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The neutron as a tool, and the neutron as an object

The neutron as a tool, and the neutron as an object. Dirk Dubbers U. Heidelberg. Weightwatcher: 40 kg of protons 32 kg of neutrons 22 g of electrons. A. The neutron as a tool: Neutron scattering (from a frog's perspective) B. The neutron as an object: ~ as a wave ~ as a particle.

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The neutron as a tool, and the neutron as an object

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  1. The neutron as a tool, and the neutron as an object Dirk Dubbers U. Heidelberg The neutron as a tool, and the neutron as an object

  2. Weightwatcher: 40 kg of protons 32 kg of neutrons 22 g of electrons A. The neutron as a tool:Neutron scattering (from a frog's perspective)B. The neutron as an object:~ as a wave~ as a particle The neutron as a tool, and the neutron as an object

  3. A. The neutron as a toolSome trivia on neutron scattering A lookintotheinteriorof matter: The neutron as a tool, and the neutron as an object

  4. Letusdream: Weplace a cameraontosomesiter0andtake a snapshotofitssurrounding: ρ(r − r0) = ρ(x) r x r0 x = r− r0 The neutron as a tool, and the neutron as an object

  5. Advanceddream: Take a videoofthemolecules:ρ(x,t)Nowadaysonestoresmovies in theFrequency Domain. Examples:1. The storageof a pieceofmusicf(t) in an mp3 player: FFTf(t) ─────> g(ω) = ∫ f(t) e−iωt dω (Bandwidthand time resolution: Δω·Δt~ 1) The neutron as a tool, and the neutron as an object

  6. 2. The storageof a snapshotρ(x) in thecloud: FFTρ(x) ─────> S(q) = ∫ρ(x) e−iq·xdqyqyxqx (Range ofwavevectorsΔq, spatial resolution Δx : Δq·Δx~ 1) The neutron as a tool, and the neutron as an object

  7. 3. The storageof a videoρ(x,t)asS(q,ω): Replay: FFT−1S(q,ω) ─────> ρ(x,t) = ∫∫ S(q,ω) ei(q·x−ωt) dx dt The neutron as a tool, and the neutron as an object

  8. Neutrons fulfillthisdream!TheyprovidetheatomicscatteringfunctionS(q,ω) ofmatter:Theysee "wheretheatomsareandwhattheatoms do" (λn~Å andEn~meV!)Main differencetothe mp3 method: Neutrons deliver a genuine 3D-quantummovieρ(x,t) ↔ S(q,ω),but takeensembleaverages.Transition fromclassicaltoquantumphysics via:EnergyE = ħω, momentump = ħqUncertaintyrelations: ħΔω·Δt = ΔE·Δt ~ħħΔq·Δx= Δp·Δx~ħ The neutron as a tool, and the neutron as an object

  9. Different neutroninstrumentsfor:- Elasticandinelasticscattering(fordiffractionS(q) andspectroscopy, S(q,ω))- Large angle andsmall angle scattering (forsmalland large objects),- Forcoherentandincoherentscattering(seebelow)- Fornonmagneticandmagneticscattering, - Using thermal andcoldneutrons, in all combinations, thisgives~ 25 ≈ 30…40 instruments.Different qandω ranges in S(q,ω): The neutron as a tool, and the neutron as an object

  10. An ensembleofparticlescanbeexcitedcoherently … … orincoherently La Ola λ Neutrons candistinguishbetweenScoh(q,ω) and Sinc(q,ω)! The neutron as a tool, and the neutron as an object

  11. The ~ 25instrumentsof Institute Laue Langevin, Grenoble: For all typesof matter: Metals, superconductors, soft matter, biomolecules, minerals, nanomaterials, …usedby: physicists, chemists, biologists, geologists, … Mixed teams from all universities and countries The neutron as a tool, and the neutron as an object

  12. Grenoble: ILL ↓ (neutrons) ESRF ↓ (X-rays) The neutron as a tool, and the neutron as an object

  13. How do neutronsgiveusS(q,ω)?Due tomomentumandenergyconservation:A change in thesystem'swavevectorqandoscillationωreappearsas a change in theneutron'smomentum (asderivedfromitsscattering angle θandwavelengthλ)andkineticenergy(asderived, e.g., fromneutronToF).In thisway, neutronscatteringsuppliesthescatteringfunction S(q,ω).IN5 at ILL: ToF Scatteringangle θ The neutron as a tool, and the neutron as an object

