The Discovery of Direct CP Violation
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REPORTS on RESEARCH PL9800669 6.1 the NA48
114 Annual Report 1996 I REPORTS ON RESEARCH PL9800669 6.1 The NA48 experiment on direct CP violation by A.Chlopik, Z.Guzik, J.Nassalski, E.Rondio, M.Szleper and W.WisIicki The NA48 experiment [1] was built and tested on the kaon beam at CERN. It aims to measure the effect of direct violation of the combined CP transformation in two-pion decays of neutral kaons with precision of 0.1 permille. To perform such a measurement beams of the long-lived and short-lived Ks are produced which decay in the common region of phase space. Decays of both kaons into charged and neutral pions are measured simultaneously. The Warsaw group contributed to the electronics of the data acquisition system, to the offline software and took part in the data taking during test runs in June and September 1996. The hardware contribution of the group consisted of design, prototype manufacturing, testing and production supervision of the data acquisition blocks: RIO Fiber Optics Links, Cluster Interconnectors and Clock Fanouts. These elements are described in a separate note of this report. We worked on the following software related issues: (i) reconstruction of data and Monte Carlo in the magnetic spectrometer consisting of four drift chambers, the bending magnet and the trigger hodoscope. Energy and momentum resolution and background sources were carefully studied, (ii) decoding and undecoding of the liquid kryptonium calorimeter data. This part of the equipment is crucial for the measurement of neutral decays, (iii) correlated Monte Carlo to use the same events to simulate KL and K^ decays and thus speed up simulation considerably. -
6.2 Transition Radiation
Contents I General introduction 9 1Preamble 11 2 Relevant publications 15 3 A first look at the formation length 21 4 Formation length 23 4.1Classicalformationlength..................... 24 4.1.1 A reduced wavelength distance from the electron to the photon ........................... 25 4.1.2 Ignorance of the exact location of emission . ....... 25 4.1.3 ‘Semi-bare’ electron . ................... 26 4.1.4 Field line picture of radiation . ............... 26 4.2Quantumformationlength..................... 28 II Interactions in amorphous targets 31 5 Bremsstrahlung 33 5.1Incoherentbremsstrahlung..................... 33 5.2Genericexperimentalsetup..................... 35 5.2.1 Detectors employed . ................... 35 5.3Expandedexperimentalsetup.................... 39 6 Landau-Pomeranchuk-Migdal (LPM) effect 47 6.1 Formation length and LPM effect.................. 48 6.2 Transition radiation . ....................... 52 6.3 Dielectric suppression - the Ter-Mikaelian effect.......... 54 6.4CERNLPMExperiment...................... 55 6.5Resultsanddiscussion....................... 55 3 4 CONTENTS 6.5.1 Determination of ELPM ................... 56 6.5.2 Suppression and possible compensation . ........ 59 7 Very thin targets 61 7.1Theory................................ 62 7.1.1 Multiple scattering dominated transition radiation . .... 62 7.2MSDTRExperiment........................ 63 7.3Results................................ 64 8 Ternovskii-Shul’ga-Fomin (TSF) effect 67 8.1Theory................................ 67 8.1.1 Logarithmic thickness dependence -
Epn2006-37-2.Pdf
europhysicsnews Fermionic atoms in an optical lattice 37/2 The origin of the Earth’s magnetic field 2006 I V 9 n CP violation in weak decays of neutral K mesons 9 o s l t e u i u t m u r o Physics in daily life: Cycling in the wind t e i s o 3 n p 7 a e l An interview with Sir Anthony Leggett r • s y n u e u b a m s r c b r i e p r t i 2 o n p r i c e : http://www.europhysicsnews.org Article available at European Physical Society contents europhysicsnews 2006 • Volume 37 • number 2 cover picture: © CNRS Photothèque - ROBERT Patrick Laboratory: CETP, Velizy, Velizy Villacoublay. Three-dimensional representation of the Terrestrial magnetic field, according to the model of Tsyganenko 87. The magnetic field is visualized in the form of "magnetic shells" of which the feet of the tension fields on the surface of the Earth have the same magnetic latitude. The sun is on the right. EDITORIAL 05 Physics in Europe Ove Poulsen HIGHLIGHTS 06 The origami of life A high-resolution Ramsey-Bordé spectrometer for optical clocks ... 