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arXiv 2022年

作者： Zhao, Guang-Yao Gómez, José L. Fuentes, Antonio Krichbaum, Thomas P. Traianou, Efthalia Lico, Rocco Cho, Ilje Ros, Eduardo Komossa, S. Akiyama, Kazunori Asada, Keiichi Blackburn, Lindy Britzen, Silke Bruni, Gabriele Crew, Geoffrey B. Dahale, Rohan Dey, Lankeswar Gold, Roman Gopakumar, Achamveedu Issaoun, Sara Janssen, Michael Jorstad, Svetlana Kim, Jae-Young Koay, Jun Yi Kovalev, Yuri Y. Koyama, Shoko Lobanov, Andrei P. Loinard, Laurent Lu, Ru-Sen Markoff, Sera Marscher, Alan P. Martí-Vidal, Iván Mizuno, Yosuke Park, Jongho Savolainen, Tuomas Toscano, Teresa Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n GranadaE-18008 Spain Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany INAF-Istituto di Radioastronomia Via P. Gobetti 101 BolognaI-40129 Italy Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road WestfordMA01886 United States National Astronomical Observatory of Japan 2-21-1 Osawa Tokyo Mitaka181-8588 Japan Black Hole Initiative at Harvard University 20 Garden Street CambridgeMA02138 United States Institute of Astronomy and Astrophysics Academia Sinica 11F of Astronomy-Mathematics Building AS/NTU No. 1 Roosevelt Rd Taipei10617 Taiwan Center for Astrophysics J Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States INAF-Istituto di Astrofisica e Planetologia Spaziali via Fosso del Cavaliere 100 Roma00133 Italy Indian Institute of Science Education and Research Kolkata Nadia West Bengal Mohanpur741246 India Department of Astronomy and Astrophysics Tata Institute of Fundamental Research Mumbai400005 India CP3-Origins University of Southern Denmark Campusvej 55 Odense MDK-5230 Denmark Radboud University P.O. Box 9010 Nijmegen6500 GL Netherlands NASA Hubble Fellowship Program Einstein Fellow Germany Institute for Astrophysical Research Boston University 725 Commonwealth Ave. BostonMA02215 United States Astronomical Institute St. Petersburg University Universitetskij pr. 28 St.Petersburg Petrodvorets198504 Russia Department of Astronomy and Atmospheric Sciences Kyungpook National University Daegu702-701 Korea Republic of Korea Astronomy and Space Science Institute Daedeok-daero 776 Yuseong-gu Daejeon34055 Korea Republic of Lebedev Physical Institute The Russian Academy of Sciences Leninsky prospekt 53 Moscow119991 Russia Moscow Institute of Physics and Technology Institutsky per. 9 Moscow region Dolgoprudny141700 Russia Niigata University 8050 Ikarashi-nino-cho Nishi-ku Niigata950-

We present the first very-long-baseline interferometric (VLBI) observations of the blazar OJ 287 carried out jointly with the Global Millimeter VLBI Array (GMVA) and the phased Atacama Large Millime ter/submillimeter Array (ALMA) at 3.5mm on April 2, 2017. Participation of phased-ALMA not only has improved the GMVA north-south resolution by a factor of ∼,3, but also has enabled fringe detection with signal-to-noise ratios up to 300 at baselines longer than 2Gλ. The high sensitivity has motivated us to image the data with the newly developed regularized maximum likelihood imaging methods, revealing the innermost jet structure with unprecedentedly high angular resolution. Our images reveal a compact and twisted jet extending along the northwest direction with two bends within the inner 200 μas that resembles a precessing jet in projection. The component at the southeastern end shows a compact morphology and high brightness temperature, and is identified as the VLBI core. An extended jet feature that lies at ∼200 μas northwest of the core shows a conical shape in both total and linearly polarized intensity, and a bimodal distribution of the linear polarization electric vector position angle. We discuss the nature of this feature by comparing our observations with models and simulations of oblique and recollimation shocks with various magnetic field configurations. Our high-fidelity images also enabled us to search for possible jet features from the secondary supermassive black hole (SMBH) and test the SMBH binary hypothesis proposed for this source. © 2022, CC BY.

