Elementary Particle Physics from Theory to Experiment
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1 Standard Model: Successes and Problems
Searching for new particles at the Large Hadron Collider James Hirschauer (Fermi National Accelerator Laboratory) Sambamurti Memorial Lecture : August 7, 2017 Our current theory of the most fundamental laws of physics, known as the standard model (SM), works very well to explain many aspects of nature. Most recently, the Higgs boson, predicted to exist in the late 1960s, was discovered by the CMS and ATLAS collaborations at the Large Hadron Collider at CERN in 2012 [1] marking the first observation of the full spectrum of predicted SM particles. Despite the great success of this theory, there are several aspects of nature for which the SM description is completely lacking or unsatisfactory, including the identity of the astronomically observed dark matter and the mass of newly discovered Higgs boson. These and other apparent limitations of the SM motivate the search for new phenomena beyond the SM either directly at the LHC or indirectly with lower energy, high precision experiments. In these proceedings, the successes and some of the shortcomings of the SM are described, followed by a description of the methods and status of the search for new phenomena at the LHC, with some focus on supersymmetry (SUSY) [2], a specific theory of physics beyond the standard model (BSM). 1 Standard model: successes and problems The standard model of particle physics describes the interactions of fundamental matter particles (quarks and leptons) via the fundamental forces (mediated by the force carrying particles: the photon, gluon, and weak bosons). The Higgs boson, also a fundamental SM particle, plays a central role in the mechanism that determines the masses of the photon and weak bosons, as well as the rest of the standard model particles. -
Gravitino Dark Matter
GRAVITINO DARK MATTER Wilfried Buchm¨uller DESY, Hamburg LAUNCH09, Nov. 2009, MPK Heidelberg Why Gravitino Dark Matter? Supergravity predicts the gravitino, analog of W and Z bosons in electroweak theory; may be LSP, natural DM candidate: m < 1keV, hot DM, (Pagels, Primack ’81) • 3/2 1keV < m3/2 < 15keV, warm DM, (Gorbunov, Khmelnitsky, Rubakov ’08) • ∼ ∼ 100keV < m < 10MeV, cold DM, gauge mediation and thermal • 3/2 leptogenesis∼ (Fuji, Ibe,∼ Yanagida ’03); recently proven to be correct by F-theory (Heckman, Tavanfar, Vafa ’08) 10GeV < m < 1TeV, cold DM, gaugino/gravity mediation and • 3/2 thermal leptogenesis∼ ∼ (Bolz, WB, Pl¨umacher ’98) Baryogenesis, (gravitino) DM and primordial nucleosynthesis (BBN) strongly correlated in cosmological history. 1 Gravitino Problem Thermally produced gravitino number density grows with reheating temperature after inflation (Khlopov, Linde ’83; Ellis, Kim, Nanopoulos ’84;...), n3/2 α3 2 TR. nγ ∝ Mp For unstable gravitinos, nucleosynthesis implies stringent upper bound on reheating temperature TR (Kawasaki, Kohri, Moroi ’05; ...), T < (1) 105 GeV, R O × hence standard mSUGRA with neutralino LSP incompatible with baryogenesis via thermal leptogenesis where T 1010 GeV !! R ∼ Possible way out: Gravitino LSP, explains dark matter! 2 Gravitino Virtue Can one understand the amount of dark matter, ΩDM 0.23, with Ω = ρ /ρ , if gravitinos are dominant component, i.e. Ω≃ Ω ? DM DM c DM ≃ 3/2 Production mechanisms: (i) WIMP decays, i.e., ‘Super-WIMPs’ (Covi, Kim, Roszkowski ’99; Feng, Rajaraman, Takayama ’03), m3/2 Ω3/2 = ΩNLSP , mNLSP independent of initial temperature TR (!), but inconsistent with BBN constraints; (ii) Thermal production, from 2 2 QCD processes, → 2 TR 100GeV mg˜(µ) Ω3/2h 0.5 10 . -
Super-Higgs in Superspace
