10 Progressing Beyond the Standard Models
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Particle Physics Dr Victoria Martin, Spring Semester 2012 Lecture 12: Hadron Decays
Particle Physics Dr Victoria Martin, Spring Semester 2012 Lecture 12: Hadron Decays !Resonances !Heavy Meson and Baryons !Decays and Quantum numbers !CKM matrix 1 Announcements •No lecture on Friday. •Remaining lectures: •Tuesday 13 March •Friday 16 March •Tuesday 20 March •Friday 23 March •Tuesday 27 March •Friday 30 March •Tuesday 3 April •Remaining Tutorials: •Monday 26 March •Monday 2 April 2 From Friday: Mesons and Baryons Summary • Quarks are confined to colourless bound states, collectively known as hadrons: " mesons: quark and anti-quark. Bosons (s=0, 1) with a symmetric colour wavefunction. " baryons: three quarks. Fermions (s=1/2, 3/2) with antisymmetric colour wavefunction. " anti-baryons: three anti-quarks. • Lightest mesons & baryons described by isospin (I, I3), strangeness (S) and hypercharge Y " isospin I=! for u and d quarks; (isospin combined as for spin) " I3=+! (isospin up) for up quarks; I3="! (isospin down) for down quarks " S=+1 for strange quarks (additive quantum number) " hypercharge Y = S + B • Hadrons display SU(3) flavour symmetry between u d and s quarks. Used to predict the allowed meson and baryon states. • As baryons are fermions, the overall wavefunction must be anti-symmetric. The wavefunction is product of colour, flavour, spin and spatial parts: ! = "c "f "S "L an odd number of these must be anti-symmetric. • consequences: no uuu, ddd or sss baryons with total spin J=# (S=#, L=0) • Residual strong force interactions between colourless hadrons propagated by mesons. 3 Resonances • Hadrons which decay due to the strong force have very short lifetime # ~ 10"24 s • Evidence for the existence of these states are resonances in the experimental data Γ2/4 σ = σ • Shape is Breit-Wigner distribution: max (E M)2 + Γ2/4 14 41. -
Nutzung Der Gefundenen Werte Far F(1) | | Und P a Bestimmt Worden
Reconstruction of B D*°e ve Decays and Determination of \Vcb\ DISSERTATION zur Erlangung des akademischen Grades Doctor rerum naturalium (Dr.rer.nat.) vorgelegt der Fakultat Mathematik und Naturwissenschaften der Technischen Universitat Dresden von Diplom-Physiker Jens Schubert geboren am 11.03.1977 in Pirna 1. Gutachter : Prof. Dr. Klaus R. Schubert 2. Gutachter : Prof. Dr. Michael Kobel 3. Gutachter : Dr. Jochen C. Dingfelder Eingereicht am: 01.12.2006 Abstract In this analysis the decay B- ^ D* 0e-Ve is measured. The underlying data sample consists of about 226 million BB-pairs accumulated on the Y(4S) resonance by the BABAR detector at the asymmetric e+e- collider PEP-II. The reconstruction of the decay uses the channels D*° ^ D0n0, D° ^ K-n+ and n0 ^ 77. The neutrino is not reconstructed. Since the rest frame of the B meson is unknown, the boost w of the D*° meson in the B meson rest frame is estimated by w. The W spectrum of the data is described in terms of the partial decay width dr/dw given by theory and the detector simulation translating each spectrum dr/dw into an expectation of the measured w spectrum. dr/dw depends on a form factor F(w) parameterizing the strong interaction in the decay process. To find the best descriptive dr/dw a fit to the data determines the following two parameters of dr/dw: (i) F(1)|VCb|, the product between F at zero D* 0-recoil and the CKM matrix element |Vcb|; (ii) p A , a parameter of the form factor F(w). -
The Flavour Puzzle, Discreet Family Symmetries
The flavour puzzle, discreet family symmetries 27. 10. 2017 Marek Zrałek Particle Physics and Field Theory Department University of Silesia Outline 1. Some remarks about the history of the flavour problem. 2. Flavour in the Standard Model. 3. Current meaning of the flavour problem? 4. Discrete family symmetries for lepton. 4.1. Abelian symmetries, texture zeros. 4.2. Non-abelian symmetries in the Standard Model and beyond 5. Summary. 