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CERN Courier–Digital Edition
CERNMarch/April 2021 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the March/April 2021 issue of CERN Courier. Hadron colliders have contributed to a golden era of discovery in high-energy physics, hosting experiments that have enabled physicists to unearth the cornerstones of the Standard Model. This success story began 50 years ago with CERN’s Intersecting Storage Rings (featured on the cover of this issue) and culminated in the Large Hadron Collider (p38) – which has spawned thousands of papers in its first 10 years of operations alone (p47). It also bodes well for a potential future circular collider at CERN operating at a centre-of-mass energy of at least 100 TeV, a feasibility study for which is now in full swing. Even hadron colliders have their limits, however. To explore possible new physics at the highest energy scales, physicists are mounting a series of experiments to search for very weakly interacting “slim” particles that arise from extensions in the Standard Model (p25). Also celebrating a golden anniversary this year is the Institute for Nuclear Research in Moscow (p33), while, elsewhere in this issue: quantum sensors HADRON COLLIDERS target gravitational waves (p10); X-rays go behind the scenes of supernova 50 years of discovery 1987A (p12); a high-performance computing collaboration forms to handle the big-physics data onslaught (p22); Steven Weinberg talks about his latest work (p51); and much more. To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING ATLAS spots rare Higgs decay Weinberg on effective field theory Hunting for WISPs CCMarApr21_Cover_v1.indd 1 12/02/2021 09:24 CERNCOURIER www. -
CERN Celebrates Discoveries
INTERNATIONAL JOURNAL OF HIGH-ENERGY PHYSICS CERN COURIER VOLUME 43 NUMBER 10 DECEMBER 2003 CERN celebrates discoveries NEW PARTICLES NETWORKS SPAIN Protons make pentaquarks p5 Measuring the digital divide pl7 Particle physics thrives p30 16 KPH impact 113 KPH impact series VISyN High Voltage Power Supplies When the objective is to measure the almost immeasurable, the VISyN-Series is the detector power supply of choice. These multi-output, card based high voltage power supplies are stable, predictable, and versatile. VISyN is now manufactured by Universal High Voltage, a world leader in high voltage power supplies, whose products are in use in every national laboratory. For worldwide sales and service, contact the VISyN product group at Universal High Voltage. Universal High Voltage Your High Voltage Power Partner 57 Commerce Drive, Brookfield CT 06804 USA « (203) 740-8555 • Fax (203) 740-9555 www.universalhv.com 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. Editor Christine Sutton CERN, 1211 Geneva 23, Switzerland E-mail: [email protected] Fax:+41 (22) 782 1906 Web: cerncourier.com COURIER Advisory Board R Landua (Chairman), P Sphicas, K Potter, E Lillest0l, C Detraz, H Hoffmann, R Bailey -
A Time of Great Growth
Newsletter | Spring 2019 A Time of Great Growth Heartfelt greetings from the UC Riverside Department of Physics and Astronomy. This is our annual newsletter, sent out each Spring to stay connected with our former students, retired faculty, and friends in the wider community. The Department continues to grow, not merely in size but also in stature and reputation. For the 2018-2019 academic year, we were pleased to welcome two new faculty: Professors Thomas Kuhlman and Barry Barish. Professor Kuhlman was previously on the faculty at the University of Illinois at Urbana-Champaign. He joins our efforts in the emerging field of biophysics. His research lies in the quantitative imaging and theoretical modeling of biological systems. He works on genome dynamics, quantification of the activity of transposable elements in living cells, and applications to the engineering of genome editing. Professor Barry Barish, who joins us from Caltech, is the winner of the 2017 Nobel Prize in Physics. He brings great prestige to our Department. Along with Professor Richard Schrock of the Department of Chemistry, who also joined UCR in 2018, UCR now has two Nobel Prize winners on its faculty. Professor Barish is an expert on the detection and physics of gravitational waves. He has been one of the key figures in the conception, construction, and operation of the LIGO detector, where gravitational waves were first discovered in 2015, and which led to his Nobel Prize. He is a member of the National Academy of Sciences and the winner of many other prestigious awards. The discovery of gravitational waves is one of the most exciting developments in physics so far this century. -
