scispace - formally typeset
Search or ask a question

Showing papers on "Elementary particle published in 1994"


Journal ArticleDOI
K. Hagiwara, Ken Ichi Hikasa1, Koji Nakamura, Masaharu Tanabashi1, M. Aguilar-Benitez, Claude Amsler2, R. M. Barnett3, Patricia R. Burchat4, C. D. Carone5, C. Caso, G. Conforto6, Olav Dahl3, Michael Doser7, Semen Eidelman8, Jonathan L. Feng9, L. K. Gibbons10, Maury Goodman11, Christoph Grab12, D. E. Groom3, Atul Gurtu7, Atul Gurtu13, K. G. Hayes14, J. J. Herna`ndez-Rey15, K. Honscheid16, Christopher Kolda17, Michelangelo L. Mangano7, David Manley18, Aneesh V. Manohar19, John March-Russell7, Alberto Masoni, Ramon Miquel3, Klaus Mönig, Hitoshi Murayama20, Hitoshi Murayama3, S. Sánchez Navas12, Keith A. Olive21, Luc Pape7, C. Patrignani, A. Piepke22, Matts Roos23, John Terning24, Nils A. Tornqvist23, T. G. Trippe3, Petr Vogel25, C. G. Wohl3, Ron L. Workman26, W-M. Yao3, B. Armstrong3, P. S. Gee3, K. S. Lugovsky, S. B. Lugovsky, V. S. Lugovsky, Marina Artuso27, D. Asner28, K. S. Babu29, E. L. Barberio7, Marco Battaglia7, H. Bichsel30, O. Biebel31, Philippe Bloch7, Robert N. Cahn3, Ariella Cattai7, R. S. Chivukula32, R. Cousins33, G. A. Cowan34, Thibault Damour35, K. Desler, R. J. Donahue3, D. A. Edwards, Victor Daniel Elvira, Jens Erler36, V. V. Ezhela, A Fassò7, W. Fetscher12, Brian D. Fields37, B. Foster38, Daniel Froidevaux7, Masataka Fukugita39, Thomas K. Gaisser40, L. Garren, H.-J. Gerber12, Frederick J. Gilman41, Howard E. Haber42, C. A. Hagmann28, J.L. Hewett4, Ian Hinchliffe3, Craig J. Hogan30, G. Höhler43, P. Igo-Kemenes44, John David Jackson3, Kurtis F Johnson45, D. Karlen, B. Kayser, S. R. Klein3, Konrad Kleinknecht46, I.G. Knowles47, P. Kreitz4, Yu V. Kuyanov, R. Landua7, Paul Langacker36, L. S. Littenberg48, Alan D. Martin49, Tatsuya Nakada7, Tatsuya Nakada50, Meenakshi Narain32, Paolo Nason, John A. Peacock47, Helen R. Quinn4, Stuart Raby16, Georg G. Raffelt31, E. A. Razuvaev, B. Renk46, L. Rolandi7, Michael T Ronan3, L.J. Rosenberg51, Christopher T. Sachrajda52, A. I. Sanda53, Subir Sarkar54, Michael Schmitt55, O. Schneider50, Douglas Scott56, W. G. Seligman57, Michael H. Shaevitz57, Torbjörn Sjöstrand58, George F. Smoot3, Stefan M Spanier4, H. Spieler3, N. J. C. Spooner59, Mark Srednicki60, A. Stahl, Todor Stanev40, M. Suzuki3, N. P. Tkachenko, German Valencia61, K. van Bibber28, Manuella Vincter62, D. R. Ward63, Bryan R. Webber63, M R Whalley49, Lincoln Wolfenstein41, J. Womersley, C. L. Woody48, O. V. Zenin 
Tohoku University1, University of Zurich2, Lawrence Berkeley National Laboratory3, Stanford University4, College of William & Mary5, University of Urbino6, CERN7, Budker Institute of Nuclear Physics8, University of California, Irvine9, Cornell University10, Argonne National Laboratory11, ETH Zurich12, Tata Institute of Fundamental Research13, Hillsdale College14, Spanish National Research Council15, Ohio State University16, University of Notre Dame17, Kent State University18, University of California, San Diego19, University of California, Berkeley20, University of Minnesota21, University of Alabama22, University of Helsinki23, Los Alamos National Laboratory24, California Institute of Technology25, George Washington University26, Syracuse University27, Lawrence Livermore National Laboratory28, Oklahoma State University–Stillwater29, University of Washington30, Max Planck Society31, Boston University32, University of California, Los Angeles33, Royal Holloway, University of London34, Université Paris-Saclay35, University of Pennsylvania36, University of Illinois at Urbana–Champaign37, University of Bristol38, University of Tokyo39, University of Delaware40, Carnegie Mellon University41, University of California, Santa Cruz42, Karlsruhe Institute of Technology43, Heidelberg University44, Florida State University45, University of Mainz46, University of Edinburgh47, Brookhaven National Laboratory48, Durham University49, University of Lausanne50, Massachusetts Institute of Technology51, University of Southampton52, Nagoya University53, University of Oxford54, Northwestern University55, University of British Columbia56, Columbia University57, Lund University58, University of Sheffield59, University of California, Santa Barbara60, Iowa State University61, University of Alberta62, University of Cambridge63
TL;DR: This biennial Review summarizes much of Particle Physics using data from previous editions, plus 2205 new measurements from 667 papers, and features expanded coverage of CP violation in B mesons and of neutrino oscillations.
Abstract: This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the first time we cover searches for evidence of extra dimensions (both in the particle listings and in a new review). Another new review is on Grand Unified Theories. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

