Tevatron Collider Run II: a Cinderella Story
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Supersymmetry Searches at the Tevatron
SUPERSYMMETRY SEARCHES AT THE TEVATRON For CDF and DØ collaborations R. Demina Department of Physics and Astronomy, University of Rochester, Rochester, USA, 14627 CDF and DØ collaborations analyzed up to 200 pb-1 of the delivered data in search for different supersymmetry signatures, so far with negative results. We present results on searches for chargino and neutralino associated production, squarks and gluinos, sbottom quarks, gauge mediated SUSY breaking and long lived heavy particles. Supersymmetry1 is a popular extension of the Standard Model originally suggested over 25 years ago. It postulates the symmetry between fermionic and bosonic degrees of freedom. As a result a variety of hypothetical particles is introduced. With presently available experimental data physicists were able to prove that if supersymmetric particles exist they must be heavier than their Standard Model partners2. In other words the Supersymmetry is broken. One possible exception is supersymmetric top quark (stop), which still has a chance to be lighter or of the same mass as top quark. With 2-4 fb-1 of data Tevatron experiments will be able to extend the limit on stop mass above that of top quark or discover it and thus establish the Supersymmetry3. Theory suggests several possible scenarios of Supersymmetry breaking mediated by gravitational or gauge interactions. In gravity mediated scenarios the number of free parameters in the model is reduced to five because of the unification of masses and couplings imposed at the grand unification scale. These parameters are M0 (M½) – masses of all bosons (fermions) at GUT scale, A0- trilinear coupling and µ0 – something Higgs and tan(β) – ratio of vacuum expectations of the Higgs doublet. -
The Large Hadron Collider Lyndon Evans CERN – European Organization for Nuclear Research, Geneva, Switzerland
34th SLAC Summer Institute On Particle Physics (SSI 2006), July 17-28, 2006 The Large Hadron Collider Lyndon Evans CERN – European Organization for Nuclear Research, Geneva, Switzerland 1. INTRODUCTION The Large Hadron Collider (LHC) at CERN is now in its final installation and commissioning phase. It is a two-ring superconducting proton-proton collider housed in the 27 km tunnel previously constructed for the Large Electron Positron collider (LEP). It is designed to provide proton-proton collisions with unprecedented luminosity (1034cm-2.s-1) and a centre-of-mass energy of 14 TeV for the study of rare events such as the production of the Higgs particle if it exists. In order to reach the required energy in the existing tunnel, the dipoles must operate at 1.9 K in superfluid helium. In addition to p-p operation, the LHC will be able to collide heavy nuclei (Pb-Pb) with a centre-of-mass energy of 1150 TeV (2.76 TeV/u and 7 TeV per charge). By modifying the existing obsolete antiproton ring (LEAR) into an ion accumulator (LEIR) in which electron cooling is applied, the luminosity can reach 1027cm-2.s-1. The LHC presents many innovative features and a number of challenges which push the art of safely manipulating intense proton beams to extreme limits. The beams are injected into the LHC from the existing Super Proton Synchrotron (SPS) at an energy of 450 GeV. After the two rings are filled, the machine is ramped to its nominal energy of 7 TeV over about 28 minutes. In order to reach this energy, the dipole field must reach the unprecedented level for accelerator magnets of 8.3 T. -
Three Extra Mirror Or Sequential Families: a Case for Heavy Higgs and Inert Doublet
Three Extra Mirror or Sequential Families: a Case for Heavy Higgs and Inert Doublet Homero Mart´ınez,1 Alejandra Melfo,2, 3 Fabrizio Nesti,4 and Goran Senjanovi´c2 1CEA, Saclay, DSM-IRFU-SPP, France 2ICTP, Trieste, Italy 3U. de Los Andes, M´erida, Venezuela 4U. di Ferrara, Ferrara, Italy (Dated: October 24, 2018) We study the possibility of the existence of extra fermion families and an extra Higgs doublet. We find that requiring the extra Higgs doublet to be inert leaves space for three extra families, allowing for mirror fermion families and a dark matter candidate at the same time. The emerging scenario is very predictive: it consists of a Standard Model Higgs boson, with mass above 400 GeV, heavy new quarks between 340 and 500 GeV, light extra neutral leptons, and an inert scalar with a mass below MZ . PACS numbers: 14.65.Jk, 12.60.Fr, 14.60.Hi, 14.60.St Introduction. It may not be well known that the idea with regard to high precision analysis they behave exactly of parity restoration in weak interactions is as old as as ordinary fermions, and thus a reader who is uncom- the suggestion of its breakdown. In their classic paper, fortable with the above setbacks can view our study as Lee and Yang [1] proposed the existence of what we will referring to the more general question of whether the SM call mirror fermions, so as to make the world left-right can host three (or more) extra families. symmetric at high energies. By this they meant another If one defines the SM by its structure, i.e. -