1. Some remarks about the history of the flavour problem The flavour problem (History began with the leptons) I.I. Rabi Who ordered that? Discovered by Anderson and Neddermayer, 1936 - Why there is such a duplication in nature? - Is the muon an excited state of the electron? - Great saga of the µ → e γ decay, (Hincks and Pontecorvo, 1948) − − - Muon decay µ → e ν ν , (Tiomno ,Wheeler (1949) and others) - Looking for muon – electron conversion process (Paris, Lagarrigue, Payrou, 1952) Neutrinos and charged leptons Electron neutrino e− 1956r ν e 1897r n p Muon neutrinos 1962r Tau neutrinos − 1936r ν µ µ 2000r n − ντ τ 1977r p n p (Later the same things happen for quark sector) Eightfold Way Murray Gell-Mann and Yuval Ne’eman (1964) Quark Model Murray Gell-Mann and George Zweig (1964) „Young man, if I could remember the names of these particles, I „Had I foreseen that, I would would have been a botanist”, have gone into botany”, Enrico Fermi to advise his student Leon Wofgang Pauli Lederman Flavour - property (quantum numbers) that distinguishes Six flavours of different members in the two groups, quarks and -
Lecture 5: Quarks & Leptons, Mesons & Baryons
Physics 3: Particle Physics Lecture 5: Quarks & Leptons, Mesons & Baryons February 25th 2008 Leptons • Quantum Numbers Quarks • Quantum Numbers • Isospin • Quark Model and a little History • Baryons, Mesons and colour charge 1 Leptons − − − • Six leptons: e µ τ νe νµ ντ + + + • Six anti-leptons: e µ τ νe̅ νµ̅ ντ̅ • Four quantum numbers used to characterise leptons: • Electron number, Le, muon number, Lµ, tau number Lτ • Total Lepton number: L= Le + Lµ + Lτ • Le, Lµ, Lτ & L are conserved in all interactions Lepton Le Lµ Lτ Q(e) electron e− +1 0 0 1 Think of Le, Lµ and Lτ like − muon µ− 0 +1 0 1 electric charge: − tau τ − 0 0 +1 1 They have to be conserved − • electron neutrino νe +1 0 0 0 at every vertex. muon neutrino νµ 0 +1 0 0 • They are conserved in every tau neutrino ντ 0 0 +1 0 decay and scattering anti-electron e+ 1 0 0 +1 anti-muon µ+ −0 1 0 +1 anti-tau τ + 0 −0 1 +1 Parity: intrinsic quantum number. − electron anti-neutrino ν¯e 1 0 0 0 π=+1 for lepton − muon anti-neutrino ν¯µ 0 1 0 0 π=−1 for anti-leptons tau anti-neutrino ν¯ 0 −0 1 0 τ − 2 Introduction to Quarks • Six quarks: d u s c t b Parity: intrinsic quantum number • Six anti-quarks: d ̅ u ̅ s ̅ c ̅ t ̅ b̅ π=+1 for quarks π=−1 for anti-quarks • Lots of quantum numbers used to describe quarks: • Baryon Number, B - (total number of quarks)/3 • B=+1/3 for quarks, B=−1/3 for anti-quarks • Strangness: S, Charm: C, Bottomness: B, Topness: T - number of s, c, b, t • S=N(s)̅ −N(s) C=N(c)−N(c)̅ B=N(b)̅ −N(b) T=N( t )−N( t )̅ • Isospin: I, IZ - describe up and down quarks B conserved in all Quark I I S C B T Q(e) • Z interactions down d 1/2 1/2 0 0 0 0 1/3 up u 1/2 −1/2 0 0 0 0 +2− /3 • S, C, B, T conserved in strange s 0 0 1 0 0 0 1/3 strong and charm c 0 0 −0 +1 0 0 +2− /3 electromagnetic bottom b 0 0 0 0 1 0 1/3 • I, IZ conserved in strong top t 0 0 0 0 −0 +1 +2− /3 interactions only 3 Much Ado about Isospin • Isospin was introduced as a quantum number before it was known that hadrons are composed of quarks. -
Quarks and Their Discovery
Quarks and Their Discovery Parashu Ram Poudel Department of Physics, PN Campus, Pokhara Email: [email protected] Introduction charge (e) of one proton. The different fl avors of Quarks are the smallest building blocks of matter. quarks have different charges. The up (u), charm They are the fundamental constituents of all the (c) and top (t) quarks have electric charge +2e/3 hadrons. They have fractional electronic charge. and the down (d), strange (s) and bottom (b) quarks Quarks never exist alone in nature. They are always have charge -e/3; -e is the charge of an electron. The found in combination with other quarks or antiquark masses of these quarks vary greatly, and of the six, in larger particle of matter. By studying these larger only the up and down quarks, which are by far the particles, scientists have determined the properties lightest, appear to play a direct role in normal matter. of quarks. Protons and neutrons, the particles that make up the nuclei of the atoms consist of quarks. There are four forces that act between the quarks. Without quarks there would be no atoms, and without They are strong force, electromagnetic force, atoms, matter would not exist as we know it. Quarks weak force and gravitational force. The quantum only form triplets called baryons such as proton and of strong force is gluon. Gluons bind quarks or neutron or doublets called mesons such as Kaons and quark and antiquark together to form hadrons. The pi mesons. Quarks exist in six varieties: up (u), down electromagnetic force has photon as quantum that (d), charm (c), strange (s), bottom (b), and top (t) couples the quarks charge. -
