Research in High Energy Physics
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Wimps and Machos ENCYCLOPEDIA of ASTRONOMY and ASTROPHYSICS
WIMPs and MACHOs ENCYCLOPEDIA OF ASTRONOMY AND ASTROPHYSICS WIMPs and MACHOs objects that could be the dark matter and still escape detection. For example, if the Galactic halo were filled –3 . WIMP is an acronym for weakly interacting massive par- with Jupiter mass objects (10 Mo) they would not have ticle and MACHO is an acronym for massive (astrophys- been detected by emission or absorption of light. Brown . ical) compact halo object. WIMPs and MACHOs are two dwarf stars with masses below 0.08Mo or the black hole of the most popular DARK MATTER candidates. They repre- remnants of an early generation of stars would be simi- sent two very different but reasonable possibilities of larly invisible. Thus these objects are examples of what the dominant component of the universe may be. MACHOs. Other examples of this class of dark matter It is well established that somewhere between 90% candidates include primordial black holes created during and 99% of the material in the universe is in some as yet the big bang, neutron stars, white dwarf stars and vari- undiscovered form. This material is the gravitational ous exotic stable configurations of quantum fields, such glue that holds together galaxies and clusters of galaxies as non-topological solitons. and plays an important role in the history and fate of the An important difference between WIMPs and universe. Yet this material has not been directly detected. MACHOs is that WIMPs are non-baryonic and Since extensive searches have been done, this means that MACHOS are typically (but not always) formed from this mysterious material must not emit or absorb appre- baryonic material. -
MASTER THESIS Linking the B-Physics Anomalies and Muon G
MSc PHYSICS AND ASTRONOMY GRAVITATION, ASTRO-, AND PARTICLE PHYSICS MASTER THESIS Linking the B-physics Anomalies and Muon g − 2 A Phenomenological Study Beyond the Standard Model By Anders Rehult 12623881 February - October 2020 60 EC Supervisor/Examiner: Second Examiner: prof. dr. Robert Fleischer prof. dr. Piet Mulders i Abstract The search for physics beyond the Standard Model is guided by anomalies: discrepancies between the theoretical predictions and experimental measurements of physical quantities. Hints of new physics are found in the recently observed B-physics anomalies and the long-standing anomalous magnetic dipole moment of the muon, muon g − 2. The former include a group of anomalous measurements related to the quark-level transition b ! s. We investigate what features are required of a theory to explain these b ! s anomalies simultaneously with muon g − 2. We then consider three kinds of models that might explain the anomalies: models with leptoquarks, hypothetical particles that couple leptons to quarks; Z0 models, which contain an additional fundamental force and a corresponding force carrier; and supersymmetric scenarios that postulate a symmetry that gives rise to a partner for each SM particle. We identify a leptoquark model that carries the necessary features to explain both kinds of anomalies. Within this model, we study the behaviour of 0 muon g − 2 and the anomalous branching ratio of Bs mesons, bound states of b and s quarks, into muons. 0 ¯0 0 ¯0 The Bs meson can spontaneously oscillate into its antiparticle Bs , a phenomenon known as Bs −Bs mixing. We calculate the effects of this mixing on the anomalous branching ratio. -
Review of Lepton Universality Tests in B Decays
January 4, 2019 Review of Lepton Universality tests in B decays Simone Bifani∗, S´ebastienDescotes-Genony, Antonio Romero Vidalz, Marie-H´el`ene Schunex Abstract Several measurements of tree- and loop-level b-hadron decays performed in the recent years hint at a possible violation of Lepton Universality. This article presents an experimental and theoretical overview of the current status of the field. arXiv:1809.06229v2 [hep-ex] 3 Jan 2019 Published in Journal of Physics G: Nuclear and Particle Physics, Volume 46, Number 2 ∗University of Birmingham, School of Physics and Astronomy Edgbaston, Birmingham B15 2TT, United Kingdom yLaboratoire de Physique Th´eorique(UMR 