The AWAKE Acceleration Scheme for New Particle Physics Experiments at CERN
AWAKE++: the AWAKE Acceleration Scheme for New Particle Physics Experiments at CERN W. Bartmann1, A. Caldwell2, M. Calviani1, J. Chappell3, P. Crivelli4, H. Damerau1, E. Depero4, S. Doebert1, J. Gall1, S. Gninenko5, B. Goddard1, D. Grenier1, E. Gschwendtner*1, Ch. Hessler1, A. Hartin3, F. Keeble3, J. Osborne1, A. Pardons1, A. Petrenko1, A. Scaachi3, and M. Wing3 1CERN, Geneva, Switzerland 2Max Planck Institute for Physics, Munich, Germany 3University College London, London, UK 4ETH Zürich, Switzerland 5INR Moscow, Russia 1 Abstract The AWAKE experiment reached all planned milestones during Run 1 (2016-18), notably the demon- stration of strong plasma wakes generated by proton beams and the acceleration of externally injected electrons to multi-GeV energy levels in the proton driven plasma wakefields. During Run 2 (2021 - 2024) AWAKE aims to demonstrate the scalability and the acceleration of elec- trons to high energies while maintaining the beam quality. Within the Physics Beyond Colliders (PBC) study AWAKE++ has explored the feasibility of the AWAKE acceleration scheme for new particle physics experiments at CERN. Assuming continued success of the AWAKE program, AWAKE will be in the position to use the AWAKE scheme for particle physics ap- plications such as fixed target experiments for dark photon searches and also for future electron-proton or electron-ion colliders. With strong support from the accelerator and high energy physics community, these experiments could be installed during CERN LS3; the integration and beam line design show the feasibility of a fixed target experiment in the AWAKE facility, downstream of the AWAKE experiment in the former CNGS area. The expected electrons on target for fixed target experiments exceeds the electrons on target by three to four orders of magnitude with respect to the current NA64 experiment, making it a very promising experiment in the search for new physics. -
Barry Barish and the Gde: Mission Achievable
INTERVIEW Barry Barish and the GDE: mission achievable The head of the Global Design Effort for a future International Linear Collider talks about challenges past, present and future. Barry Barish likes a challenge. He admits to a complete tendency to go for the difficult in his research – in his view, life is an adventure. Some might say that his most recent challenge would fit well with a certain famous TV series: “Your mission, should you choose to accept it… is to produce a design for the International Linear Collider that includes a detailed design concept, performance assessments, reliable international costing, an industrialization plan, and siting analysis, as well as detector concepts and scope.” Barish did indeed accept the challenge in March 2005, when he became director of the Global Design Effort (GDE) for a proposed International Linear Collider (ILC). He started in a directorate of one – himself – at the head of a “virtual” laboratory of hundreds of physicists and engineers around the globe. To run the “lab” he has set up a small executive committee, which includes three regional directors (for the Americas, Asia and Europe), three project manag- ers and two leading accelerator experts. There are also boards for R&D, change control and design cost. Barish operates from his base at Caltech, where he has been since 1962 and ultimately became Linde Professor of Physics (now emeri- tus). His taste for research challenges became evident in the 1970s, when he was co-spokesperson with Frank Sciulli (also at Caltech) of the “narrow band” neutrino experiment at Fermilab that studied Barish became director of the Global Design Effort for the International weak neutral currents and the quark substructure of the nucleon. -
