Particle Physics and the Standard Model
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The Five Common Particles
The Five Common Particles The world around you consists of only three particles: protons, neutrons, and electrons. Protons and neutrons form the nuclei of atoms, and electrons glue everything together and create chemicals and materials. Along with the photon and the neutrino, these particles are essentially the only ones that exist in our solar system, because all the other subatomic particles have half-lives of typically 10-9 second or less, and vanish almost the instant they are created by nuclear reactions in the Sun, etc. Particles interact via the four fundamental forces of nature. Some basic properties of these forces are summarized below. (Other aspects of the fundamental forces are also discussed in the Summary of Particle Physics document on this web site.) Force Range Common Particles It Affects Conserved Quantity gravity infinite neutron, proton, electron, neutrino, photon mass-energy electromagnetic infinite proton, electron, photon charge -14 strong nuclear force ≈ 10 m neutron, proton baryon number -15 weak nuclear force ≈ 10 m neutron, proton, electron, neutrino lepton number Every particle in nature has specific values of all four of the conserved quantities associated with each force. The values for the five common particles are: Particle Rest Mass1 Charge2 Baryon # Lepton # proton 938.3 MeV/c2 +1 e +1 0 neutron 939.6 MeV/c2 0 +1 0 electron 0.511 MeV/c2 -1 e 0 +1 neutrino ≈ 1 eV/c2 0 0 +1 photon 0 eV/c2 0 0 0 1) MeV = mega-electron-volt = 106 eV. It is customary in particle physics to measure the mass of a particle in terms of how much energy it would represent if it were converted via E = mc2. -
(Anti)Proton Mass and Magnetic Moment
FFK Conference 2019, Tihany, Hungary Precision measurements of the (anti)proton mass and magnetic moment Wolfgang Quint GSI Darmstadt and University of Heidelberg on behalf of the BASE collaboration spokesperson: Stefan Ulmer 2019 / 06 / 12 BASE – Collaboration • Mainz: Measurement of the magnetic moment of the proton, implementation of new technologies. • CERN Antiproton Decelerator: Measurement of the magnetic moment of the antiproton and proton/antiproton q/m ratio • Hannover/PTB: Laser cooling project, new technologies Institutes: RIKEN, MPI-K, CERN, University of Mainz, Tokyo University, GSI Darmstadt, University of Hannover, PTB Braunschweig C. Smorra et al., EPJ-Special Topics, The BASE Experiment, (2015) WE HAVE A PROBLEM mechanism which created the obvious baryon/antibaryon asymmetry in the Universe is not understood One strategy: Compare the fundamental properties of matter / antimatter conjugates with ultra-high precision CPT tests based on particle/antiparticle comparisons R.S. Van Dyck et al., Phys. Rev. Lett. 59 , 26 (1987). Recent B. Schwingenheuer, et al., Phys. Rev. Lett. 74, 4376 (1995). Past CERN H. Dehmelt et al., Phys. Rev. Lett. 83 , 4694 (1999). G. W. Bennett et al., Phys. Rev. D 73 , 072003 (2006). Planned M. Hori et al., Nature 475 , 485 (2011). ALICE G. Gabriesle et al., PRL 82 , 3199(1999). J. DiSciacca et al., PRL 110 , 130801 (2013). S. Ulmer et al., Nature 524 , 196-200 (2015). ALICE Collaboration, Nature Physics 11 , 811–814 (2015). M. Hori et al., Science 354 , 610 (2016). H. Nagahama et al., Nat. Comm. 8, 14084 (2017). M. Ahmadi et al., Nature 541 , 506 (2017). M. Ahmadi et al., Nature 586 , doi:10.1038/s41586-018-0017 (2018). -
Interactions of Antiprotons with Atoms and Molecules
