DOCSLIB.ORG

Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-Year Measurement of the Isotropic Gamma-Ray Background

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-Year Measurement of the Isotropic Gamma-Ray Background Prepared for submission to JCAP ULB/14-21 Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background The Fermi LAT Collaboration M. Ackermann1 M. Ajello2 A. Albert3 L. Baldini4 G. Barbiellini5;6 D. Bastieri7;8 K. Bechtol9 R. Bellazzini4 E. Bissaldi10 E. D. Bloom3 R. Bonino11;12 J. Bregeon13 P. Bruel14 R. Buehler1 S. Buson7;8 G. A. Caliandro3;15 R. A. Cameron3 M. Caragiulo16 P. A. Caraveo17 C. Cecchi18;19 E. Charles3 A. Chekhtman20 J. Chiang3 G. Chiaro8 S. Ciprini21;22 R. Claus3 J. Cohen-Tanugi13 J. Conrad23;24;25;26 A. Cuoco24;11;12 S. Cutini21;22 F. D'Ammando27;28 A. de Angelis29 F. de Palma16;30 C. D. Dermer31 S. W. Digel3 P. S. Drell3 A. Drlica-Wagner32 C. Favuzzi33;16 E. C. Ferrara34 A. Franckowiak3;? Y. Fukazawa36 S. Funk3 P. Fusco33;16 F. Gargano16 D. Gasparrini21;22 N. Giglietto33;16 F. Giordano33;16 M. Giroletti27 G. Godfrey3 S. Guiriec34;37 M. Gustafsson38;64? J.W. Hewitt39;40 X. Hou41 T. Kamae3 M. Kuss4 S. Larsson23;24;42 L. Latronico11 F. Longo5;6 F. Loparco33;16 M. N. Lovellette31 P. Lubrano18;19 D. Malyshev3 F. Massaro43 M. Mayer1 M. N. Mazziotta16 P. F. Michelson3 W. Mitthumsiri44 T. Mizuno45 M. E. Monzani3 A. Morselli46 I. V. Moskalenko3 S. Murgia47 M. Negro3;11 R. Nemmen48 E. Nuss13 T. Ohsugi45 M. Orienti27 E. Orlando3 J. F. Ormes49 D. Paneque50;3 J. S. Perkins34 M. Pesce-Rollins4 F. Piron13 G. Pivato4 S. Rain`o33;16 R. Rando7;8 M. Razzano4;51 arXiv:1501.05464v2 [astro-ph.CO] 16 Sep 2015 A. Reimer52;3 O. Reimer52;3 M. S´anchez-Conde24;23;? A. Schulz1 C. Sgr`o4 E. J. Siskind53 G. Spandre4 P. Spinelli33;16 A. W. Strong54 D. J. Suson55 H. Tajima3;56 H. Takahashi36 J. G. Thayer3 J. B. Thayer3 L. Tibaldo3 M. Tinivella4 D. F. Torres57;58 E. Troja34;59 Y. Uchiyama60 G. Vianello3 M. Werner52 B. L. Winer61 K. S. Wood31 M. Wood3 G. Zaharijas10;62;63;? 1Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany 2Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clem- son, SC 29634-0978, USA 3W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stan- ford University, Stanford, CA 94305, USA 4Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy 5Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste, Italy 6Dipartimento di Fisica, Universit`adi Trieste, I-34127 Trieste, Italy 7Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova, Italy 8Dipartimento di Fisica e Astronomia \G. Galilei", Universit`adi Padova, I-35131 Padova, Italy 9Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637, USA 10Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Universit`adi Trieste, I-34127 Trieste, Italy 11Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino, Italy 12Dipartimento di Fisica Generale \Amadeo Avogadro" , Universit`adegli Studi di Torino, I-10125 Torino, Italy 13Laboratoire Univers et Particules de Montpellier, Universit´eMontpellier 2, CNRS/IN2P3, Montpellier, France 14Laboratoire Leprince-Ringuet, Ecole´ polytechnique, CNRS/IN2P3, Palaiseau, France 15Consorzio Interuniversitario per la Fisica Spaziale (CIFS), I-10133 Torino, Italy 16Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70126 Bari, Italy 17INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano, Italy 18Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia, Italy 19Dipartimento di Fisica, Universit`adegli Studi di Perugia, I-06123 Perugia, Italy 20Center for Earth Observing and Space Research, College of Science, George Mason Uni- versity, Fairfax, VA 22030, resident at Naval Research Laboratory, Washington, DC 20375, USA 21Agenzia Spaziale Italiana (ASI) Science Data Center, I-00133 Roma, Italy 22INAF Osservatorio Astronomico di Roma, I-00040 Monte Porzio Catone (Roma), Italy 23Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden 