Carnegie Mellon University MELLON COLLEGE of SCIENCE
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Jul/Aug 2013
I NTERNATIONAL J OURNAL OF H IGH -E NERGY P HYSICS CERNCOURIER WELCOME V OLUME 5 3 N UMBER 6 J ULY /A UGUST 2 0 1 3 CERN Courier – digital edition Welcome to the digital edition of the July/August 2013 issue of CERN Courier. This “double issue” provides plenty to read during what is for many people the holiday season. The feature articles illustrate well the breadth of modern IceCube brings particle physics – from the Standard Model, which is still being tested in the analysis of data from Fermilab’s Tevatron, to the tantalizing hints of news from the deep extraterrestrial neutrinos from the IceCube Observatory at the South Pole. A connection of a different kind between space and particle physics emerges in the interview with the astronaut who started his postgraduate life at CERN, while connections between particle physics and everyday life come into focus in the application of particle detectors to the diagnosis of breast cancer. And if this is not enough, take a look at Summer Bookshelf, with its selection of suggestions for more relaxed reading. To sign up to the new issue alert, please visit: http://cerncourier.com/cws/sign-up. To subscribe to the magazine, the e-mail new-issue alert, please visit: http://cerncourier.com/cws/how-to-subscribe. ISOLDE OUTREACH TEVATRON From new magic LHC tourist trail to the rarest of gets off to a LEGACY EDITOR: CHRISTINE SUTTON, CERN elements great start Results continue DIGITAL EDITION CREATED BY JESSE KARJALAINEN/IOP PUBLISHING, UK p6 p43 to excite p17 CERNCOURIER www. -
Pos(RAD COR 2007)025 Ce
Automated calculation of QED corrections to lepton g − 2 PoS(RAD COR 2007)025 Tatsumi Aoyama∗ Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK) E-mail: [email protected] Masashi Hayakawa Department of Physics, Nagoya University Toichiro Kinoshita Laboratory for Elementary-Particle Physics, Cornell University Makiko Nio Theoretical Physics Laboratory, Nishina Center, RIKEN This article reports our project on the automated calculation of QED corrections to the anomalous magnetic moment of leptons. Our major concern is the tenth-order correction, which is urgently needed considering the recent improvementof electron g−2 measurements. We focus on a type of diagrams that have no internal lepton loops, and have devised the automated code-generating sys- tem for the UV-renormalized amplitude. We have newly developed and implemented an efficient algorithm to perform subtractions of IR divergences. This enables us to obtain finite amplitudes that are free from both UV and IR divergences. Currently the numerical evaluation of these dia- grams of tenth order is in progress. 8th International Symposium on Radiative Corrections October 1-5, 2007 Florence, Italy ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ Automated calculation of QED corrections to lepton g − 2 TatsumiAoyama 1. Introduction The anomalous magnetic moment g−2 of the electron is one of the most precisely studied quantities in the particle physics, and it has provided the most stringent test of QED. Recently, a new measurement was carried out by a Harvard group using the Penning trap with cylindrical cavity. -
SL Paper 3 Markscheme
theonlinephysicstutor.com SL Paper 3 This question is about leptons and mesons. Leptons are a class of elementary particles and each lepton has its own antiparticle. State what is meant by an Unlike leptons, the meson is not an elementary particle. State the a. (i) elementary particle. [2] (ii) antiparticle of a lepton. b. The electron is a lepton and its antiparticle is the positron. The following reaction can take place between an electron and positron. [3] Sketch the Feynman diagram for this reaction and identify on your diagram any virtual particles. c. (i) quark structure of the meson. [2] (ii) reason why the following reaction does not occur. Markscheme a. (i) a particle that cannot be made from any smaller constituents/particles; (ii) has the same rest mass (and spin) as the