Author
Mihoko M. Nojiri
Other affiliations: Kyoto University, Institute for the Physics and Mathematics of the Universe, Yukawa Institute for Theoretical Physics ...read more
Bio: Mihoko M. Nojiri is an academic researcher from KEK. The author has contributed to research in topics: Large Hadron Collider & Supersymmetry. The author has an hindex of 48, co-authored 193 publications receiving 8902 citations. Previous affiliations of Mihoko M. Nojiri include Kyoto University & Institute for the Physics and Mathematics of the Universe.
Papers published on a yearly basis
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TL;DR: In this paper, the authors evaluate the gamma ray flux in the case that the dark matter has an electroweak SU(2)_L charge in the minimal supersymmetric standard model (MSSM) when the lightest SUSY particle is the Higgsino- or Wino-like neutralino.
Abstract: Detection of gamma rays from dark matter annihilation in the galactic center is one of the feasible techniques to search for dark matter. We evaluate the gamma ray flux in the case that the dark matter has an electroweak SU(2)_L charge. Such dark matter is realized in the minimal supersymmetric standard model (MSSM) when the lightest SUSY particle is the Higgsino- or Wino-like neutralino. When the dark matter is heavy compared to the weak gauge bosons, the leading-order calculation of the annihilation cross sections in perturbation breaks down due to a threshold singularity. We take into account non-perturbative effects by using the non-relativistic effective theory for the two-body states of the dark matter and its SU(2)_L partner(s), and evaluate precise cross sections relevant to the gamma ray fluxes. We find that the annihilation cross sections may be enhanced by several orders of magnitude due to resonances when the dark matter mass is larger than 1 TeV. Furthermore, the annihilation cross sections in the MSSM may be changed by factors even when the mass is about 500 GeV. We also discuss sensitivities to gamma ray signals from the galactic center in the GLAST satellite detector and the large Air Cerenkov Telescope arrays.
612 citations
TL;DR: In the current Universe, in which the DM is highly nonrelativistic, the nonperturbative effect may enhance the DM annihilation cross sections, especially for that to two photons, by several orders of magnitude.
Abstract: In this Letter we study pair annihilation processes of dark matter (DM) in the Universe, in the case that the DM is an electroweak gauge nonsinglet. In the current Universe, in which the DM is highly nonrelativistic, the nonperturbative effect may enhance the DM annihilation cross sections, especially for that to two photons, by several orders of magnitude. We also discuss sensitivities in future searches for anomalous gamma rays from the galactic center, which originate from DM annihilation.
496 citations
Stanford University1, Rutgers University2, Johns Hopkins University3, Cornell University4, Fermilab5, University of California, Davis6, University of Oregon7, University of California, Berkeley8, Michigan State University9, University of Tokyo10, University of California, Santa Barbara11, Stony Brook University12, Boston University13, École Polytechnique Fédérale de Lausanne14, University of Pittsburgh15, Northwestern University16, Argonne National Laboratory17, Carleton University18, CERN19, University of Wisconsin-Madison20, Syracuse University21, Seoul National University22, Tohoku University23, Korea Institute for Advanced Study24, Harvard University25, University of Michigan26, Princeton University27, TRIUMF28, Florida State University29, University of California, San Diego30, Lawrence Berkeley National Laboratory31, University of Florida32, Massachusetts Institute of Technology33, University of Arizona34, University of California, Irvine35, University of Washington36, York University37, Perimeter Institute for Theoretical Physics38, University of Illinois at Chicago39, University of Zurich40, Yale University41, University of Hawaii at Manoa42, Austrian Academy of Sciences43, New York University44
TL;DR: A collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results is presented in this paper.
Abstract: This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first similar to 50-500 pb(-1) of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.
491 citations
Durham University1, University of Helsinki2, University of Wisconsin-Madison3, University of Rochester4, University of Catania5, Weizmann Institute of Science6, University of Warsaw7, University of Southampton8, CERN9, Lawrence Livermore National Laboratory10, Indian Institute of Science11, University of Montpellier12, University of Zurich13, Spanish National Research Council14, ETH Zurich15, Stanford University16, Northwestern University17, University of Pittsburgh18, Carleton University19, University of Hamburg20, Moscow State University21, University of Florida22, Paul Scherrer Institute23, University of Würzburg24, Imperial College London25, Florida State University26, University of Florence27, University of Bonn28, University at Buffalo29, RWTH Aachen University30, University of Sheffield31, University of California, Irvine32, Laboratoire d'Annecy-le-Vieux de physique des particules33, Brookhaven National Laboratory34, Argonne National Laboratory35, University of Bergen36, University of Mainz37, Centers for Medicare and Medicaid Services38, Lancaster University39, University of California, Santa Cruz40, University of Copenhagen41, University of Tokyo42, Austrian Academy of Sciences43, University of Manchester44, University College London45, University of Edinburgh46, University of California, Davis47, University of California, Berkeley48, University of Glasgow49, University of Barcelona50, Max Planck Society51, University of Chicago52, University of Turin53, Royal Holloway, University of London54, Kobe University55, University of Oslo56, Kyoto University57
TL;DR: In this paper, the authors discuss the possible interplay between the Large Hadron Collider (LHC) and the International e(+)e(-) Linear Collider (ILC) in testing the Standard Model and in discovering and determining the origin of new physics.
422 citations
TL;DR: In this article, the authors address the possible interplay between the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) in testing the Standard Model and in discovering and determining the origin of new physics.
Abstract: Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC / LC Study Group so far is summarised in this report. Possible topics for future studies are outlined.
334 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.
12,798 citations
TL;DR: The Pythia program as mentioned in this paper can be used to generate high-energy-physics ''events'' (i.e. sets of outgoing particles produced in the interactions between two incoming particles).
Abstract: The Pythia program can be used to generate high-energy-physics ''events'', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, underlying events and beam remnants, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest.
6,300 citations
TL;DR: The current status of particle dark matter, including experimental evidence and theoretical motivations, including direct and indirect detection techniques, is discussed in this paper. But the authors focus on neutralinos in models of supersymmetry and Kaluza-Klein dark matter in universal extra dimensions.
4,614 citations
Journal Article•
TL;DR: In this paper, the ATLAS experiment is described as installed in i ts experimental cavern at point 1 at CERN and a brief overview of the expec ted performance of the detector is given.
Abstract: This paper describes the ATLAS experiment as installed in i ts experimental cavern at point 1 at CERN. It also presents a brief overview of the expec ted performance of the detector.
2,798 citations