Four Decades of Computing in Subnuclear Physics – from Bubble Chamber to Lhca
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Muon Bundles As a Sign of Strangelets from the Universe
Draft version October 19, 2018 Typeset using LATEX default style in AASTeX61 MUON BUNDLES AS A SIGN OF STRANGELETS FROM THE UNIVERSE P. Kankiewicz,1 M. Rybczynski,´ 1 Z. W lodarczyk,1 and G. Wilk2 1Institute of Physics, Jan Kochanowski University, 25-406 Kielce, Poland 2National Centre for Nuclear Research, Department of Fundamental Research, 00-681 Warsaw, Poland Submitted to ApJ ABSTRACT Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project). Originally it was argued that they apparently stem from the primary cosmic rays with a heavy masses. We propose an alternative possibility arguing that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe. We also address the possibility of additionally deducing their directionality which could be of astrophysical interest. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. Keywords: astroparticle physics: cosmic rays: reference systems arXiv:1612.04749v2 [hep-ph] 17 Mar 2017 Corresponding author: M. Rybczy´nski [email protected], [email protected], [email protected], [email protected] 2 Kankiewicz et al. 1. INTRODUCTION Cosmic ray physics is our unique source of information on events in the energy range which will never be accessible in Earth-bound experiments Dar & De Rujula(2008); Letessier-Selvon & Stanev(2011). This is why one of the most important aspects of their investigation is the understanding of the primary cosmic ray (CR) flux and its composition. -
Trigger and Data Acquisition
Trigger and data acquisition N. Ellis CERN, Geneva, Switzerland Abstract The lectures address some of the issues of triggering and data acquisition in large high-energy physics experiments. Emphasis is placed on hadron-collider experiments that present a particularly challenging environment for event se- lection and data collection. However, the lectures also explain how T/DAQ systems have evolved over the years to meet new challenges. Some examples are given from early experience with LHC T/DAQ systems during the 2008 single-beam operations. 1 Introduction These lectures concentrate on experiments at high-energy particle colliders, especially the general- purpose experiments at the Large Hadron Collider (LHC) [1]. These experiments represent a very chal- lenging case that illustrates well the problems that have to be addressed in state-of-the-art high-energy physics (HEP) trigger and data-acquisition (T/DAQ) systems. This is also the area in which the author is working (on the trigger for the ATLAS experiment at LHC) and so is the example that he knows best. However, the lectures start with a more general discussion, building up to some examples from LEP [2] that had complementary challenges to those of the LHC. The LEP examples are a good reference point to see how HEP T/DAQ systems have evolved in the last few years. Students at this school come from various backgrounds — phenomenology, experimental data analysis in running experiments, and preparing for future experiments (including working on T/DAQ systems in some cases). These lectures try to strike a balance between making the presentation accessi- ble to all, and going into some details for those already familiar with T/DAQ systems. -
Lesson 46: Cloud & Bubble Chambers
Lesson 46: Cloud & Bubble Chambers Imagine you're on a really stupid game show where they put a whole bunch of ping pong balls on the floor, turn off the lights, and then send you in to count them. How would you do it? • I'm thinking that your only chance is to get down on your hands and knees and try to touch them around you. • One of the problems is that in the very act of counting them (by reaching out), you change them by pushing them around, maybe even missing some of them. This is kind of the same problem that subatomic physicists have. They have to reach around “in the dark” to measure something that they can't see. • The amazing part is that methods have been developed to do this, and actually do it accurately. • This is the beginning of our journey into the modern subatomic realm of physics. Cloud Chambers In 1894 the Scottish physicist Charles Wilson was interested in the odd shadows that can sometimes be formed on cloud tops by mountain climbers (called Brocken Spectre). • To be able to study this further, he came up with a way water to build a device called a cloud chamber that would droplets allow him to make his own mini-clouds inside a glass chamber. ◦ To be able to do this he made his device so that he could keep the air inside supersaturated with water. ▪ Air can usually only hold a certain amount of path of vapour. Supersaturated means the air was charged particle holding more vapour than it would normally be Illustration 1: Water droplets condense able to at that pressure and temperature. -
A BOINC-Based Volunteer Computing Infrastructure for Physics Studies At