lepton but opposite charge (and opposite lepton number); b. Award [1] for each correct section of the diagram. correct direction ; correct direction and ; virtual electron/positron; Accept all three time orderings. @TOPhysicsTutor facebook.com/TheOnlinePhysicsTutor c. (i) / up and anti-down; theonlinephysicstutor.com (ii) baryon number is not conserved / quarks are not conserved; Examiners report a. Part (a) was often correct. b. The Feynman diagrams rarely showed the virtual particle. c. A significant number of candidates had a good understanding of quark structure. This question is about fundamental interactions. The kaon decays into an antimuon and a neutrino as shown by the Feynman diagram. b.i.Explain why the virtual particle in this Feynman diagram must be a weak interaction exchange particle. [2] c. A student claims that the is produced in neutron decays according to the reaction . -
Charmed Baryon Spectroscopy in a Quark Model
Charmed baryon spectroscopy in a quark model Tokyo tech, RCNP A,RIKEN B, Tetsuya Yoshida,Makoto Oka , Atsushi HosakaA , Emiko HiyamaB, Ktsunori SadatoA Contents Ø Motivation Ø Formalism Ø Result ü Spectrum of single charmed baryon ü λ-mode and ρ-mode Ø Summary Motivation Many unknown states in heavy baryons ü We know the baryon spectra in light sector but still do not know heavy baryon spectra well. ü Constituent quark model is successful in describing Many unknown state baryon spectra and we can predict unknown states of heavy baryons by using the model. Σ Difference from light sector ΛC C ü λ-mode state and ρ-mode state split in heavy quark sector ü Because of HQS, we expect that there is spin-partner Motivation light quark sector vs heavy quark sector What is the role of diquark? How is it in How do spectrum and the heavy quark limit? wave function change? heavy quark limit m m q Q ∞ λ , ρ mode ü we can see how the spectrum and wave-funcon change ü Is charm sector near from heavy quark limit (or far) ? Hamiltonian ij ij ij Confinement H = ∑Ki +∑(Vconf + Hhyp +VLS ) +Cqqq i i< j " % " % 2 π 1 1 brij 2α (m p 2m ) $ ' (r) $ Coul ' Spin-Spin = ∑ i + i i + αcon ∑$ 2 + 2 'δ +∑$ − ' i 3 i< j # mi mj & i< j # 2 3rij & ) # &, 2αcon 8π 3 2αten 1 3Si ⋅ rijS j ⋅ rij + + Si ⋅ S jδ (rij )+ % − Si ⋅ S j (. ∑ 3 % 2 ( Coulomb i< j *+3m i mj 3 3mimj rij $ rij '-. the cause of mass spliPng Tensor 1 2 2 4 l s C +∑αSO 2 3 (ξi +ξ j + ξiξ j ) ij ⋅ ij + qqq i< j 3mq rij Spin orbit ü We determined the parameter that the result of the Strange baryon will agree with experimental results . -
Ask a Scientist Answers
Ask a scientist answers. GN I quote the beginning of the question, then my answer: Q11: “Since beta decay is when …” A11: Good question. The weak force is responsible for changing one quark into another, in this case a d-quark into a u-quark. Because the electric charge must conserved one needs to emit a negative charge (the neutron is neutral, the proton is +1, so you need a -1- type particle). In principle there could be other -1 particles emitted (say a mu-) but nature is lazy and will go with the easiest to come by (as in the “lowest possible energy” needed to do the job) particle, an electron. Of course, because we have an electron in the final state now we also need a matching anti-neutrino, as the lepton number (quantum number that counts the electrons, neutrinos, and their kind – remember the slide with the felines in my presentation) needs to be conserved as well. Now, going back to your original question “…where they come from?” the energy of the original nucleus. Remember E=m * c^2. That is a recipe for creating particles (mass) if one has enough initial energy. In this case in order for the beta decay to occur (naturally) you need the starting nucleus to have a higher sum of the energies of the daughter nucleus one gets after decay and the energies of the electron and antineutrino combined. That energy difference can then be “spent” in creating the mass of the electron and antineutrino (and giving them, and the daughter nucleus some kinetic energy, assuming there are energy leftovers). -