Pos(ICHEP2012)321
Parity of Pions and CP Violation in Neutral Kaon System PoS(ICHEP2012)321 Brian Robson Department of Theoretical Physics, Research School of Physics and Engineering The Australian National University, Canberra, ACT 0200, Australia E-mail: [email protected] The parity of pions is discussed within the framework of the Generation Model of particle physics and it is shown that both the 1954 determination of the parity of the charged pions and the 2008 determination of the parity of the neutral pion are compatible with the mixed-parity nature of the pions predicted by a recent composite Generation Model. The development of the Generation Model as an alternative to the Standard Model of particle physics is discussed. It is demonstrated how the Generation Model leads to a unified classification of leptons and quarks and how this makes feasible a composite model of the fundamental particles of the Standard Model. In particular it is shown that the 1964 CP violating experiment of Christenson et al. may be understood without CP violation. 36th International Conference on High Energy Physics July 4-11, 2012 Melbourne, Australia Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it Parity of Pions and CP Violation in Neutral Kaon System Brian Robson 1. Introduction This paper summarizes the Generation Model (GM) of particle physics, which has been developed over the last decade [1-4]. Essentially, the GM is obtained from the Standard Model (SM) [5] by making two postulates, which together maintain the same transition probabilities for both hadronic and leptonic processes as the SM so that agreement with experiment is preserved. -
The Quantum Chromodynamics Theory of Tetraquarks and Mesomesonic Particles Unfinished Draft Version
The Quantum Chromodynamics Theory Of Tetraquarks And Mesomesonic Particles Unfinished draft version Based on a generalized particle diagram of baryons and anti-baryons which, in turn, is based on symmetry principles, this theory predicts the existence of all the tetraquarks and dimeson molecules (mesomesonic particles) there exist in nature. by R. A. Frino Electronics Engineer - Degree from the University of Mar del Plata. March 4th, 2016 (v1) Keywords: mirror symmetry, parity, P symmetry, charge conjugation, C symmetry, time reversal, T symmetry, CP symmetry, CPT symmetry, PC+ symmetry, Q symmetry, quantum electrodynamics, quantum chromodynamics, quark, antiquark, up quark, down quark, strange quark, charm quark, bottom quark, top quark, anti-up quark, anti-down quark, anti-strange quark, anti-charm quark, anti-bottom quark, anti-top quark, tetraquark, pentaquark, antitetraquark, non-strange tetraquark, colour charge, anticolour, anticolour charge, strangeness, charmness, bottomness, topness, fermion, hadron, baryon, meson, boson, photon, gluon, mesobaryonic particle, meso-baryonic particle, mesobaryonic molecule, meso-mesonic molecule, meso-mesonic particle, dimeson particle, dimeson molecule, Pauli exclusion principle, force carrier, omega- minus particle, matter-antimatter way, quadruply flavoured tetraquark, MAW, MMP, MMM, LHC. (see next page) The Quantum Chromodynamics Theory Of Tetraquarks And Mesomesonic Particles - v1. Copyright © 2016 Rodolfo A. Frino. All rights reserved. 1 1. Introduction Quantum Chromodynamics (QCD) [1, 2, 3, 4] is a quantum mechanical description of the strong nuclear force. The strong force is mediated by gluons [4, 5] which are spin 1ℏ bosons (spin is quoted in units of reduced Plank's constant: ℏ =h/2π ). Gluons act on quarks only (only quarks feel the strong force). -
Isospin and Isospin/Strangeness Correlations in Relativistic Heavy Ion Collisions