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln US Department of Energy Publications U.S. Department of Energy 1988 INTERACTIONS OF ANTIPROTONS WITH ATOMS AND MOLECULES Mitio Inokuti Argonne National Laboratory Follow this and additional works at: https://digitalcommons.unl.edu/usdoepub Part of the Bioresource and Agricultural Engineering Commons Inokuti, Mitio, "INTERACTIONS OF ANTIPROTONS WITH ATOMS AND MOLECULES" (1988). US Department of Energy Publications. 89. https://digitalcommons.unl.edu/usdoepub/89 This Article is brought to you for free and open access by the U.S. Department of Energy at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in US Department of Energy Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. /'Iud Tracks Radial. Meas., Vol. 16, No. 2/3, pp. 115-123, 1989 0735-245X/89 $3.00 + 0.00 Inl. J. Radial. Appl .. Ins/rum., Part D Pergamon Press pic printed in Great Bntam INTERACTIONS OF ANTIPROTONS WITH ATOMS AND MOLECULES* Mmo INOKUTI Argonne National Laboratory, Argonne, Illinois 60439, U.S.A. (Received 14 November 1988) Abstract-Antiproton beams of relatively low energies (below hundreds of MeV) have recently become available. The present article discusses the significance of those beams in the contexts of radiation physics and of atomic and molecular physics. Studies on individual collisions of antiprotons with atoms and molecules are valuable for a better understanding of collisions of protons or electrons, a subject with many applications. An antiproton is unique as' a stable, negative heavy particle without electronic structure, and it provides an excellent opportunity to study atomic collision theory. -
Color Breaking in the Quantum Leaped Stop Decay
Color breaking in the quantum leaped stop decay Imre Czövek [email protected] Abstract. The superfield propagator contains a measurable quantum leap, which comes from the definition of SUSY. In the sfermion -> Goldstino + fermion vertex change: 1. the spin of sparticle with discrete 1/2, 2. the Grassman superspace with the Goldstino shift operator. 3. the spacetime as the result of extra dimensional leap. The leap nature of SUSY transformations appears in the squark decay, it is the analog definition of SUSY. The quantum leaped outgoing propagators are determined and break locally the energy and the charge. Like to the teleportation the entangled pairs are here the b quark and the Goldstino. The dominant stop production is from gluons. The stop-antistop pair decay to quantum leaped b (c or t) quark, and the decay break the color. I get for the (color breaking) quantum leap: 10^-18 m. 10^-11 m color breaking would be needed for a color breaking chain reaction. The open question is: Are the colliders producing supersymmetry charge? Because some charges in QGP can make long color breaking and a chain reaction. A long color broken QGP state in the re-Big Bang theory could explain the near infinite energy and the near infinite mass of the universe: - at first was random color QGP in the flat space-time, - at twice the color restoration in the curved space-time, which eats the Goldstinos, - and finally the baryon genesis. The re Big Bang make a supernova like collapse and a flat explosion of Universe. This explanation of SUSY hides the Goldstone fermion in the extra dimensions, the Goldstino propagate only in superspace and it is a not observable dark matter. -
Quantum Field Theory*
Quantum Field Theory y Frank Wilczek Institute for Advanced Study, School of Natural Science, Olden Lane, Princeton, NJ 08540 I discuss the general principles underlying quantum eld theory, and attempt to identify its most profound consequences. The deep est of these consequences result from the in nite number of degrees of freedom invoked to implement lo cality.Imention a few of its most striking successes, b oth achieved and prosp ective. Possible limitation s of quantum eld theory are viewed in the light of its history. I. SURVEY Quantum eld theory is the framework in which the regnant theories of the electroweak and strong interactions, which together form the Standard Mo del, are formulated. Quantum electro dynamics (QED), b esides providing a com- plete foundation for atomic physics and chemistry, has supp orted calculations of physical quantities with unparalleled precision. The exp erimentally measured value of the magnetic dip ole moment of the muon, 11 (g 2) = 233 184 600 (1680) 