DOCSLIB.ORG

Supersymmetric Particle Searches

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Supersymmetric Particle Searches Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update Supersymmetric Particle Searches m m The exclusion of particle masses within a mass range ( 1, 2) m −m will be denoted with the notation “none 1 2” in the VALUE column of the following Listings. The latest unpublished results are described in the “Supersymmetry: Experiment” review. See the related review(s): Supersymmetry, Part I (Theory) Supersymmetry, Part II (Experiment) CONTENTS: χ0 (Lightest Neutralino) mass limit e1 Accelerator limits for stable χ0 − e1 Bounds on χ0 from dark matter searches − e1 χ0-p elastic cross section − 1 eSpin-dependent interactions Spin-independent interactions Other bounds on χ0 from astrophysics and cosmology − e1 Unstable χ0 (Lightest Neutralino) mass limit − e1 χ0, χ0, χ0 (Neutralinos) mass limits e2 e3 e4 χ±, χ± (Charginos) mass limits e1 e2 Long-lived χ± (Chargino) mass limit ν (Sneutrino)e mass limit Chargede sleptons R-parity conserving e (Selectron) mass limit − R-partiy violating e e(Selectron) mass limit − R-parity conservinge µ (Smuon) mass limit − R-parity violating µ e(Smuon) mass limit − R-parity conservinge τ (Stau) mass limit − R-parity violating τ e(Stau) mass limit − Long-lived ℓ (Slepton)e mass limit − e q (Squark) mass limit e R-parity conserving q (Squark) mass limit − R-parity violating q e(Squark) mass limit − Long-lived q (Squark) masse limit b (Sbottom)e mass limit e R-parity conserving b (Sbottom) mass limit − e R-parity violating b (Sbottom) mass limit − e t (Stop) mass limit e R-parity conserving t (Stop) mass limit − R-parity violating t (Stop)e mass limit − Heavy g (Gluino) mass limite R-paritye conserving heavy g (Gluino) mass limit − R-parity violating heavy g e(Gluino) mass limit − Long-lived g (Gluino) mass limite Light G (Gravitino)e mass limits from collider experiments e Supersymmetry miscellaneous results HTTP://PDG.LBL.GOV Page 1 Created: 8/2/2019 16:43 Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update Most of the results shown below, unless stated otherwise, are based on the Minimal Supersymmetric Standard Model (MSSM), as described in the Note on Supersymmetry. Unless otherwise indicated, this includes the assumption of common gaugino and scalar masses at the scale of Grand Unification (GUT), and use of the resulting relations in the spectrum and decay branching ratios. Unless otherwise indicated, it is also assumed that R-parity (R) is conserved and that: 0 1) The χ1 is the lighest supersymmetric particle (LSP) e 2) m = m , where fL,R refer to the scalar partners of left- fL fR e ande right-handede fermions. Limits involving different assumptions are identified in the Comments or in the Footnotes. We summarize here the nota- tions used in this Chapter to