The Search for Charged Massive Supersymmetric Particles at the LHC
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Searching for Stable Massive Particles in the ATLAS Transition Radiation Tracker
Searching for Stable Massive Particles in the ATLAS Transition Radiation Tracker by Steven Schramm A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Science (Hons) in THE FACULTY OF SCIENCE (Physics and Astronomy) The University Of British Columbia (Vancouver) April 2011 c Steven Schramm, 2011 Abstract The search for new particles is an important topic in modern particle physics. New stable massive particles are predicted by various models, including R-parity con- serving variants of supersymmetry. The ATLAS Transition Radiation Tracker can be used to look for charged stable massive particles by using the momentum and velocity of particles passing through the detector to calculate its mass. A program named TRTCHAMP has been written to perform this analysis. Recently, ATLAS changed their data retention policies to phase out the use of a particular format of output file created during reconstruction. TRTCHAMP relies on this file type, and therefore this change prevents the algorithm from work- ing in its original state. However, this problem can be resolved by integrating TRTCHAMP into the official reconstruction, which has now been done. This paper documents the changes involved in integrating TRTCHAMP with the existing InDetLowBetaFinder reconstruction package. Topics discussed in- clude the structure of reconstruction algorithms in ATLAS, the retrieval of calibra- tion constants from the detector conditions database, and the parsing of necessary parameters from multiple reconstruction data containers. To conclude, the output of TRTCHAMP is shown to accurately estimate the velocity of protons in mini- mum bias tracks. Additionally, mass plots generated with the TRTCHAMP results are shown to agree with the known mass for both monte carlo and real protons in minimum bias tracks, and agreement is shown between the input and output masses for a monte carlo sample of 300 GeV R-Hadrons. -
Non-Collider Searches for Stable Massive Particles
Non-collider searches for stable massive particles S. Burdina, M. Fairbairnb, P. Mermodc,, D. Milsteadd, J. Pinfolde, T. Sloanf, W. Taylorg aDepartment of Physics, University of Liverpool, Liverpool L69 7ZE, UK bDepartment of Physics, King's College London, London WC2R 2LS, UK cParticle Physics department, University of Geneva, 1211 Geneva 4, Switzerland dDepartment of Physics, Stockholm University, 106 91 Stockholm, Sweden ePhysics Department, University of Alberta, Edmonton, Alberta, Canada T6G 0V1 fDepartment of Physics, Lancaster University, Lancaster LA1 4YB, UK gDepartment of Physics and Astronomy, York University, Toronto, ON, Canada M3J 1P3 Abstract The theoretical motivation for exotic stable massive particles (SMPs) and the results of SMP searches at non-collider facilities are reviewed. SMPs are defined such that they would be suffi- ciently long-lived so as to still exist in the cosmos either as Big Bang relics or secondary collision products, and sufficiently massive such that they are typically beyond the reach of any conceiv- able accelerator-based experiment. The discovery of SMPs would address a number of important questions in modern physics, such as the origin and composition of dark matter and the unifi- cation of the fundamental forces. This review outlines the scenarios predicting SMPs and the techniques used at non-collider experiments to look for SMPs in cosmic rays and bound in mat- ter. The limits so far obtained on the fluxes and matter densities of SMPs which possess various detection-relevant properties such as electric and magnetic charge are given. Contents 1 Introduction 4 2 Theory and cosmology of various kinds of SMPs 4 2.1 New particle states (elementary or composite) . -
Il Nostro Mondo