24The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova, SE-106 91 Stockholm, Swe- den 25Royal Swedish Academy of Sciences Research Fellow, funded by a grant from the K. A. Wallenberg Foundation 26The Royal Swedish Academy of Sciences, Box 50005, SE-104 05 Stockholm, Sweden 27INAF Istituto di Radioastronomia, 40129 Bologna, Italy 28Dipartimento di Astronomia, Universit`adi Bologna, I-40127 Bologna, Italy 29Dipartimento di Fisica, Universit`adi Udine and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Gruppo Collegato di Udine, I-33100 Udine 30Universitagrave Telematica Pegaso, Piazza Trieste e Trento, 48, 80132 Napoli, Italy 31Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352, USA 32Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510, USA 33Dipartimento di Fisica \M. Merlin" dell'Universit`ae del Politecnico di Bari, I-70126 Bari, Italy 34NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 36Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739- 8526, Japan 37NASA Postdoctoral Program Fellow, USA 38Service de Physique Theorique, Universite Libre de Bruxelles (ULB), Bld du Triomphe, CP225, 1050 Brussels, Belgium 39Department of Physics and Center for Space Sciences and Technology, University of Mary- land Baltimore County, Baltimore, MD 21250, USA 40Center for Research and Exploration in Space Science and Technology (CRESST) and NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 41Centre d'Etudes´ Nucl´eairesde Bordeaux Gradignan, IN2P3/CNRS, Universit´eBordeaux 1, BP120, F-33175 Gradignan Cedex, France 42Department of Astronomy, Stockholm University, SE-106 91 Stockholm, Sweden 43Department of Astronomy, Department of Physics and Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06520-8120, USA 44Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand 45Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hi- roshima 739-8526, Japan 46Istituto Nazionale di Fisica Nucleare, Sezione di Roma \Tor Vergata", I-00133 Roma, Italy 47Center for Cosmology, Physics and Astronomy Department, University of California, Irvine, CA 92697-2575, USA 48Instituto de Astronomia, Geof´ısicae Cincias Atmosf´ericas,Universidade de S~aoPaulo, Rua do Mat~ao,1226, S~aoPaulo - SP 05508-090, Brazil 49Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA 50Max-Planck-Institut f¨urPhysik, D-80805 M¨unchen, Germany 51Funded by contract FIRB-2012-RBFR12PM1F from the Italian Ministry of Education, University and Research (MIUR) 52Institut f¨urAstro- und Teilchenphysik and Institut f¨urTheoretische Physik, Leopold- Franzens-Universit¨atInnsbruck, A-6020 Innsbruck, Austria 53NYCB Real-Time Computing Inc., Lattingtown, NY 11560-1025, USA 54Max-Planck Institut f¨urextraterrestrische Physik, 85748 Garching, Germany 55Department of Chemistry and Physics, Purdue University Calumet, Hammond, IN 46323- 2094, USA 56Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601, Japan 57Institute of Space Sciences (IEEC-CSIC), Campus UAB, E-08193 Barcelona, Spain 58Instituci´oCatalana de Recerca i Estudis Avan¸cats(ICREA), Barcelona, Spain 59Department of Physics and Department of Astronomy, University of Maryland, College Park, MD 20742, USA 603-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan 61Department of Physics, Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210, USA 62The Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, Trieste 34151 - Italy 63Laboratory for Astroparticle Physics, University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia 64Institut f¨urTheoretische Physik, Friedrich-Hund-Platz 1, D-37077 G¨ottingen,Germany ?corresponding author E-mail: [email protected], [email protected], [email protected], [email protected] Abstract. We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Tele- scope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predic- tions compared to previous work. More specifically, we estimate the cosmologically- induced gamma-ray intensity to have an uncertainty of a factor ∼ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals. Keywords: gamma ray experiments, dark matter experiments, dark matter theory, gamma ray theory, dark matter simulations Contents 1 Introduction1 2 Theoretical predictions