5,143 citations


Journal ArticleDOI
TL;DR: The regions of the (m(S),lambda(S)) parameter space which can be probed by present and future experiments designed to detect scattering of S dark matter particles from Ge nuclei, and to observe upward-moving muons and contained events in neutrino detectors due to high-energy neutrinos from annihilations of Sdark matter particles in the Sun and the Earth, are discussed.
Abstract: We consider a very simple extension of the standard model in which one or more gauge singlet scalars S-i couples to the standard model via an interaction of the form lambda(S)S(i)(dagger)S(i)H(dagger)H, where H is the standard model Higgs doublet. The thermal relic density of S scalars is calculated as a function of the coupling lambda(S) and the S scalar mass ms. The regions of the (m(S),lambda(S)) parameter space which can be probed by present and future experiments designed to detect scattering of S dark matter particles from Ge nuclei, and to observe upward-moving muons and contained events in neutrino detectors due to high-energy neutrinos from annihilations of S dark matter particles in the Sun and the Earth, are discussed. Present experimental bounds place only very weak constraints on the possibility of thermal relic S scalar dark matter. The next generation of cryogenic Ge detectors and of large area (10(4) m(2)) neutrino detectors will be able to investigate most of the parameter space corresponding to thermal relic S scalar dark matter up to m(S) approximate to 50 GeV, while a 1 km(2) detector would in general be able to detect thermal relic S scalar dark matter up to m(S) approximate to 100 GeV and would be able to detect up to m(S) approximate to 500 GeV or more if the Higgs boson is lighter than 100 GeV.

1,025 citations


Journal ArticleDOI
TL;DR: This work presents an example of such a model with a horizontal gauge symmetry that naturally explains the fermion mass hierarchy and the small mixing angles of the Kobayashi-Maskawa matrix and achieves the unification of the lepton and the down-quark Yukawa couplings without introducing large Higgs multiplets.
Abstract: Radiative corrections to the down-type fermion masses at the supersymmetric threshold are enhanced by the ratio of vacuum expectation values, tan[beta]. This can have a strong impact on the unification of Yukawa couplings in supersymmetric grand unified theories. We present an example of such a model with a horizontal gauge symmetry that naturally explains the fermion mass hierarchy and the small mixing angles of the Kobayashi-Maskawa matrix. The unification of the lepton and the down-quark Yukawa couplings is achieved without introducing large Higgs multiplets.

