The Nuclear Physics of Muon Capture
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The Particle Zoo
219 8 The Particle Zoo 8.1 Introduction Around 1960 the situation in particle physics was very confusing. Elementary particlesa such as the photon, electron, muon and neutrino were known, but in addition many more particles were being discovered and almost any experiment added more to the list. The main property that these new particles had in common was that they were strongly interacting, meaning that they would interact strongly with protons and neutrons. In this they were different from photons, electrons, muons and neutrinos. A muon may actually traverse a nucleus without disturbing it, and a neutrino, being electrically neutral, may go through huge amounts of matter without any interaction. In other words, in some vague way these new particles seemed to belong to the same group of by Dr. Horst Wahl on 08/28/12. For personal use only. particles as the proton and neutron. In those days proton and neutron were mysterious as well, they seemed to be complicated compound states. At some point a classification scheme for all these particles including proton and neutron was introduced, and once that was done the situation clarified considerably. In that Facts And Mysteries In Elementary Particle Physics Downloaded from www.worldscientific.com era theoretical particle physics was dominated by Gell-Mann, who contributed enormously to that process of systematization and clarification. The result of this massive amount of experimental and theoretical work was the introduction of quarks, and the understanding that all those ‘new’ particles as well as the proton aWe call a particle elementary if we do not know of a further substructure. -
Neutron Stars
Chandra X-Ray Observatory X-Ray Astronomy Field Guide Neutron Stars Ordinary matter, or the stuff we and everything around us is made of, consists largely of empty space. Even a rock is mostly empty space. This is because matter is made of atoms. An atom is a cloud of electrons orbiting around a nucleus composed of protons and neutrons. The nucleus contains more than 99.9 percent of the mass of an atom, yet it has a diameter of only 1/100,000 that of the electron cloud. The electrons themselves take up little space, but the pattern of their orbit defines the size of the atom, which is therefore 99.9999999999999% Chandra Image of Vela Pulsar open space! (NASA/PSU/G.Pavlov et al. What we perceive as painfully solid when we bump against a rock is really a hurly-burly of electrons moving through empty space so fast that we can't see—or feel—the emptiness. What would matter look like if it weren't empty, if we could crush the electron cloud down to the size of the nucleus? Suppose we could generate a force strong enough to crush all the emptiness out of a rock roughly the size of a football stadium. The rock would be squeezed down to the size of a grain of sand and would still weigh 4 million tons! Such extreme forces occur in nature when the central part of a massive star collapses to form a neutron star. The atoms are crushed completely, and the electrons are jammed inside the protons to form a star composed almost entirely of neutrons. -
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. -
Arxiv:2010.09509V2 [Hep-Ph] 2 Apr 2021 in Searches for CLFV Or LNV, Incoming Muons Are the Source of Both the Μ → E Signal and the RMC Back- Ground
FERMILAB-PUB-20-525-T The high energy spectrum of internal positrons from radiative muon capture on nuclei Ryan Plestid1, 2, ∗ and Richard J. Hill1, 2, y 1Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506, USA 2Theoretical Physics Department, Fermilab, Batavia, IL 60510,USA (Dated: April 5, 2021) The Mu2e and COMET collaborations will search for nucleus-catalyzed muon conversion to positrons (µ− ! e+) as a signal of lepton number violation. A key background for this search is radiative muon capture where either: 1) a real photon converts to an e+e− pair “externally" in surrounding material; or 2) a virtual photon mediates the production of an e+e− pair “internally”. If the e+ has an energy approaching the signal region then it can serve as an irreducible background. In this work we describe how the near end-point internal positron spectrum can be related to the real photon spectrum from the same nucleus, which encodes all non-trivial nuclear physics. I. INTRODUCTION Specifically, on a nucleus (e.g. aluminum), the reaction µ− + [A; Z] ! e+ + [A; Z − 2] ; (1) Charged lepton flavor violation (CLFV) is a smok- ing gun signature of physics beyond the Standard Model becomes a viable target for observation (see also [7]). (SM) and is one of the most sought-after signals at the While neutrinoless double beta (0νββ) decay is often intensity frontier [1–4]. Important search channels in- touted as the most promising direction for the discovery volving the lightest two lepton generations are µ ! 3e, of LNV, there do exist extensions of the SM that predict µ ! eγ, and nucleus-catalyzed µ ! e [1–6]. -