Load more

Recommended publications
  • BABAR Studies Matter-Antimatter Asymmetry in Τ Lepton Decays
    BABAR studies matter-antimatter asymmetry in τττ lepton decays Humans have wondered about the origin of matter since the dawn of history. Physicists address this age-old question by using particle accelerators to recreate the conditions that existed shortly after the Big Bang. At an accelerator, energy is converted into matter according to Einstein’s famous energy-mass relation, E = mc 2 , which offers an explanation for the origin of matter. However, matter is always created in conjunction with the same amount of antimatter. Therefore, the existence of matter – and no antimatter – in the universe indicates that there must be some difference, or asymmetry, between the properties of matter and antimatter. Since 1999, physicists from the BABAR experiment at SLAC National Accelerator Laboratory have been studying such asymmetries. Their results have solidified our understanding of the underlying micro-world theory known as the Standard Model. Despite its great success in correctly predicting the results of laboratory experiments, the Standard Model is not the ultimate theory. One indication for this is that the matter-antimatter asymmetry allowed by the Standard Model is about a billion times too small to account for the amount of matter seen in the universe. Therefore, a primary quest in particle physics is to search for hard evidence for “new physics”, evidence that will point the way to the more complete theory beyond the Standard Model. As part of this quest, BABAR physicists also search for cracks in the Standard Model. In particular, they study matter-antimatter asymmetries in processes where the Standard Model predicts that asymmetries should be very small or nonexistent.
    [Show full text]
  • The Belle-II Experiment at Superkekb
    Gary S. Varner, Hawai’i The Belle-II Experiment at SuperKEKB Gary S. Varner University of Hawai’i at Manoa Boston (Cambridge), July 26, 2011 Luminosity at the B Factories Gary S. Varner, Hawai’i Fantastic performance much beyond design values! Need O(100x) more data Next generation B-factories Gary S. Varner, Hawai’i SuperKEKB + SuperB 40 times higher luminosity KEKB PEP-II Asymmetric B factories Gary S. Varner, Hawai’i √s=10.58 GeV + - B e e z ~ c Υ(4s) B Υ(4s) B ~ 200m BaBar p(e-)=9 GeV p(e+)=3.1 GeV =0.56 Belle p(e-)=8 GeV p(e+)=3.5 GeV =0.42 Belle II p(e-)=7 GeV p(e+)=4 GeV =0.28 Full Reconstruction Method Gary S. Varner, Hawai’i • Fully reconstruct one of the B’s to – Tag B flavor/charge – Determine B momentum – Exclude decay products of one B from further analysis Decays of interest B BXu l , BK e e+(3.5GeV) (8GeV) BD, Υ(4S) B full reconstruction BD etc. (~0.5%) Offline B meson beam! Powerful tool for B decays with neutrinos “Super” B Factory motivation Gary S. Varner, Hawai’i For details on physics opportunities: See Kay Kinoshita talk 17:20 B factories is SM with CKM right? Thursday, July 28 – Section 5I Super B factories How is the SM wrong? Need much more data (two orders!) because the SM worked so well until now Super B factory e+e- machines running at (or near) Y(4s) will have considerable advantages in several classes of measurements, and will be complementary in many more to LHCb and BESIII Recent update of the physics reach with 50 ab-1 (75 ab-1): Physics at Super B Factory (Belle II authors + guests) hep-ex > arXiv:1002 .5012 SuperB Progress Reports: Physics (SuperB authors + guests) hep-ex > arXiv:1008.1541 TSUKUBA Area (Belle) High Energy Ring (HER) for Electron HER LER How to do it? Interaction Region Low Energy Ring (LER) for Positron Gary S.