关键词： Polarization

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Electromagnetic scattering characteristics of the plasma sheath around Re-entry hypersonic vehicles

Electromagnetic scattering characteristics of the plasma she...

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IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)

作者： Run-hui Wu Jia-qi Liu Gang Meng Xin Liu Ai-min Ren Xia Ai Song Chai Ju-yan Zhao Ya-nan Li Ming-liang Wang National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical No.1 Dahongmen South Road Fengtai District Beijing 100076 China

ISBN: (纸本)9781538616093

In order to analyze electromagnetic scattering of reentry vehicle, models of the expected electromagnetic scattering properties of the aircrafts must be developed. This paper begins with a discussion of the plasma sheath characteristics, and the interactions between electromagnetic wave and plasma sheath, and the simulation model of plasma sheath scattering is described by using physical optics and hierarchical approximation technique. Then rigorous calculations of radar cross section(RCS) for a double conical target, plasma-clad body, 30km, 40km, 50km altitude, 4km/s, 5km/s velocity are presented in context with 9.8GHz, 5.8GHz, 3.2GHz, 1.5GHz of incident wave frequency. The results are shown that plasma sheath can increase or decrease the RCS of vehicles for different altitude, velocity and wave frequency. When the aircraft has a low altitude and high-speed flight, electron density of plasma sheath will increase continuously. Influenced by it, the RCS of vehicles shows a decreasing trend.

关键词： Plasma sheaths Electromagnetic scattering Atmospheric modeling Mathematical model Radar cross-sections

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Local-measurement-based quantum state tomography via neural networks

arXiv

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arXiv 2018年

作者： Xin, Tao Lu, Sirui Cao, Ningping Anikeeva, Galit Lu, Dawei Li, Jun Long, Guilu Zeng, Bei Shenzhen Institute for Quantum Science and Engineering Department of Physics Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing100084 China Department of Mathematics & Statistics University of Guelph GuelphONN1G 2W1 Canada Institute for Quantum Computing University of Waterloo WaterlooONN2L 3G1 Canada Tsinghua National Laboratory of Information Science and Technology Innovative Center of Quantum Matter Beijing100084 China Beijing Academy of Quantum Information Sciences Beijing100193 China

Quantum state tomography is a daunting challenge of experimental quantum computing even in moderate system size. One way to boost the efficiency of state tomography is via local measurements on reduced density matrices, but the reconstruction of the full state thereafter is hard. Here, we present a machine learning method to recover the full quantum state from its local information, where a fully-connected neural network is built to fulfill the task with up to seven qubits. In particular, we test the neural network model with a practical dataset, that in a 4-qubit nuclear magnetic resonance system our method yields global states via the 2-local information with high accuracy. Our work paves the way towards scalable state tomography in large quantum systems. Copyright © 2018, The Authors. All rights reserved.

关键词： Quantum optics

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Gravitational test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole

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Physical Review Letters 2020年第14期125卷 141104-141104页