Article Super-Higgs in Superspace Gianni Tallarita 1,* and Moritz McGarrie 2 1 Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago 7941169, Chile 2 Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg, Germany; [email protected] * Correspondence: [email protected] or [email protected] Received: 1 April 2019; Accepted: 10 June 2019; Published: 14 June 2019 Abstract: We determine the effective gravitational couplings in superspace whose components reproduce the supergravity Higgs effect for the constrained Goldstino multiplet. It reproduces the known Gravitino sector while constraining the off-shell completion. We show that these couplings arise by computing them as quantum corrections. This may be useful for phenomenological studies and model-building. We give an example of its application to multiple Goldstini. Keywords: supersymmetry; Goldstino; superspace 1. Introduction The spontaneous breakdown of global supersymmetry generates a massless Goldstino [1,2], which is well described by the Akulov-Volkov (A-V) effective action [3]. When supersymmetry is made local, the Gravitino “eats” the Goldstino of the A-V action to become massive: The super-Higgs mechanism [4,5]. In terms of superfields, the constrained Goldstino multiplet FNL [6–12] is equivalent to the A-V formulation (see also [13–17]). It is, therefore, natural to extend the description of supergravity with this multiplet, in superspace, to one that can reproduce the super-Higgs mechanism. In this paper we address two issues—first we demonstrate how the Gravitino, Goldstino, and multiple Goldstini obtain a mass. Secondly, by using the Spurion analysis, we write down the most minimal set of new terms in superspace that incorporate both supergravity and the Goldstino multiplet in order to reproduce the super-Higgs mechanism of [5,18] at lowest order in M¯ Pl. -
Gravitino Dark Matter with Constraints from Higgs Boson Mass …
Vol. 44 (2013) ACTA PHYSICA POLONICA B No 11 GRAVITINO DARK MATTER WITH CONSTRAINTS FROM HIGGS BOSON MASS AND SNEUTRINO DECAYS∗ L. Roszkowskiy, S. Trojanowski National Centre for Nuclear Research, Hoża 69, 00-681, Warszawa, Poland K. Turzyński Institute of Theoretical Physics, Faculty of Physics, University of Warsaw Hoża 69, 00-681, Warszawa, Poland K. Jedamzik Laboratoire de Physique Theorique et Astroparticules, UMR5207-CRNS Université Montpellier II, 34095 Montpellier, France (Received October 21, 2013) We investigate gravitino dark matter produced thermally at high tem- peratures and in decays of a long-lived sneutrino in the framework of the Non-Universal Higgs Model (NUHM). We apply relevant collider and cos- mological bounds. Generally, we find allowed values of the reheating tem- 9 perature TR below 10 GeV, i.e. somewhat smaller than the values needed for thermal leptogenesis, even with a conservative lower bound of 122 GeV on the Higgs boson mass. Requiring mass values closer to 126 GeV implies 7 TR below 10 GeV and the gravitino mass less than 10 GeV. DOI:10.5506/APhysPolB.44.2367 PACS numbers: 14.80.Ly, 14.80.Da, 95.35.+d, 26.35.+c Gravitino as the lightest supersymmetric particle is a well-motivated dark matter (DM) candidate. It is extremely weakly interacting and hence can escape detection in direct searches. Scenarios with gravitino DM can be, however, strongly constrained by the Big Bang Nucleosynthesis (BBN). ∗ Presented at the XXXVII International Conference of Theoretical Physics “Matter to the Deepest” Ustroń, Poland, September 1–6, 2013. y On leave of absence from the University of Sheffield, UK. -
Introduction to Elementary Particle Physics
Introduction to Elementary Particle Physics Joachim Meyer DESY Lectures DESY Summer Student Program 2009 Preface ● This lecture is not a powerpoint show ● This lecture does not substitute an university course ● I know that your knowledge about the topic varies a lot ● So we have to make compromises in simplicity and depth ● Still I hope that all of you may profit somehow ● The viewgraphs shown are only for illustrations ● We will develop things together in discussion and at blackboard ● I hope there are lots of questions. I shall ask you a lot 2 Structures at different sizes Elementary Particle Physics 3 3 Fermion Generations Interactions through Gauge Boson Exchange This lecture is going to tell you something about HOW we arrived at this picture 4 Content of this lectures . Its only a sketch : Depending on your preknowledge we will go more or less in detail in the different subjects 5 6 WHY High Energies ? 7 The very basic minimum you have to know about Relativistic Kinematics 8 Which CM-energy do we reach at HERA ? 9 HEP 100 Years ago : Radioactive Decay Energy region : MeV =He−nucleus....=electron...= photon 10 Today : Some more particles : 11 The Particle Zoo I can't spare you this chapter. Quarks are nice to EXPLAIN observed phenomena. But, what we OBSERVE are particles like protons, muons, pions,.......... 12 'Artificial' Production of New Particles (Resonances): − p scattering 13 Particle classification Hadrons : strongly interacting Leptons : not Strongly interacting 14 All these particles are listed in the Particle Data Booklet -