Reconstruction Study of the S Particle Dark Matter Candidate at ALICE
Department of Physics and Astronomy University of Heidelberg Reconstruction study of the S particle dark matter candidate at ALICE Master Thesis in Physics submitted by Fabio Leonardo Schlichtmann born in Heilbronn (Germany) March 2021 Abstract: This thesis deals with the sexaquark S, a proposed particle with uuddss quark content which might be strongly bound and is considered to be a reasonable dark matter can- didate. The S is supposed to be produced in Pb-Pb nuclear collisions and could interact with detector material, resulting in characteristic final states. A suitable way to observe final states is using the ALICE experiment which is capable of detecting charged and neutral particles and doing particle identification (PID). In this thesis the full reconstruction chain for the S particle is described, in particular the purity of particle identification for various kinds of particle species is studied in dependence of topological restrictions. Moreover, nuclear interactions in the detector material are considered with regard to their spatial distribution. Conceivable reactions channels of the S are discussed, a phase space simulation is done and the order of magnitude of possibly detectable S candidates is estimated. With regard to the reaction channels, various PID and topology cuts were defined and varied in order to find an S candidate. In total 2:17 · 108 Pb-Pb events from two different beam times were analyzed. The resulting S particle candidates were studied with regard to PID and methods of background estimation were applied. In conclusion we found in the channel S + p ! ¯p+ K+ + K0 + π+ a signal with a significance of up to 2.8, depending on the cuts, while no sizable signal was found in the other studied channels. -
Fine Structure Constant, Electron Anomalous Magnetic Moment, and Quantum Electrodynamics
Fine Structure Constant, Electron Anomalous Magnetic Moment, and Quantum Electrodynamics Toichiro Kinoshita Laboratory for Elementary-Particle Physics, Cornell University based on the work carried out in collaboration with M. Nio, T. Aoyama, M. Hayakawa, N. Watanabe, K. Asano. presented at Nishina Hall, RIKEN November 17, 2010 T. Kinoshita () 1 / 57 Introduction The fine structure constant e2 α = 2ǫ0hc is a dimensionless fundamental constant of physics: e = electric charge of electron, ǫ0 = dielectric constant of vacuum, h = Planck constant, c = velocity of light in vacuum. Since α is basically measure of magnitude of e, it can be measured by any physical system involving electron directly or indirectly. T. Kinoshita () 2 / 57 Some high precision measurements of α: Mohr,Taylor,Newell, RMP 80, 633 (2008) − α 1(ac Josephson)= 137.035 987 5 (43) [31 ppb] − α 1(quantum Hall)= 137.036 003 0 (25) [18 ppb] − α 1(neutron wavelength)= 137.036 007 7 (28) [21 ppb] − α 1(atom interferometry)= 137.036 000 0 (11) [7.7 ppb] − α 1(optical lattice)= 137.035 998 83 (91) [6.7 ppb] T. Kinoshita () 3 / 57 However, by far the most accurate α comes from the measurement of electron anomalous magnetic moment ae and the theoretical calculation in quantum electrodynamics (QED) and Standard Model (SM): −1 α (ae)= 137.035 999 085 (12)(37)(33) [0.37 ppb] where 12,37,33 are the uncertainties of 8th-order term, estimated 10th-order term, and measurement of ae. T. Kinoshita () 4 / 57 (α-1 - 137.036) × 107 Muonium H.F.S. ac Josephson Quantum Hall h/m(Cs) h/m(Rb) ae UW87 ae HV06 ae HV08 -200 -100 0 +100 +200 Figure: Comparison of various α−1 of high precision. -
Asked Steven Weinberg. but Quantum Electrodynamic