IL NOSTRO MONDO THE DESIGN, CONSTRUCTION AND PERFORMANCE OF THE CERN INTERSECTING STORAGE RINGS (ISR) A RECOLLECTION OF WORLD’S FIRST PROTON-PROTON COLLIDER KURT HÜBNER CERN, Geneva, Switzerland 1 Design which had a beam energy of 160 MeV. The interaction points to increase the collision rate The concept of colliding beams appeared design of these colliders started in 1957. but without special lattice insertions as one first in a German patent by Rolf Widerøe In 1961, the Accelerator Research Group would use these days. registered in 1943 and published in 1952. Division was expanded into the Accelerator Combined-function magnets were chosen However, at that time the intensity of beams Division as experienced manpower had as in the PS, i.e. the main magnets had a was too low for an exploitable collision rate as become available after the running-in of the magnetic dipole field to bend the beam and a beam accumulation had not yet been invented. PS in 1960. At the same time it was decided quadrupole field to focus the beam. This type The first ideas of a realistic design were to construct a small accelerator to test rf of magnet provided space for the elaborate published in 1956 by Gerard O’Neill and by the stacking, a technique to be experimentally pole-face windings foreseen to control the MURA Group lead by Donald Kerst in the USA. proven, as it was essential for the performance magnetic field to a very high precision. It also MURA had come up with beam accumulation and success of the ISR. -
Pos(ICRC2019)446
New Results from the Cosmic-Ray Program of the NA61/SHINE facility at the CERN SPS PoS(ICRC2019)446 Michael Unger∗ for the NA61/SHINE Collaborationy Karlsruhe Institute of Technology (KIT), Postfach 3640, D-76021 Karlsruhe, Germany E-mail: [email protected] The NA61/SHINE experiment at the SPS accelerator at CERN is a unique facility for the study of hadronic interactions at fixed target energies. The data collected with NA61/SHINE is relevant for a broad range of topics in cosmic-ray physics including ultrahigh-energy air showers and the production of secondary nuclei and anti-particles in the Galaxy. Here we present an update of the measurement of the momentum spectra of anti-protons produced in p−+C interactions at 158 and 350 GeV=c and discuss their relevance for the understanding of muons in air showers initiated by ultrahigh-energy cosmic rays. Furthermore, we report the first results from a three-day pilot run aimed at investigating the ca- pability of our experiment to measure nuclear fragmentation cross sections for the understanding of the propagation of cosmic rays in the Galaxy. We present a preliminary measurement of the production cross section of Boron in C+p interactions at 13.5 AGeV=c and discuss prospects for future data taking to provide the comprehensive and accurate reaction database of nuclear frag- mentation needed in the era of high-precision measurements of Galactic cosmic rays. 36th International Cosmic Ray Conference -ICRC2019- July 24th - August 1st, 2019 Madison, WI, U.S.A. ∗Speaker. yhttp://shine.web.cern.ch/content/author-list c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). -
NA61/SHINE Facility at the CERN SPS: Beams and Detector System
Preprint typeset in JINST style - HYPER VERSION NA61/SHINE facility at the CERN SPS: beams and detector system N. Abgrall11, O. Andreeva16, A. Aduszkiewicz23, Y. Ali6, T. Anticic26, N. Antoniou1, B. Baatar7, F. Bay27, A. Blondel11, J. Blumer13, M. Bogomilov19, M. Bogusz24, A. Bravar11, J. Brzychczyk6, S. A. Bunyatov7, P. Christakoglou1, T. Czopowicz24, N. Davis1, S. Debieux11, H. Dembinski13, F. Diakonos1, S. Di Luise27, W. Dominik23, T. Drozhzhova20 J. Dumarchez18, K. Dynowski24, R. Engel13, I. Efthymiopoulos10, A. Ereditato4, A. Fabich10, G. A. Feofilov20, Z. Fodor5, A. Fulop5, M. Ga´zdzicki9;15, M. Golubeva16, K. Grebieszkow24, A. Grzeszczuk14, F. Guber16, A. Haesler11, T. Hasegawa21, M. Hierholzer4, R. Idczak25, S. Igolkin20, A. Ivashkin16, D. Jokovic2, K. Kadija26, A. Kapoyannis1, E. Kaptur14, D. Kielczewska23, M. Kirejczyk23, J. Kisiel14, T. Kiss5, S. Kleinfelder12, T. Kobayashi21, V. I. Kolesnikov7, D. Kolev19, V. P. Kondratiev20, A. Korzenev11, P. Koversarski25, S. Kowalski14, A. Krasnoperov7, A. Kurepin16, D. Larsen6, A. Laszlo5, V. V. Lyubushkin7, M. Mackowiak-Pawłowska´ 9, Z. Majka6, B. Maksiak24, A. I. Malakhov7, D. Maletic2, D. Manglunki10, D. Manic2, A. Marchionni27, A. Marcinek6, V. Marin16, K. Marton5, H.