10 ; (1) exp: for example, should b e compared with the theoretical prediction 11 (g 2) = 233 183 478 (308) 10 : (2) theor: In quantum chromo dynamics (QCD) we cannot, for the forseeable future, aspire to to comparable accuracy.Yet QCD provides di erent, and at least equally impressive, evidence for the validity of the basic principles of quantum eld theory. Indeed, b ecause in QCD the interactions are stronger, QCD manifests a wider variety of phenomena characteristic of quantum eld theory. These include esp ecially running of the e ective coupling with distance or energy scale and the phenomenon of con nement. -
BOTTOM, STRANGE MESONS (B = ±1, S = ∓1) 0 0 ∗ Bs = Sb, Bs = S B, Similarly for Bs ’S
Citation: P.A. Zyla et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2020, 083C01 (2020) BOTTOM, STRANGE MESONS (B = ±1, S = ∓1) 0 0 ∗ Bs = sb, Bs = s b, similarly for Bs ’s 0 P − Bs I (J ) = 0(0 ) I , J, P need confirmation. Quantum numbers shown are quark-model predictions. Mass m 0 = 5366.88 ± 0.14 MeV Bs m 0 − mB = 87.38 ± 0.16 MeV Bs Mean life τ = (1.515 ± 0.004) × 10−12 s cτ = 454.2 µm 12 −1 ∆Γ 0 = Γ 0 − Γ 0 = (0.085 ± 0.004) × 10 s Bs BsL Bs H 0 0 Bs -Bs mixing parameters 12 −1 ∆m 0 = m 0 – m 0 = (17.749 ± 0.020) × 10 ¯h s Bs Bs H BsL = (1.1683 ± 0.0013) × 10−8 MeV xs = ∆m 0 /Γ 0 = 26.89 ± 0.07 Bs Bs χs = 0.499312 ± 0.000004 0 CP violation parameters in Bs 2 −3 Re(ǫ 0 )/(1+ ǫ 0 )=(−0.15 ± 0.70) × 10 Bs Bs 0 + − CKK (Bs → K K )=0.14 ± 0.11 0 + − SKK (Bs → K K )=0.30 ± 0.13 0 ∓ ± +0.10 rB(Bs → Ds K )=0.37−0.09 0 ± ∓ ◦ δB(Bs → Ds K ) = (358 ± 14) −2 CP Violation phase βs = (2.55 ± 1.15) × 10 rad λ (B0 → J/ψ(1S)φ)=1.012 ± 0.017 s λ = 0.999 ± 0.017 A, CP violation parameter = −0.75 ± 0.12 C, CP violation parameter = 0.19 ± 0.06 S, CP violation parameter = 0.17 ± 0.06 L ∗ 0 ACP (Bs → J/ψ K (892) ) = −0.05 ± 0.06 k ∗ 0 ACP (Bs → J/ψ K (892) )=0.17 ± 0.15 ⊥ ∗ 0 ACP (Bs → J/ψ K (892) ) = −0.05 ± 0.10 + − ACP (Bs → π K ) = 0.221 ± 0.015 0 + − ∗ 0 ACP (Bs → [K K ]D K (892) ) = −0.04 ± 0.07 HTTP://PDG.LBL.GOV Page1 Created:6/1/202008:28 Citation: P.A. -
An Introduction to the Quark Model
An Introduction to the Quark Model Garth Huber Prairie Universities Physics Seminar Series, November, 2009. Particles in Atomic Physics • View of the particle world as of early 20th Century. • Particles found in atoms: –Electron – Nucleons: •Proton(nucleus of hydrogen) •Neutron(e.g. nucleus of helium – α-particle - has two protons and two neutrons) • Related particle mediating electromagnetic interactions between electrons and protons: Particle Electric charge Mass – Photon (light!) (x 1.6 10-19 C) (GeV=x 1.86 10-27 kg) e −1 0.0005 p +1 0.938 n 0 0.940 γ 0 0 Dr. Garth Huber, Dept. of Physics, Univ. of Regina, Regina, SK S4S0A2, Canada. 2 Early Evidence for Nucleon Internal Structure • Apply the Correspondence Principle to the Classical relation for q magnetic moment: µ = L 2m • Obtain for a point-like spin-½ particle of mass mp: qqeq⎛⎞⎛⎞ µ == =µ ⎜⎟ ⎜⎟ N 2222memepp⎝⎠ ⎝⎠ 2 Experimental values: µp=2.79 µN (p) µn= -1.91 µN (n) • Experimental values inconsistent with point-like assumption. • In particular, the neutron’s magnetic moment does not vanish, as expected for a point-like electrically neutral particle. This is unequivocal evidence that the neutron (and proton) has an internal structure involving a distribution of charges. Dr. Garth Huber, Dept. of Physics, Univ. of Regina, Regina, SK S4S0A2, Canada. 3 The Particle Zoo • Circa 1950, the first particle accelerators began to uncover many new particles. • Most of these particles are unstable and decay very quickly, and hence had not been seen in cosmic ray experiments. • Could all these particles be fundamental? Dr. Garth Huber, Dept. -
1 Quark Model of Hadrons