  14. Neutron scattering−oneexample: Lipoproteins in the blood provide D2O cholesterol and fat for peripheral tissue. Their shapes were measured with SANS at PSI, their dynamics with quasielastic n-scattering on IN5 and IN6 at ILL, their flexibility ("mean square displacement") with incoherent elastic scatterung on IN13 at ILL, to find out "where the atoms are and what they do" (in D2O solution, pressures up to 3000 bar!) J. Peters, N. Martinez, B. Lehofer, R. Prassl, Institute for Biophysics, U. Graz, U. Grenoble, ILL, PSI, Eur. Phys. J. E 40, 68 (2017) Results: Good lipoprotein is not affected by pressure, is well adapted to extreme external conditions. Bad lipoprotein shows strong changes (×2) in its dynamics and flexibility, is less adapted. Hope: Could help to develop new concepts for diagnosis and therapy. The neutron as a tool, and the neutron as an object

  15. B. The neutronasan object1. The neutron as a wave(Main topic of this meeting)What impressed me most in recent years:- Simultaneous entanglement of neutron's position, momentum and spin to form a GHZ-state with one single particle!- A new basis for the uncertainty relation (Ozawa)- Stability of Berry's phase against perturbations, + … The neutron as a tool, and the neutron as an object

  16. 2. The neutron as a particleSome trivia on the standard model of particle physics:Nature consists of point particles: Interesting, OK The neutron as a tool, and the neutron as an object

  17. The standard model − more interesting: Verysmallinput: SYMMETRIES: Gauge principle: ψ'(x) = eiφ(x)ψ(x), etc. = symmetry under arbitrary phase modulations: Veryrichoutput: INTERACTIONS: →Equationsofmotion (Dirac, Schrödinger, Maxwell, Newton) →Existenceofphotons, gluons, W±, Z0 (= mediatorsofinteractions) → Conservationofcharges (= sourcesofinteractions) But SM isnot thefullpicture… many open questions The neutron as a tool, and the neutron as an object

  18. Neutron particle physics: one example Ultracoldneutrons: Free fall of the neutron: quantized version Example: 1↔3 and 1↔4: The neutron as a tool, and the neutron as an object

  19. Gravitational Resonance Spectroscopy and Dark Energy These transitions are very sensitive to Dark Energy interactions Results: G. Cronenberg, P. Brax, H. Filter, P. Geltenbort, T. Jenke, G. Pignol, M. Pitschmann, M. Thalhammer, H. Abele, TU Vienna, U. Saclay, ILL Grenoble, Nature 14, 1022, Oct. 2018 The neutron as a tool, and the neutron as an object

  20. Addendum on neutron decay Low-energy physics n-decay: d → ue−νe High-energy physics p-anti p:dū →e−νe Both reactions are linked by Effective Field Theory. Sometimes LEP better, sometimes HEP. Recent issue: Is the n-lifetime anomaly due to dark decays of the neutron? 2018-19: more than 20 publications, mostly PRL, Nature, Science. Based on n-decay data by Märkisch, Abele, et al., PRL "Ed's. suggestion", in print: Result: The neutron as a tool, and the neutron as an object

  21. Neutrons as a tool, Neutrons as an object (wave or particle): Neutrons regularly produce exciting results, in many fields, at the forefront of science. The Atominstitut and Austria are strong players in these fields. My congratulations to Helmut Rauch! Thank you for your attention The neutron as a tool, and the neutron as an object

  22. 20 sec. Werbung "Quantum Physics: The Bottom-Up Approach" From the Simple Two-Level System to Irreducible Representations D. Dubbers and H.-J. Stöckmann On Generalized spin precession equations, etc., see also: New J. Phys. 16, 053050 (2014) "FröhlicheWissenschaft" u.a. übermeineZeit am ILL, auf Anfrage The neutron as a tool, and the neutron as an object

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