    [Show full text]
  • Superb Report Intensity Frontier Workshop 1 Introduction
    SuperB Report Intensity Frontier Workshop 1 Introduction The Standard Model (SM) has been very successful in explaining a wide range of electroweak and strong processes with high precision. In the flavor sector, observation of CP violation in B decays at BABAR and Belle, and the extraordinary consistency between the CKM matrix elements, established the SM as the primary source of CP violation in nature (leading to the 2008 Nobel Prize in physics). However, the remarkable success of the SM in describing all known flavor-physics measurements presents a puzzle to the search for New Physics (NP) at the LHC. New particles below the TeV scale should contribute to low-energy processes through virtual loop diagrams and cause observable effects in the flavor sector. The lack of any such effects suggests that either the NP mass scale is much higher than the TeV scale, or that NP flavor-violating operators are suppressed. In either scenario, flavor physics at the intensity frontier is poised to remain a central element of particle physics research in the coming decades. The INFN-sponsored SuperB project [1–3] in Italy is an asymmetric-energy electron- positron collider in the 10 GeV energy region with an initial design average luminosity of 1036 cm−2s−1, which will deliver up to 75 ab−1 in five years of operation (see Fig. 1 for details) to a new SuperB detector derived from the existing BABAR. A new innovative concept in accelerator design, employing very low-emittance beams and a “crab waist” final focus, makes possible this large increase (100-fold) in instantaneous luminosity over present B Factory colliders with no corresponding increase in power consumption, and similar backgrounds for the detector.
    [Show full text]
  • Discovery at the Large Hadron Collider
    Discovery at the Large Hadron Collider Michel Lefebvre University of Victoria ATLAS Canada Collaboration CAP Congress 27 May 2013 Abstract Discovery at the Large Hadron Collider The recent discovery of a new particle is a historic event in our exploration of the fundamental constituents of matter and the interactions between them. To date, the Standard Model of particle physics is extremely successful and accounts for all measured subatomic phenomena. However the postulated Higgs mechanism, from which fundamental particles acquire mass, remains to be verified experimentally. Research at the energy frontier is being carried out at the Large Hadron Collider (LHC), operating at CERN near Geneva since 2010. From 2010 to 2012, the LHC provided proton-proton collisions at a centre of mass energy of 7 to 8 TeV, allowing the exploration of distance scales smaller than a tenth of an attometer. The products of these collisions were successfully recorded by the ATLAS detector, which will be introduced in this lecture, with emphasis on Canadian contributions. The ATLAS physics programme features Standard Model measurements and a rich array of searches for new physics phenomena. The discovery of a new Higgs-like particle and other important results will be presented. The future increase in energy and intensity at the LHC, and the associated ATLAS plans, will also be discussed. These are exciting times indeed for particle physics! Michel Lefebvre, UVic and ATLAS Canada CAP Congress, 27 May 2013 2 Scattering experiment We see through the scatter of
    [Show full text]
  • Introduction to Flavour Physics
    Introduction to flavour physics Y. Grossman Cornell University, Ithaca, NY 14853, USA Abstract In this set of lectures we cover the very basics of flavour physics. The lec- tures are aimed to be an entry point to the subject of flavour physics. A lot of problems are provided in the hope of making the manuscript a self-study guide. 1 Welcome statement My plan for these lectures is to introduce you to the very basics of flavour physics. After the lectures I hope you will have enough knowledge and, more importantly, enough curiosity, and you will go on and learn more about the subject. These are lecture notes and are not meant to be a review. In the lectures, I try to talk about the basic ideas, hoping to give a clear picture of the physics. Thus many details are omitted, implicit assumptions are made, and no references are given. Yet details are important: after you go over the current lecture notes once or twice, I hope you will feel the need for more. Then it will be the time to turn to the many reviews [1–10] and books [11, 12] on the subject. I try to include many homework problems for the reader to solve, much more than what I gave in the actual lectures. If you would like to learn the material, I think that the problems provided are the way to start. They force you to fully understand the issues and apply your knowledge to new situations. The problems are given at the end of each section.