characterize some of the most common deviations from the MSSM (for further details, see the Note on Supersymmetry). Theories with R-parity violation (R6 ) are characterized c ′ c by a superpotential of the form: λijkLiLjek + λijkLiQjdk + ′′ c c c λ ijkui djdk, where i, j, k are generation indices. The presence of any of these couplings is often identified in the following by the symbols LLE, LQD, and UDD. Mass limits in the presence of R6 will often refer to “direct” and “indirect” decays. Direct refers to R6 decays of the particle in consideration. Indi- rect refers to cases where R6 appears in the decays of the LSP. 0 The LSP need not be the χ1. In several models, moste notably in theories with so-called Gauge Mediated Supersymmetry Breaking (GMSB), the grav- itino (G) is the LSP. It is usually much lighter than any other e massive particle in the spectrum, and mG is then neglected in all decay processes involving gravitinos.e In these scenarios, particles other than the neutralino are sometimes considered as the next-to-lighest supersymmetric particle (NLSP), and are HTTP://PDG.LBL.GOV Page 2 Created: 8/2/2019 16:43 Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update assumed to decay to their even-R partner plus G. If the lifetime e is short enough for the decay to take place within the detector, G is assumed to be undetected and to give rise to missing e energy (E6 ) or missing transverse energy (E6 T ) signatures. When needed, specific assumptions on the eigenstate con- tent of χ0 and χ± states are indicated, using the notation γ e e e (photino), H (higgsino), W (wino), and Z (zino) to signal that e f e the limit of pure states was used. The terms gaugino is also used, to generically indicate wino-like charginos and zino-like neutralinos. In the listings we have made use of the following abbre- viations for simplified models employed by the experimental collaborations in supersymmetry searches published in the past year. Simplified Models Table 0 Tglu1A: gluino pair production withg ˜ → qq¯χ˜1. 0 Tglu1B: gluino pair production withg ˜ → qq′χ˜1±,χ ˜1± → W ±χ˜1. Tglu1C: gluino pair production with a 2/3 probability of having a 0 g˜ → qq′χ˜1±,χ ˜1± → W ±χ˜1 decay and a 1/3 probability of 0 0 0 having ag ˜ → qqχ˜2,χ ˜2 → Z±χ˜1 decay. ¯ Tglu1D: gluino pair production with one gluino decaying to qq′χ˜1± with ˜ 0 χ˜1± → W ± + G, and the other gluino decaying to qq¯χ˜1 with 0 ˜ χ˜1 → γ + G. 0 Tglu1E: gluino pair production withg ˜ → qq′χ˜1±,χ ˜1± → W ±χ˜2 and 0 0 χ˜ → Z±χ˜ where m ± = (m˜g + m 0)/2, m 0 = (m ± + 2 1 χ˜1 χ˜1 χ˜2 χ˜1 m 0 )/2. χ˜1 0 Tglu1F: gluino pair production withg ˜ → qq′χ˜1± org ˜ → qqχ˜2 with equal branching ratios, whereχ ˜1± decays through an intermediate 0 0 scalar tau lepton or sneutrino to τνχ˜1 and whereχ ˜2 decays through an intermediate scalar tau lepton or sneutrino to + 0 0 τ τ −χ˜ or νν¯χ˜ ; the mass hierarchy is such that m ± ∼ 1 1 χ1 m 0 =(m˜g + m 0 )/2 and mτ,˜ ν˜ =(m ± + m 0)/2. χ˜2 χ1 χ˜1 χ˜1 0 0 Tglu1G: gluino pair production withg ˜ → qq¯χ˜2, andχ ˜2 decaying + 0 through an intermediate slepton or sneutrino to ℓ ℓ−χ˜1 or νν¯χ˜0 where m 0 =(m + m 0 )/2 and m =(m 0 + m 0 )/2. 