07 Transportation of nitrogen atoms in an atmospheric pressure... ᭡ PAGE 06 Refractive index gradients in TiO2 thin films grown by atomic layer deposition Highlights: transportation of NEWS 08 2006 Agilent Technologies Europhysics Prize nitrogen atoms 09 Letters on the EPN 36/6 Special Issue 12 Report on ICALEPCS’2005 14 Discovery Space 15 EPS sponsors physics students to participate in the reunion of Nobel Laureates 16 EPS Accelerator Group and European Particle Accelerator Conference 17 Report on the 1st European Physics Education Conference FEATURES 18 Fermionic atoms in an optical lattice: a new synthetic material ᭡ PAGE 18 Michael Köhl and Tilman Esslinger Fermionic atoms in an 22 The origin of the Earth’s magnetic field: fundamental or environmental research? optical lattice: a new Emmanuel Dormy 26 First observation of direct CP violation in weak decays of neutral K mesons synthetic material Konrad Kleinknecht and Heinrich Wahl 29 Physics in daily life: Cycling in the wind L.J.F. -
Mayda M. VELASCO Northwestern University, Dept. of Physics And
Mayda M. VELASCO Northwestern University, Dept. of Physics and Astronomy 2145 Sheridan Road, Evanston, IL 60208, USA Phone: Work: +1 847 467 7099 Cell: +1 847 571 3461 E-mail: [email protected] Last Updated: May 2016 Research Interest { High Energy Experimental Elementary Particle Physics: Work toward the understanding of fundamental interactions and its important role in: (a) solving the problem of CP violation in the Universe { Why is there more matter than anti- matter?; (b) explaning how mass is generated { Higgs mechanism and (c) finding the particle nature of Dark-Matter, if any... The required \new" physics phenomena is accessible at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN). I am an active member of the Compact Muon Solenoid (CMS) collaboration already collect- ing data at the LHC, that led to the discovery of the Higgs boson or \God particle" in 2012. Education: • Ph.D. 1995: Northwestern University (NU) Experimental Particle Physics • 1995: Sicily, Italy ERICE: Spin Structure of Nucleon • 1994: Sorento, Italy CERN Summer School • B.S. 1988: University of Puerto Rico (UPR) Physics (Major) and Math (Minor) Rio Piedras Campus Fellowships and Honors: • 2015: NU, The Graduate School (TGS) Dean's Faculty Award for Diversity. • 2008-09: Paid leave of absence sponsored by US Department of Energy (DOE). • 2002-04: Sloan Research Fellow from Sloan Foundation. • 2002-03: Woodrow Wilson Fellow from Mellon Foundation. • 1999: CERN Achievement Award { Post-doctoral. • 1996-98: CERN Fellowship with Experimental Physics Division { Post-doctoral. • 1989-1995: Fermi National Accelerator Laboratory(FNAL)/URA Fellow { Doctoral. -
Sub Atomic Particles and Phy 009 Sub Atomic Particles and Developments in Cern Developments in Cern
1) Mahantesh L Chikkadesai 2) Ramakrishna R Pujari [email protected] [email protected] Mobile no: +919480780580 Mobile no: +917411812551 Phy 009 Sub atomic particles and Phy 009 Sub atomic particles and developments in cern developments in cern Electrical and Electronics Electrical and Electronics KLS’s Vishwanathrao deshpande rural KLS’s Vishwanathrao deshpande rural institute of technology institute of technology Haliyal, Uttar Kannada Haliyal, Uttar Kannada SUB ATOMIC PARTICLES AND DEVELOPMENTS IN CERN Abstract-This paper reviews past and present cosmic rays. Anderson discovered their existence; developments of sub atomic particles in CERN. It High-energy subato mic particles in the form gives the information of sub atomic particles and of cosmic rays continually rain down on the Earth’s deals with basic concepts of particle physics, atmosphere from outer space. classification and characteristics of them. Sub atomic More-unusual subatomic particles —such as particles also called elementary particle, any of various self-contained units of matter or energy that the positron, the antimatter counterpart of the are the fundamental constituents of all matter. All of electron—have been detected and characterized the known matter in the universe today is made up of in cosmic-ray interactions in the Earth’s elementary particles (quarks and leptons), held atmosphere. together by fundamental forces which are Quarks and electrons are some of the elementary represente d by the exchange of particles known as particles we study at CERN and in other gauge bosons. Standard model is the theory that laboratories. But physicists have found more of describes the role of these fundamental particles and these elementary particles in various experiments. -