作者： Dimitrios Psaltis Lia Medeiros Pierre Christian Feryal Özel Kazunori Akiyama Antxon Alberdi Walter Alef Keiichi Asada Rebecca Azulay David Ball Mislav Baloković John Barrett Dan Bintley Lindy Blackburn Wilfred Boland Geoffrey C. Bower Michael Bremer Christiaan D. Brinkerink Roger Brissenden Silke Britzen Dominique Broguiere Thomas Bronzwaer Do-Young Byun John E. Carlstrom Andrew Chael Chi-kwan Chan Shami Chatterjee Koushik Chatterjee Ming-Tang Chen Yongjun Chen Ilje Cho John E. Conway James M. Cordes Geoffrey B. Crew Yuzhu Cui Jordy Davelaar Mariafelicia De Laurentis Roger Deane Jessica Dempsey Gregory Desvignes Jason Dexter Ralph P. Eatough Heino Falcke Vincent L. Fish Ed Fomalont Raquel Fraga-Encinas Per Friberg Christian M. Fromm Charles F. Gammie Roberto García Olivier Gentaz Ciriaco Goddi José L. Gómez Minfeng Gu Mark Gurwell Kazuhiro Hada Ronald Hesper Luis C. Ho Paul Ho Mareki Honma Chih-Wei L. Huang Lei Huang David H. Hughes Makoto Inoue Sara Issaoun David J. James Buell T. Jannuzi Michael Janssen Wu Jiang Alejandra Jimenez-Rosales Michael D. Johnson Svetlana Jorstad Taehyun Jung Mansour Karami Ramesh Karuppusamy Tomohisa Kawashima Garrett K. Keating Mark Kettenis Jae-Young Kim Junhan Kim Jongsoo Kim Motoki Kino Jun Yi Koay Patrick M. Koch Shoko Koyama Michael Kramer Carsten Kramer Thomas P. Krichbaum Cheng-Yu Kuo Tod R. Lauer Sang-Sung Lee Yan-Rong Li Zhiyuan Li Michael Lindqvist Rocco Lico Jun Liu Kuo Liu Elisabetta Liuzzo Wen-Ping Lo Andrei P. Lobanov Colin Lonsdale Ru-Sen Lu Jirong Mao Sera Markoff Daniel P. Marrone Alan P. Marscher Iván Martí-Vidal Satoki Matsushita Yosuke Mizuno Izumi Mizuno James M. Moran Kotaro Moriyama Monika Moscibrodzka Cornelia Müller Gibwa Musoke Alejandro Mus Mejías Hiroshi Nagai Neil M. Nagar Ramesh Narayan Gopal Narayanan Iniyan Natarajan Roberto Neri Aristeidis Noutsos Hiroki Okino Héctor Olivares Tomoaki Oyama Daniel C. M. Palumbo Jongho Park Nimesh Patel Ue-Li Pen Vincent Piétu Richard Plambeck Aleksandar PopStefanija Ben Prather Jorge A. Preciado-López Venkatessh Ramak Steward Observatory and Department of Astronomy University of Arizona 933 North Cherry Avenue Tucson Arizona 85721 USA School of Natural Sciences Institute for Advanced Study 1 Einstein Drive Princeton New Jersey 08540 USA National Radio Astronomy Observatory 520 Edgemont Road Charlottesville Virginia 22903 USA Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road Westford Massachusetts 01886 USA National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Black Hole Initiative at Harvard University 20 Garden Street Cambridge Massachusetts 02138 USA Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n E-18008 Granada Spain Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 D-53121 Bonn Germany Institute of Astronomy and Astrophysics Academia Sinica 11F of Astronomy-Mathematics Building AS/NTU No. 1 Sec. IV Roosevelt Road Taipei 10617 Taiwan Republic of China Departament d’Astronomia i Astrofísica Universitat de València C. Dr. Moliner 50 E-46100 Burjassot València Spain Observatori Astronmic Universitat de València C. Catedrático José Beltrán 2 E-46980 Paterna València Spain Center for Astrophysics–Harvard & Smithsonian 60 Garden Street Cambridge Massachusetts 02138 USA East Asian Observatory 660 North A’ohoku Place Hilo Hawaii 96720 USA Nederlandse Onderzoekschool voor Astronomie (NOVA) P.O. Box 9513 2300 RA Leiden Netherlands Institute of Astronomy and Astrophysics Academia Sinica 645 North A’ohoku Place Hilo Hawaii 96720 USA Institut de Radioastronomie Millimétrique 300 rue de la Piscine F-38406 Saint Martin d’Hères France Department of Astrophysics Institute for Mathematics Astrophysics and Particle Physics (IMAPP) Radboud University P.O. Box 9010 6500 GL Nijmegen Netherlands Korea Astronomy and Space Science Institute Daedeok-daero 776 Yuseong-gu Daejeon 34055 Republic of Korea University of Science and Technology Gajeong-ro 217 Yuseong-gu Daejeon 34113 Re

The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources.