1 χ˜2 ˜g χ˜1 ˜ℓ,ν˜ χ˜2 χ˜1 0 0 0 0( ) Tglu1H: gluino pair production withg ˜ → qq¯χ˜2, andχ ˜2 → χ˜1Z ∗ . HTTP://PDG.LBL.GOV Page 3 Created: 8/2/2019 16:43 Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update 0 0 0 Tglu1I: gluino pair production withg ˜ → qq¯χ˜2, andχ ˜2 → χ˜1H. 0 0 Tglu1J: gluino pair production withg ˜ → qq¯χ˜2, and BR(˜χ2 → 0 0( ) 0 0 χ˜1Z ∗ ) = BR(˜χ2 → χ˜1H)=0.5. ¯ 0 Tglu2A: gluino pair production withg ˜ → bbχ˜1. ¯ 0 Tglu3A: gluino pair production withg ˜ → ttχ˜1. Tglu3B: gluino pair production withg ˜ → t¯t˜ where t˜ decays exclusively 0 to tχ˜1. Tglu3C: gluino pair production withg ˜ → t¯t˜ where t˜ decays exclusively 0 to cχ˜1. ¯ 0 Tglu3D: gluino pair production withg ˜ → tbχ˜1± withχ ˜1± → W ±χ˜1. Tglu3E: gluino pair production where the gluino decays 25% of the ¯ 0 ¯ 0 time throughg ˜ → ttχ˜1, 25% of the time throughg ˜ → bbχ˜1 ¯ 0 and 50% of the time throughg ˜ → tbχ˜1± withχ ˜1± → W ±χ˜1 ¯ Tglu4A: gluino pair production with one gluino decaying to qq′χ˜1± with ˜ 0 χ˜1± → W ± + G, and the other gluino decaying to qq¯χ˜1 with 0 ˜ χ˜1 → γ + G. 0 Tglu4B: gluino pair production with gluinos decaying to qq¯χ˜1 and 0 ˜ χ˜1 → γ + G. 0 Tglu4C: gluino pair production with gluinos decaying tog ˜ → qq¯χ˜1 and 0 ˜ χ˜1 → Z + G. Tglu1RPV: gluino pair production with gluinos decaying tog ˜ → qiqjqk via λijk′′ . 0 Tglu2RPV: gluino pair production with gluinos decaying tog ˜ → qq¯χ˜1, 0 + withχ ˜1 → [ℓ ℓ′−ν(λijk); ℓ±qq′/νqq′(λijk′ ); qq′q′′(λijk′′ )]. ———————— 0 Tsqk1: squark pair production withq ˜ → qχ˜1. 0 0 0 Tsqk2: squark pair production withq ˜ → qχ˜2 andχ ˜2 → Z +χ ˜1. 0 Tsqk3: squark pair production withq ˜ → q′χ˜1±,χ ˜1± → W ±χ˜1 (like Tglu1B but for squarks) 0 Tsqk4: squark pair production with squarks decaying to qχ˜1 and 0 ˜ χ˜1 → γ + G. Tsqk4A: squark pair production with one squark decaying to qχ˜1± with ˜ 0 χ˜1± → W ± + G, and the other squark decaying to qχ˜1 with 0 ˜ χ˜1 → γ + G. 0 Tsqk4B: squark pair production with squarks decaying to qχ˜1 and 0 ˜ χ˜1 → γ + G. ———————— ˜ 0 Tstop1: stop pair production with t → tχ˜1. ˜ 0 Tstop2: stop pair production with t → bχ˜1± withχ ˜1± → W ±χ˜1. ˜ 0 Tstop3: stop pair production with the four-body decay t → bff ′χ˜1 where f represents a lepton or a quark. ˜ 0 Tstop4: stop pair production with t → cχ˜1. Tstop5: stop pair production with t˜→ bν¯τ˜ withτ ˜ → τG˜. HTTP://PDG.LBL.GOV Page 4 Created: 8/2/2019 16:43 Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update ˜ 0 0 0 Tstop6: stop pair production with t → t +χ ˜2, whereχ ˜2 → Z +χ ˜1 or 0 H +χ ˜1 each with Br=50%.