    [Show full text]
  • Italy Cancels €1Bn Superb Collider - Physicsworld.Com 30/11/12 20.01
    Italy cancels €1bn SuperB collider - physicsworld.com 30/11/12 20.01 This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy. Italy cancels €1bn SuperB collider Nov 28, 2012 11 comments Path not taken: the planned route of SuperB Physics World can confirm rumours that the Italian government is to withdraw €250m from the €1bn SuperB particle accelerator, which was set to be built at the University of Tor Vergata on the outskirts of Rome. The decision, which effectively cancels the project, was made yesterday when Fernando Ferroni, president of the National Institute for Nuclear Physics (INFN), met Italian science minister Francesco Profumo to discuss funding for the project. "Given the difficult economic conditions of the country, the government is willing to confirm the contribution of €250m but not [for] the project," says a government statement, which was released today and seen by Physics World. As outlined in the statement, the INFN, which was set to build SuperB, will keep the €250m but will now spend the money on other projects. The INFN has already appointed two committees to look at what options it has, which includes converting SuperB into a scaled down "tau-charm factory" (called SuperC) or using the money elsewhere. The committees will report by 20 December, with a decision set for early January. Rumours of the funding cancellation first emerged on the blog A Quantum Diaries Survivor, which is written by the CERN-based researcher Tommaso Dorigo. Mystery of antimatter SuperB was designed to produce beams of electrons and positrons inside a linear accelerator to an energy of 6.7 GeV before injecting them into two rings each more than 1 km in circumference, where they would have then been collided to allow the decay of particles such as B mesons.
    [Show full text]
  • The EN Department
    On behalf of Katy Foraz, Head of the EN Department, Welcome to all of you! The Engineering Department in a Nutshell Katy Foraz Where are we? CERN: founded in 1954: 12 European States “Science for Peace” Today: 23 Member States Employees: ~2 700 staff, 800 fellows Associates: ~12 400 users, 1 300 others Budget (2019) ~ 1 200 MCHF Member States: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovak Republic, Spain, Sweden, Switzerland and United Kingdom Associate Members in the Pre-Stage to Membership: Cyprus, Slovenia Associate Member States: Croatia, India, Lithuania, Pakistan, Turkey, Ukraine Applications for Membership or Associate Membership: Brazil, Estonia Observers to Council: Japan, Russia, United States of America; European Union, JINR and UNESCO Welcome to the EN Department 4 Science is getting more and more global Welcome to the EN Department 5 What are we doing? The Missions of CERN . Push forward the frontiers of knowledge e.g. the secrets of the Big Bang … what was the matter like within the first moments of the Universe’s existence? . Develop new technologies for accelerators and detectors Information technology - the Web and the GRID Medicine - diagnosis and therapy . Train the scientists and the engineers of tomorrow . Unite people from different countries and cultures Welcome to the EN Department 7 The next scientific challenge is to understand the very first moments of our Universe after the Big Bang LHC 10-10s Welcome to the EN Department 8 How are we doing what we are doing? The instruments used 1.