Supersymmetric Particle Searches
Citation: K.A. Olive et al. (Particle Data Group), Chin. Phys. C38, 090001 (2014) (URL: http://pdg.lbl.gov) Supersymmetric Particle Searches A REVIEW GOES HERE – Check our WWW List of Reviews A REVIEW GOES HERE – Check our WWW List of Reviews SUPERSYMMETRIC MODEL ASSUMPTIONS The exclusion of particle masses within a mass range (m1, m2) will be denoted with the notation “none m m ” in the VALUE column of the 1− 2 following Listings. The latest unpublished results are described in the “Supersymmetry: Experiment” review. A REVIEW GOES HERE – Check our WWW List of Reviews CONTENTS: χ0 (Lightest Neutralino) Mass Limit 1 e Accelerator limits for stable χ0 − 1 Bounds on χ0 from dark mattere searches − 1 χ0-p elastice cross section − 1 eSpin-dependent interactions Spin-independent interactions Other bounds on χ0 from astrophysics and cosmology − 1 Unstable χ0 (Lighteste Neutralino) Mass Limit − 1 χ0, χ0, χ0 (Neutralinos)e Mass Limits 2 3 4 χe ,eχ e(Charginos) Mass Limits 1± 2± Long-livede e χ± (Chargino) Mass Limits ν (Sneutrino)e Mass Limit Chargede Sleptons e (Selectron) Mass Limit − µ (Smuon) Mass Limit − e τ (Stau) Mass Limit − e Degenerate Charged Sleptons − e ℓ (Slepton) Mass Limit − q (Squark)e Mass Limit Long-livede q (Squark) Mass Limit b (Sbottom)e Mass Limit te (Stop) Mass Limit eHeavy g (Gluino) Mass Limit Long-lived/lighte g (Gluino) Mass Limit Light G (Gravitino)e Mass Limits from Collider Experiments Supersymmetrye Miscellaneous Results HTTP://PDG.LBL.GOV Page1 Created: 8/21/2014 12:57 Citation: K.A. Olive et al. -
Search for Long-Lived Stopped R-Hadrons Decaying out of Time with Pp Collisions Using the ATLAS Detector
PHYSICAL REVIEW D 88, 112003 (2013) Search for long-lived stopped R-hadrons decaying out of time with pp collisions using the ATLAS detector G. Aad et al.* (ATLAS Collaboration) (Received 24 October 2013; published 3 December 2013) An updated search is performed for gluino, top squark, or bottom squark R-hadrons that have come to rest within the ATLAS calorimeter, and decay at some later time to hadronic jets and a neutralino, using 5.0 and 22:9fbÀ1 of pp collisions at 7 and 8 TeV, respectively. Candidate decay events are triggered in selected empty bunch crossings of the LHC in order to remove pp collision backgrounds. Selections based on jet shape and muon system activity are applied to discriminate signal events from cosmic ray and beam-halo muon backgrounds. In the absence of an excess of events, improved limits are set on gluino, stop, and sbottom masses for different decays, lifetimes, and neutralino masses. With a neutralino of mass 100 GeV, the analysis excludes gluinos with mass below 832 GeV (with an expected lower limit of 731 GeV), for a gluino lifetime between 10 s and 1000 s in the generic R-hadron model with equal branching ratios for decays to qq~0 and g~0. Under the same assumptions for the neutralino mass and squark lifetime, top squarks and bottom squarks in the Regge R-hadron model are excluded with masses below 379 and 344 GeV, respectively. DOI: 10.1103/PhysRevD.88.112003 PACS numbers: 14.80.Ly R-hadrons may change their properties through strong I. -
MIT at the Large Hadron Collider—Illuminating the High-Energy Frontier