Bulgaria: QED In fact, at least three of them could be discerned at a workshop held in June in Sandansky, Bulgaria, entitled "Frontier tests of QED and physics of the vacuum". The first concerns such exotic atomic systems as metastable antiprotonic helium (a helium atom with an antiproton substituted QED: for one electron), singly-charged heavy ions such as uranium-91+, muonium (a bound state of a muon and an electron), and anti- hydrogen (an antiproton with an orbital positron). Beyond a certain level of experimental precision, each of these hydrogen- and helium like systems is a testbench atom for one QED aspect or another. The second frontier is the study of macroscopic consequences of surviving QED, with effects like vacuum polarization (spontaneous transient particles) and zero-point energy (the "dressing" surrounding a bare particle); hence the weak birefringence acquired by a vacuum under a magnetic field (a consequence of vacuum polarization) and the Casimir force between objects in the vacuum, this being related to the change of zero-point energy when the vacuum's domain of quan tization is restricted by boundaries. (The Casimir force between two the bad parallel plates is proportional to the inverse fourth power of their separation and has magnitude of about 0.2xl0-5 newtons for 1 cm2 plates separated by 0.5 microns - equivalent to a mosquito stand ing on one of the plates.) Finally there is what might be called the Popperian frontier - the line beyond which QED might yet be found lacking.The holy grail of press researchers in this latter domain is to discover some effect that does not agree with the predictions of Feynman's hocus-pocus. -
Particle Physics Detector in Space
Particle physics detector in space QED IN BULGARIA STARING AT THE SUN HADRON THERAPY Researchers are still pushing at How will Gran Sasso's Borexino The Proton-Ion Medical Machine the frontiers of QED, as a workshop experiment work and what will it tell Study is exploring how particle physics in Bulgaria revealed us about the nature of neutrinos? can benefit medical treatment All the F.W. Bel I (s) and Whistles. RS -232I/O Port Built-in Rechargeable Battery Min/Maxl Peak Hold 0.25% DC Accuracy Frequency Range DC-20 kHz The New6000Series Gauss/Teslameter Delivers Laboratory Accuracy in a Portable Package You spoke and we listened! The New Model 6010 is the As with all F.W. Bell products, you can expect a superior latest development in the measurement of magnetic flux level of performance, satisfaction and support that can come density using F.W. Bell's state-of-the-art Hall-effect only from a world leader. Look to F.W. Bell when quality and technology. performance matter most. The Model 6010 performs Magnetic field measurements Act Now! from zero to 300 kG (30 T) over 6 ranges with a resolution Special Introductory Free Probe Offer! of 1 mG (0.1 JJT). The Model 6010 measures both DC & Call Today at (407) 678-6900 USA or True RMS AC magnetic fields, at frequencies up to 20 kHz, Go to the Web! www.fwbell.com/html/cerncourier.html with a basic DC accuracy of 0.25%. The Model 6010 provides readings in Gauss, Tesla & Ampere/Meters. The new 6000 Series Hall-effect probe features F.W. -
Table of Contents (Print)
PHYSICAL REVIEW D PERIODICALS For editorial and subscription correspondence, Postmaster send address changes to: please see inside front cover (ISSN: 1550-7998) APS Subscription Services P.O. Box 41 Annapolis Junction, MD 20701 THIRD SERIES, VOLUME 96, NUMBER 1 CONTENTS D1 JULY 2017 The Table of Contents is a total listing of Parts A and B. Part A consists of articles 011101–014509, and Part B articles 014510–019903(E) PART A RAPID COMMUNICATIONS Observation of the Bþ → DÃ−Kþπþ decay (10 pages) ................................................................................. 011101(R) R. Aaij et al. (LHCb Collaboration) Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5 × 1021 protons on target (9 pages) ....................................................................................................................... 011102(R) K. Abe et al. (The T2K Collaboration) One more hard three-loop correction to parapositronium energy levels (5 pages) ................................................. 011301(R) Michael I. Eides and Valery A. Shelyuto Decay of the dimuonium into a photon and a neutral pion (4 pages) ............................................................... 011302(R) Andrzej Czarnecki and Savely G. Karshenboim Resolving the atmospheric octant by an improved measurement of the reactor angle (6 pages) ................................ 