372 citations


Journal ArticleDOI
TL;DR: The smallness of the quark sector parameters and the hierarchy between them could be the result of a horizontal symmetry broken by a small parameter as discussed by the authors, which can also lead to many interesting results: quark-squark alignment that would suppress, without squark degeneracy, neutral currents induced by supersymmetric particles, exact relations between mass ratios and mixing angles, a solution of the μ-problem and a natural mechanism for obtaining hierarchy among various symmetry-breaking scales.

294 citations


Journal ArticleDOI
TL;DR: In this paper, the authors reanalyze the lower limit in detail as a function of m t and Λ, showing that the Higgs particle is too heavy to be found at LEP if the Standard Model is valid up to a sufficiently large scale Λ.

282 citations


Journal ArticleDOI
F. Abe1, M. G. Albrow1, S. R. Amendolia1, D. Amidei1  +394 moreInstitutions (1)
TL;DR: In this paper, a search for the top quark with the Collider Detector at Fermilab (CDF) in a sample of pp collisions at √s=1.8 TeV with an integrated luminosity of 19.3±0.7 pb−1 is summarized.
Abstract: A search[1] for the top quark with the Collider Detector at Fermilab (CDF) in a sample of pp collisions at √s=1.8 TeV with an integrated luminosity of 19.3±0.7 pb−1 is summarized. We find 12 events consistent with either two W bosons, or a W boson and at least one b jet. The probability that the measured yield is consistent with the background is 0.26%. Though the statistics are too limited to establish firmly the existence of the top quark, a natural interpretation of the excess is that it is due to tt production. Under this assumption, constrained fits to individual events yield a top quark mass of 174±10+13−12 GeV/c2. The tt production cross section is measured to be 13.9+6.1−4.8 pb. Some implications of the measured value of the top mass are discussed.

276 citations


Journal ArticleDOI
TL;DR: In this article, the stability of multiply strange baryonic systems was investigated in the context of a mean field approach obtained from an underlying set of phenomenological meson-baryon interactions.

239 citations


Journal ArticleDOI
TL;DR: In this article, a systematic on-shell renormalization for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model was carried out for the 2-and 3-point Green's functions.

230 citations


Journal ArticleDOI
TL;DR: In this paper, the cross section for the J/ψ and ϒ interaction with light hadrons is calculated in short-distance QCD, based on the large heavy quark mass and the resulting large energy gap to open charm or beauty.

207 citations


Journal ArticleDOI
TL;DR: This work extends parameterization to physics at much lower energies, > 100 GeV, and shows that in this more general case neutral-current experiments are sensitive to only two additional parameters.
Abstract: The contribution to precision electroweak measurements due to TeV physics which couples primarily to the W ± and Z bosons may be parameterized in terms of the three ‘oblique correction’ parameters, S, T and U. We extend this parameterization to physics at much lower energies, > 100 GeV, and show that in this more general case neutral-current experiments are sensitive to only two additional parameters. A third new parameter enters into the W ± width. The standard electroweak theory has recently come of age, with experiments now probing its predictions with sufficient accuracy to test its r corrections in some detail. Besides providing a detailed test of the model, these precision measurements are also very useful for the constraints they impose on any potential new physics that might exist at energies higher than those that have been hitherto experimentally explored. A particularly interesting class of new physics that is constrained by these measure

204 citations



Journal ArticleDOI
TL;DR: In this paper, the authors compared the performance of a traditional cone-type algorithm and a recently proposed cluster-based algorithm for the reconstruction of the hadronic decays of heavy particles using jet algorithms and found that the cluster algorithm offers considerable advantages in the former case and a slight advantage in the latter.
Abstract: We discuss the reconstruction of the hadronic decays of heavy particles using jet algorithms. The ability to reconstruct the mass of the decaying particles is compared between a traditional cone-type algorithm and a recently proposed cluster-type algorithm. The specific examples considered are the semileptonic decays of a heavy Higgs boson at $$\sqrt s = 16$$ TeV, and of top quark-antiquark pairs at $$\sqrt s = 1.8$$ TeV. We find that the cluster algorithm offers considerable advantages in the former case, and a slight advantage in the latter. We briefly discuss the effects of calorimeter energy resolution, and show that a typical resolution dilutes these advantages, but does not remove them entirely.