关键词： Astrophysical studies of gravity Classical black holes Experimental studies of gravity Astronomical black holes

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The polarized image of a synchrotron emitting ring of gas orbiting a Black Hole

arXiv

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arXiv 2021年

作者： Narayan, Ramesh Palumbo, Daniel C.M. Johnson, Michael D. Gelles, Zachary Himwich, Elizabeth Chang, Dominic O. Ricarte, Angelo Dexter, Jason Gammie, Charles F. Chael, Andrew A. Akiyama, Kazunori Alberdi, Antxon Alef, Walter Algaba, Juan Carlos Anantua, Richard Asada, Keiichi Azulay, Rebecca Baczko, Anne-Kathrin Ball, David Baloković, Mislav Barrett, John Benson, Bradford A. Bintley, Dan Blackburn, Lindy Blundell, Raymond Boland, Wilfred Bouman, Katherine L. Bower, Geoffrey C. Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broderick, Avery E. Broguiere, Dominique Bronzwaer, Thomas Byun, Do-Young Carlstrom, John E. Chan, Chi-Kwan Chatterjee, Shami Chatterjee, Koushik Chen, Ming-Tang Chen, Yongjun Chesler, Paul M. Cho, Ilje Christian, Pierre Conway, John E. Cordes, James M. Crawford, Thomas M. Crew, Geoffrey B. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy de Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Doeleman, Sheperd S. Eatough, Ralph P. Falcke, Heino Farah, Joseph Fish, Vincent L. Fomalont, Ed Alyson Ford, H. Fraga-Encinas, Raquel Friberg, Per Fromm, Christian M. Fuentes, Antonio Galison, Peter García, Roberto Gentaz, Olivier Georgiev, Boris Goddi, Ciriaco Gold, Roman Gómez, José L. Gómez-Ruiz, Arturo I. Gu, Minfeng Gurwell, Mark Hada, Kazuhiro Haggard, Daryl Hecht, Michael H. Hesper, Ronald Ho, Luis C. Ho, Paul Honma, Mareki Huang, Chih-Wei L. Huang, Lei Hughes, David H. Ikeda, Shiro Inoue, Makoto Issaoun, Sara James, David J. Jannuzi, Buell T. Janssen, Michael Jeter, Britton Jiang, Wu Jimenez-Rosales, Alejandra Jorstad, Svetlana Jung, Taehyun Karami, Mansour Karuppusamy, Ramesh Kawashima, Tomohisa Keating, Garrett K. Kettenis, Mark Kim, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kino, Motoki Koay, Jun Yi Kofuji, Yutaro Koch, Patrick M. Koyama, Shoko Kramer, Michael Kramer, Carsten Krichbaum, Thomas P. Kuo, Cheng-Yu Lauer, Tod R. Lee, Sang-Sung Levis, Aviad Li, Yan-Rong Li, Zhiyuan Lindqvist, Michael Lico, Rocco Lindahl, Greg Liu, Jun Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Black Hole Initiative at Harvard University 20 Garden Street CambridgeMA02138 United States Center for the Fundamental Laws of Nature Harvard University CambridgeMA02138 United States JILA Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States Department of Physics University of Illinois at Urbana-Champaign 1110 West Green Street UrbanaIL61801 United States Department of Astronomy University of Illinois at Urbana-Champaign 1002 West Green Street UrbanaIL61801 United States Princeton Center for Theoretical Science Jadwin Hall Princeton University PrincetonNJ08544 United States NASA Hubble Fellowship Program Einstein United States Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road WestfordMA01886 United States National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n GranadaE-18008 Spain Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Department of Physics Faculty of Science University of Malaya Kuala Lumpur50603 Malaysia Center for Astrophysics - Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Center for Computational Astrophysics Flatiron Institute 162 Fifth Avenue New YorkNY10010 United States Institute of Astronomy and Astrophysics Academia Sinica 11F of Astronomy-Mathematics Building AS/NTU No. 1 Sec. 4 Roosevelt Rd Taipei10617 Taiwan Departament d'Astronomia i Astrofísica Universitat de València C. Dr. Moliner 50 Burjassot ValènciaE-46100 Spain Observatori Astronòmic Universitat de València C. Catedrático José Beltrán 2 Paterna ValènciaE-46980 Spain Steward Observatory Department of Astronomy University of Arizona 933 N. Cherry Ave. TucsonAZ85721 United States Fermi National Accelerator Laboratory

Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black hole. By using an approximate expression for the null geodesics derived by Beloborodov (2002) and conservation of the Walker-Penrose constant, we provide analytic estimates for the image polarization. We test this model using currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions, such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent with the clockwise rotation inferred from total intensity images. Copyright © 2021, The Authors. All rights reserved.

关键词： Black holes

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A new tool for cme arrival time prediction using machine learning algorithms: Cat-puma

arXiv

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arXiv 2018年

作者： Liu, Jiajia Ye, Yudong Shen, Chenglong Wang, Yuming Erdélyi, Robert School of Mathematics and Statistics University of Sheffield SheffieldS3 7RH United Kingdom State Key Laboratory of Space Weather National Space Science Center Sigma Weather Group Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China Department of Geophysics and Planetary Sciences Cas Key Laboratory of Geospace Environment University of Science and Technology of China Hefei Anhui230026 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui230026 China Department of Astronomy Eötvös Loránd University BudapestH-1117 Hungary

Coronal Mass Ejections (CMEs) are arguably the most violent eruptions in the Solar System. CMEs can cause severe disturbances in the interplanetary space and even affect human activities in many respects, causing damages to infrastructure and losses of revenue. Fast and accurate prediction of CME arrival time is then vital to minimize the disruption CMEs may cause when interacting with geospace. In this paper, we propose a new approach for partial-/full-halo CME Arrival Time Prediction Using Machine learning Algorithms (CAT-PUMA). Via detailed analysis of the CME features and solar wind parameters, we build a prediction engine taking advantage of 182 previously observed geo-effective partial-/full-halo CMEs and using algorithms of the Support Vector Machine (SVM). We demonstrate that CAT-PUMA is accurate and fast. In particular, predictions after applying CAT-PUMA to a test set, that is unknown to the engine, show a mean absolute prediction error ∼5.9 hours of the CME arrival time, with 54% of the predictions having absolute errors less than 5.9 hours. Comparison with other models reveals that CATPUMA has a more accurate prediction for 77% of the events investigated;and can be carried out very fast, i.e. within minutes after providing the necessary input parameters of a CME. A practical guide containing the CAT-PUMA engine and the source code of two examples are available in the Appendix, allowing the community to perform their own applications for prediction using CAT-PUMA. Copyright © 2018, The Authors. All rights reserved.

关键词： Engines

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Measurement of the CKM matrix element |Vcb| from B0→D*−ℓ+νℓ at Belle

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Physical Review D 2019年第5期100卷 052007-052007页