Direct CP Violation in K 0 → Ππ
IFIC/17-56, FTUV/17-1218 Direct CP violation in K0 ! ππ: Standard Model Status Hector Gisbert and Antonio Pich Departament de F´ısicaTe`orica,IFIC, Universitat de Val`encia{ CSIC Apt. Correus 22085, E-46071 Val`encia,Spain Abstract In 1988 the NA31 experiment presented the first evidence of direct CP violation in the K0 ! ππ decay amplitudes. A clear signal with a 7:2 σ statistical significance was later established with the full data samples from the NA31, E731, NA48 and KTeV experiments, confirming that CP violation is associated with a ∆S = 1 quark transition, as predicted by the Standard Model. However, the theoretical prediction for the measured ratio "0=" has been a subject of strong controversy along the years. Although the underlying physics was already clarified in 2001, the recent release of improved lattice data has revived again the theoretical debate. We review the current status, discussing in detail the different ingredients that enter into the calculation of this observable and the reasons why seemingly contradictory predictions were obtained in the past by several groups. An update of the Standard Model prediction is presented and the prospects for future improvements are analysed. Taking into account all known short-distance and long-distance contributions, one obtains Re ("0=") = (15 ± 7) · 10−4, in good agreement with the experimental measurement. arXiv:1712.06147v1 [hep-ph] 17 Dec 2017 Contents Page 1 Historical prelude 2 2 Isospin decomposition of the K ! ππ amplitudes 5 3 Short-distance contributions 7 4 Hadronic matrix elements 10 5 Effective field theory description 12 5.1 Chiral perturbation theory . -
Spring 2007 Prizes & Awards
APS Announces Spring 2007 Prize and Award Recipients Thirty-nine prizes and awards will be presented theoretical research on correlated many-electron states spectroscopy with synchrotron radiation to reveal 1992. Since 1992 he has been a Permanent Member during special sessions at three spring meetings of in low dimensional systems.” the often surprising electronic states at semicon- at the Kavli Institute for Theoretical Physics and the Society: the 2007 March Meeting, March 5-9, Eisenstein received ductor surfaces and interfaces. His current interests Professor at the University of California at Santa in Denver, CO, the 2007 April Meeting, April 14- his PhD in physics are self-assembled nanostructures at surfaces, such Barbara. Polchinski’s interests span quantum field 17, in Jacksonville, FL, and the 2007 Atomic, Mo- from the University of as magnetic quantum wells, atomic chains for the theory and string theory. In string theory, he dis- lecular and Optical Physics Meeting, June 5-9, in California, Berkeley, in study of low-dimensional electrons, an atomic scale covered the existence of a certain form of extended Calgary, Alberta, Canada. 1980. After a brief stint memory for testing the limits of data storage, and structure, the D-brane, which has been important Citations and biographical information for each as an assistant professor the attachment of bio-molecules to surfaces. His in the nonperturbative formulation of the theory. recipient follow. The Apker Award recipients ap- of physics at Williams more than 400 publications place him among the His current interests include the phenomenology peared in the December 2006 issue of APS News College, he moved to 100 most-cited physicists. -
U. E. R Institut National De De Physique Nucléaire Université Paris-Sud Et De Physique Des Particules