Bright Prospects for Tevatron Run II
INTERNATIONAL JOURNAL OF HIGH-ENERGY PHYSICS CERN COURIER VOLUME 43 NUMBER 1 JANUARY/FEBRUARY 2003 Bright prospects for Tevatron Run II JLAB Virginia laboratory delivers terahertz light p6 ^^^J Modular and expandable power supplies WÊ H Communications via TCP/IP içert. n_.___910S.CAEN '^^^*aBOKS^^^^ • ÊÊÊ WÊÊÊSêSê É TÏSjj à OPC Server to ease integration in DCS J Directly interfaced to JCOP Framework p " j^pj ^ ^^^^ Wa9neticFie,dand^ ^^HTJHj^^^^^^^^^^^^^^^^^^^^^^E' ' tfHl far IM Éfefi-*il * CAEN: your largest choice of HV & LV )^ H MULTICHANNEL POWER SUPPLIES CONTENTS Covering current developments in high- energy physics and related fields worldwide CERN Courier (ISSN 0304-288X) is distributed to member state governments, institutes and laboratories affiliated with CERN, and to their personnel. It is published monthly, except for January and August, in English and French editions. The views expressed are CERN not necessarily those of the CERN management. Editors James Gillies and Christine Sutton CERN, 1211 Geneva 23, Switzerland Email [email protected] Fax+41 (22) 782 1906 Web cerncourier.com COURIER Advisory Board R Landua (Chairman), F Close, E Lillest0l, VOLUME 43 NUMBER 1 JANUARY/FEBRUARY 2003 H Hoffmann, C Johnson, K Potter, P Sphicas Laboratory correspondents: Argonne National Laboratory (US): D Ayres Brookhaven, National Laboratory (US): PYamin Cornell University (US): D G Cassel DESY Laboratory (Germany): Ilka Flegel, P Waloschek Fermi National Accelerator Laboratory (US): Judy Jackson GSI Darmstadt (Germany): G Siegert INFN -
Tevatron Accelerator Physics and Operation Highlights A
FERMILAB-CONF-11-129-APC TEVATRON ACCELERATOR PHYSICS AND OPERATION HIGHLIGHTS A. Valishev for the Tevatron group, FNAL, Batavia, IL 60510, U.S.A. Abstract Table 1: Integrated luminosity performance by fiscal year. The performance of the Tevatron collider demonstrated FY07 FY08 FY09 FY10 continuous growth over the course of Run II, with the peak luminosity reaching 4×1032 cm-2 s-1, and the weekly Total integral (fb-1) 1.3 1.8 1.9 2.47 -1 integration rate exceeding 70 pb . This report presents a review of the most important advances that contributed to Until the middle of calendar year 2009, the luminosity this performance improvement, including beam dynamics growth was dominated by improvements of the antiproton modeling, precision optics measurements and stability production rate [2], which remains stable since. control, implementation of collimation during low-beta Performance improvements over the last two years squeeze. Algorithms employed for optimization of the became possible because of implementation of a few luminosity integration are presented and the lessons operational changes, described in the following section. learned from high-luminosity operation are discussed. Studies of novel accelerator physics concepts at the Tevatron are described, such as the collimation techniques using crystal collimator and hollow electron beam, and compensation of beam-beam effects. COLLIDER RUN II PERFORMANCE Tevatron collider Run II with proton-antiproton collisions at the center of mass energy of 1.96 TeV started in March 2001. Since then, 10.5 fb-1 of integrated luminosity has been delivered to CDF and D0 experiments (Fig. 1). All major technical upgrades of the accelerator complex were completed by 2007 [1]. -
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. -
01Ii Beam Line