-J.Mathes13, T. Matulewicz23, V. Matveev7;16, G. L. Melkumov7, M. Messina4, St. Mrówczynski´ 15, S. Murphy11, T. Nakadaira21, M. Nirkko4, K. Nishikawa21, T. Palczewski22, G. Palla5, A. D. Panagiotou1, T. Paul17, W. Peryt24;∗, O. Petukhov16 C.Pistillo4 R. Płaneta6, J. Pluta24, B. A. Popov7;18, M. Posiadala23, S. Puławski14, J. Puzovic2, W. Rauch8, M. Ravonel11, A. Redij4, R. Renfordt9, E. Richter-Wa¸s6, A. Robert18, D. Röhrich3, E. Rondio22, B. Rossi4, M. Roth13, A. Rubbia27, A. Rustamov9, M. -
Arxiv:1802.10184V1 [Hep-Ph] 26 Feb 2018 Charged Particles Experimentum Crucis for Dark Atoms of Composite Dark Matter
March 1, 2018 1:20 WSPC/INSTRUCTION FILE New_physics International Journal of Modern Physics D c World Scientific Publishing Company Probes for Dark Matter Physics Maxim Yu. Khlopov National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia APC laboratory 10, rue Alice Domon et Leonie Duquet 75205 Paris Cedex 13, France [email protected] Received Day Month Year Revised Day Month Year The existence of cosmological dark matter is in the bedrock of the modern cosmology. The dark matter is assumed to be nonbaryonic and to consist of new stable particles. Weakly Interacting Massive Particle (WIMP) miracle appeals to search for neutral stable weakly interacting particles in underground experiments by their nuclear recoil and at colliders by missing energy and momentum, which they carry out. However the lack of WIMP effects in their direct underground searches and at colliders can appeal to other forms of dark matter candidates. These candidates may be weakly interacting slim parti- cles, superweakly interacting particles, or composite dark matter, in which new particles are bound. Their existence should lead to cosmological effects that can find probes in the astrophysical data. However if composite dark matter contains stable electrically charged leptons and quarks bound by ordinary Coulomb interaction in elusive dark atoms, these charged constituents of dark atoms can be the subject of direct experimental test at the colliders. The models, predicting stable particles with charge -2 without stable parti- cles with charges +1 and -1 can avoid severe constraints on anomalous isotopes of light elements and provide solution for the puzzles of dark matter searches. -
Improving the Slow Extraction Efficiency of the CERN Super
Improving the slow extraction efficiency of the CERN Super Proton Synchrotron Brunner Kristóf Faculty of Science Eötvös Loránd University Supervisors: Barna Dániel, Wigner RCP Christoph Wiesner, CERN May 2018 Contents 1 Introduction4 2 CERN accelerator complex5 2.1 Accelerators..................................... 5 2.2 Experiments..................................... 6 2.2.1 Colliders .................................. 7 2.2.2 Fixed target experiments.......................... 7 2.3 Current and future demands of fixed target experiments.............. 7 3 Introduction to accelerator physics9 3.1 History of linear and circular accelerators ..................... 9 3.2 Design orbit, focusing................................. 11 3.3 Betatron oscillation, the behaviour of single particles ................ 11 3.4 The Twiss-ellipse, the behaviour of the beam ................... 13 3.5 Normalised phase space............................... 15 3.6 Tune and resonances ................................ 16 4 Extraction from a synchrotron 19 4.1 Fast extraction.................................... 19 4.2 Multi-turn extraction ................................ 20 4.3 Sextupole driven slow extraction........................... 21 4.4 Possible enhancements............................... 24 4.4.1 Diffuser................................... 24 4.4.2 Dynamic bump............................... 26 4.4.3 Phase space folding............................. 26 5 Massless septum 28 5.1 Method of phase space folding using a massless septum.............. 29 6 Simulation -