作者： E. Waheed P. Urquijo D. Ferlewicz I. Adachi K. Adamczyk H. Aihara S. Al Said D. M. Asner H. Atmacan T. Aushev R. Ayad V. Babu I. Badhrees V. Bansal P. Behera C. Beleño F. Bernlochner B. Bhuyan T. Bilka J. Biswal A. Bobrov G. Bonvicini A. Bozek M. Bračko T. E. Browder M. Campajola D. Červenkov P. Chang V. Chekelian A. Chen B. G. Cheon K. Chilikin H. E. Cho K. Cho S.-K. Choi Y. Choi S. Choudhury D. Cinabro S. Cunliffe S. Di Carlo Z. Doležal T. V. Dong D. Dossett S. Eidelman D. Epifanov J. E. Fast B. G. Fulsom R. Garg V. Gaur A. Garmash A. Giri P. Goldenzweig B. Golob O. Grzymkowska J. Haba T. Hara K. Hayasaka H. Hayashii M. T. Hedges W.-S. Hou C.-L. Hsu T. Iijima K. Inami G. Inguglia A. Ishikawa M. Iwasaki Y. Iwasaki W. W. Jacobs H. B. Jeon S. Jia Y. Jin D. Joffe K. K. Joo J. Kahn A. B. Kaliyar G. Karyan T. Kawasaki C. H. Kim D. Y. Kim K. T. Kim S. H. Kim K. Kinoshita P. Kodyš S. Korpar D. Kotchetkov P. Križan R. Kroeger P. Krokovny T. Kuhr R. Kulasiri A. Kuzmin Y.-J. Kwon J. S. Lange J. Y. Lee S. C. Lee C. H. Li L. K. Li Y. B. Li L. Li Gioi J. Libby K. Lieret D. Liventsev P.-C. Lu T. Luo J. MacNaughton M. Masuda D. Matvienko M. Merola F. Metzner K. Miyabayashi H. Miyata R. Mizuk G. B. Mohanty T. Mori R. Mussa I. Nakamura M. Nakao K. J. Nath Z. Natkaniec M. Nayak M. Niiyama N. K. Nisar S. Nishida K. Nishimura S. Ogawa H. Ono P. Pakhlov G. Pakhlova B. Pal S. Pardi H. Park S.-H. Park S. Paul R. Pestotnik L. E. Piilonen V. Popov E. Prencipe M. Prim A. Rostomyan G. Russo Y. Sakai M. Salehi S. Sandilya T. Sanuki V. Savinov O. Schneider G. Schnell J. Schueler C. Schwanda Y. Seino K. Senyo O. Seon M. E. Sevior V. Shebalin C. P. Shen J.-G. Shiu B. Shwartz F. Simon A. Sokolov E. Solovieva S. Stanič M. Starič Z. S. Stottler J. F. Strube T. Sumiyoshi M. Takizawa K. Tanida F. Tenchini K. Trabelsi M. Uchida T. Uglov Y. Unno S. Uno Y. Usov G. Varner K. E. Varvell A. Vinokurova A. Vossen C. H. Wang M.-Z. Wang P. Wang E. Won S. B. Yang H. Ye Y. Yusa Z. P. Zhang V. Zhilich V. Zhukova School of Physics University of Melbourne Victoria 3010 High Energy Accelerator Research Organization (KEK) Tsukuba 305-0801 SOKENDAI (The Graduate University for Advanced Studies) Hayama 240-0193 H. Niewodniczanski Institute of Nuclear Physics Krakow 31-342 Department of Physics University of Tokyo Tokyo 113-0033 Department of Physics Faculty of Science University of Tabuk Tabuk 71451 Department of Physics Faculty of Science King Abdulaziz University Jeddah 21589 Brookhaven National Laboratory Upton New York 11973 University of South Carolina Columbia South Carolina 29208 Moscow Institute of Physics and Technology Moscow Region 141700 Tata Institute of Fundamental Research Mumbai 400005 King Abdulaziz City for Science and Technology Riyadh 11442 Pacific Northwest National Laboratory Richland Washington 99352 Indian Institute of Technology Madras Chennai 600036 II. Physikalisches Institut Georg-August-Universität Göttingen 37073 Göttingen University of Bonn 53115 Bonn Indian Institute of Technology Guwahati Assam 781039 Faculty of Mathematics and Physics Charles University 121 16 Prague J. Stefan Institute 1000 Ljubljana Budker Institute of Nuclear Physics SB RAS Novosibirsk 630090 Novosibirsk State University Novosibirsk 630090 Wayne State University Detroit Michigan 48202 University of Maribor 2000 Maribor University of Hawaii Honolulu Hawaii 96822 INFN—Sezione di Napoli 80126 Napoli Università di Napoli Federico II 80055 Napoli Department of Physics National Taiwan University Taipei 10617 Max-Planck-Institut für Physik 80805 München National Central University Chung-li 32054 Hanyang University Seoul 133-791 P.N. Lebedev Physical Institute of the Russian Academy of Sciences Moscow 119991 Korea Institute of Science and Technology Information Daejeon 305-806 Gyeongsang National University Chinju 660-701 Sungkyunkwan University Suwon 440-746 Indian Institute of Technology Hyderabad Telangana 502285 Deutsches Elektronen–Synchrotron 22607 Hamburg LAL Univ. Paris-Sud

