 1964

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What the neutrino physics could do for kolkhoznik
from Ryazan?

• I dont know how the neutrino physics could helps
  to a kolkhoznik of Ryazan, but to some persons
  the study of neutrino physics really helps to
  earn some money.
• Me, for instance.

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• To my mind the human being have no right not to
  study structure of matter.
• Recently I was in Italy and deliver a lecture in
  Scuola Normale in Pisa. Greatest italian
  mathematics and physics, such as Fermi,
  Bernardini, Rubbia etc. have graduated from this
  School . The theme of my lecture was similar to
  the present one. But in Pisa I dont stressed
  enough this duty of the human being for the
  fundamental knowledge.

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• fatti non foste a viver come bruti
• ma per seguir virtute e canoscenza
• Dante
• Scepticism about abstract science is not
  unexpected. FERMI, SLOW NEUTRONS

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• We dont know exactly what practical outcome will
  be from investigation of the structure and
  properties of the elementary particles. But we
  are absolutely sure that these investigations
  will lead to the practical benefits. The prove of
  that is the whole history of physics.
• Developing science we are working in this way for
  the good of our children, for the good of next
  generations.
• B.Pontecorvo