Cosmological Reflection of Particle Symmetry
S S symmetry Review Cosmological Reflection of Particle Symmetry Maxim Khlopov 1,2 1 Laboratory of Astroparticle Physics and Cosmology 10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France; [email protected] 2 Center for Cosmopartcile Physics “Cosmion” and National Research Nuclear University “MEPHI” (Moscow State Engineering Physics Institute), Kashirskoe Shosse 31, Moscow 115409, Russia Academic Editor: Sergei D. Odintsov Received: 31 May 2016; Accepted: 10 August 2016; Published: 20 August 2016 Abstract: The standard model involves particle symmetry and the mechanism of its breaking. Modern cosmology is based on inflationary models with baryosynthesis and dark matter/energy, which involves physics beyond the standard model. Studies of the physical basis of modern cosmology combine direct searches for new physics at accelerators with its indirect non-accelerator probes, in which cosmological consequences of particle models play an important role. The cosmological reflection of particle symmetry and the mechanisms of its breaking are the subject of the present review. Keywords: elementary particles; dark matter; early universe; symmetry breaking 1. Introduction The laws of known particle interactions and transformations are based on the gauge symmetry-extension of the gauge principle of quantum electrodynamics to strong and weak interactions. Starting from isotopic invariance of nuclear forces, treating proton and neutron as different states of one particle-nucleon; the development of this approach led to the successful -
Particle Physics Lecture 4: the Large Hadron Collider and Other Accelerators November 13Th 2009
Subatomic Physics: Particle Physics Lecture 4: The Large Hadron Collider and other accelerators November 13th 2009 • Previous colliders • Accelerating techniques: linacs, cyclotrons and synchrotrons • Synchrotron Radiation • The LHC • LHC energy and luminosity 1 Particle Acceleration Long-lived charged particles can be accelerated to high momenta using electromagnetic fields. • e+, e!, p, p!, µ±(?) and Au, Pb & Cu nuclei have been accelerated so far... Why accelerate particles? • High beam energies ⇒ high ECM ⇒ more energy to create new particles • Higher energies probe shorter physics at shorter distances λ c 197 MeV fm • De-Broglie wavelength: = 2π pc ≈ p [MeV/c] • e.g. 20 GeV/c probes a distance of 0.01 fm. An accelerator complex uses a variety of particle acceleration techniques to reach the final energy. 2 A brief history of colliders • Colliders have driven particle physics forward over the last 40 years. • This required synergy of - hadron - hadron colliders - lepton - hadron colliders & - lepton - lepton colliders • Experiments at colliders discovered W- boson, Z-boson, gluon, tau-lepton, charm, bottom and top-quarks. • Colliders provided full verification of the Standard Model. DESY Fermilab CERN SLAC BNL KEK 3 SppS̅ at CERNNo b&el HERAPrize for atPhy sDESYics 1984 SppS:̅ Proton anti-Proton collider at CERN. • Given to Carlo Rubbia and Simon van der Meer • Ran from 1981 to 1984. Nobel Prize for Physics 1984 • Centre of Mass energy: 400 GeV • “For their decisive • 6.9 km in circumference contributions to large • Two experiments: -
ATLAS Document
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN) Submitted to: Phys. Rev. D. CERN-EP-2016-063 8th July 2016 Search for metastable heavy chargedp particles with large ionization energy loss in pp collisions at s = 13 TeV using the ATLAS experiment The ATLAS Collaboration Abstract This paperp presents a search for massive charged long-lived particles produced in pp colli- sions at s = 13 TeV at the LHC using the ATLAS experiment. The dataset used corres- ponds to an integrated luminosity of 3:2 fb−1. Many extensions of the Standard Model pre- dict the existence of massive charged long-lived particles, such as R-hadrons. These massive particles are expected to be produced with a velocity significantly below the speed of light, and