Journal ArticleDOI
TL;DR: The production of the standard model Higgs particle at high-energy colliders through the reaction [ital e][sup +][ital e[minus]][r arrow][ital ZH] is elaborate, with particular emphasis on the intermediate mass range.
Abstract: We elaborate on the production of the standard model Higgs particle at high-energy [ital e][sup +][ital e[minus]] colliders through the reaction [ital e][sup +][ital e[minus]][r arrow][ital ZH]. Particular emphasis is put on the intermediate mass range. In addition to the signal we discuss in detail the background processes. Angular distributions which are sensitive to the spin and parity of the Higgs particle are analyzed.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the possibility of measuring anomalous couplings between gauge bosons at electron-positron-colliders with optimal observables and showed that such observables contain all information on the coupling parameters that can be extracted in a given reaction.
Abstract: We investigate the prospects of measuring anomalous couplings between gauge bosons at electron-positron-colliders with optimal observables Such observables are shown to contain all information on the coupling parameters that can be extracted in a given reaction Their sensitivity to the form factors in the general expressions of the triple gauge verticesWWZ andWWγ, includingCP violating terms and absorptive parts, is calculated in view of LEP2 and the NLC

Journal ArticleDOI
TL;DR: The Higgs bosons which decay principally to top quarks, such as in the minimal supersymmetric model, produce a peak-dip structure in the gg→t t invariant mass spectrum as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, a detailed presentation of the electroweak one-loop contributions to the production mechanisms of top quark pairs, q q → t t and g g → t T, for the energy range of future hadron colliders is given.

Journal ArticleDOI
TL;DR: In this article, a light Z' boson was constructed and phenomenological bounds were derived for the two-body decay of the Z' cosmonuclear model, which is known as the two body decay.
Abstract: A model of a light Z' boson is constructed and phenomenological bounds are derived. This Z' boson arises from a very simple extension to the standard model, and it is constrained to be light because the vacuum expectation values which generate its mass also break the electroweak gauge group. It is difficult to detect experimentally because it couples exclusively or primarily (depending on symmetry-breaking details) to second and third generation leptons. However, if the Z' boson is sufficiently light, then there exists the possibility of the two-body decay \ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\mu}Z' occurring. This will provide a striking signature to test the model.

Journal ArticleDOI
TL;DR: It turns out that this two-loop leading electroweak radiative correction to the Higgs-boson--gluon coupling is well under control across the physically interesting quark mass ranges.
Abstract: At proton colliders, Higgs particles are dominantly produced in the gluon-gluon fusion mechanism. The Higgs-boson--gluon coupling is mediated by heavy quark loops, and the process can serve to count the number of heavy strongly interacting particles whose masses are generated by the Higgs mechanism. We present the two-loop leading electroweak radiative correction to this coupling, which is quadratically proportional to the heavy quark masses. It turns out that this correction is well under control across the physically interesting quark mass ranges.

Journal ArticleDOI
TL;DR: A broad review of the quantum effects related to the Higgs boson, to highlight their phenomenological relevance, to list the most important formulae for quick reference, and to generate a rich bibliography, so that the interested reader can find the source of the results.

Journal ArticleDOI
TL;DR: In this paper, the authors compared the Minimal Supersymmetric Standard Model (MSSM) and the standard model with the light Higgs boson mass Mh.

Journal ArticleDOI
TL;DR: In this article, the effects induced by new neutral fetmions below their mass threshold, due to their possible mixing with the standard neutrinos, were studied. But the experimental constraints on lepton universality and the measurement of the,X decay rate were not considered.