Load more

Recommended publications
  • PHY323:Lecture 11 SUSY and UED
    PHY323:Lecture 11 SUSY and UED •Higgs and Supersymmetry •The Neutralino •Extra Dimensions •How WIMPs interact Candidates for Dark Matter III The New Particle Zoo Here are a few of the candidates on a plot showing cross section vs. mass. An enormous range. We will focus on WIMPs thanks to L. Roszkowski (Sheffield) Freeze Out of Thermal DM Particles WIMP Candidate 1 Supersymmetric Dark Matter Each particle gets a “sparticle” counterpart. Bosons get fermions and vice versa. e.g. Photon Photino W Wino Z Zino etc The Lightest Supersymmetric Particle (LSP) is predicted to be stable. This is called the NEUTRALINO. Supersymmetry Theory What we are aiming to do, e.g.: At higher energies, where symmetries are unbroken, you might expect a unified theory should have a single coupling constant Supersymmetry Theory and the Higgs To make things simpler, it would be nice if all the forces of nature were unified under the same theoretical framework. The energy at which this is likely called the Planck energy (1019 GeV). This was started in the 1970s - the result is the electroweak theory. The theory is intricate and complicated, partly because the photon is massless, but the W & Z are heavy. The electroweak theory posits that the very different carriers, and therefore properties, of these forces at energy scales present in nature today are actually the result of taking a much more symmteric theory at higher energies, above the ‘electroweak scale’ of 90GeV (the W and Z rest energy) and ‘spontaneously breaking’ it. The theoretical mechanism for spontaneous symmetry breaking requires yet another new particle, a spin zero particle called the HIGGS BOSON.
    [Show full text]
  • 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.
    [Show full text]
  • Goldstini Can Give the Higgs a Boost
    Goldstini Can Give the Higgs a Boost The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Thaler, Jesse, and Zachary Thomas. “Goldstini can give the Higgs a boost.” Journal of High Energy Physics 2011.7 (2011). As Published http://dx.doi.org/10.1007/jhep07(2011)060 Publisher Springer Berlin/Heidelberg Version Author's final manuscript Citable link http://hdl.handle.net/1721.1/72016 Terms of Use Creative Commons Attribution-Noncommercial-Share Alike 3.0 Detailed Terms http://creativecommons.org/licenses/by-nc-sa/3.0/ Preprint typeset in JHEP style - HYPER VERSION MIT-CTP 4226 Goldstini Can Give the Higgs a Boost Jesse Thaler and Zachary Thomas Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA E-mail: [email protected], [email protected] Abstract: Supersymmetric collider phenomenology depends crucially on whether the lightest observable-sector supersymmetric particle (LOSP) decays, and if so, what the LOSP decay products are. For instance, in SUSY models where the gravitino is lighter than the LOSP, the LOSP decays to its superpartner and a longitudinal gravitino via super- current couplings. In this paper, we show that LOSP decays can be substantially modified when there are multiple sectors that break supersymmetry, where in addition to the grav- itino there are light uneaten goldstini. As a particularly striking example, a bino-like LOSP can have a near 100% branching fraction to a higgs boson and an uneaten goldstino, even if the LOSP has negligible higgsino fraction. This occurs because the uneaten goldstino is unconstrained by the supercurrent, allowing additional operators to mediate LOSP decay.
    [Show full text]
  • Constraints from Electric Dipole Moments on Chargino Baryogenesis in the Minimal Supersymmetric Standard Model
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by National Tsing Hua University Institutional Repository PHYSICAL REVIEW D 66, 116008 ͑2002͒ Constraints from electric dipole moments on chargino baryogenesis in the minimal supersymmetric standard model Darwin Chang NCTS and Physics Department, National Tsing-Hua University, Hsinchu 30043, Taiwan, Republic of China and Theory Group, Lawrence Berkeley Lab, Berkeley, California 94720 We-Fu Chang NCTS and Physics Department, National Tsing-Hua University, Hsinchu 30043, Taiwan, Republic of China and TRIUMF Theory Group, Vancouver, British Columbia, Canada V6T 2A3 Wai-Yee Keung NCTS and Physics Department, National Tsing-Hua University, Hsinchu 30043, Taiwan, Republic of China and Physics Department, University of Illinois at Chicago, Chicago, Illinois 60607-7059 ͑Received 9 May 2002; revised 13 September 2002; published 27 December 2002͒ A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model ͑MSSM͒ depends on the CP violating relative phase between the gaugino mass and the Higgsino ␮ term. The direct constraint on this phase comes from the limit of electric dipole moments ͑EDM’s͒ of various light fermions. To avoid such a constraint, a scheme which assumes that the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric dipole moment of the electron, the neutron, or atoms via the chargino sector at the two-loop level. As a result, the allowed parameter space for baryogenesis in the MSSM is severely constrained, independent of the masses of the first two generation sfermions.