Open Eng. 2017; 7:379–393 Research article Javier Barranco, Yunhai Cai, David Cameron, Matthew Crouch, Riccardo De Maria, Laurence Field, Massimo Giovannozzi*, Pascal Hermes, Nils Høimyr, Dobrin Kaltchev, Nikos Karastathis, Cinzia Luzzi, Ewen Maclean, Eric McIntosh, Alessio Mereghetti, James Molson, Yuri Nosochkov, Tatiana Pieloni, Ivan D. Reid, Lenny Rivkin, Ben Segal, Kyrre Sjobak, Peter Skands, Claudia Tambasco, Frederik Van der Veken, and Igor Zacharov LHC@Home: a BOINC-based volunteer computing infrastructure for physics studies at CERN https://doi.org/10.1515/eng-2017-0042 Received October 6, 2017; accepted November 28, 2017 1 Introduction Abstract: The LHC@Home BOINC project has provided This paper addresses the use of volunteer computing at computing capacity for numerical simulations to re- CERN, and its integration with Grid infrastructure and ap- searchers at CERN since 2004, and has since 2011 been plications in High Energy Physics (HEP). The motivation expanded with a wider range of applications. The tradi- for bringing LHC computing under the Berkeley Open In- tional CERN accelerator physics simulation code SixTrack frastructure for Network Computing (BOINC) [1] is that enjoys continuing volunteers support, and thanks to vir- available computing resources at CERN and in the HEP tualisation a number of applications from the LHC ex- community are not sucient to cover the needs for nu- periment collaborations and particle theory groups have merical simulation capacity. Today, active BOINC projects joined the consolidated LHC@Home BOINC project. This together harness about 7.5 Petaops of computing power, paper addresses the challenges related to traditional and covering a wide range of physical application, and also virtualized applications in the BOINC environment, and particle physics communities can benet from these re- how volunteer computing has been integrated into the sources of donated simulation capacity. -
Cosmic-Ray Studies with Experimental Apparatus at LHC
S S symmetry Article Cosmic-Ray Studies with Experimental Apparatus at LHC Emma González Hernández 1, Juan Carlos Arteaga 2, Arturo Fernández Tellez 1 and Mario Rodríguez-Cahuantzi 1,* 1 Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y 18 Sur, Edif. EMA3-231, Ciudad Universitaria, 72570 Puebla, Mexico; [email protected] (E.G.H.); [email protected] (A.F.T.) 2 Instituto de Física y Matemáticas, Universidad Michoacana, 58040 Morelia, Mexico; [email protected] * Correspondence: [email protected] Received: 11 September 2020; Accepted: 2 October 2020; Published: 15 October 2020 Abstract: The study of cosmic rays with underground accelerator experiments started with the LEP detectors at CERN. ALEPH, DELPHI and L3 studied some properties of atmospheric muons such as their multiplicity and momentum. In recent years, an extension and improvement of such studies has been carried out by ALICE and CMS experiments. Along with the LHC high luminosity program some experimental setups have been proposed to increase the potential discovery of LHC. An example is the MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles detector (MATHUSLA) designed for searching of Ultra Stable Neutral Particles, predicted by extensions of the Standard Model such as supersymmetric models, which is planned to be a surface detector placed 100 meters above ATLAS or CMS experiments. Hence, MATHUSLA can be suitable as a cosmic ray detector. In this manuscript the main results regarding cosmic ray studies with LHC experimental underground apparatus are summarized. The potential of future MATHUSLA proposal is also discussed. Keywords: cosmic ray physics at CERN; atmospheric muons; trigger detectors; muon bundles 1. -
The Cell Geometry Is Adapted to the Manufacturing Process. One Side Of
R&D for the Future 443 The cell geometry is adapted to the manufacturing process. One side of the cell carries all the features required for the RF, whereas the other side is flat for bonding (Fig. 12.11). The cells are diamond machined, joined by diffusion bonding under hydrogen at about 1000°C and vacuum baked at 650°C. With exacting machining tolerances, typically in the 1 µm range, the tuning of the final structure is avoided. A number of test facilities is in operation worldwide including those at CERN which houses the only facility modelling the two-beam scheme in addition to a number of test stands powered by klystrons for high turn-around of testing structure variants. Nominal accelerating gradients of 100 MV/m have been achieved in the accelerating structures under development in a worldwide collaboration with the required low break-down rate while the PETSs have been tested at the nominal output power of 150 MW. However, more variants of these two structures have to be built and examined to address HOM damping, lifetime, breakdown statistics, industrial-scale fabrication, and better understanding of the break-down mechanisms. The Next Energy Frontier e+e− Collider: Innovation in Detectors Lucie Linssen Throughout the history of particle physics, both protons and electrons, with their respective antiparticles, have been used extensively for high energy colliders [Box 4.1]. The merits and difficulties of physics research with high luminosity proton–proton colliders are briefly described in the Box 8.3. Electrons, in contrast to protons, are genuine elementary particles. Apart from initial-state radiation and beamstrahlung effects (see below), they provide very good knowledge of the initial state of the collision. -