LAL 92-26 Gestion INIS May 1992 Doe. enreg. Ie N* TFW : 0L Destination : I,t+D,D NEW RESULTS ON DIRECT CP VIOLATION FROM THE NA31 EXPERIMENT Olivier PERDEREAU For the NA31 collaboration CERN, Edinburgh. Main/., Orsay, Pisa and Sicg cn Talk given at the XXVIlth Rencontres de Moriond Uectroweak Interactions and Unified Theories" Les Arcs, Savoie, March 15-22,1992 U. E. R Institut National de de Physique Nucléaire Université Paris-Sud et de Physique des Particules Bâtiment 200 - 91405 ORSAY Cedex LAL 92-26 May 1992 New results on direct CP violation from the NA31 experiment O. Perdereau Laboratoire de l'Accélérateur Linéaire, IN2P3-CNRS et Université de Paris-Sud, F-91405 Orsay Cedex, France. For the NA31 collaboration : CERN, Edinburgh, Mainz, Orsay, Pisa and Siegen Abstract The NA31 experiment has published the first evidence for direct CP violation by measuring a non-zero value for the X(e'/e) parameter. Further data-taking periods took place in 1988 and 1989, producing two datasets with statistics comparable to the original one. This paper presents the final result of the anal- ysis of tbe 1988 dataset together with a preliminary result of the analysis of the 1989 one. The combined, preliminary, measurement of NA31 is R(e'/e) = (2.3 ± 0.7 ) 10~3, thus confirming our initial measurement and also in agree- ment with the standard model. Introduction Since its discovery, 28 years ago, the non respect of the discrete CP symetry, so-called "CP violation", has up to now been observed only in neutral Kaon decays. -
Results on Direct CP Violation from NA48 1 Introduction
Results on Direct CP Violation from NA48 Giles Barr NA48 Collaboration CERN, Geneva, Switzerland 1 Introduction A long-standing question in high energy physics has been the origin of the phe- nomenon of CP violation. CP violation was first observed in the decay KL → + − 0 0 π π [1]. Effects have subsequently been found in KL → π π [2], the charge ± ∓ ± ∓ + − asymmetry of KL → e π ν (Ke3) [3] and KL → µ π ν (Kµ3) [4], KL → π π γ [5] and most recently in KL → ππee [6]. All of these effects can be explained by applying a single CP violating effect in the mixing between K0 and K0 which pro- ceeds through the box Feynman diagram and are characterized by the parameter ε. A second form of CP violation with different characteristics can also be in- vestigated in the decay of the neutral K-mesons. The CP =−1 kaon state (the K2) can decay directly into a 2π final state without first mixing into a kaon with CP =+1. This effect, referred to as direct CP violation, may proceed by the pen- guin Feynman diagram, and is characterized by the parameter ε. The measured quantity is the double ratio of the decay widths, which, in the NA48 experiment is equivalent to the double ratio of four event-counts Γ (K → π 0π 0)/ Γ (K → π 0π 0) R ≡ L S + − + − Γ (KL → π π )/ Γ (KS → π π ) N(K → π 0π 0)/ N(K → π 0π 0) = L S (1) + − + − N(KL → π π )/ N(KS → π π ) 1 − 6Re(ε/ε). -
Cerncourier Www
CERN Courier March 2014 CERN Courier March 2014 60 years of CERN 60 years of CERN Microelectronics at CERN: from infancy to maturity The LAA The LAA programme, proposed by Antonino Zichichi and fi nanced by the Italian government, was launched as a comprehensive R&D project to study new experimental techniques for the next step in hadron-collider physics at multi-tera-electron-volt energies. The project provided a unique opportunity for Europe to take a leading role in advanced technology for high-energy physics. It was open to all physicists and engineers interested in participating. A total of 40 physicists, engineers and technicians were recruited, and more than 80 associates joined the programme. Later in the 1990s, during the operation of LEP for physics, the programme was complemented by the activities overseen by CERN’s Detector R&D Committee. years 1984–1985 Heijne was seconded to the University of Leuven, where the microelectronics research facility had just become the Interuniversity MicroElectronics Centre (IMEC). It soon became apparent that CMOS technology was the way ahead, and the expe- rience with IMEC led to Jarron’s design of the AMPLEX. (Earlier, in 1983, a collaboration between SLAC, Stanford Uni- versity Integrated Circuits Laboratory, the University of Hawaii and Bernard Hyams from CERN had already initiated the design of Two decades of microelectronics at CERN – enabled by the LAA project. In 1988, the AMPLEX multiplexed read-out chip (top left) allowed UA2 to fi t a silicon-pad detector (bottom left) in the 9 mm gap around the beam the “Microplex” – a silicon-microstrip detector read-out chip using pipe (Image credit: C Gößling, TU Dortmund). -
