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DISCOVERING THE NUCLEUS OF THE INDIVISIBLE BLUEPRINT FOR THE LEGACY OF FUNDAMENTAL PHYSICS Tristan Hübsch Howard University, Washington DC University of Central Florida, Orlando FL & Faculty of Natural Sciences, Novi Sad http://homepage.mac.com/thubsch/ Monday, November 7, 11 Briefly: Pan Rutherford’s discovery ? x o b s ’ a r o d First: e– & “plum pudding” model Test: using !++-rays and Rutherford’s formula Planetary model of the atoma …and quantum physics Collision experiments Nuclei have a structure; consist of nucleons Nucleons have a structure, consist of quarks Quarks and leptons have no structure, as best as we know. So, what now? Theoretical developments way ahead of experiments Waiting experiments are not fully complementary New ideas? 2 Monday, November 7, 11 Pre 1909: 2 ½ millennia ago: Democritus & Leucippus, … 18th–19th century chemists (John Dalton, 1801–1803)… 1897: Joseph J. Thomson discovered: y r o t a r bo rsity a L h s e i v d i n n e U v Ca ge d i r b at Cam cathode rays = beams of electrons, ~2 000 times lighter that the lightest atom. An atom is neutral and of ~1 Å size. ~1 Å So: + e– e– ≪1Å e– e– e– 3 Monday, November 7, 11 + e– e– m u l “p ing” d d u p Pre 1909: Manchester Litera ry and Philosophic (““Lit & P al S hil”), where John ociety D alton introduced atomism a centu ry earlier… Ernest Rutherford Student of J.J. Thomson, but situated in Manchester Defined #-rays (w/ Paul Villard) 1899–1900, …proved #-particles to be Helium ions (w/Thomas Royds, 1907)… …used these #-particles (w/Hans Geiger & Ernest Marsden) to bombard a gold foil… …than record and study the scattering pattern. 4 Monday, November 7, 11 Pre 1909: Manchester Litera ry and Philosophic (““Lit & P al S hil”), where John ociety D alton introduced atomism a centu ry earlier… Ernest Rutherford Student of J.J. Thomson, but situated in Manchester Defined #-rays (w/ Paul Villard) 1899–1900, …proved #-particles to be Helium ions (w/Thomas Royds, 1907)… …used these #-particles (w/Hans Geiger & Ernest Marsden) to bombard a gold foil… …than record and study the scattering pattern. 4 Monday, November 7, 11 1909–1911: Ernest Rutherford (+ Hans Geiger & Ernest Marsden) template experiment mathematical analysis planetary model + e– e– e– e– } sma exp shin erim g ents e– e– expected Monday, November 7, 11 legacy of the 20th century Physics 5 ? observed 1911: Manchester Literary and Philosophical Society 110 years after J. Dalton’s indivisible atoms Rutherford: d⇧ = d 2 e /4⇤⇥ 2m 0 2 v0 6 Monday, November 7, 11 ⇥2 1 4 sin (⌅/2) 400 Intensity 1911: 4 3 300 2 Rutherford: d⇧ = d e2 /4⇤⇥ 2m 0 v02 ⇥2 1 sin4 (⌅/2) describes that: 200 1 ! 100 150 250 100 Angle 0 50 100 150 vast majority of #-particles passes unhindered a few #-particles deflect a little from their direction a teeeeee nsy few #-particles ricochet “straight back”!?! ee 6 Monday, November 7, 11 200 200 250 300 350 – – + ++ – – – – 400 Intensity 1911: 4 3 300 2 Rutherford: d⇧ = d e2 /4⇤⇥ 2m 0 v02 ⇥2 1 sin4 (⌅/2) describes that: 200 1 ! 100 200 250 100 Angle 0 50 vast majority of #-particles passes unhindered a few #-particles deflect a little from their direction a teeeeee nsy few #-particles ricochet “straight back”!?! ee 6 Monday, November 7, 11 150 100 150 200 250 300 350 Planetary model – – + + + – – – – 1911: Rutherford’s experiment, analysis & result Nixed his former advisor’s “plum pudding” model; proved that the atom (formerly named as indivisible), …the smallest portion of any element… …is in fact mostly void; ushered the planetary model Planetary model …where negative electrons… – …orbit the positive nucleus… – …held by Coulomb’s force, + + just as planets are held by… + – – …Newton’s force of gravity. – – A remarkable repetition in structure! 