The Lamb Shift Experiment in Muonic Hydrogen
The Lamb Shift Experiment in Muonic Hydrogen Dissertation submitted to the Physics Faculty of the Ludwig{Maximilians{University Munich by Aldo Sady Antognini from Bellinzona, Switzerland Munich, November 2005 1st Referee : Prof. Dr. Theodor W. H¨ansch 2nd Referee : Prof. Dr. Dietrich Habs Date of the Oral Examination : December 21, 2005 Even if I don't think, I am. Itsuo Tsuda Je suis ou` je ne pense pas, je pense ou` je ne suis pas. Jacques Lacan A mia mamma e mio papa` con tanto amore Abstract The subject of this thesis is the muonic hydrogen (µ−p) Lamb shift experiment being performed at the Paul Scherrer Institute, Switzerland. Its goal is to measure the 2S 2P − energy difference in µp atoms by laser spectroscopy and to deduce the proton root{mean{ −3 square (rms) charge radius rp with 10 precision, an order of magnitude better than presently known. This would make it possible to test bound{state quantum electrody- namics (QED) in hydrogen at the relative accuracy level of 10−7, and will lead to an improvement in the determination of the Rydberg constant by more than a factor of seven. Moreover it will represent a benchmark for QCD theories. The experiment is based on the measurement of the energy difference between the F=1 F=2 2S1=2 and 2P3=2 levels in µp atoms to a precision of 30 ppm, using a pulsed laser tunable at wavelengths around 6 µm. Negative muons from a unique low{energy muon beam are −1 stopped at a rate of 70 s in 0.6 hPa of H2 gas. -
MODERN DEVELOPMENT of MAGNETIC RESONANCE Abstracts 2020 KAZAN * RUSSIA
MODERN DEVELOPMENT OF MAGNETIC RESONANCE abstracts 2020 KAZAN * RUSSIA OF MA NT GN E E M T P IC O L R E E V S E O N D A N N R C E E D O M K 20 AZAN 20 MODERN DEVELOPMENT OF MAGNETIC RESONANCE ABSTRACTS OF THE INTERNATIONAL CONFERENCE AND WORKSHOP “DIAMOND-BASED QUANTUM SYSTEMS FOR SENSING AND QUANTUM INFORMATION” Editors: ALEXEY A. KALACHEV KEV M. SALIKHOV KAZAN, SEPTEMBER 28–OCTOBER 2, 2020 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machines or similar means, and storage in data banks. © 2020 Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS, Kazan © 2020 Igor A. Aksenov, graphic design Printed in Russian Federation Published by Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS, Kazan www.kfti.knc.ru v CHAIRMEN Alexey A. Kalachev Kev M. Salikhov PROGRAM COMMITTEE Kev Salikhov, chairman (Russia) Vadim Atsarkin (Russia) Elena Bagryanskaya (Russia) Pavel Baranov (Russia) Marina Bennati (Germany) Robert Bittl (Germany) Bernhard Blümich (Germany) Michael Bowman (USA) Gerd Buntkowsky (Germany) Sergei Demishev (Russia) Sabine Van Doorslaer (Belgium) Rushana Eremina (Russia) Jack Freed (USA) Philip Hemmer (USA) Konstantin Ivanov (Russia) Alexey Kalachev (Russia) Vladislav Kataev (Germany) Walter Kockenberger (Great Britain) Wolfgang Lubitz (Germany) Anders Lund (Sweden) Sergei Nikitin (Russia) Klaus Möbius (Germany) Hitoshi Ohta (Japan) Igor Ovchinnikov (Russia) Vladimir Skirda (Russia) Alexander Smirnov( Russia) Graham Smith (Great Britain) Mark Smith (Great Britain) Murat Tagirov (Russia) Takeji Takui (Japan) Valery Tarasov (Russia) Violeta Voronkova (Russia) vi LOCAL ORGANIZING COMMITTEE Kalachev A.A., chairman Kupriyanova O.O. -
Identical Particles
8.06 Spring 2016 Lecture Notes 4. Identical particles Aram Harrow Last updated: May 19, 2016 Contents 1 Fermions and Bosons 1 1.1 Introduction and two-particle systems .......................... 1 1.2 N particles ......................................... 3 1.3 Non-interacting particles .................................. 5 1.4 Non-zero temperature ................................... 7 1.5 Composite particles .................................... 7 1.6 Emergence of distinguishability .............................. 9 2 Degenerate Fermi gas 10 2.1 Electrons in a box ..................................... 10 2.2 White dwarves ....................................... 12 2.3 Electrons in a periodic potential ............................. 16 3 Charged particles in a magnetic field 21 3.1 The Pauli Hamiltonian ................................... 21 3.2 Landau levels ........................................ 