    [Show full text]
  • Download -.:: Natural Sciences Publishing
    Quant. Phys. Lett. 5, No. 3, 33-47 (2016) 33 Quantum Physics Letters An International Journal http://dx.doi.org/10.18576/qpl/050302 About Electroweak Symmetry Breaking, Electroweak Vacuum and Dark Matter in a New Suggested Proposal of Completion of the Standard Model In Terms Of Energy Fluctuations of a Timeless Three-Dimensional Quantum Vacuum Davide Fiscaletti* and Amrit Sorli SpaceLife Institute, San Lorenzo in Campo (PU), Italy. Received: 21 Sep. 2016, Revised: 18 Oct. 2016, Accepted: 20 Oct. 2016. Published online: 1 Dec. 2016. Abstract: A model of a timeless three-dimensional quantum vacuum characterized by energy fluctuations corresponding to elementary processes of creation/annihilation of quanta is proposed which introduces interesting perspectives of completion of the Standard Model. By involving gravity ab initio, this model allows the Standard Model Higgs potential to be stabilised (in a picture where the Higgs field cannot be considered as a fundamental physical reality but as an emergent quantity from most elementary fluctuations of the quantum vacuum energy density), to generate electroweak symmetry breaking dynamically via dimensional transmutation, to explain dark matter and dark energy. Keywords: Standard Model, timeless three-dimensional quantum vacuum, fluctuations of the three-dimensional quantum vacuum, electroweak symmetry breaking, dark matter. 1 Introduction will we discover beyond the Higgs door? In the Standard Model with a light Higgs boson, an The discovery made by ATLAS and CMS at the Large important problem is that the electroweak potential is Hadron Collider of the 126 GeV scalar particle, which in destabilized by the top quark. Here, the simplest option in the light of available data can be identified with the Higgs order to stabilise the theory lies in introducing a scalar boson [1-6], seems to have completed the experimental particle with similar couplings.
    [Show full text]
  • Report of the Supersymmetry Theory Subgroup
    Report of the Supersymmetry Theory Subgroup J. Amundson (Wisconsin), G. Anderson (FNAL), H. Baer (FSU), J. Bagger (Johns Hopkins), R.M. Barnett (LBNL), C.H. Chen (UC Davis), G. Cleaver (OSU), B. Dobrescu (BU), M. Drees (Wisconsin), J.F. Gunion (UC Davis), G.L. Kane (Michigan), B. Kayser (NSF), C. Kolda (IAS), J. Lykken (FNAL), S.P. Martin (Michigan), T. Moroi (LBNL), S. Mrenna (Argonne), M. Nojiri (KEK), D. Pierce (SLAC), X. Tata (Hawaii), S. Thomas (SLAC), J.D. Wells (SLAC), B. Wright (North Carolina), Y. Yamada (Wisconsin) ABSTRACT Spacetime supersymmetry appears to be a fundamental in- gredient of superstring theory. We provide a mini-guide to some of the possible manifesta- tions of weak-scale supersymmetry. For each of six scenarios These motivations say nothing about the scale at which nature we provide might be supersymmetric. Indeed, there are additional motiva- tions for weak-scale supersymmetry. a brief description of the theoretical underpinnings, Incorporation of supersymmetry into the SM leads to a so- the adjustable parameters, lution of the gauge hierarchy problem. Namely, quadratic divergences in loop corrections to the Higgs boson mass a qualitative description of the associated phenomenology at future colliders, will cancel between fermionic and bosonic loops. This mechanism works only if the superpartner particle masses comments on how to simulate each scenario with existing are roughly of order or less than the weak scale. event generators. There exists an experimental hint: the three gauge cou- plings can unify at the Grand Uni®cation scale if there ex- I. INTRODUCTION ist weak-scale supersymmetric particles, with a desert be- The Standard Model (SM) is a theory of spin- 1 matter tween the weak scale and the GUT scale.