    [Show full text]
  • Positron Annihilation on Atoms and Molecules, Ph.D
    UNIVERSITY OF CALIFORNIA SAN DIEGO Positron Annihilation on Atoms and Molecules A dissertation submitted in partial satisfaction of the requirements for the degree of Do ctor of PhilosophyinPhysics by Ko ji Iwata Committee in charge Cliord M Surko Chair John M Go o dkind William E Mo erner Lu J Sham John D Simon Copyright Ko ji Iwata All rights reserved The dissertation of Ko ji Iwata is approved and it is acceptable in quality and form for publication on microlm Chairman University of California San Diego iii iv Contents Signature Page iii Table of Contents iv List of Figures ix List of Tables xi Acknowledgments xiii Vita Publications and Fields of Study xv Abstract xviii Intro duction Simple illustration of a p ositron interacting with a molecule Background in p ositron physics Prediction and discovery of the p ositron Positron sources Physics involved in the interaction of a p ositron with a molecule Long range p olarization and dip olecharge interactions Shortrange interactions r a Potential from atomic nuclei Pauli exclusion principle Positronium atom formation Annihilation Interaction of p ositrons with solids liquids and gases Solids Positron mo derators Liquids Gases Outline of dissertation Overview of previous atomic and molecular physics studies us ing p ositrons Densegas and lowpressure
    [Show full text]
  • The Dawn of the Post-Naturalness Era Arxiv:1710.07663V1 [Physics.Hist-Ph]
    CERN-TH-2017-205 The Dawn of the Post-Naturalness Era Gian Francesco Giudice CERN, Theoretical Physics Department, Geneva, Switzerland Abstract In an imaginary conversation with Guido Altarelli, I express my views on the status of particle physics beyond the Standard Model and its future prospects. Contribution to the volume \From My Vast Repertoire" { The Legacy of Guido Altarelli. 1 A Master and a Friend Honour a king in his own land; honour a wise man everywhere. | Tibetan proverb [1] Guido Altarelli was an extraordinary theoretical physicist. Not only was Guido one of the heroes of the Standard Model, but he incarnated the very essence of that theory: a perfect synthesis of pure elegance and brilliance. With his unique charisma, he had a great influence on CERN and contributed much in promoting the role of theoretical physics in the life of the laboratory. With the right mixture of vision, authority, and practical common sense, he led the Theory Division from 2000 to 2004. I have always admired Guido for his brilliance, humour, knowledge, leadership, and intellectual integrity. I learned much from his qualities and his example is a precious legacy for me and for all of his colleagues. Guido had a very pragmatic attitude towards scientific theories. He was not attracted arXiv:1710.07663v1 [physics.hist-ph] 18 Oct 2017 by elaborate mathematical constructions, but wanted to understand the essence behind the formalism and get straight to the concept. In physics, I would define him as a conservative revolutionary or as an optimistic skeptical. One episode illustrates the meaning of this definition.
    [Show full text]
  • 13 June 2011 - INFN: the Superb Factory Will Be Built at the University of Rome 'Tor Vergata' 14/06/11 09:59
    13 June 2011 - INFN: The SuperB Factory will be built at the University of Rome 'Tor Vergata' 14/06/11 09:59 Interactions.org - Particle Physics News and Resources A COMMUNICATION RESOURCE FROM THE WORLD'S PARTICLE PHYSICS LABORATORIES Interactions News Wire #25 - 11 Share this page: 13 June 2011 http://www.interactions.org ******************************************* Email this page Source: INFN and University of Rome Tor Vergata Content: Press Release Blink Date Issued: 13 June 2011 Del.icio.us ******************************************* The SuperB Factory will be built at the University of Rome 'Tor Digg Vergata' Furl Google The SuperB Factory, a major international research centre for fundamental and applied physics will be built on the campus of reddit the University of Rome 'Tor Vergata'. The project proposed by the INFN is the first on the list of the 14 flagship projects of the National Research Plan of the Italian Ministry for Education, Universities and Research (MIUR). The announcement was made Simpy last week by Roberto Petronzio, President of the Italian National Institute for Nuclear Physics. 300 physicists from all over the world gathered in Elba island (Italy) for the kick-off meeting of SuperB, which marked a crucial milestone on the road towards Spurl realization of the accelerator. The project involves the construction of a large underground electron-positron collider which will occupy an area of approximately 30 hectares on the University of Rome 'Tor Vergata' campus and be closely linked to the StumbleUpon INFN Frascati National Laboratories, located nearby. The SuperB, which will ultimately cost few hundred million euros, obtained Y! MyWeb funding approval for 250 million euros in the Italian government's CIPE Economic Planning Document.