1 QUARK MODEL OF HADRONS 1 Quark model of hadrons 1.1 Symmetries and evidence for quarks 1 Hadrons as bound states of quarks – point-like spin- 2 objects, charged (‘coloured’) under the strong force. Baryons as qqq combinations. Mesons as qq¯ combinations. 1 Baryon number = 3 (N(q) − N(¯q)) and its conservation. You are not expected to know all of the names of the particles in the baryon and meson multiplets, but you are expected to know that such multiplets exist, and to be able to interpret them if presented with them. You should also know the quark contents of the simple light baryons and mesons (and their anti-particles): p = (uud) n = (udd) π0 = (mixture of uu¯ and dd¯) π+ = (ud¯) K0 = (ds¯) K+ = (us¯). and be able to work out others with some hints. P 1 + Lowest-lying baryons as L = 0 and J = 2 states of qqq. P 3 + Excited versions have L = 0 and J = 2 . Pauli exclusion and non existence of uuu, ddd, sss states in lowest lying multiplet. Lowest-lying mesons as qq¯0 states with L = 0 and J P = 0−. First excited levels (particles) with same quark content have L = 0 and J P = 1−. Ability to explain contents of these multiplets in terms of quarks. J/Ψ as a bound state of cc¯ Υ (upsilon) as a bound state of b¯b. Realization that these are hydrogenic-like states with suitable reduced mass (c.f. positronium), and subject to the strong force, so with energy levels paramaterized by αs rather than αEM Top is very heavy and decays before it can form hadrons, so no top hadrons exist. -
The Structure of Quarks and Leptons
The Structure of Quarks and Leptons They have been , considered the elementary particles ofmatter, but instead they may consist of still smaller entities confjned within a volume less than a thousandth the size of a proton by Haim Harari n the past 100 years the search for the the quark model that brought relief. In imagination: they suggest a way of I ultimate constituents of matter has the initial formulation of the model all building a complex world out of a few penetrated four layers of structure. hadrons could be explained as combina simple parts. All matter has been shown to consist of tions of just three kinds of quarks. atoms. The atom itself has been found Now it is the quarks and leptons Any theory of the elementary particles to have a dense nucleus surrounded by a themselves whose proliferation is begin fl. of matter must also take into ac cloud of electrons. The nucleus in turn ning to stir interest in the possibility of a count the forces that act between them has been broken down into its compo simpler-scheme. Whereas the original and the laws of nature that govern the nent protons and neutrons. More recent model had three quarks, there are now forces. Little would be gained in simpli ly it has become apparent that the pro thought to be at least 18, as well as six fying the spectrum of particles if the ton and the neutron are also composite leptons and a dozen other particles that number of forces and laws were thereby particles; they are made up of the small act as carriers of forces. -
Remembering Alvin Tollestrup: 1924-2020 – CERN Courier
3/26/2020 Remembering Alvin Tollestrup: 1924-2020 – CERN Courier PEOPLE | NEWS Remembering Alvin Tollestrup: 1924-2020 6 March 2020 Alvin Tollestrup, who passed away on 9 February at the age of 95, was a visionary. When I joined his group at Caltech in the summer of 1960, experiments in particle physics at universities were performed at accelerators located on campus. Alvin had helped build Caltech’s electron synchrotron, the highest energy photon-producing accelerator at the time. But he thought more exciting physics could be performed elsewhere, and managed to get approval to run an experiment at Berkeley Lab’s Bevatron to measure a rare decay mode of the K+ meson. This was the rst time an outsider was allowed to access Berkeley’s machine, much to the consternation of Luis Alvarez and other university faculty. When I joined Alvin’s group he asked a postdoc, Ricardo Gomez, and me to design, build and test https://cerncourier.com/a/remembering-alvin-tollestrup-1924-2020/ 1/5 3/26/2020 Remembering Alvin Tollestrup: 1924-2020 – CERN Courier Machine maestro – Alvin Tollestrup led the pioneering a new type of particle detector called a spark work of designing and testing the superconducting magnets for the Tevatron, the rst large-scale chamber. He gave us a paper by two Japanese application of superconductivity. Credit: Fermilab authors on “A new type of particle detector: the discharge chamber”, not what he wanted, but a place to start. In retrospect it was remarkable that Alvin was willing to risk the success of his experiment on the creation of new technology. -