    [Show full text]
  • Supersymmetric Dark Matter
    Supersymmetric dark matter G. Bélanger LAPTH- Annecy Plan | Dark matter : motivation | Introduction to supersymmetry | MSSM | Properties of neutralino | Status of LSP in various SUSY models | Other DM candidates z SUSY z Non-SUSY | DM : signals, direct detection, LHC Dark matter: a WIMP? | Strong evidence that DM dominates over visible matter. Data from rotation curves, clusters, supernovae, CMB all point to large DM component | DM a new particle? | SM is incomplete : arbitrary parameters, hierarchy problem z DM likely to be related to physics at weak scale, new physics at the weak scale can also solve EWSB z Stable particle protect by symmetry z Many solutions – supersymmetry is one best motivated alternative to SM | NP at electroweak scale could also explain baryonic asymetry in the universe Relic density of wimps | In early universe WIMPs are present in large number and they are in thermal equilibrium | As the universe expanded and cooled their density is reduced Freeze-out through pair annihilation | Eventually density is too low for annihilation process to keep up with expansion rate z Freeze-out temperature | LSP decouples from standard model particles, density depends only on expansion rate of the universe | Relic density | A relic density in agreement with present measurements (Ωh2 ~0.1) requires typical weak interactions cross-section Coannihilation | If M(NLSP)~M(LSP) then maintains thermal equilibrium between NLSP-LSP even after SUSY particles decouple from standard ones | Relic density then depends on rate for all processes
    [Show full text]
  • The Standard Model of Particle Physics and Beyond
    Clases de Master FisyMat, Desarrollos Actuales The Standard Model of particle physics and Beyond Date and time: 02/03 to 07/04/2021 15:30–17:00 Video/Sala CAJAL Organizer and Lecturer: Abdelhak Djouadi ([email protected]) You can find the pdfs of the lectures at: https://www.ugr.es/˜adjouadi/ 6. Supersymmetric theories 6.1 Basics of Supersymmetry 6.2 The minimal Supesymmetric Standard Model 6.3 The constrained MSSM’s 6.4 The superparticle spectrum 6.5 The Higgs sector of the MSSM 6.6 Beyond the MSSM 1 6.1 Basics of Supersymmetry Here, we give only basic facts needed later in the phenomenological discussion. For details on theoretical issues, see basic textbooks like Drees, Godbole, Roy. SUperSYmmetry: is a symmetry that relates scalars/vector bosons and fermions. The SUSY generators transform fermions into bosons and vice–versa, namely: FermionQ > Boson > , Boson > Fermion > Q| | Q| | must be an anti–commuting (and thus rather complicated) object. Q † is also a distinct symmetry generator: Q † Fermion > Boson > , † Boson > Fermion > Q | | Q | | Highly restricted [e.g., no go theorem] theories and in 4-dimension with chiral fermions: 1 , † carry spin– with left- and right- helicities and they should obey Q Q 2 .... The SUSY algebra: which schematically is given by µ , † = P , , =0 , †, † =0, {Qµ Q } µ {Q Q} a {Q Qa } [P , ]=0, [P , †]=0, [T , ]=0, [T , †]=0 Q Q Q Q P µ: is the generator of space–time transformations. T a are the generators of internal (gauge) symmetries. SUSY: unique extension of the Poincar´egroup of space–time symmetry to include ⇒ a four–dimensional Quantum Field Theory..