therefore to have a specific ionization higher than any Standard Model particle of unit charge at high momenta. The Pixel subsystem of the ATLAS detector is used to measure the ionization energy loss of reconstructed charged particles and to search for such highly ion- izing particles. The search presented here hasp much greater sensitivity than a similar search performed using the ATLAS detector in the s = 8 TeV dataset, thanks to the increase in expected signal cross-section due to the higher center-of-mass energy of collisions, to an upgraded detector with a new silicon layer close to the interaction point, and to analysis improvements. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on R-hadron production cross-sections and arXiv:1604.04520v1 [hep-ex] 15 Apr 2016 masses are set. -
THE PROTON-ANTIPROTON COLLIDER Lecture Delivered at CERN on 25 November 1987 Lyndon Evans
CERN 88-01 11 March 1988 ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN ACCELERATOR SCHOOL Third John Adams Memorial Lecture THE PROTON-ANTIPROTON COLLIDER Lecture delivered at CERN on 25 November 1987 Lyndon Evans GENEVA 1988 ABSTRACT The subject of this lecture is the CERN Proton-Antiproton (pp) Collider, in which John Adams was intimately involved at the design, development, and construction stages. Its history is traced from the original proposal in 1966, to the first pp collisions in the Super Proton Synchrotron (SPS) in 1981, and to the present time with drastically improved performance. This project led to the discovery of the intermediate vector boson in 1983 and produced one of the most exciting and productive physics periods in CERN's history. RN —Service d'Information Scientifique-RD/757-3000-Mars 1988 iii CONTENTS Page 1. INTRODUCTION 1 2. BEAM COOLING l 3. HISTORICAL DEVELOPMENT OF THE pp COLLIDER CONCEPT 2 4. THE SPS AS A COLLIDER 4 4.1 Operation 4 4.2 Performance 5 5. IMPACT OF EARLIER CERN DEVELOPMENTS 5 6. PROPHETS OF DOOM 7 7. IMPACT ON THE WORLD SCENE 9 8. CONCLUDING REMARKS: THE FUTURE OF THE pp COLLIDER 9 REFERENCES 10 Plates 11 v 1. INTRODUCTION The subject of this lecture is the CERN Proton-Antiproton (pp) Collider and let me say straightaway that some of you might find that this talk is rather polarized towards the Super Proton Synchrotron (SPS). In fact, the pp project was a CERN-wide collaboration 'par excellence'. However, in addition to John Adams' close involvement with the SPS there is a natural tendency for me to remain within my own domain of competence. -
Discovery Machines
DISCOVERY MACHINES 2019 was noteworthy for being the start of Long Shutdown 2 (LS2) of the CERN accelerator complex. Across all the machines, teams began the tasks of maintaining or renovating numerous items of equipment or replacing them with new, innovative systems. These major upgrades are being carried out in preparation for the third run of the LHC and for the High-Luminosity LHC (HL-LHC). What’s more, they will benefit the users of all the accelerators as many aspects of the work are being carried out as part of the LHC Injectors Upgrade (LIU) project. ISOLDE The front-ends for the LINEAR ACCELERATOR 4 (LINAC4) isotope separator targets have been built, tested Linac4 is now connected to the LHC and partially installed. accelerator chain. A nominal beam The new Offline2 test of 160 MeV reached the Linac4 beam facility, equipped with dump in October. a laser ion source, was (CERN-PHOTO-201704-093-27) commissioned. (CERN-PHOTO-201911-394-28) PS BOOSTER (PSB) Seventy of the 215 metres of the PSB’s beam lines have been removed to allow the installation of new equipment. More than 60 magnets have been renovated or replaced in the accelerator. A new RF acceleration system has been installed. After LS2, the energy of the PS Booster will increase from 1.4 to 2 GeV. (CERN-PHOTO-201906-149-11) 22 | CERN SUPER PROTON SYNCHROTRON (SPS) LARGE HADRON COLLIDER (LHC) A new RF acceleration system is under The electrical insulation of the diodes has construction. The SPS beam dump is being been completed on 94% of the accelerator’s replaced.