Four Results of Jon Kleinberg a Talk for St.Petersburg Mathematical Society
Four Results of Jon Kleinberg A Talk for St.Petersburg Mathematical Society Yury Lifshits Steklov Institute of Mathematics at St.Petersburg May 2007 1 / 43 2 Hubs and Authorities 3 Nearest Neighbors: Faster Than Brute Force 4 Navigation in a Small World 5 Bursty Structure in Streams Outline 1 Nevanlinna Prize for Jon Kleinberg History of Nevanlinna Prize Who is Jon Kleinberg 2 / 43 3 Nearest Neighbors: Faster Than Brute Force 4 Navigation in a Small World 5 Bursty Structure in Streams Outline 1 Nevanlinna Prize for Jon Kleinberg History of Nevanlinna Prize Who is Jon Kleinberg 2 Hubs and Authorities 2 / 43 4 Navigation in a Small World 5 Bursty Structure in Streams Outline 1 Nevanlinna Prize for Jon Kleinberg History of Nevanlinna Prize Who is Jon Kleinberg 2 Hubs and Authorities 3 Nearest Neighbors: Faster Than Brute Force 2 / 43 5 Bursty Structure in Streams Outline 1 Nevanlinna Prize for Jon Kleinberg History of Nevanlinna Prize Who is Jon Kleinberg 2 Hubs and Authorities 3 Nearest Neighbors: Faster Than Brute Force 4 Navigation in a Small World 2 / 43 Outline 1 Nevanlinna Prize for Jon Kleinberg History of Nevanlinna Prize Who is Jon Kleinberg 2 Hubs and Authorities 3 Nearest Neighbors: Faster Than Brute Force 4 Navigation in a Small World 5 Bursty Structure in Streams 2 / 43 Part I History of Nevanlinna Prize Career of Jon Kleinberg 3 / 43 Nevanlinna Prize The Rolf Nevanlinna Prize is awarded once every 4 years at the International Congress of Mathematicians, for outstanding contributions in Mathematical Aspects of Information Sciences including: 1 All mathematical aspects of computer science, including complexity theory, logic of programming languages, analysis of algorithms, cryptography, computer vision, pattern recognition, information processing and modelling of intelligence. -
Gravitational Waves from the Early Universe
Gravitational Waves from the Early Universe Lecture 1A: Gravitational Waves, Theory Kai Schmitz (CERN) Chung-Ang University, Seoul, South Korea j June 2 – 4 1/21 ◦ 1916: Albert Einstein predicts GWs based on his general theory of relativity ◦ 2016: The LIGO/Virgo Collaboration announces the detection of GW150914 ◦ 2017: Nobel Prize in Physics awarded to Rainer Weiss, Barry Barish, and Kip Thorne → Milestone in fundamental physics, triumph of general relativity → Discovery of a new class of astrophysical objects: heavy black holes in binary systems First direct detection of gravitational waves [Nicolle Rager Fuller for sciencenews.org] 2/21 ◦ 2016: The LIGO/Virgo Collaboration announces the detection of GW150914 ◦ 2017: Nobel Prize in Physics awarded to Rainer Weiss, Barry Barish, and Kip Thorne → Milestone in fundamental physics, triumph of general relativity → Discovery of a new class of astrophysical objects: heavy black holes in binary systems First direct detection of gravitational waves [Nicolle Rager Fuller for sciencenews.org] ◦ 1916: Albert Einstein predicts GWs based on his general theory of relativity 2/21 ◦ 2017: Nobel Prize in Physics awarded to Rainer Weiss, Barry Barish, and Kip Thorne → Milestone in fundamental physics, triumph of general relativity → Discovery of a new class of astrophysical objects: heavy black holes in binary systems First direct detection of gravitational waves [Nicolle Rager Fuller for sciencenews.org] ◦ 1916: Albert Einstein predicts GWs based on his general theory of relativity ◦ 2016: The LIGO/Virgo -
Navigability of Small World Networks
Navigability of Small World Networks Pierre Fraigniaud CNRS and University Paris Sud http://www.lri.fr/~pierre Introduction Interaction Networks • Communication networks – Internet – Ad hoc and sensor networks • Societal networks – The Web – P2P networks (the unstructured ones) • Social network – Acquaintance – Mail exchanges • Biology (Interactome network), linguistics, etc. Dec. 19, 2006 HiPC'06 3 Common statistical properties • Low density • “Small world” properties: – Average distance between two nodes is small, typically O(log n) – The probability p that two distinct neighbors u1 and u2 of a same node v are neighbors is large. p = clustering coefficient • “Scale free” properties: – Heavy