8627), CNRS, Universit´eParis-Sud, Universit´eParis-Saclay, 91405 Orsay, France zInstituto Galego de F´ısicade Altas Enerx´ıas(IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain xLaboratoire de l'Acc´el´erateurLin´eaire,CNRS/IN2P3, Universit´eParis-Sud, Universit´eParis-Saclay, 91440 Orsay, France Contents 1 Introduction 1 2 Lepton Universality in the Standard Model 2 3 Overview of Lepton Universality tests beyond the B sector 3 3.1 Electroweak sector . .4 3.2 Decays of pseudoscalar mesons . .5 3.3 Purely leptonic decays . .7 3.4 Quarkonia decays . .7 3.5 Summary . .7 4 Theoretical treatment of b-quark decays probing Lepton Universality 8 4.1 Effective Hamiltonian . .8 4.2 Hadronic quantities . 10 4.3 Lepton Universality observables . 13 5 Experiments at the B-factories and at the Large Hadron Collider 13 5.1 B-factories . 13 5.2 Large Hadron Collider . 16 5.3 Complementarity between the B-factories and the LHC . -
Structure of Matter
STRUCTURE OF MATTER Discoveries and Mysteries Part 2 Rolf Landua CERN Particles Fields Electromagnetic Weak Strong 1895 - e Brownian Radio- 190 Photon motion activity 1 1905 0 Atom 191 Special relativity 0 Nucleus Quantum mechanics 192 p+ Wave / particle 0 Fermions / Bosons 193 Spin + n Fermi Beta- e Yukawa Antimatter Decay 0 π 194 μ - exchange 0 π 195 P, C, CP τ- QED violation p- 0 Particle zoo 196 νe W bosons Higgs 2 0 u d s EW unification νμ 197 GUT QCD c Colour 1975 0 τ- STANDARD MODEL SUSY 198 b ντ Superstrings g 0 W Z 199 3 generations 0 t 2000 ν mass 201 0 WEAK INTERACTION p n Electron (“Beta”) Z Z+1 Henri Becquerel (1900): Beta-radiation = electrons Two-body reaction? But electron energy/momentum is continuous: two-body two-body momentum energy W. Pauli (1930) postulate: - there is a third particle involved + + - neutral - very small or zero mass p n e 휈 - “Neutrino” (Fermi) FERMI THEORY (1934) p n Point-like interaction e 휈 Enrico Fermi W = Overlap of the four wave functions x Universal constant G -5 2 G ~ 10 / M p = “Fermi constant” FERMI: PREDICTION ABOUT NEUTRINO INTERACTIONS p n E = 1 MeV: σ = 10-43 cm2 휈 e (Range: 1020 cm ~ 100 l.yr) time Reines, Cowan (1956): Neutrino ‘beam’ from reactor Reactions prove existence of neutrinos and then ….. THE PREDICTION FAILED !! σ ‘Unitarity limit’ > 100 % probability E2 ~ 300 GeV GLASGOW REFORMULATES FERMI THEORY (1958) p n S. Glashow W(eak) boson Very short range interaction e 휈 If mass of W boson ~ 100 GeV : theory o.k. -
Snowmass 2021 Letter of Interest: Hadron Spectroscopy at Belle II
Snowmass 2021 Letter of Interest: Hadron Spectroscopy at Belle II on behalf of the U.S. Belle II Collaboration D. M. Asner1, Sw. Banerjee2, J. V. Bennett3, G. Bonvicini4, R. A. Briere5, T. E. Browder6, D. N. Brown2, C. Chen7, D. Cinabro4, J. Cochran7, L. M. Cremaldi3, A. Di Canto1, K. Flood6, B. G. Fulsom8, R. Godang9, W. W. Jacobs10, D. E. Jaffe1, K. Kinoshita11, R. Kroeger3, R. Kulasiri12, P. J. Laycock1, K. A. Nishimura6, T. K. Pedlar13, L. E. Piilonen14, S. Prell7, C. Rosenfeld15, D. A. Sanders3, V. Savinov16, A. J. Schwartz11, J. Strube8, D. J. Summers3, S. E. Vahsen6, G. S. Varner6, A. Vossen17, L. Wood8, and J. Yelton18 1Brookhaven National Laboratory, Upton, New York 11973 2University of Louisville, Louisville, Kentucky 40292 3University of Mississippi, University, Mississippi 38677 4Wayne State University, Detroit, Michigan 48202 5Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 6University of Hawaii, Honolulu, Hawaii 96822 7Iowa State University, Ames, Iowa 50011 8Pacific Northwest National Laboratory, Richland, Washington 99352 9University of South Alabama, Mobile, Alabama 36688 10Indiana University, Bloomington, Indiana 47408 11University of Cincinnati, Cincinnati, Ohio 45221 12Kennesaw State University, Kennesaw, Georgia 30144 13Luther College, Decorah, Iowa 52101 14Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 15University of South Carolina, Columbia, South Carolina 29208 16University of Pittsburgh, Pittsburgh, Pennsylvania 15260 17Duke University, Durham, North Carolina 27708 18University of Florida, Gainesville, Florida 32611 Corresponding Author: B. G. Fulsom (Pacific Northwest National Laboratory), [email protected] Thematic Area(s): (RF07) Hadron Spectroscopy 1 Abstract: The Belle II experiment at the SuperKEKB energy-asymmetric e+e− collider is a substantial upgrade of the B factory facility at KEK in Tsukuba, Japan. -