Isospin and Isospin/Strangeness Correlations in Relativistic Heavy Ion Collisions Aram Mekjian Rutgers University, Department of Physics and Astronomy, Piscataway, NJ. 08854 & California Institute of Technology, Kellogg Radiation Lab 106-38, Pasadena, Ca 91125 Abstract A fundamental symmetry of nuclear and particle physics is isospin whose third component is the Gell-Mann/Nishijima expression I Z =Q − (B + S) / 2 . The role of isospin symmetry in relativistic heavy ion collisions is studied. An isospin I Z , strangeness S correlation is shown to be a direct and simple measure of flavor correlations, vanishing in a Qg phase of uncorrelated flavors in both symmetric N = Z and asymmetric N ≠ Z systems. By contrast, in a hadron phase, a I Z / S correlation exists as long as the electrostatic charge chemical potential µQ ≠ 0 as in N ≠ Z asymmetric systems. A parallel is drawn with a Zeeman effect which breaks a spin degeneracy PACS numbers: 25.75.-q, 25.75.Gz, 25.75.Nq Introduction A goal of relativistic high energy collisions such as those done at CERN or BNL RHIC is the creation of a new state of matter known as the quark gluon plasma. This phase is produced in the initial stages of a collision where a high density ρ and temperatureT are produced. A heavy ion collision then proceeds through a subsequent expansion to lower ρ andT where the colored quarks and anti-quarks form isolated colorless objects which are the well known particles whose properties are tabulated in ref[1]. Isospin plays an important role in the classification of these particles [1,2]. -
Dr Victoria Martin, Prof Steve Playfer Spring Semester 2013 Lecture 13: Hadron Decays
Particle Physics Dr Victoria Martin, Prof Steve Playfer Spring Semester 2013 Lecture 13: Hadron Decays ★Decays and Quantum numbers ★CKM matrix 1 Decays of Hadrons Force Typical τ (s) QCD 10−20 - 10−23 • The proton is the only completely stable hadron QED 10−20 - 10−16 • The free neutron has a weak decay (~15 mins) Weak 10−13 - 103 • Decay length of a particle is distance it travels before decaying L=βγcτ ± ± 0 • π , K , KL mesons are long-lived (~10 ns) and have weak decays ➡ These particles live long enough to travel outside radii of collider detectors (~10 m) 0 0 • KS mesons and Λ hyperons are long-lived (~100 ps) and have weak decays with decay lengths of ~ cm. • π0→γγ, η→γγ are electromagnetic decays, reconstructed from pairs of photons. 2 2 mπ =(p(γ1)+p(γ2)) • ρ, ω, φ, Κ∗, Δ, Σ∗, Ξ∗ are resonances with strong decays. ➡Reconstructed as broad structures with widths ~100 MeV. 2 Decay Conservation Laws • Relevant quantum numbers are: • strong isospin (I, I3) • parity (P) • quark flavour: described using strangeness (S=N(s)−N(s)̅ ), charm (C=N(c)−N(c)̅ ), bottomness (B=N(b)−N(b)̅ ) • Baryon number and lepton numbers are always conserved! Strong Strong baryon Flavour, Isospin, Isospin, Parity, P number S, C, B I I3 Strong Y Y Y Y Y EM Y N Y Y Y Weak Y N N N N 3 Decays of Charmonium • The J/ψ meson is a2007/08 c c —̅ state. Physics 3: Particle It Physics must decay to particles4 without charm quarks as M(J/ψ) < 2 M(D). -
Arxiv:1609.04034V1 [Physics.Gen-Ph] 8 Sep 2016 Asnme() 26.C 53.Q 98.80.Bp 95.30.Cq, 12.60.Rc, Number(S): PACS Atom
The generation model of particle physics and the cosmological matter-antimatter asymmetry problem B.A. Robson∗ Department of Theoretical Physics, Research School of Physics and Engineering, The Australian National University, Acton ACT 2601, Australia ∗[email protected] The matter-antimatter asymmetry problem, corresponding to the virtual nonexis- tence of antimatter in the universe, is one of the greatest mysteries of cosmology. Within the framework of the Generation Model (GM) of particle physics, it is demon- strated that the matter-antimatter asymmetry problem may be understood in terms of the composite leptons and quarks of the GM. It is concluded that there is essen- tially no matter-antimatter asymmetry in the present universe and that the observed hydrogen-antihydrogen asymmetry may be understood in terms of statistical fluctu- ations associated with the complex many-body processes involved in the formation of either a hydrogen atom or an antihydrogen atom. Keywords: Generation model; antimatter; big bang. PACS Number(s): 12.60.Rc, 95.30.Cq, 98.80.Bp arXiv:1609.04034v1 [physics.gen-ph] 8 Sep 2016 1. Introduction The matter-antimatter asymmetry problem, corresponding to the virtual nonexis- tence of