23 3.3 The de Haas-van Alphen effect .............................. 24 3.4 Integer Quantum Hall Effect ............................... 27 3.5 Aharonov-Bohm Effect ................................... 33 1 Fermions and Bosons 1.1 Introduction and two-particle systems Previously we have discussed multiple-particle systems using the tensor-product formalism (cf. Section 1.2 of Chapter 3 of these notes). But this applies only to distinguishable particles. In reality, all known particles are indistinguishable. In the coming lectures, we will explore the mathematical and physical consequences of this. First, consider classical many-particle systems. If a single particle has state described by position and momentum (~r; p~), then the state of N distinguishable particles can be written as (~r1; p~1; ~r2; p~2;:::; ~rN ; p~N ). The notation (·; ·;:::; ·) denotes an ordered list, in which different posi tions have different meanings; e.g. in general (~r1; p~1; ~r2; p~2)6 = (~r2; p~2; ~r1; p~1). 1 To describe indistinguishable particles, we can use set notation. -
Muonium-Antimuonium Conversion Abstract
SciPost Phys. Proc. 5, 009 (2021) Muonium-antimuonium conversion Lorenz Willmann? and Klaus Jungmann Van Swinderen Institute, University of Groningen, 9747 AA, Groningen, The Netherlands ? [email protected] Review of Particle Physics at PSI doi:10.21468/SciPostPhysProc.5 Abstract The MACS experiment performed at PSI in the 1990s provided an yet unchallenged upper bound on the probability for a spontaneous conversion of the muonium atom, + + M =(µ e−), into its antiatom, antimuonium M =(µ−e ). It comprises the culmination of a series of measurements at various accelerator laboratories worldwide. The experimen- tal limits on the process have provided input and steering for the further development of a variety of theoretical models beyond the standard theory, in particular for mod- els which address lepton number violating processes and matter-antimatter oscillations. Several models beyond the standard theory could be strongly disfavored. There is inter- est in a new measurement and improved sensitivity could be reached by exploiting the time evolution of the conversion process, e.g., at intense pulsed muonium sources. Copyright L. Willmann and K. Jungmann. Received 16-02-2021 This work is licensed under the Creative Commons Accepted 28-04-2021 Check for Attribution 4.0 International License. Published 06-09-2021 updates Published by the SciPost Foundation. doi:10.21468/SciPostPhysProc.5.009 9.1 Introduction + The bound state of a positive muon (µ ) and an electron (e−) is an exotic atom which has been named muonium (M) by V.Telegdi. This exotic atom was first produced and observed by V.W. Hughes and collaborators in 1960 [1]. -
Muon Decay 1
Muon Decay 1 LIFETIME OF THE MUON Introduction Muons are unstable particles; otherwise, they are rather like electrons but with much higher masses, approximately 105 MeV. Radioactive nuclear decays do not release enough energy to produce them; however, they are readily available in the laboratory as the dominant component of the cosmic ray flux at the earth’s surface. There are two types of muons, with opposite charge, and they decay into electrons or positrons and two neutrinos according to the rules + + µ → e νe ν¯µ − − µ → e ν¯e νµ . The muon decay is a radioactiveprocess which follows the usual exponential law for the probability of survival for a given time t. Be sure that you understand the basis for this law. The goal of the experiment is to measure the muon lifetime which is roughly 2 µs. With care you can make the measurement with an accuracy of a few percent or better. In order to achieve this goal in a conceptually simple way, we look only at those muons that happen to come to rest inside our detector. That is, we first capture a muon and then measure the elapsed time until it decays. Muons are rather penetrating particles, they can easily go through meters of concrete. Nevertheless, a small fraction of the muons will be slowed down and stopped in the detector. As shown in Figure 1, the apparatus consists of two types of detectors. There is a tank filled with liquid scintillator (a big metal box) viewed by two photomultiplier tubes (Left and Right) and two plastic scintillation counters (flat panels wrapped in black tape), each viewed by a photomul- tiplier tube (Top and Bottom). -
UC Irvine UC Irvine Previously Published Works