An Original Way of Teaching Geometrical Optics C. Even
Learning through experimenting: an original way of teaching geometrical optics C. Even1, C. Balland2 and V. Guillet3 1 Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France 2 Sorbonne Universités, UPMC Université Paris 6, Université Paris Diderot, Sorbonne Paris Cite, CNRS-IN2P3, Laboratoire de Physique Nucléaire et des Hautes Energies (LPNHE), 4 place Jussieu, F-75252, Paris Cedex 5, France 3 Institut d’Astrophysique Spatiale, CNRS, Université Paris-Sud, Université Paris-Saclay, F- 91405 Orsay, France E-mail : [email protected] Abstract Over the past 10 years, we have developed at University Paris-Sud a first year course on geometrical optics centered on experimentation. In contrast with the traditional top-down learning structure usually applied at university, in which practical sessions are often a mere verification of the laws taught during preceding lectures, this course promotes “active learning” and focuses on experiments made by the students. Interaction among students and self questioning is strongly encouraged and practicing comes first, before any theoretical knowledge. Through a series of concrete examples, the present paper describes the philosophy underlying the teaching in this course. We demonstrate that not only geometrical optics can be taught through experiments, but also that it can serve as a useful introduction to experimental physics. Feedback over the last ten years shows that our approach succeeds in helping students to learn better and acquire motivation and autonomy. This approach can easily be applied to other fields of physics. Keywords : geometrical optics, experimental physics, active learning 1. Introduction Teaching geometrical optics to first year university students is somewhat challenging, as this field of physics often appears as one of the less appealing to students. -
Acoustic Particle Detection – from Early Ideas to Future Benefits
Nuclear Instruments and Methods in Physics Research A ] (]]]]) ]]]–]]] Contents lists available at ScienceDirect Nuclear Instruments and Methods in Physics Research A journal homepage: www.elsevier.com/locate/nima Acoustic particle detection – From early ideas to future benefits Rolf Nahnhauer n Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen, Germany article info abstract The history of acoustic neutrino detection technology is shortly reviewed from the first ideas 50 years ago Keywords: to the detailed R&D programs of the last decade. The physics potential of ultra-high energy neutrino Cosmogenic neutrinos interaction studies is discussed for some examples. Ideas about the necessary detector size and suitable Ultra-high energy neutrino detection design are presented. Acoustic detection technology & 2010 Elsevier B.V. All rights reserved. 1. The dawn of neutrino astroparticle physics 2. First ideas about ‘‘particle sound’’ Very soon after the 1956 Science publication of Cowan et al. [1] Fifty years ago a well developed method to observe elementary about the discovery of neutrino interactions at the Savannah River particles in accelerator and cosmic ray experiments was to look for light reactor first ideas about experiments detecting neutrinos produced in they produced through Cherenkov radiation or scintillation effects the Earth atmosphere or in distant astrophysical sources appeared. In when passing transparent media. At accelerators bubble chambers his talk ‘‘On high energy neutrino physics’’ at the 1960 Rochester started their two decades lasting successful application, having their conference [2] Markov stated: ‘‘in papers by Zhelesnykh1 and myself working principle still under study. In this context Askaryan [6] (1958, 1960) possibilities of experiments with cosmic ray neutrinos published in 1957 a paper about ‘‘Hydrodynamic radiation from the are analyzed. -
Detectors for Extreme Luminosity: Belle II