tailed probability distributions (e.g., of the degrees) Dec. 19, 2006 HiPC'06 4 Gaussian vs. Heavy tail Example : human sizes Example : salaries µ Dec. 19, 2006 HiPC'06 5 Power law loglog ppk prob{prob{ X=kX=k }} ≈≈ kk-α loglog kk Dec. 19, 2006 HiPC'06 6 Random graphs vs. Interaction networks • Random graphs: prob{e exists} ≈ log(n)/n – low clustering coefficient – Gaussian distribution of the degrees • Interaction networks – High clustering coefficient – Heavy tailed distribution of the degrees Dec. 19, 2006 HiPC'06 7 New problematic • Why these networks share these properties? • What model for – Performance analysis of these networks – Algorithm design for these networks • Impact of the measures? • This lecture addresses navigability Dec. 19, 2006 HiPC'06 8 Navigability Milgram Experiment • Source person s (e.g., in Wichita) • Target person t (e.g., in Cambridge) – Name, professional occupation, city of living, etc. • Letter transmitted via a chain of individuals related on a personal basis • Result: “six degrees of separation” Dec. -
A Decade of Lattice Cryptography
Full text available at: http://dx.doi.org/10.1561/0400000074 A Decade of Lattice Cryptography Chris Peikert Computer Science and Engineering University of Michigan, United States Boston — Delft Full text available at: http://dx.doi.org/10.1561/0400000074 Foundations and Trends R in Theoretical Computer Science Published, sold and distributed by: now Publishers Inc. PO Box 1024 Hanover, MA 02339 United States Tel. +1-781-985-4510 www.nowpublishers.com [email protected] Outside North America: now Publishers Inc. PO Box 179 2600 AD Delft The Netherlands Tel. +31-6-51115274 The preferred citation for this publication is C. Peikert. A Decade of Lattice Cryptography. Foundations and Trends R in Theoretical Computer Science, vol. 10, no. 4, pp. 283–424, 2014. R This Foundations and Trends issue was typeset in LATEX using a class file designed by Neal Parikh. Printed on acid-free paper. ISBN: 978-1-68083-113-9 c 2016 C. Peikert All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, photocopying, recording or otherwise, without prior written permission of the publishers. Photocopying. In the USA: This journal is registered at the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923. Authorization to photocopy items for in- ternal or personal use, or the internal or personal use of specific clients, is granted by now Publishers Inc for users registered with the Copyright Clearance Center (CCC). The ‘services’ for users can be found on the internet at: www.copyright.com For those organizations that have been granted a photocopy license, a separate system of payment has been arranged. -
AWAKE! Allen Caldwell Even Larger Accelerators ?
Swapan Chattopadhyay Symposium April 30, 2021 AWAKE! Allen Caldwell Even larger Accelerators ? Energy limit of circular proton collider given by magnetic field strength. P B R / · Energy gain relies in large part on magnet development Linear Electron Collider or Muon Collider? proton P P Leptons preferred: Collide point particles rather than complex objects But, charged particles radiate energy when accelerated. Power α (E/m)4 Need linear electron accelerator or m large (muon 200 heavier than electron) A plasma: collection of free positive and negative charges (ions and electrons). Material is already broken down. A plasma can therefore sustain very high fields. C. Joshi, UCLA E. Adli, Oslo An intense particle beam, or intense laser beam, can be used to drive the plasma electrons. Plasma frequency depends only on density: Ideas of ~100 GV/m electric fields in plasma, using 1018 W/cm2 lasers: 1979 T.Tajima and J.M.Dawson (UCLA), Laser Electron Accelerator, Phys. Rev. Lett. 43, 267–270 (1979). Using partice beams as drivers: P. Chen et al. Phys. Rev. Lett. 54, 693–696 (1985) Energy Budget: Introduction Witness: Staging Concepts 1010 particles @ 1 TeV ≈ few kJ Drivers: PW lasers today, ~40 J/Pulse FACET (e beam, SLAC), 30J/bunch SPS@CERN 20kJ/bunch Leemans & Esarey, Phys. Today 62 #3 (2009) LHC@CERN 300 kJ/bunch Dephasing 1 LHC driven stage SPS: ~100m, LHC: ~few km E. Adli et al. arXiv:1308.1145,2013 FCC: ~ 1<latexit sha1_base64="TR2ZhSl5+Ed6CqWViBcx81dMBV0=">AAAB7XicbZBNS8NAEIYn9avWr6pHL4tF8FQSEeyx4MVjBfsBbSib7aZdu9mE3YkQQv+DFw+KePX/ePPfuG1z0NYXFh7emWFn3iCRwqDrfjuljc2t7Z3ybmVv/+DwqHp80jFxqhlvs1jGuhdQw6VQvI0CJe8lmtMokLwbTG/n9e4T10bE6gGzhPsRHSsRCkbRWp2BUCFmw2rNrbsLkXXwCqhBodaw+jUYxSyNuEImqTF9z03Qz6lGwSSfVQap4QllUzrmfYuKRtz4+WLbGbmwzoiEsbZPIVm4vydyGhmTRYHtjChOzGptbv5X66cYNvxcqCRFrtjyozCVBGMyP52MhOYMZWaBMi3sroRNqKYMbUAVG4K3evI6dK7qnuX761qzUcRRhjM4h0vw4AaacActaAODR3iGV3hzYufFeXc+lq0lp5g5hT9yPn8Avy+PMg==</latexit> A. Caldwell and K. V. Lotov, Phys. -