    [Show full text]
  • Gaugino-Induced Quark and Lepton Masses in a Truly Minimal Left-Right
    UCRHEP-T354 ULB-TH/03-16 NSF-KITP-03-32 May 2003 Gaugino-induced quark and lepton masses in a truly minimal left-right model J.-M. Fr`ere1,3 and Ernest Ma2,3 1 Service de Physique Th´eorique, Universit´eLibre de Bruxelles, B-1050 Brussels, Belgium 2 Physics Department, University of California, Riverside, California 92521, USA 3 Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA arXiv:hep-ph/0305155v2 20 Aug 2003 Abstract It has recently been proposed that all fundamental fermion masses (whether Dirac or Majorana) come from effective dimension-five operators in the context of a truly minimal left-right model. We show how a particularly economical scheme emerges in a supersymmetric framework, where chiral symmetry breaking originates in the gaugino sector. In the Standard Model of particle interactions, the spontaneous breaking of the SU(2)L × U(1)Y gauge symmetry to U(1)em is achieved through the vacuum expectation value of the scalar doublet Φ = (φ+,φ0). At the same time, since left-handed quarks and leptons are doublets under SU(2)L U(1)Y whereas right-handed quarks and leptons are singlets, chiral × symmetry is also broken by φ0 , thus allowing quarks and leptons to acquire the usual Dirac h i masses. The only exception is the neutrino which gets a small Majorana mass through the unique dimension-five operator [1, 2] fij 0 + 0 + Λ = (νiφ eiφ )(νjφ ejφ )+ H.c. (1) L 2Λ − − Suppose we now extend the standard-model gauge symmetry to SU(3)C SU(2)L × × SU(2)R U(1)B L [3], then the spontaneous breaking of SU(2)R U(1)B L to U(1)Y is × − × − simply achieved by the scalar doublet + 0 ΦR =(φ ,φ ) (1, 1, 2, 1), (2) R R ∼ where the notation refers to the dimension of the non-Abelian representation or the value of the Abelian charge B L or Y in the convention − 1 Y Q = I3L + I3R + (B L)= I3L + , (3) 2 − 2 while the corresponding field + 0 ΦL =(φ ,φ ) (1, 2, 1, 1), (4) L L ∼ becomes the same as the usual scalar doublet of the Standard Model, and breaks SU(2)L × U(1)Y in turn to U(1)em.
    [Show full text]
  • Arxiv:1712.01768V1 [Hep-Ex] 5 Dec 2017
    Prospects of the SHiP and NA62 experiments at CERN for hidden sector searches Philippe Mermod∗, on behalf of the SHiP Collaboration Particle Physics Department, Faculty of Science, University of Geneva, Geneva, Switzerland E-mail: [email protected] High-intensity proton beams impinging on a fixed target or beam dump allow to probe new physics via the production of new weakly-coupled particles in hadron decays. The CERN SPS provides opportunities to do so with the running NA62 experiment and the planned SHiP ex- periment. Reconstruction of kaon decay kinematics (beam mode) allows NA62 to probe for the existence of right-handed neutrinos and dark photons with masses below 0.45 GeV. Direct recon- struction of displaced vertices from the decays of new neutral particles (dump mode) will allow NA62 and SHiP to probe right-handed neutrinos with masses up to 5 GeV and mixings down to several orders of magnitude smaller than current constraints, in regions favoured in models which explain at once neutrino masses, matter-antimatter asymmetry and dark matter. arXiv:1712.01768v1 [hep-ex] 5 Dec 2017 The 19th International Workshop on Neutrinos from Accelerators-NUFACT2017 25-30 September, 2017 Uppsala University, Uppsala, Sweden ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). https://pos.sissa.it/ Hidden sector searches with SHiP and NA62 Philippe Mermod 1. Introduction The LHC experiments have been running for several years without finding new physics at the TeV scale. A complementary approach is to probe the presence of new particles at lower energy scales with couplings to the Standard Model so weak that they have escaped detection in previous searches.