UC Irvine UC Irvine Previously Published Works Title Astrophysics in 2006 Permalink https://escholarship.org/uc/item/5760h9v8 Journal Space Science Reviews, 132(1) ISSN 0038-6308 Authors Trimble, V Aschwanden, MJ Hansen, CJ Publication Date 2007-09-01 DOI 10.1007/s11214-007-9224-0 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Space Sci Rev (2007) 132: 1–182 DOI 10.1007/s11214-007-9224-0 Astrophysics in 2006 Virginia Trimble · Markus J. Aschwanden · Carl J. Hansen Received: 11 May 2007 / Accepted: 24 May 2007 / Published online: 23 October 2007 © Springer Science+Business Media B.V. 2007 Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords Cosmology: general · Galaxies: general · ISM: general · Stars: general · Sun: general · Planets and satellites: general · Astrobiology · Star clusters · Binary stars · Clusters of galaxies · Gamma-ray bursts · Milky Way · Earth · Active galaxies · Supernovae 1 Introduction Astrophysics in 2006 modifies a long tradition by moving to a new journal, which you hold in your (real or virtual) hands. The fifteen previous articles in the series are referenced oc- casionally as Ap91 to Ap05 below and appeared in volumes 104–118 of Publications of V. -
4 Muon Capture on the Deuteron 7 4.1 Theoretical Framework
February 8, 2008 Muon Capture on the Deuteron The MuSun Experiment MuSun Collaboration model-independent connection via EFT http://www.npl.uiuc.edu/exp/musun V.A. Andreeva, R.M. Careye, V.A. Ganzhaa, A. Gardestigh, T. Gorringed, F.E. Grayg, D.W. Hertzogb, M. Hildebrandtc, P. Kammelb, B. Kiburgb, S. Knaackb, P.A. Kravtsova, A.G. Krivshicha, K. Kuboderah, B. Laussc, M. Levchenkoa, K.R. Lynche, E.M. Maeva, O.E. Maeva, F. Mulhauserb, F. Myhrerh, C. Petitjeanc, G.E. Petrova, R. Prieelsf , G.N. Schapkina, G.G. Semenchuka, M.A. Sorokaa, V. Tishchenkod, A.A. Vasilyeva, A.A. Vorobyova, M.E. Vznuzdaeva, P. Winterb aPetersburg Nuclear Physics Institute, Gatchina 188350, Russia bUniversity of Illinois at Urbana-Champaign, Urbana, IL 61801, USA cPaul Scherrer Institute, CH-5232 Villigen PSI, Switzerland dUniversity of Kentucky, Lexington, KY 40506, USA eBoston University, Boston, MA 02215, USA f Universit´eCatholique de Louvain, B-1348 Louvain-la-Neuve, Belgium gRegis University, Denver, CO 80221, USA hUniversity of South Carolina, Columbia, SC 29208, USA Co-spokespersons underlined. 1 Abstract: We propose to measure the rate Λd for muon capture on the deuteron to better than 1.5% precision. This process is the simplest weak interaction process on a nucleus that can both be calculated and measured to a high degree of precision. The measurement will provide a benchmark result, far more precise than any current experimental information on weak interaction processes in the two-nucleon system. Moreover, it can impact our understanding of fundamental reactions of astrophysical interest, like solar pp fusion and the ν + d reactions observed by the Sudbury Neutrino Observatory. -
KAONIC and OTHER EXOTIC ATOMS 243 Atoms Got Underway in Earnest with the Invention and Application of Semiconductor Detectors
Copyright 1975. All rights reserved KAONIC AND OTHER :.:5562 EXOTIC ATOMS Ryoichi Seki California State University, Northridge, California 91324 Clyde E. Wiegand Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 CONTENTS 1 INTRODUCTION................................................ 241 2 BASIC CHARACTERISTICS OF EXOTIC ATOMS. .. 245 3 EXPERIMENTAL FINDINGS. .. 248 3.1 X-Ray Intensities.. .. .. .. .. .. .. .. .. .. .. 248 248 3.1.1 Kaonic.atoms....................................... .. 3.1.2 Sigmonic atoms.. 250 . .. 3.1.3 Antiprotonic atoms. 250 . .. 3.2 Level Shifts and Widths. 250 . .. 256 3.3 Particle Properties Derivedfrom Exotic Atoms. 3.3.1 Mass.. 257 . .. 258 3.3.2 Magnetic moment.. 259 3.3.3 Polarizability....................................... .. 3.4 Atomic Phenomena Directly Related to Nuclear Properties. 260 '. .. 260 3.4.1 Nuclear quadrupole moment..... ............... .. 260 3.4.2 Dynamical quadrupole (E2) mixing. .. 261 3.5 Products from Nuclear Absorption of K-, �-, and p. 3. 5. 1 Particles observed in nuclear emulsions and bubble chambers.. 261 . 264 3.5.2 Nuclear y rays.. 4 THEORETICAL UNDERSTANDING. .. .. .. .. .. .. .. .. .. 265 . 4.1 Atomic Capture and Cascade.. 266 Annu. Rev. Nucl. Sci. 1975.25:241-281. Downloaded from www.annualreviews.org Atomic capture.. 266 Access provided by Pennsylvania State University on 02/13/15. For personal use only. 4.1.1 .. .. .. .. .. 267 4.1.2 Atomic cascade.. 268 4.2 Strong Interactions with Nuclei.. 269 4.2.1 K --nucleus optical potential.. - . 4.2.2 p- and � -nucleus optical potential. 276 27 4.3 Two- and One-Nucleon Absorption Products. .. .. .. .. .. .. .. 7 . .. 278 5 CONCLUDING REMARKS. 1 INTRODUCTION In this article we attempt to tell what is known about kaonie, sigmonic, and anti protonic atoms.