We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from B0→D*−ℓ+νℓ decays, reconstructed with the full Belle data set of 711 fb−1 integrated luminosity. Two form factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F(1)ηEW|Vcb| and the decay form factors, where F(1) is the normalization factor and ηEW is a small electroweak correction. In the CLN parametrization we find F(1)ηEW|Vcb|=(35.06±0.15±0.56)×10−3, ρ2=1.106±0.031±0.007, R1(1)=1.229±0.028±0.009, R2(1)=0.852±0.021±0.006. For the BGL parametrization we obtain F(1)ηEW|Vcb|=(34.93±0.23±0.59)×10−3, which is consistent with the world average when correcting for F(1)ηEW. The branching fraction of B0→D*−ℓ+νℓ is measured to be B(B0→D*−ℓ+νℓ)=(4.90±0.02±0.16)%. We also present a new test of lepton flavor universality violation in semileptonic B decays, B(B0→D*−e+ν)B(B0→D*−μ+ν)=1.01±0.01±0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of F(1)ηEW|Vcb| and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.

关键词： Electroweak radiative corrections Flavor changing neutral currents Form factors Particle interactions W & Z bosons

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Research on networking communication technology based on small spacecraft 67

Research on networking communication technology based on sma...

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67th International Astronautical Congress, IAC 2016

作者： Peng, Qin Yang, Cao Lu, Gao Zhiye, Jiang Jinliang, Bai National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics China Academy of Launch Vehicle Technology No. 1 Nan Da Hong Men Road Beijing China

Small spacecrafts have many advantages such as distribution area controllable, flexible, easy networking and co-optimal allocation of resources. The distributed collaborative networking technology can make several small spacecrafts to co-ordinate and work together as a whole. The technology has good prospects in the aerospace field and has obtained wide attention, for it can achieve communication transmission, space exploration, decision-making tasks and other functions. This paper proposes a collaborative networking solution based on small spacecraft, focusing on the research of key technologies such as networking method, communication protocols, synchronous communication and interference. This paper designed a collaborative network communication system solution, developed a prototype and verified the feasibility of the solution through simulation analysis and prototype testing. This paper also suggested the ideas and methods to improve future collaborative network communication system. Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved.

关键词： Spacecraft

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test of lepton flavor universality and search for lepton flavor violation in B → K decays

