1 / 23

Standard Model (s)

Standard Model (s). Organizing our data helps us see deeper relationships and ultimately the underlying laws of nature. Standard Models. Parts and how they go together 1) Atoms – Periodic Table 2) Nuclei – Chart of the nuclides

perras
Download Presentation

Standard Model (s)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Standard Model (s) Organizing our data helps us see deeper relationships and ultimately the underlying laws of nature.

  2. Standard Models • Parts and how they go together • 1) Atoms – Periodic Table • 2) Nuclei – Chart of the nuclides • 3) Particle Physics – Quark Ensembles Mesons and Hadrons • 4) “Bulk” Quark Matter – Quark-Gluon Plasma

  3. The parts of the Atomic Model and the roles they play • Electrons Nuclei • Negative Charge, e Positive Charge, Ze • Small Mass (2000 A) Large Mass • Fill the atom ((10^4)^3) Tiny at center • 5x10^-11 m (2 to 6) 10^-15 m • Volley ball (20 cm) vs. VU Campus (2 km)

  4. Magic numbers or shells: 2, 2+6=8, 2+6+8+10 with 10 held back, and holding back gets more complicated beyond this • Most stable (noble) end period • Note that these are ground states • Excited states have one or more electrons of an atom in a higher orbit. • Excited atoms decay, usually in nanoseconds, to ground states. • Hydrogen atom decay picture on next slide.

  5. Looks Familiar, but now antiproton at center and positron (antielectron) circles it

  6. The numbers of neutrons and protons in the nucleus change. Why can we ignore that change in making our periodic chart? • These charts are for chemistry-type energy changes, a few kiloJoules/mole or eV/atom. Nuclear changes typically require 10^5 times as much energy. • Physicists think about single atoms while chemists think about moles of atoms, physicists prefer to think about 1 eV of energy rather than 6e-19 J – even though it is the same thing! You could give the mass of a piece of jewelry in tons, but why would you want to? • Size of atom – does not increase much with more electrons, not as cube root of number of electrons.

  7. What do the electrons care about in a nucleus? • The charge, Ze, of the nucleus and that it is much heavier than an electron are the most (by far) important properties of the nucleus. Nuclear physics is a thousand to a million times more violent than chemistry and in this more violent world pieces can be knocked off the nucleus. • What can nature build out of protons and neutrons? Does nature respect rules or magic numbers when neutrons and protons are merged?

  8. Let’s make a chart of Nuclei to see if there are regularities like we found with atoms • Vertical – Number of protons • Horizontal – Number of neutrons • There must be a new, short range, force much stronger than the electrostatic force or protons could not be held so close together. • Magic Numbers (either neutrons or protons) • 2, 8, 20, 28, 50, 82, 126 • Strong force can’t tell proton from neutron

  9. Magic numbers of n, p – separately:2, 8, 20, 28, 50, 82, 126, …

  10. * Actinides o 93 neptunium Np o 94 plutonium Pu o 95 americium Am o 96 curium Cm o 97 berkelium Bk o 98 californium Cf o 99 einsteinium Es o 100 fermium Fm o 101 mendelevium Md o 102 nobelium No o 103 lawrencium Lr * Transactinide elements o 104 rutherfordium Rf o 105 dubnium Db o 106 seaborgium Sg o 107 bohrium Bh o 108 hassium Hs o 109 meitnerium Mt o 110 darmstadtium Ds o 111 roentgenium Rg o 112 copernicium Cn o 113 ununtrium Uut* o 114 ununquadium Uuq* o 115 ununpentium Uup* o 116 ununhexium Uuh* o 117 ununseptium Uus* o 118 ununoctium Uuo* Bang two elements together, to get a new element. 117 is latest. 126 coming???

  11. A cyclotron in Dubna accelerates a beam of Ca48 to hit a 22 mg Bk249 target

  12. The Building blocks of the next level standard model 27 particle physicists have won Nobel prizes for making the experimental discoveries and theoretical breakthroughs that led to our present understanding. The Higgs boson? Interesting to remember that 35 years ago only knew up, down, strange, e, muon, 2 neutrinos, and the photon.

  13. Particle – anti particle reminder. All thosequarks and and leptons have antis too

  14. And there are antiquarks corresponding to each quark. • Charge quark flavor • +2/3 up, charm, top • -1/3 down, strange, bottom • Anti on each • -2/3 u, c, t • +1/3 d, s, b • Quark Chemistry • Baryons: 3 quarks, Antibaryons: 3 antiquarks p = 2 up + down; n = 2 down + up • Mesons: a quark and an antiquark pi = up + anti down

  15. When we only knew about 3 quarks (up to 1975), we could summarize it (spin ½)

  16. Or for spin 3/2 combinations

  17. Spin 0 Mesons

  18. And for Spin 1 Mesons

  19. LHC Accelerator Protons are accelerated by powerful electric fields to very close to the speed of light. And are guided around their circular orbits by powerful superconducting dipole magnets. The dipole magnets operate at 8.3 Tesla (200’000 x Earth’s magnetic field) & 1.9 K (-271°C) in superfluid helium. Protons travel in a tube which is under a better vacuum and at a lower temperature than that in inter-planetary space. wrt Tevatron (USA) Energy (7-14 TeV)x 3.5-7 No. of interactions/second x 30

More Related