Journal ArticleDOI
TL;DR: In this article, a small admixture of V+A interactions is incorporated to study the polarisation dependent neutrino distribution which is particularly sensitive towards deviations from the V-A structure.

Journal ArticleDOI
TL;DR: This work studies meson decays mediated by the heavy gauge bosons of the Pati-Salam model of quark-lepton unification and considers the scenarios in which the [tau] lepton is associated with the third, second, and first generation of quarks.
Abstract: We study meson decays mediated by the heavy gauge bosons of the Pati-Salam model of quark-lepton unification. We consider the scenarios in which the \ensuremath{\tau} lepton is associated with the third, second, and first generation of quarks. The most sensitive probes, depending on the scenario, are rare K, \ensuremath{\pi}, and B decays.

Journal ArticleDOI
TL;DR: In this article, the authors explored the prospect of detecting a Higgs particle at LHC via its associated production with a gluon, Z or W boson, while the signal/background ratio is too small for the first process.

Journal ArticleDOI
TL;DR: In this article, the parity of Higgs particles in the Standard Model and its supersymmetric extensions is analyzed and a production process for Higgs particle fusion in linearly polarized photon-photon collisions is discussed.
Abstract: We analyze the prospects of measuring the parity of Higgs particles in the Standard Model and its supersymmetric extensions. Higgs decays are discussed in this context as well as production processes including, in particular, the fusion of Higgs particles in linearly polarized photon-photon collisions.

Journal ArticleDOI
TL;DR: A nonperturbative parameter which measures the net transverse alignment of the light degrees of freedom in the fragmentation process is used to estimate the polarization retention of charm and bottom baryons.
Abstract: We discuss the production via fragmentation of excited heavy mesons and baryons, and their subsequent decay. In particular, we consider the question of whether a net polarization of the initial heavy quark may be detected, either in a polarization of the final ground state or in anisotropies in the decay products of the excited hadron. The result hinges in part on a nonperturbative parameter which measures the net transverse alignment of the light degrees of freedom in the fragmentation process. We use existing data on charmed mesons to extract this quantity for certain excited mesons. Using this result we estimate the polarization retention of charm and bottom baryons.

Journal ArticleDOI
TL;DR: In this paper, it is shown that photon-photon scattering should be easily observable at PLC and separation of the W loop contribution (which dominates at high energies) will be possible at e + e − c.m.

Journal ArticleDOI
TL;DR: In this article, the Minimal Supersymmetric Standard Model (MSM) was studied in the full (m A, tan β ) parameter space, and it was shown that the danger of washing out any baryon asymmetry created at the electroweak scale is in general no less than in the Standard Model.

Journal ArticleDOI
TL;DR: The upper bound on the number of relativistic species present at nucleosynthesis has been used to constrain particles with electric charge and the bound previously calculated for millicharged particles that interact with a shadow photon is correct.
Abstract: The upper bound on the number of relativistic species present at nucleosynthesis has been used to constrain particles with electric charge $\ensuremath{\epsilon}e({10}^{\ensuremath{-}8}l\ensuremath{\epsilon}l1)$. We correct the bound previously calculated for millicharged particles that interact with a shadow photon. We also discuss the additional constraints from the properties of red giants and of Supernova 1987A.

Journal ArticleDOI
TL;DR: The one-loop radiative corrections to the semileptonic decay of a charged particle at finite gauge boson mass justifies the operator product expansion for inclusive decays of heavy charged particles and implies that infrared effects are suppressed by at least three powers of the heavy mass.
Abstract: We investigate the one-loop radiative corrections to the semileptonic decay of a charged particle at finite gauge boson mass. Extending the Bloch-Nordsieck cancellation of infrared logarithms, the two subsequent nonanalytic terms are also found to vanish after eliminating the pole mass of the decaying particle in favor of a mass defined at short distances. This observation justifies the operator product expansion for inclusive decays of heavy charged particles and implies that infrared effects are suppressed by at least three powers of the heavy mass.