antimatter in the universe, is one of the greatest mysteries of cosmology, along with dark matter and dark energy.1 Recently, an understanding of both dark matter and dark energy has been provided by the development of a new quan- tum theory of gravity,2,3 which is based on the Generation Model (GM) of particle physics.4 In this paper it is demonstrated that the matter-antimatter asymmetry problem may also be understood in terms of the composite leptons and quarks of the GM, contrary to the elementary leptons and quarks of the Standard Model (SM) of particle physics.5 According to the SM of particle physics, the universe is made essentially of mat- ter comprising three kinds of elementary particles: electrons, up quarks and down quarks. -
Introduction to Elementary Particle Physics
Introduction to Elementary Particle Physics Néda Sadooghi Department of Physics Sharif University of Technology Tehran - Iran Elementary Particle Physics Lecture 9 and 10: Esfand 18 and 20, 1397 1397-98-II Leptons and quarks Lectrue 9 Leptons Lectrue 9 Remarks: I Lepton flavor number conservation: - Lepton flavor number of leptons Le; Lµ; Lτ = +1 - Lepton flavor number of antileptons Le; Lµ; Lτ = −1 Assumption: No neutrino mixing + + − + + Ex.: π ! µ + νµ; n ! p + e +ν ¯e; µ ! e + νe +ν ¯µ But, µ+ ! e+ + γ is forbidden I Two other quantum numbers for leptons - Weak hypercharge YW : It is 1 for all left-handed leptons - Weak isospin T3: ( ) ( ) e− − 1 ! 2 For each lepton generation, for example T3 = 1 νe + 2 I Type of interaction: - Charged leptons undergo both EM and weak interactions - Neutrinos interact only weakly Lectrue 9 Quarks Lectrue 9 Remarks I Hadrons are bound states of constituent (valence) quarks I Bare (current) quarks are not dressed. We denote the current quark mass by m0 I Dressed quarks are surrounded by a cloud of virtual quarks and gluons (Sea quarks) I This cloud explains the large constituent-quark mass M I For hadrons the constituent quark mass M = the binding energy required to make the hadrons spontaneously emit a meson containing the valence quark For light quarks (u,d,s): m0 ≪ M For heavy quarks (c,b,t): m0 ' M Lectrue 9 Remarks: I Type of interaction: - All quarks undergo EM and strong interactions I Mean lifetime (typical time of interaction): In general, - Particles which mainly decay through strong interactions have a mean lifetime of about 10−23 sec - Particles which mainly decay through electromagnetic interactions, signaled by the production of photons, have a mean lifetime in the range of 10−20 − 10−16 sec - Particles that decay through weak forces have a mean lifetime in the range of 10−10 − 10−8 sec Lectrue 9 Other quantum numbers (see Perkins Chapter 4) Flavor Baryon Spin Isospin Charm Strangeness Topness Bottomness El. -
Particle Properties
Particle Properties You don’t have to remember this information! In an exam the masses of the particles are given on the constant sheet. Any other required information will be given to you. What you should know, or be able to work out, is: • the quantum numbers, and if they are conserved are or not • the force responsible for a decay, from the lifetime • the main decay modes, using a Feynman diagram • that the +, − and 0 superscripts correspond to the electric charge of the particles • the relationship between a particle and its antiparticle. Anti-particles are not named in the tables. Anti-particles have the same mass, same lifetime, opposite quantum numbers from the particle. Anti-particles decay into the anti-particles of the shown modes. For example, an anti-muon, µ+, has a mass of 2 −6 105.7 MeV/c and a lifetime of 2.197 × 10 s. Its quantum numbers are Le = 0,Lµ = + + −1,Lτ = 0 and Q = +1. Its main decay mode is µ → e νeν¯µ. Quantum Numbers The following quantum numbers are conserved in all reactions: • Total quark number, Nq = N(q) − N(¯q). – Nq = +1 for all quarks – Nq = −1 for all anti-quarks – Nq = 0 for all leptons and anti-leptons – Nq = 3 for baryons and Nq = 0 for mesons. • The three lepton flavour quantum numbers: − + – Electron Number: Le = N(e ) − N(e ) + N(νe) − N(¯νe) − + – Muon Number: Lµ = N(µ ) − N(µ ) + N(νµ) − N(¯νµ) − + – Tau Number: Lτ = N(τ ) − N(τ ) + N(ντ ) − N(¯ντ ) • Electric charge, Q.