Nuclear Inst. and Methods in Physics Research, A 907 (2018) 46–59 Contents lists available at ScienceDirect Nuclear Inst. and Methods in Physics Research, A journal homepage: www.elsevier.com/locate/nima Detectors for extreme luminosity: Belle II I. Adachi a,b , T.E. Browder c, P. Kriºan d,e, *, S. Tanaka a,b , Y. Ushiroda a,b,f , (on behalf of the Belle II Collaboration) a High Energy Accelerator Research Organization (KEK), Tsukuba, Japan b SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan c University of Hawaii, Honolulu, HI, United States d Faculty of Mathematics and Physics, University of Ljubljana, Slovenia e Joºef Stefan Institute, Ljubljana, Slovenia f Department of Physics, Graduate School of Science, University of Tokyo, Japan ARTICLEINFO ABSTRACT Keywords: We describe the Belle II detector at the SuperKEKB electron–positron accelerator. SuperKEKB operates at the Belle II energy of the 훶 .4S/ resonance where pairs of B mesons are produced in a coherent quantum mechanical state Super B Factory with no additional particles. Belle II, the first Super B factory detector, aims to achieve performance comparable SuperKEKB to the original Belle and BaBar B factory experiments, which first measured the large CP violating effects in the Magnetic spectrometer B meson system, with much higher luminosity collisions and larger beam-induced backgrounds. Flavor physics Contents 1. Introduction ..................................................................................................................................................................................................... -
Week 3: Thermal History of the Universe
Week 3: Thermal History of the Universe Cosmology, Ay127, Spring 2008 April 21, 2008 1 Brief Overview Before moving on, let’s review some of the high points in the history of the Universe: T 10−4 eV, t 1010 yr: today; baryons and the CMB are entirely decoupled, stars and • ∼ ∼ galaxies have been around a long time, and clusters of galaxies (gravitationally bound systems of 1000s of galaxies) are becoming common. ∼ T 10−3 eV, t 109 yr; the first stars and (small) galaxies begin to form. • ∼ ∼ T 10−1−2 eV, t millions of years: baryon drag ends; at earlier times, the baryons are still • ∼ ∼ coupled to the CMB photons, and so perturbations in the baryon cannot grow; before this time, the gas distribution in the Universe remains smooth. T eV, t 400, 000 yr: electrons and protons combine to form hydrogen atoms, and CMB • ∼ ∼ photons decouple; at earlier times, photons are tightly coupled to the baryon fluid through rapid Thomson scattering from free electrons. T 3 eV, t 10−(4−5) yrs: matter-radiation equality; at earlier times, the energy den- • ∼ ∼ sity of the Universe is dominated by radiation. Nothing really spectacular happens at this time, although perturbations in the dark-matter density can begin to grow, providing seed gravitational-potential wells for what will later become the dark-matter halos that house galaxies and clusters of galaxies. T keV, t 105 sec; photons fall out of chemical equilibrium. At earlier times, interac- • ∼ ∼ tions that can change the photon number occur rapidly compared with the expansion rate; afterwards, these reactions freeze out and CMB photons are neither created nor destroyed. -
Supersymmetry in the Shadow of Photini
Photini in the UV Photini in the IR Photini at the LHC Supersymmetry in the shadow of photini Ken Van Tilburg August 24, 2012 In collaboration with: Masha Baryakhtar (Stanford), Nathaniel Craig (Rutgers, IAS) Reference: arXiv:1206.0751; JHEP 1207 (2012) 164 Arvanitaki et al: arXiv:0909:5440; Phys.Rev.D81 (2010) 075018 1/6 Photini in the UV Photini in the IR Photini at the LHC Table of contents 1 Photini in the UV 2 Photini in the IR 3 Photini at the LHC 2/6 Photini in the UV Photini in the IR Photini at the LHC Photini in the UV Main features of string theory: 1 supersymmetry assume broken at low energy to solve hierarchy problem 2 extra dimensions (6) assume small size generically complex compactification manifold to get SM very simple manifold: 6-torus ! six 1- and 5-cycles, fifteen 2- and 4-cycles, twenty 3-cycles IIB string theory: 4-form gauge field integrated over 3-cycle i R ! 4D vector gauge field without charged matter Aµ = C4 Σi string theory ! SUSY SM many extra \photon" superfields without any charged matter can in principle mix with U(1) hypercharge and among each other 3/6 Photini in the UV Photini in the IR Photini at the LHC Photini in the IR in SUSY limit, no observable effect: Z 2 L ⊃ d θ WaWa + WbWb − 2WaWb shift away mixing: W ! W − W and g ! p ga b b a a 1−2 physical effects from SUSY breaking, when gauginos get mass y µ δL ⊃ zijλi iσ @µλj − mijλi λj expect sizeable number of photini to be lighter than the bino bino-photino + interphotini cascade via emissions of h; Z; γ 4/6 gluino-bino model gluino-squark-bino model drastically weakened hadronic search limits: slightly enhanced leptonic search sensitivity: Photini in the UV Photini in the IR Photini at the LHC Photini at the LHC reduction of missing ET 1.0 bino 150 GeV L . -