    [Show full text]
  • Table of Contents (Print)
    PERIODICALS PHYSICAL REVIEW D Postmaster send address changes to: For editorial and subscription correspondence, PHYSICAL REVIEW D please see inside front cover APS Subscription Services „ISSN: 0556-2821… Suite 1NO1 2 Huntington Quadrangle Melville, NY 11747-4502 THIRD SERIES, VOLUME 69, NUMBER 7 CONTENTS D1 APRIL 2004 RAPID COMMUNICATIONS ϩ 0 ⌼ ϩ→ ␺ ϩ 0→ ␺ 0 Measurement of the B /B production ratio from the (4S) meson using B J/ K and B J/ KS decays (7 pages) ............................................................................ 071101͑R͒ B. Aubert et al. ͑BABAR Collaboration͒ Cabibbo-suppressed decays of Dϩ→␲ϩ␲0,KϩK¯ 0,Kϩ␲0 (5 pages) .................................. 071102͑R͒ K. Arms et al. ͑CLEO Collaboration͒ Ϯ→␹ Ϯ ͑ ͒ Measurement of the branching fraction for B c0K (7 pages) ................................... 071103R B. Aubert et al. ͑BABAR Collaboration͒ Generalized Ward identity and gauge invariance of the color-superconducting gap (5 pages) .............. 071501͑R͒ De-fu Hou, Qun Wang, and Dirk H. Rischke ARTICLES Measurements of ␺(2S) decays into vector-tensor final states (6 pages) ............................... 072001 J. Z. Bai et al. ͑BES Collaboration͒ Measurement of inclusive momentum spectra and multiplicity distributions of charged particles at ͱsϳ2 –5 GeV (7 pages) ................................................................... 072002 J. Z. Bai et al. ͑BES Collaboration͒ Production of ␲ϩ, ␲Ϫ, Kϩ, KϪ, p, and ¯p in light ͑uds͒, c, and b jets from Z0 decays (26 pages) ........ 072003 Koya Abe et al. ͑SLD Collaboration͒ Heavy flavor properties of jets produced in pp¯ interactions at ͱsϭ1.8 TeV (21 pages) .................. 072004 D. Acosta et al. ͑CDF Collaboration͒ Electric charge and magnetic moment of a massive neutrino (21 pages) ............................... 073001 Maxim Dvornikov and Alexander Studenikin ␶→␲␲␲␯␶ decays in the resonance effective theory (13 pages) ....................................
    [Show full text]
  • Supersymmetry!
    The Cosmos … Time Space … and the LHC John ELLIS, CERN, Geneva, Switzerland 300,000 Formation years of atoms 3 Formation minutes of nuclei Formation 1 micro- of protons second & neutrons Origin of dark matter? 1 pico- Appearance second of mass? Origin of Matter? A Strange Recipe for a Universe Ordinary Matter The ‘Concordance Model’ prompted by astrophysics & cosmology Open Cosmological Questions • Where did the matter come from? LHC? 1 proton for every 1,000,000,000 photons • What is the dark matter? LHC? Much more than the normal matter • What is the dark energy? LHC? Even more than the dark matter • Why is the Universe so big and old? LHC? Mechanism for cosmological inflation Need particle physics to answer these questions The Very Early Universe • Size: a zero • Age: t zero • Temperature: T large T ~ 1/a, t ~ 1/T2 • Energies: E ~ T • Rough magnitudes: T ~ 10,000,000,000 degrees E ~ 1 MeV ~ mass of electron t ~ 1 second Need particle physics to describe earlier history DarkDark MatterMatter in in the the Universe Universe Astronomers say thatAstronomers most of tellthe matterus that mostin the of the Universematter in theis invisibleuniverse is Darkinvisible Matter „Supersymmetric‟ particles ? WeWe shallwill look look for for it themwith thewith LHC the LHC Where does the Matter come from? Dirac predicted the existence of antimatter: same mass opposite internal properties: electric charge, … Discovered in cosmic rays Studied using accelerators Matter and antimatter not quite equal and opposite: WHY? 2008 Nobel Physics Prize: Kobayashi
    [Show full text]