7 Monday, November 7, 11 1911: Rutherford’s planetary model of the atom also opened Pandora’s box of new questions. “… the stability of the atom proposed need not be considered at this stage…” – wrote Rutherford in his 1911 paper Niels Bohr May 1911, PhD Planetary model 6 months with Thomson, – March 1912 with Rutherford, – …angular momentum is an + + + integral multiple of … – – Quantum physics (Planck, Einstein, – – Bohr, Compton, Heisenberg, Schrödinger, Dirac, …) 8 Monday, November 7, 11 HOWEVER, THAT’S NOT ALL, FOLKS! Conceptual shift in understanding Legacy in experimenting methods ections; thank you! — DRAFT Let me sleep, already! Monday, November 7, 11 knock knock Input signal Outcome signal Divisibility & Atom Structure divisibility implies (sub)structure: 10 Monday, November 7, 11 Divisibility & Atom Structure Indivisibility implies not the lack of (sub)structure: Hydrogen atom: Not divisible by chemical processes! Not a chemical process! p+ e– p+ Ionization Recombination (“all by themselves”) 10 Monday, November 7, 11 Thus, quite literally, a Hydrogen atom is never really divided. e– Nevertheless, it evidently does have a (sub)structure. Divisibility & the Structure of Matter Indivisibility implies not the lack of (sub)structure: Atomic nuclei: Not divisible by chemical/atomic processes. p+ n0 Nevertheless, there is a (sub)structure. Proton, neutron: Again, there is a (sub)structure. Not divisible by any known process. (Regardless of the fact that quarks cannot, in fact, be isolated!) quarks 11 Monday, November 7, 11 [email protected], with any comments / suggestions / corrections; spring. At a certain point, determined the spring elasticity, the sp dretched spring. At a certain point, determined bydetermined the by spring elasticity, the spring of the stretched spring. At a certain point, by the spring elasticity of the stretched spring. At a certain point, determined by the spring reaks. Analogously, two particles (so-called quarks) bound the strong nuclear Analogously, two particles (so-called quarks) bound quarks) by the by strong nuclear insimply breaks. Analogously, two particles (so-called bound by the strong simply breaks. Analogously, two particles (so-called quarks) bound by t nbe may be separated tolarder ever larder distances—only by incessant investing ever m separated tobeever distances—only by incessant investing ever more teraction may separated to ever larder distances—only by incessant investin teraction may be separated to ever larder distances—only by incessant This be could becould doable arbitrarily long, and the two the quarks could becould separated a ould doable arbitrarily long,arbitrarily and the two quarks could be separated arbienergy. This be doable long, and two quarks be sep energy. This could be doable arbitrarily long, and the two quarks coul fromother, each other, it not the fact that the that invested work sooner l mar each were itwere not for thefor fact that the invested work sooner orwork lateror trarily far from each other, were it not for the fact the invested soo trarily far from each other, were it not for the fact that the invested w sufficient to create acreate particle-antiparticle pair. one Each of newly these newly min ient to create a particle-antiparticle pair. Each ofone these minted Indivisibility implies not becomes sufficient to a particle-antiparticle pair. Each one of these ne becomes sufficient to create a particle-antiparticle pair. Each one of thenwith binds with of the “old” ones, so that the attempt to separate two quark binds one of one thewith “old” ones, so that the attempt to the separate twotoquarks to tw particles then binds one of the “old” ones, so that attempt separate Qualitatively, particles then binds with one of the “old” ones, so that the attempt to se the lack of15(sub)structure: 15 15 instead sr bigger ⇠m 10 minstead fails: of having separated one quark from thefro ot than ⇠than 10 fails:⇠ offails: having separated one quark from the other, just like 15 distances bigger than 10 m instead of having separated one quark distances bigger than ⇠ 10 m fails: instead of having separated one q k we werewe trying totrying movetobecomes bound with thewith newly minted antiquark, were trying to were move becomes bound with the newly minted antiquark, andant Protons, neutrons, hadrons: springs the quark move becomes bound the newly minted the quark we were trying to move becomes bound with the newly mi ruark oldother quark is quark joined the newly minted quark replacing the oldThis one. This qu is joined by theisby newly minted quark replacing the old one. quarkstrings the old joined by the newly minted quark replacing the old one. thebound other old quark joined by the newly minted