First Determination of the Electric Charge of the Top Quark
First Determination of the Electric Charge of the Top Quark PER HANSSON arXiv:hep-ex/0702004v1 1 Feb 2007 Licentiate Thesis Stockholm, Sweden 2006 Licentiate Thesis First Determination of the Electric Charge of the Top Quark Per Hansson Particle and Astroparticle Physics, Department of Physics Royal Institute of Technology, SE-106 91 Stockholm, Sweden Stockholm, Sweden 2006 Cover illustration: View of a top quark pair event with an electron and four jets in the final state. Image by DØ Collaboration. Akademisk avhandling som med tillst˚and av Kungliga Tekniska H¨ogskolan i Stock- holm framl¨agges till offentlig granskning f¨or avl¨aggande av filosofie licentiatexamen fredagen den 24 november 2006 14.00 i sal FB54, AlbaNova Universitets Center, KTH Partikel- och Astropartikelfysik, Roslagstullsbacken 21, Stockholm. Avhandlingen f¨orsvaras p˚aengelska. ISBN 91-7178-493-4 TRITA-FYS 2006:69 ISSN 0280-316X ISRN KTH/FYS/--06:69--SE c Per Hansson, Oct 2006 Printed by Universitetsservice US AB 2006 Abstract In this thesis, the first determination of the electric charge of the top quark is presented using 370 pb−1 of data recorded by the DØ detector at the Fermilab Tevatron accelerator. tt¯ events are selected with one isolated electron or muon and at least four jets out of which two are b-tagged by reconstruction of a secondary decay vertex (SVT). The method is based on the discrimination between b- and ¯b-quark jets using a jet charge algorithm applied to SVT-tagged jets. A method to calibrate the jet charge algorithm with data is developed. A constrained kinematic fit is performed to associate the W bosons to the correct b-quark jets in the event and extract the top quark electric charge. -
ANTIMATTER a Review of Its Role in the Universe and Its Applications
A review of its role in the ANTIMATTER universe and its applications THE DISCOVERY OF NATURE’S SYMMETRIES ntimatter plays an intrinsic role in our Aunderstanding of the subatomic world THE UNIVERSE THROUGH THE LOOKING-GLASS C.D. Anderson, Anderson, Emilio VisualSegrè Archives C.D. The beginning of the 20th century or vice versa, it absorbed or emitted saw a cascade of brilliant insights into quanta of electromagnetic radiation the nature of matter and energy. The of definite energy, giving rise to a first was Max Planck’s realisation that characteristic spectrum of bright or energy (in the form of electromagnetic dark lines at specific wavelengths. radiation i.e. light) had discrete values The Austrian physicist, Erwin – it was quantised. The second was Schrödinger laid down a more precise that energy and mass were equivalent, mathematical formulation of this as described by Einstein’s special behaviour based on wave theory and theory of relativity and his iconic probability – quantum mechanics. The first image of a positron track found in cosmic rays equation, E = mc2, where c is the The Schrödinger wave equation could speed of light in a vacuum; the theory predict the spectrum of the simplest or positron; when an electron also predicted that objects behave atom, hydrogen, which consists of met a positron, they would annihilate somewhat differently when moving a single electron orbiting a positive according to Einstein’s equation, proton. However, the spectrum generating two gamma rays in the featured additional lines that were not process. The concept of antimatter explained. In 1928, the British physicist was born.