Front-End Electronic Readout System for the Belle II Imaging Time-Of- Propagation Detector
Front-end electronic readout system for the Belle II imaging Time-Of- Propagation detector Dmitri Kotchetkova, Oskar Hartbricha,*, Matthew Andrewa, Matthew Barretta,1, Martin Bessnera, Vishal Bhardwajb,2, Thomas Browdera, Julien Cercillieuxa, Ryan Conradc, Istvan Dankod, Shawn Dubeya, James Fastc, Bryan Fulsomc, Christopher Kettera, Brian Kirbya,3, Alyssa Loosb, Luca Macchiaruloa, Boštjan Mačeka,4, Kurtis Nishimuraa, Milind Purohitb, Carl Rosenfeldb, Ziru Sanga, Vladimir Savinovd, Gary Varnera, Gerard Vissere, Tobias Webera,5, Lynn Woodc a. Department of Physics and Astronomy, University of Hawaii at Manoa, 2505 Correa Road, Honolulu, HI 96822, USA b. Department of Physics and Astronomy, University of South Carolina, 712 Main Street, Columbia, SC 29208, USA c. Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99354, USA d. Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USA e. Center for Exploration of Energy and Matter, Indiana University, 2401 North Milo B. Sampson Lane, Bloomington, IN 47408, USA * Corresponding author. Phone: 1-808-956-4097. Fax: 1-808-956-2930 E-mail address: [email protected] 1Present address: Department of Physics and Astronomy, Wayne State University, 666 W Hancock St, Detroit, MI 48201, USA 2Present address: Indian Institute of Science Education and Research Mohali, Knowledge city, Sector 81, SAS Nagar, Manauli PO 140306, India 3Present address: Physics Department, Brookhaven National Laboratory, Upton, NY 11973, USA 4Present address: Department of Experimental Particle Physics, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia 5Present address: Ruhr-Universität Bochum, 44780 Bochum, Germany Abstract The Time-Of-Propagation detector is a Cherenkov particle identification detector based on quartz radiator bars for the Belle II experiment at the SuperKEKB e+e– collider. -
The Belle II Experiment: Status and Prospects
universe Article The Belle II Experiment: Status and Prospects Paolo Branchini † INFN Sezione di RomaTre Via Della Vasca Navale, 84, 00146 Roma, Italy; [email protected] † On behalf of the Belle II Collaboration. Received: 16 September 2018; Accepted: 29 September 2018; Published: 1 October2018 Abstract: The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKBenergy-asymmetric e+e− collider. The accelerator has already successfully completed the first phase of commissioning in 2016. The first electron versus positron collisions in Belle II were delivered in April 2018. The design luminosity of SuperKEKB is 8 × 1035 cm−2 s−1, and the Belle II experiment aims to record 50 ab−1 of data, a factor of 50 more than the Belle experiment. This large dataset will be accumulated with low backgrounds and high trigger efficiencies in a clean e+e− environment. This contribution will review the detector upgrade, the achieved detector performance and the plans for the commissioning of Belle II. Keywords: flavor; dark matter 1. Introduction Even though the Standard Model (SM) is currently the best description of the subatomic world, it does not explain the complete picture. The theory incorporates only three out of the four fundamental forces, omitting gravity. Moreover, there are also important questions that it does not answer, such as the matter versus antimatter asymmetry in the number of quark and lepton generations. Many New Physics (NP) scenarios have been proposed. Experiments in high-energy physics search for NP using two complementary approaches. The first, at the energy frontier, is able to discover new particles directly produced in pp collisions (ATLAS, CMS).