Future Perspectives at CERN 3 Unprecedented Accuracy
Future Perspectives at CERN John Ellis1 Theoretical Physics Division, CERN, Geneva, Switzerland Abstract. Current and future experiments at CERN are reviewed,with emphasis on those relevant to astrophysics and cosmology. These include experiments related to nuclear astrophysics, matter-antimatter asymmetry, dark matter, axions, gravitational waves, cosmic rays, neutrino oscillations, inflation, neutron stars and the quark-gluon plasma. The centrepiece of CERN’s future programme is the LHC, but some ideas for perspectives after the LHC are also presented. CERN-TH/2002-119 astro-ph/0206054 Talk given at the CERN-ESA-ESO Symposium, M¨unchen, April 2002 1 Outline The scientific mission of CERN is to provide Europe with unique accelerators for the study of the fundamental particles of matter and the interactions between them. The scientific programme of CERN for the next decade is centred on the LHC accelerator, which is scheduled for completion in 2006, so that its experi- ments can start taking in 2007. A description of the LHC scientific programme is the centrepiece of this talk. The motivations for this and other new accelera- tors provided by ideas about possible physics beyond the Standard Model were discussed earlier at this meeting [1]. Between now and the startup of the LHC, CERN has a very limited pro- gramme of running experiments. However, scientific diversity at CERN is en- hanced by a number of recognized experiments, that do not use the CERN ac- celerators and are not supported by CERN, but whose scientists are allowed to use other CERN facilities. In parallel with the construction of the LHC, CERN arXiv:astro-ph/0206054v1 4 Jun 2002 is also preparing to send a long-baseline neutrino beam to the Gran Sasso under- ground laboratory in Italy, in a special programme largely supported by extra contributions from interested countries. -
Theoretical Summary Lecture for EPS HEP99
SLAC-PUB-8351 February, 2000 Theoretical Summary Lecture for EPS HEP99 Michael E. Peskin1 Stanford Linear Accelerator Center Stanford University, Stanford, California 94309 USA ABSTRACT This is the proceedings article for the concluding lecture of the 1999 High En- ergy Physics Conference of the European Physical Society. In this article, I review a number of topics that were highlighted at the meeting and have more general importance in high energy physics. The major topics discussed are (1) precision electroweak physics, (2) CP violation, (3) new directions in QCD, (4) supersym- metry spectroscopy, and (5) the experimental physics of extra dimensions. arXiv:hep-ph/0002041v2 31 May 2000 invited lecture presented at the International Europhysics Conference on High-Energy Physics July 15-21, 1999, Tampere, Finland 1Work supported by the Department of Energy, contract DE–AC03–76SF00515. 1 Introduction In this theoretical summary lecture at the High Energy Physics 99 conference of the Eu- ropean Physical Society, I am charged to review some of the new conceptual developments presented at this conference. At the same time, I would like to review more generally the progress of high-energy physics over the past year, and to highlight areas in which our basic understanding has been affected by the new developments. There is no space here for a sta- tus report on the whole field. But I would like to give extended discussion to five areas that I think have special importance this year. These are (1) precision electroweak physics, which celebrates its tenth anniversary this summer; (2) CP violation, which entered a new era this summer with the inauguration of the SLAC and KEK B-factories; (3) QCD, which now branches into new lines of investigation; and two rapidly developing topics from physics be- yond the Standard Model, (4) supersymmetry spectroscopy and (5) the experimental study of extra dimensions.