Very Elementary Particle Physics
17 Very Elementary Particle Physics Martinus J.G. Veltman Abstract This address was presented by Martinus J.G. Veltman as the Nishina Memorial Lecture at the High Energy Accelerator Research Organization on April 4, 2003, and at the University of Tokyo on April 11, 2003 Introduction Today we believe that everything, matter, radiation, gravita- tional fields, is made up from elementary particles. The ob- ject of particle physics is to study the properties of these el- ementary particles. Knowing all about them in principle im- plies knowing all about everything. That is a long way off, we do not know if our knowledge is complete, and also the way from elementary particles to the very complicated Uni- verse around us is very very difficult. Yet one might think that at least everything can be explained once we know all about the elementary particles. Of course, when we look to Martinus J.G. Veltman such complicated things as living matter, an animal or a hu- c NMF man being, it is really hard to see how one could understand all that. And of course, there may be specific properties of particles that elude the finest detection instruments and are yet crucial to complex systems such as a human being. In the second half of the twentieth century the field of elementary particle physics came into existence and much progress has been made. Since 1948 about 25 Nobel prizes have been given to some 42 physicists working in this field, and this can be seen as a measure of the amount of ingenuity involved and the results achieved. -
Proton Synchrotron
PROTON SYNCHROTRON 1. Introduction of the machine. The earliest operational runs were carried out without any of the correcting devices The 25 GeV proton synchrotron has now been being employed, except for the self-powered pole put into operation. Towards the end of November face windings needed to correct eddy currents in 1959 protons were accelerated up to 24 GeV kinetic the metal vacuum chamber at injection when the energy and a few weeks later, after adjustments guiding magnetic field is only 140 gauss. The had been made to the shape of the magnetic field proton beam then disappeared at a magnetic field at field values above 12 OOO gauss by means of pole of about 12 kgauss due to the number of free face windings, the maximum energy was increased oscillations of the particles per revolution becoming to 28 GeV. The intensity of the accelerated beam an integer. As the magnet yoke saturates, the focus of protons was measured as 1010 protons per pulse ing forces diminish slightly, and instead of the and there was no noticeable loss of particles during machine working in the stable region between the the whole acceleration period up to the maximum unstable resonance bands, the operating point is energy. slowly forced into a resonance and the particles Measurements so far carried out on the PS are are lost to the walls of the vacuum chamber. In necessarily preliminary and incomplete. It will take later runs the pole face windings were energized by at least six months of measurement work before programmed generators designed to keep the sufficient is known about the behaviour of the ma focusing forces constant up to magnetic fields of chine to exploit it as a working nuclear physics tool. -
Learning Physics from ALEPH Events
Learning Physics from ALEPH Events This document is an adaptation of the Web pages created by Joe Rothberg and Henri Videau at CERN. These pages can be found at http://aleph.web.cern.ch/aleph/educ/Welcome.html. Last updated: PTD, 5/Oct/2007 1 Introduction The aim of the following project is to provide some means for you to improve your knowledge of particle physics by studying some real data recently collected in the ALEPH experiment. To make it possible we provide some description of the experiment, of its detector and of some physics topics. It will help greatly if you have a copy of a recent particle physics text book to help you with any new concepts. A suggested text is “Introduction to High Energy Physics” by D.H.Perkins. You will need to access the world wide web throughout this project. Various URL’s (internet addresses) will be provided where you can find additional information on specific points. It is highly recommended that you take advantage of this extra information. You will also need access to your Windows account on the lab PC’s, so make sure you have your username validated in advance for this. 2 The Project The project is intended to require three days (21 hours) of study and work, with an additional 6 hours to write up. 1. On day one you should read the sections on “The LEP Collider”, “The ALEPH Exper- iment” and on “Starting with PAW”. After these sections are understood, there are a set of questions to be answered and the answers are to be included in your final report. -