011303(R) Sabya Sachi Chatterjee, Pedro Pasquini, and J. W. F. Valle Probing the top-quark width using the charge identification of b jets (6 pages) ................................................... 011901(R) Pier Paolo Giardino and Cen Zhang ARTICLES þ − Observation of e e → ηhc at center-of-mass energies from 4.085 to 4.600 GeV (13 pages) .................................. 012001 M. Ablikim et al. (BESIII Collaboration) þ ¯ 0 þ þ 0 þ Analysis of D → K e νe and D → π e νe semileptonic decays (15 pages) ................................................... 012002 M. Ablikim et al. -
Towards Excited Radiative Transitions in Charmonium
Doctoral Thesis Towards Excited Radiative Transitions in Charmonium Author: Supervisor: Cian O'Hara Prof. Sin´eadRyan A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in the School of Mathematics March 2019 Declaration of Authorship I declare that this thesis has not been submitted as an excercise for a degree at this or any other university and is entirely my own work. I agree to deposit this thesis in the University's open acess institutional repository or allow the Library to do so on my behalf, subject to Irish Copyright Legislation and Trinity College Library conditions of use and acknowledgement. Signed: Date: ii Abstract Towards Excited Radiative Transitions in Charmonium by Cian O'Hara In this thesis lattice QCD is utilised to investigate the spectrum of charmonium and charmed mesons with the aim of working towards investigating radiative tran- sitions between excited states in the charmonium spectrum. Results are presented from a dynamical Nf = 2 + 1 lattice QCD study of the excited spectrum of Ds and D mesons at a single lattice spacing with pion mass Mπ = 236 MeV, which has been published in reference [1]. A robust determination of the highly excited spectrum of states, up to spin J = 4, was achieved with the use of distillation and the variational method. A comparison with earlier studies of the spectra on lattices with heavier light quarks was performed and the spectrum was found to have little dependence on the light quark mass. Results from an investigation into radiative transitions in the charmonium spectrum are also presented. -
Numerical Evaluation of QED Contribution to Lepton G−2
Numerical evaluation of QED contribution to lepton g−2 T. Aoyama KMI, Nagoya University The 33rd International Symposium on Lattice Field Theory (LATTICE 2015) July 14–18, 2015, Kobe Anomalous magnetic moment of lepton ◮ Electrons and Muons have magnetic moment along their spins, given by e~ ~µ = g ~s 2m It is known that g-factor deviates from Dirac’s value (g = 2), and it is called Anomalous magnetic moment aℓ (g 2)/2 ≡ − It is much precisely measured for electron and muon. ◮ Electron g 2 is explained almost entirely by QED interaction between electron and− photons. It has provided the most stringent test of QED. ◮ Muon g 2 is more sensitive to high energy physics, and thus a window to new physics− beyond the standard model. 1/55 10th-order project ◮ Numerical evaluation of the entire 10th order QED contribution to lepton g 2 has been conducted by the collaboration with: − Toichiro Kinoshita (Cornell, and UMass Amherst) Makiko Nio (RIKEN) Masashi Hayakawa (Nagoya University) Noriaki Watanabe (Nagoya University) Katsuyuki Asano (Nagoya University) 2/55 Electron g−2 figure from the slide by S. Fogwell Hoogerheide at Lepton moments 2014 Anomalous magnetic moment of electron ◮ Latest measurement by Harvard group by the resonance of cyclotron and spin levels for a single electron in a cylindrical Penning trap: ae(HV06) = 0.001 159 652 180 85 (76) [0.66ppb] Odom, Hanneke, D’Urso, Gabrielse, PRL97, 030801 (2006) ae(HV08) = 0.001 159 652 180 73 (28) [0.24ppb] Hanneke, Fogwell, Gabrielse, PRL100, 120801 (2008) Hanneke, Fogwell Hoogerheide, Gabrielse, PRA83, 052122 (2011) trap cavity electron top endcap electrode quartz spacer compensation electrode nickel rings ring electrode 0.5 cm compensation bottom endcap electrode electrode field emission microwave inlet point FIG.