quark replacing the states of is (anti)quarks, k pair aforms a new system (so-called meson) that really be separated arbitra forms new system (so-called meson) that really can be can separated arbitrarily antiquark pair forms a new system (so-called meson) that really can be separate antiquark pair forms a new system (so-called meson) that really can be dist. …which cannot be observed he original quarks un-extracted [+ –1.5]. figure –1.5]. ginal quarks remainremain un-extracted [+ figure far, but the original quarks remain un-extracted [+ figure[+ –1.5]. far, but the original quarks remain un-extracted figure –1.5]. Potential Energy Divisibility & the Structure of Matter as sufficiently isolated particles. No qu free ark s (so as to be handled regardless of the rest) –1.5: Inseparability ofInseparability quarks and antiquarks investing everbymore Figure –1.5: Inseparability of quarks and antiquarks by investing everenergy moreever energy 12 by Figure –1.5: of quarks and antiquarks investing moreever en Figure –1.5: Inseparability of quarks and antiquarks by investing Monday, November 7, 11 Divisibility & the Structure of Matter Indivisibility implies not the lack of (sub)structure: But, why can we separate e– and p+, but not quarks? Binding energy of H-atom = 13.6 eV. Rest energy of e– = 510,999 eV. En = – ½ !e2 m c2 #e = ⅟&'( Ratio ≈ 0.000 0266 ≈ 1/37,573. On the other hand, Rest energy of u,d quarks = 1–6 MeV. Binding energy in (u,d)-mesons is at least as big! Ratio ≥1!!! #s ~1 13 Monday, November 7, 11 Divisibility & the Structure of Matter 1 1 Fundamental physics of elementary particles…20 Table 0.3: The content of the Standard Model of elementary particle physics; see (0.46a) Substance Gen. 1. 2. 3. Leptons ne nµ nt Interactions (spin-1/2 fermions) e µ t Quarks u c t d s b onelectromagnetico g interaction ± 0 W ,Z weak nuclear gluons strong nuclear interaction dgµn gravitation (bosons) (spin-1) (spin-1) (spin-2) Higgs boson (spin-0): gives mass to the particles with which it interacts …describes all tangible matter and all its fundamental interactions …in agreement with all experiments ever performed to date. (Except that the Higgs particle is still sought for…) (And, perhaps… just very, very perhaps, the impish neutrinos of the recent fervor…) 14 Monday, November 7, 11 …& experiments PP E f o st o m r o ts f n e e t m a i l er p x e Temp y ur t n e c 20t h Rutherford-esque colliding processes! 15 Monday, November 7, 11 …& experiments PP E f o st o m r o ts f n e e t m a i l er p x e Temp y ur t n e c 20t h Rutherford-esque colliding processes! human! 15 Monday, November 7, 11 …& experiments PP E f o st o m r o ts f n e e t m a i l er p x e Temp y ur t n e c 20t h Rutherford-esque colliding processes! 15 Monday, November 7, 11 …& experiments PP E f o st o m r o ts f n e e t m a i l er p x e Temp y ur t n e c 20t h Rutherford-esque colliding processes! •CERN is a •multi-national •multi-cultural •multi-social •multi-political •multi-financed •complex structure •Really, really, really •…expensive. •& Foreordained. You can’t turn CERN on a dime! 15 Monday, November 7, 11 …& experiments And then there are the “waiting experiments” Deck out an abandoned mine with detectors… …fill it with water (the price is right)… …and wait. The more time passes without registering an event, the smaller the probability for the event to happen at all. Typically, not as complex/political/expensive/BIG as the smashing experiments… …but, they tend to produce “limits from one side,” …and they too are carefully planned/designed. 16 Monday, November 7, 11 …& experiments You cannot plan/design for “accidental discoveries” Thales noticed that amber (ήλεκτρον) attracts lint… Alessandro Volta poked frog legs with various wires… Hans Christian Ørsted saw the magnetic needle turn… Henry Becquerel noticed materials to affect photo-plates… …and there’s nothing accidental about multi-complex experimentation as is being done nowadays. Needed: a radically new type of experiment complementary to “waiting experiments” more maneuverable than CERN, SLAC, FNAL, … A world of new discovery left to the Young! 17 Monday, November 7, 11 Don't Panic ! THANKS! See you, if virtually, at: http://homepage.mac.com/thubsch/ Monday, November 7, 11