Constraint Based Dimension Correlation and Distance
Preface The papers in this volume were presented at the Fourteenth Annual IEEE Conference on Computational Complexity held from May 4-6, 1999 in Atlanta, Georgia, in conjunction with the Federated Computing Research Conference. This conference was sponsored by the IEEE Computer Society Technical Committee on Mathematical Foundations of Computing, in cooperation with the ACM SIGACT (The special interest group on Algorithms and Complexity Theory) and EATCS (The European Association for Theoretical Computer Science). The call for papers sought original research papers in all areas of computational complexity. A total of 70 papers were submitted for consideration of which 28 papers were accepted for the conference and for inclusion in these proceedings. Six of these papers were accepted to a joint STOC/Complexity session. For these papers the full conference paper appears in the STOC proceedings and a one-page summary appears in these proceedings. The program committee invited two distinguished researchers in computational complexity - Avi Wigderson and Jin-Yi Cai - to present invited talks. These proceedings contain survey articles based on their talks. The program committee thanks Pradyut Shah and Marcus Schaefer for their organizational and computer help, Steve Tate and the SIGACT Electronic Publishing Board for the use and help of the electronic submissions server, Peter Shor and Mike Saks for the electronic conference meeting software and Danielle Martin of the IEEE for editing this volume. The committee would also like to thank the following people for their help in reviewing the papers: E. Allender, V. Arvind, M. Ajtai, A. Ambainis, G. Barequet, S. Baumer, A. Berthiaume, S. -
The BBVA Foundation Recognizes Charles H. Bennett, Gilles Brassard
www.frontiersofknowledgeawards-fbbva.es Press release 3 March, 2020 The BBVA Foundation recognizes Charles H. Bennett, Gilles Brassard and Peter Shor for their fundamental role in the development of quantum computation and cryptography In the 1980s, chemical physicist Bennett and computer scientist Brassard invented quantum cryptography, a technology that using the laws of quantum physics in a way that makes them unreadable to eavesdroppers, in the words of the award committee The importance of this technology was demonstrated ten years later, when mathematician Shor discovered that a hypothetical quantum computer would drive a hole through the conventional cryptographic systems that underpin the security and privacy of Internet communications Their landmark contributions have boosted the development of quantum computers, which promise to perform calculations at a far greater speed and scale than machines, and enabled cryptographic systems that guarantee the inviolability of communications The BBVA Foundation Frontiers of Knowledge Award in Basic Sciences has gone in this twelfth edition to Charles Bennett, Gilles Brassard and Peter Shor for their outstanding contributions to the field of quantum computation and communication Bennett and Brassard, a chemical physicist and computer scientist respectively, invented quantum cryptography in the 1980s to ensure the physical inviolability of data communications. The importance of their work became apparent ten years later, when mathematician Peter Shor discovered that a hypothetical quantum computer would render effectively useless the communications. The award committee, chaired by Nobel Physics laureate Theodor Hänsch with quantum physicist Ignacio Cirac acting as its secretary, remarked on the leap forward in quantum www.frontiersofknowledgeawards-fbbva.es Press release 3 March, 2020 technologies witnessed in these last few years, an advance which draws heavily on the new .