Studies of Jet Energy Corrections at the CMS Experiment and Their Automation
Master’s thesis Theoretical and Computational Methods Studies of jet energy corrections at the CMS experiment and their automation Adelina Lintuluoto February 2021 Supervisor: Asst. prof. Mikko Voutilainen Advisor: Dr. Clemens Lange Examiners: Asst. prof. Mikko Voutilainen Dr. Kati Lassila-Perini UNIVERSITY OF HELSINKI DEPARTMENT OF PHYSICS PB 64 (Gustaf Hällströms gata 2a) 00014 Helsingfors universitet Tiedekunta – Fakultet – Faculty Koulutusohjelma – Utbildningsprogram – Degree programme Faculty of Science Master’s programme Opintosuunta – Studieinrikting – Study track Theoretical and computational methods Tekijä – Författare – Author Adelina Lintuluoto Työn nimi – Arbetets titel – Title Studies of jet energy corrections at the CMS experiment and their automation Työn laji – Arbetets art – Level Aika – Datum – Month and year Sivumäärä – Sidoantal – Number of pages Master’s thesis February 2021 69 Tiivistelmä – Referat – Abstract At the Compact Muon Solenoid (CMS) experiment at CERN (European Organization for Nuclear Research), the building blocks of the Universe are investigated by analysing the observed final-state particles resulting from high-energy proton-proton collisions. However, direct detection of final-state quarks and gluons is not possible due to a phenomenon known as colour confinement. Instead, event properties with a close correspondence with their distributions are studied. These event properties are known as jets. Jets are central to particle physics analysis and our understanding of them, and hence of our Universe, is dependent upon our ability to accurately measure their energy. Unfortunately, current detector technology is imprecise, necessitating downstream correction of measurement discrepancies. To achieve this, the CMS experiment employs a sequential multi-step jet calibration process. The process is performed several times per year, and more often during periods of data collection. -
Mmw11111m1111111111m11111~11~M1111wh CM-P00043015
CHS-26 '-0 November 1988 N I -VJ CERN LIBRARIES, GENEYA mmw11111m1111111111m11111~11~m1111wH CM-P00043015 STUDIES IN CERN HISTORY The Construction of CERN's First Hydrogen Bubble Chambers Laura Weiss GENEVA 1988 The Study of CERN History is a project financed by Institutions in several CERN Member Countries. This report presents preliminary findings, and is intended for incorporation into a more comprehensive study of CERN's history. It is distributed primarily to historians and scientists to provoke discussion, and no part of ii should be ci1ed or reproduced wi1hout written permission from the author. Comments are welcome and should be sent to: Study Team for CERN History c!o CERN CH-1211 GENEVE 23 Switzerland Copyright Study Team for CERN History, Geneva 1988 CHS-26 November 1988 STUDIES IN CERN HISTORY The Construction of CERN's First Hydrogen Bubble Chambers Laura Weiss GENEVA 1988 The Study of CERN History is a project financed by Institutions in several CERN Member Countries. This report presents preliminary findings, and is intended for incorporation into a more comprehensive study of CERN's history. It is distributed primarily to historians and scientists to provoke discussion, and no part of it should be cited or reproduced without written permission from the author. Comments are welcome and should be sent to: Study Team for CERN History c/oCERN CH-1211GENEVE23 Switzerland " Copyright Study Team for CERN History, Geneva 1988 CERN~ Service d'information scicntifique - 400 - novembre 1988 TABLE OF CONTENTS 8.1 Historical overview -
Bubble Chamber
1: Bubble Chamber Purpose The purpose of this experiment is to determine the rest mass of the pion (mπ) and the rest mass of the muon (mµ). Introduction Particle physics (a.k.a. high energy physics) is the division of physics which investigates the behavior of particles involved in \high" energy collisions. (\High" here means energies greater than those found in nuclear reactions, i.e., more than 100 MeV=0.1 GeV. The highest energy particle accelerators available today produce collisions with energies of a few million MeV = TeV.) The first \new" particles discovered (circa 1940) by particle physicists were the pion (π) and the muon (µ). In spite of roughly similar masses (near 100 MeV, compare: electron mass = .511 MeV and proton mass = 938 MeV), these two particles have quite different properties. The muon is a relative of the electron (and hence is called a lepton). It comes in particle − + 1 (µ ) and anti-particle (µ ) versions and has spin 2 . Unlike the electron, the muon is unstable. It decays into two neutrinos (ν) and an electron (or positron) after a mean life of 2 10−6 s: × µ+ ν¯ + ν + e+ (1.1) −! µ− ν + ν¯ + e− (1.2) −! The pion belongs to the class of particles called mesons. Unlike leptons, mesons interact with protons and neutrons through an additional force called the strong nuclear force (a.k.a., color force). (Particles that can feel this force are called hadrons.) Unlike leptons, mesons are known to be composite particles: each is made of a quark and an antiquark.