STA N FO RD LIN EA R A C C ELERA TO R C EN TER Fall 2001, Vol. 31, No. 3 CONTENTS A PERIODICAL OF PARTICLE PHYSICS FALL 2001 VOL. 31, NUMBER 3 Guest Editor MICHAEL RIORDAN Editors RENE DONALDSON, BILL KIRK Contributing Editors GORDON FRASER JUDY JACKSON, AKIHIRO MAKI MICHAEL RIORDAN, PEDRO WALOSCHEK Editorial Advisory Board PATRICIA BURCHAT, DAVID BURKE LANCE DIXON, EDWARD HARTOUNI ABRAHAM SEIDEN, GEORGE SMOOT HERMAN WINICK Illustrations TERRY ANDERSON Distribution CRYSTAL TILGHMAN The Beam Line is published quarterly by the Stanford Linear Accelerator Center, Box 4349, Stanford, CA 94309. Telephone: (650) 926-2585. EMAIL: [email protected] FAX: (650) 926-4500 Issues of the Beam Line are accessible electroni- cally on the World Wide Web at http://www.slac. stanford.edu/pubs/beamline. SLAC is operated by Stanford University under contract with the U.S. Department of Energy. The opinions of the authors do not necessarily reflect the policies of the Stanford Linear Accelerator Center. Cover: The Sudbury Neutrino Observatory detects neutrinos from the sun. This interior view from beneath the detector shows the acrylic vessel containing 1000 tons of heavy water, surrounded by photomultiplier tubes. (Courtesy SNO Collaboration) Printed on recycled paper 2 FOREWORD 32 THE ENIGMATIC WORLD David O. Caldwell OF NEUTRINOS Trying to discern the patterns of neutrino masses and mixing. FEATURES Boris Kayser 42 THE K2K NEUTRINO 4 PAULI’S GHOST EXPERIMENT A seventy-year saga of the conception The world’s first long-baseline and discovery of neutrinos. neutrino experiment is beginning Michael Riordan to produce results. Koichiro Nishikawa & Jeffrey Wilkes 15 MINING SUNSHINE The first results from the Sudbury 50 WHATEVER HAPPENED Neutrino Observatory reveal TO HOT DARK MATTER? the “missing” solar neutrinos. -
Fermi National Accelerator Laboratory 132 Nsec Bunch Spacing in The
Fermi National Accelerator Laboratory FERMILAR-TM-1920 132 nsec Bunch Spacing in the Tevatron Proton-Antiproton Collider S. D. Holmes et al. Fermi National Accelerator Laboratory P.O. Box 500, Batavia, Illinois 60510 December 1994 0 Operated by Universities Research Association Inc. under Contract No. DE-ACOZ-76CH030W with the United States Department of Energy Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infn’nge privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof 132 nsec Bunch Spacing in the Tevatron Proton-Antiproton Collider SD. Holmes, J. Holt, J.A. Johnstone, J. Marriner, M. Martens, D. McGinnis Fermi National Accelerator Laboratory December 23, 1994 Abstract Following completion of the Fermilah Main Injector it is expected that the Tevatron proton-antiproton collider will be operating at a luminosity in excess of 5x1031 cm-%ec-1 with 36 proton and antiproton bunches spaced at 396 nsec. At this luminosity, each of the experimental detectors will see approximately 1.3 interactions per crossing. -
The Compact Linear E E− Collider (CLIC): Physics Potential
+ The Compact Linear e e− Collider (CLIC): Physics Potential Input to the European Particle Physics Strategy Update on behalf of the CLIC and CLICdp Collaborations 18 December 2018 1) Contact person: P. Roloff ∗ †‡ §¶ Editors: R. Franceschini , P. Roloff∗, U. Schnoor∗, A. Wulzer∗ † ‡ ∗ CERN, Geneva, Switzerland, Università degli Studi Roma Tre, Rome, Italy, INFN, Sezione di Roma Tre, Rome, Italy, § Università di Padova, Padova, Italy, ¶ LPTP, EPFL, Lausanne, Switzerland Abstract + The Compact Linear Collider, CLIC, is a proposed e e− collider at the TeV scale whose physics poten- tial ranges from high-precision measurements to extensive direct sensitivity to physics beyond the Standard Model. This document summarises the physics potential of CLIC, obtained in detailed studies, many based on full simulation of the CLIC detector. CLIC covers one order of magnitude of centre-of-mass energies from 350 GeV to 3 TeV, giving access to large event samples for a variety of SM processes, many of them for the + first time in e e− collisions or for the first time at all. The high collision energy combined with the large + luminosity and clean environment of the e e− collisions enables the measurement of the properties of Stand- ard Model particles, such as the Higgs boson and the top quark, with unparalleled precision. CLIC might also discover indirect effects of very heavy new physics by probing the parameters of the Standard Model Effective Field Theory with an unprecedented level of precision. The direct and indirect reach of CLIC to physics beyond the Standard Model significantly exceeds that of the HL-LHC. This includes new particles detected in challenging non-standard signatures. -