    [Show full text]
  • 12. CP Violation in Meson Decays 1 12
    12. CP violation in meson decays 1 12. CP VIOLATION IN MESON DECAYS Revised May 2012 by D. Kirkby (UC Irvine) and Y. Nir (Weizmann Institute). The CP transformation combines charge conjugation C with parity P . Under C, particles and antiparticles are interchanged, by conjugating all internal quantum numbers, e.g., Q Q for electromagnetic charge. Under P , the handedness of space is reversed, → − − ~x ~x. Thus, for example, a left-handed electron eL is transformed under CP into a → − + right-handed positron, eR. If CP were an exact symmetry, the laws of Nature would be the same for matter and for antimatter. We observe that most phenomena are C- and P -symmetric, and therefore, also CP -symmetric. In particular, these symmetries are respected by the gravitational, electromagnetic, and strong interactions. The weak interactions, on the other hand, violate C and P in the strongest possible way. For example, the charged W bosons − couple to left-handed electrons, eL , and to their CP -conjugate right-handed positrons, + + eR, but to neither their C-conjugate left-handed positrons, eL , nor their P -conjugate − right-handed electrons, eR. While weak interactions violate C and P separately, CP is still preserved in most weak interaction processes. The CP symmetry is, however, violated in certain rare processes, as discovered in neutral K decays in 1964 [1], and − + observed in recent years in B decays. A KL meson decays more often to π e νe than to + − π e νe, thus allowing electrons and positrons to be unambiguously distinguished, but the decay-rate asymmetry is only at the 0.003 level.
    [Show full text]
  • The Physics Case for a Super B Factory
    The Physics Case For a Super B Factory Adrian Bevan Overview •Physics – Super B physics case. – Matter-antimatter asymmetry. – Higgs and new physics constraints. • Accelerator – Physics driven target luminosity. – Location(s) and current design. •Detector – Current design. • Conclusions Adrian Bevan 2 Overview •Physics – Super B physics case. – Matter-antimatter asymmetry. – Higgs and new physics constraints. • Accelerator – Physics driven target luminosity. – Location(s) and current design. •Detector – Current design. • Conclusions Adrian Bevan 3 Super B physics case g~ b ss b ~ (δ d ) + RR 23 η’ bR φ,η ,(KK) 0 s~ g ss ′ CP B R ss Ks0 ddd d KS • There is new physics at Λ~TeV. – it will have a flavour structure. – It will affect precision measurements at low energies through virtual loop corrections. • Many physics channelsAIMS: are complementary to the(1) LHC Precision programmes. understanding of SM flavour physics. • Many measurements are experimentally limited at 75ab(2) Elucidate-1. flavour structure beyond the SM. Adrian Bevan 4 Super B physics case g~ b ss b ~ (δ d ) + RR 23 η’ bR φ,η ,(KK) 0 s~ g ss ′ CP B R ss Ks0 ddd d KS • There is no new physics at Λ~TeV. – Higher scale new particles will affect precision measurements at low energies through virtual loop corrections. • Many physics channels are complementary to the LHC programmes.AIMS: (1) Precision understanding of SM flavour physics. • Many measurements are experimentally limited -1 at 75ab(2) Constrain. flavour structure beyond the SM. Adrian Bevan 5 Super B physics case g~ b ss b ~ (δ d ) + RR 23 η’ bR φ,η ,(KK) 0 s~ g ss ′ CP B R ss Ks0 ddd d KS • There is new physics at Λ~TeV.
    [Show full text]