Mit at the large hadron collider—Illuminating the high-energy frontier 40 ) roland | klute mit physics annual 2010 gunther roland and Markus Klute ver the last few decades, teams of physicists and engineers O all over the globe have worked on the components for one of the most complex machines ever built: the Large Hadron Collider (LHC) at the CERN laboratory in Geneva, Switzerland. Collaborations of thousands of scientists have assembled the giant particle detectors used to examine collisions of protons and nuclei at energies never before achieved in a labo- ratory. After initial tests proved successful in late 2009, the LHC physics program was launched in March 2010. Now the race is on to fulfill the LHC’s paradoxical mission: to complete the Stan- dard Model of particle physics by detecting its last missing piece, the Higgs boson, and to discover the building blocks of a more complete theory of nature to finally replace the Standard Model. The MIT team working on the Compact Muon Solenoid (CMS) experiment at the LHC stands at the forefront of this new era of particle and nuclear physics. The High Energy Frontier Our current understanding of the fundamental interactions of nature is encap- sulated in the Standard Model of particle physics. In this theory, the multitude of subatomic particles is explained in terms of just two kinds of basic building blocks: quarks, which form protons and neutrons, and leptons, including the electron and its heavier cousins. From the three basic interactions described by the Standard Model—the strong, electroweak and gravitational forces—arise much of our understanding of the world around us, from the formation of matter in the early universe, to the energy production in the Sun, and the stability of atoms and mit physics annual 2010 roland | klute ( 41 figure 1 A photograph of the interior, central molecules. -
Introduction to Supersymmetry
Introduction to Supersymmetry Pre-SUSY Summer School Corpus Christi, Texas May 15-18, 2019 Stephen P. Martin Northern Illinois University [email protected] 1 Topics: Why: Motivation for supersymmetry (SUSY) • What: SUSY Lagrangians, SUSY breaking and the Minimal • Supersymmetric Standard Model, superpartner decays Who: Sorry, not covered. • For some more details and a slightly better attempt at proper referencing: A supersymmetry primer, hep-ph/9709356, version 7, January 2016 • TASI 2011 lectures notes: two-component fermion notation and • supersymmetry, arXiv:1205.4076. If you find corrections, please do let me know! 2 Lecture 1: Motivation and Introduction to Supersymmetry Motivation: The Hierarchy Problem • Supermultiplets • Particle content of the Minimal Supersymmetric Standard Model • (MSSM) Need for “soft” breaking of supersymmetry • The Wess-Zumino Model • 3 People have cited many reasons why extensions of the Standard Model might involve supersymmetry (SUSY). Some of them are: A possible cold dark matter particle • A light Higgs boson, M = 125 GeV • h Unification of gauge couplings • Mathematical elegance, beauty • ⋆ “What does that even mean? No such thing!” – Some modern pundits ⋆ “We beg to differ.” – Einstein, Dirac, . However, for me, the single compelling reason is: The Hierarchy Problem • 4 An analogy: Coulomb self-energy correction to the electron’s mass A point-like electron would have an infinite classical electrostatic energy. Instead, suppose the electron is a solid sphere of uniform charge density and radius R. An undergraduate problem gives: 3e2 ∆ECoulomb = 20πǫ0R 2 Interpreting this as a correction ∆me = ∆ECoulomb/c to the electron mass: 15 0.86 10− meters m = m + (1 MeV/c2) × . -
Constraints on the Mass of the Superlight Gravitino from the Muon Anomaly
CORE Metadata, citation and similar papers at core.ac.uk Provided by CERN Document Server UAB–FT–416 Constraints on the mass of the superlight gravitino from the muon anomaly F.Ferrer and J.A.Grifols Grup de F´ısica Te`orica and Institut de F´ısica d’Altes Energies, Universitat Aut`onoma de Barcelona, E–08193 Bellaterra, Barcelona, Spain (April 1997) Abstract We reexamine the limits on the gravitino mass supplied by the muon anomaly in the frame of supergravity models with a superlight gravitino and a su- perlight scalar S and a superlight pseudoscalar P . PACS number(s): 14.80.Ly, 13.40.Em, 04.65.+e, 12.60.Jv Typeset using REVTEX 1 In a wide class of supergravity models with SUSY breaking scale in the TeV range, 2 the gravitino can be very light (m3/2 ∼ MSUSY /MPl). In fact, its mass could lie anywhere between µeV and keV . Examples for this are those models where gauge interactions mediate the breakdown of supersymmetry [1] or models where an anomalous U(1) gauge symmetry induces SUSY breaking [2]. Also, no–scale models can accomodate superlight gravitinos [3]. Clearly, it is important to bound and eventually determine the mass of the gravitino. To mention only an instance where the gravitino mass is of great physical significance, let us recall that a mass on the order of a few keV can be relevant for the dark matter problem. The sources of direct (laboratory) information on the gravitino mass are rare [4–7] and perhaps the best one comes from the (g − 2)µ of the muon [6,7]. -