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i ' Do^y^W-S- 2 Progress report 2.1 The D0 Experiment The D0 detector had its first data run in the period May 1992 till June 1993. The first two thirds of the run period were characterized by low luminosity and frequent machine development periods. The luminosity gradually climbed, and the machine ultimately delivered 31 pb_1 to the experiment. The detector performed admirably well, and data analysis tracked data taking closely. The overall D0 efficiency was 54% and 16.7 pb_1 of data were collected; due to high backgrounds during Main Ring injection and transition, and beam gas interactions in the MR pipe that intersects our calorimeter, triggers in D0 were vetoed for about 29% of the store time; data acquisition busy (7%), experiment down time (5%), and run startup overhead (5%) added another 17% to the inefficiency. Many cycles of reconstruction software upgrade were done as experience with real data was gained, bugs were corrected, and new data corrections were added. First results were presented at the Spring 1993 APS meeting, the Summer conferences, and at the Fall 1993 pp symposium in Tsukuba. Several papers (See Attached [LeptoQuark PRL, RapGap PRL, Top PRL]) have appeared in print, a lepto-quark search, a rapidity-gap study, and. a lower mass limit on the Standard Model top quark where we also present a spectacular event that has laxge $y, a high energy electron and a high momentum muon, both isolated, and two sizable jets. When interpreted as a it event, a top mass around 145 GeV (with a large 30 GeV error) is obtained. -
The ATLAS Detector: a General Purpose Experiment at the Large Hadron Collider at CERN
FR9806097 The ATLAS detector: a general purpose experiment at the Large Hadron Collider at CERN J. Schwindling CEA, DSM/DAPNIA, CE Saclay, 91191 Gif sur Yvette, France 1 Introduction The ATLAS collaboration has designed a general purpose detector to be operated at the Large Hadron Collider (LHC) at CERN [1]. The design of the detector took into account the requirements from the physics and the constraints from the collider, but also the cost and technological aspects. It is supported by a large amount of detailed simulations and test activities. The performances which are required to meet the physics goals are the following: - The search for Higgs bosons through their decays into two photons or four elec- trons requires a good electromagnetic calorimetry. - The search for Higgs bosons decaying into four muons requires a robust muon system. - Supersymmetric particles often decay into an invisible neutralino plus other parti- cles, leading to a missing energy signature which can be measured with an hermetic detector. - The measurement of the top quark mass requires a good measurement of jets. - b quark and r lepton identification requires the precise measurement of secondary vertices. The ATLAS detector is shown in figure 1. It covers a large fraction of the 4n angle, offers robust and redundant physics measurements and allows for triggering at low PT (about 10 GeV) thresholds. In order to achieve the design LHC luminosity of 1034 cm"2 s"1, the bunch spacing will be only 25 ns, leading to about 20 minimum bias events ("pile-up") and about 1000 charged tracks produced at each bunch crossing. -
Scaling Behavior of Circular Colliders Dominated by Synchrotron Radiation
SCALING BEHAVIOR OF CIRCULAR COLLIDERS DOMINATED BY SYNCHROTRON RADIATION Richard Talman Laboratory for Elementary-Particle Physics Cornell University White Paper at the 2015 IAS Program on the Future of High Energy Physics Abstract time scales measured in minutes, for example causing the The scaling formulas in this paper—many of which in- beams to be flattened, wider than they are high [1] [2] [3]. volve approximation—apply primarily to electron colliders In this regime scaling relations previously valid only for like CEPC or FCC-ee. The more abstract “radiation dom- electrons will be applicable also to protons. inated” phrase in the title is intended to encourage use of This paper concentrates primarily on establishing scaling the formulas—though admittedly less precisely—to proton laws that are fully accurate for a Higgs factory such as CepC. colliders like SPPC, for which synchrotron radiation begins Dominating everything is the synchrotron radiation formula to dominate the design in spite of the large proton mass. E4 Optimizing a facility having an electron-positron Higgs ∆E / ; (1) R factory, followed decades later by a p,p collider in the same tunnel, is a formidable task. The CepC design study con- stitutes an initial “constrained parameter” collider design. relating energy loss per turn ∆E, particle energy E and bend 1 Here the constrained parameters include tunnel circumfer- radius R. This is the main formula governing tunnel ence, cell lengths, phase advance per cell, etc. This approach circumference for CepC because increasing R decreases is valuable, if the constrained parameters are self-consistent ∆E. and close to optimal.