General Neutralino NLSP with Gravitino Dark Matter Vs. Big Bang Nucleosynthesis
General Neutralino NLSP with Gravitino Dark Matter vs. Big Bang Nucleosynthesis II. Institut fur¨ Theoretische Physik, Universit¨at Hamburg Deutsches Elektronen-Synchrotron DESY, Theory Group Diplomarbeit zur Erlangung des akademischen Grades Diplom-Physiker (diploma thesis - with correction) Verfasser: Jasper Hasenkamp Matrikelnummer: 5662889 Studienrichtung: Physik Eingereicht am: 31.3.2009 Betreuer(in): Dr. Laura Covi, DESY Zweitgutachter: Prof. Dr. Gun¨ ter Sigl, Universit¨at Hamburg ii Abstract We study the scenario of gravitino dark matter with a general neutralino being the next- to-lightest supersymmetric particle (NLSP). Therefore, we compute analytically all 2- and 3-body decays of the neutralino NLSP to determine the lifetime and the electro- magnetic and hadronic branching ratio of the neutralino decaying into the gravitino and Standard Model particles. We constrain the gravitino and neutralino NLSP mass via big bang nucleosynthesis and see how those bounds are relaxed for a Higgsino or a wino NLSP in comparison to the bino neutralino case. At neutralino masses & 1 TeV, a wino NLSP is favoured, since it decays rapidly via a newly found 4-vertex. The Higgsino component becomes important, when resonant annihilation via heavy Higgses can occur. We provide the full analytic results for the decay widths and the complete set of Feyn- man rules necessary for these computations. This thesis closes any gap in the study of gravitino dark matter scenarios with neutralino NLSP coming from approximations in the calculation of the neutralino decay rates and its hadronic branching ratio. Zusammenfassung Diese Diplomarbeit befasst sich mit dem Gravitino als Dunkler Materie, wobei ein allge- meines Neutralino das n¨achstleichteste supersymmetrische Teilchen (NLSP) ist. -
The Higgs Boson in the Periodic System of Elementary Particles
Southern Adventist University KnowledgeExchange@Southern Faculty Works Physics and Engineering Department 3-2013 The iH ggs Boson in the Periodic System of Elementary Particles Ding-Yu Chung Ray Hefferlin Follow this and additional works at: https://knowledge.e.southern.edu/facworks_physics Part of the Elementary Particles and Fields and String Theory Commons Recommended Citation Chung, Ding-Yu and Hefferlin, Ray, "The iH ggs Boson in the Periodic System of Elementary Particles" (2013). Faculty Works. 12. https://knowledge.e.southern.edu/facworks_physics/12 This Article is brought to you for free and open access by the Physics and Engineering Department at KnowledgeExchange@Southern. It has been accepted for inclusion in Faculty Works by an authorized administrator of KnowledgeExchange@Southern. For more information, please contact [email protected]. Journal of Modern Physics, 2013, 4, 21-26 doi:10.4236/jmp.2013.44A004 Published Online April 2013 (http://www.scirp.org/journal/jmp) The Higgs Boson in the Periodic System of Elementary Particles Ding-Yu Chung1, Ray Hefferlin2 1Utica, Michigan, USA 2Department of Physics, Southern Adventist University, Collegedale, USA Email: [email protected], [email protected] Received February 12, 2013; revised March 15, 2013; accepted March 27, 2013 Copyright © 2013 Ding-Yu Chung, Ray Hefferlin. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT It is proposed that the observed Higgs Boson at the LHC is the Standard Model Higgs boson that adopts the existence of the hidden lepton condensate. The hidden lepton is in the forbidden lepton family, outside of the three lepton families of the Standard Model.