arXiv

引用

arXiv 2019年

作者： Choudhury, S. Sandilya, Saurabh Trabelsi, K. Giri, A. Aihara, H. Al Said, S. Asner, D.M. Atmacan, H. Aulchenko, V. Aushev, T. Ayad, R. Babu, V. Bahinipati, S. Behera, P. Beleño, C. Belous, K. Bennett, J. Bernlochner, F. Bessner, M. Bhardwaj, V. Bilka, T. Biswal, J. Bonvicini, G. Bozek, A. Bračko, M. Browder, T.E. Campajola, M. Červenkov, D. Chang, M.-C. Chang, P. Chekelian, V. Chen, A. Cheon, B.G. Chilikin, K. Cho, K. Choi, S.-K. Choi, Y. Cinabro, D. Cunliffe, S. Dash, N. de Nardo, G. Dhamija, R. Di Capua, F. Dingfelder, J. Doležal, Z. Dong, T.V. Dossett, D. Dubey, S. Eidelman, S. Epifanov, D. Ferber, T. Ferlewicz, D. Fulsom, B.G. Garg, R. Gaur, V. Gabyshev, N. Garmash, A. Goldenzweig, P. Golob, B. Greenwald, D. Hadjivasiliou, C. Hartbrich, O. Hayashii, H. Hedges, M.T. Hernandez Villanueva, M. Higuchi, T. Hou, W.-S. Hsu, C.-L. Iijima, T. Inami, K. Ishikawa, A. Itoh, R. Iwasaki, M. Iwasaki, Y. Jacobs, W.W. Jang, E.-J. Jeon, H.B. Jia, S. Jin, Y. Joo, C.W. Joo, K.K. Kahn, J. Kaliyar, A.B. Kang, K.H. Karyan, G. Kichimi, H. Kiesling, C. Kim, B.H. Kim, D.Y. Kim, K.-H. Kim, K.T. Kim, S.H. Kim, Y.-K. Kinoshita, K. Kodyš, P. Korpar, S. Kotchetkov, D. Križan, P. Kroeger, R. Krokovny, P. Kuhr, T. Kulasiri, R. Kumar, R. Kumara, K. Kuzmin, A. Kwon, Y.-J. Lalwani, K. Lee, S.C. Lewis, P. Li, C.H. Li, L.K. Li, Y.B. Li Gioi, L. Libby, J. Lieret, K. Liptak, Z. Liventsev, D. Luo, T. Masuda, M. Matsuda, T. Matvienko, D. Merola, M. Miyabayashi, K. Mizuk, R. Mohanty, G.B. Mohanty, S. Moon, T.J. Mori, T. Nakamura, I. Nakamura, K.R. Nakao, M. Natkaniec, Z. Natochii, A. Nayak, L. Nayak, M. Niiyama, M. Nisar, N.K. Nishida, S. Ogawa, K. Ono, H. Onuki, Y. Oskin, P. Pakhlov, P. Pakhlova, G. Pardi, S. Park, H. Park, S.-H. Patra, S. Paul, S. Pedlar, T.K. Pestotnik, R. Piilonen, L.E. Podobnik, T. Popov, V. Prencipe, E. Prim, M.T. Rabusov, A. Rostomyan, A. Rout, N. Rozanska, M. Hiroshima University Japan University of the Basque Country UPV EHU Bilbao48080 Spain University of Bonn Bonn53115 Germany Brookhaven National Laboratory UptonNY11973 United States Budker Institute of Nuclear Physics SB RAS Novosibirsk630090 Russia Faculty of Mathematics and Physics Charles University Prague121 16 Czech Republic Chonnam National University Gwangju61186 Korea Republic of University of Cincinnati CincinnatiOH45221 United States Deutsches Elektronen-Synchrotron Hamburg22607 Germany University of Florida GainesvilleFL32611 United States Department of Physics Fu Jen Catholic University Taipei24205 Taiwan Institute of Modern Physics Fudan University Shanghai200443 China II. Physikalisches Institut Georg-August-Universität Göttingen Göttingen37073 Germany Hayama240-0193 Japan Gyeongsang National University Jinju52828 Korea Republic of Department of Physics Institute of Natural Sciences Hanyang University Seoul04763 Korea Republic of University of Hawaii HonoluluHI96822 United States Tsukuba305-0801 Japan Tsukuba305-0801 Japan Moscow101000 Russia Forschungszentrum Jülich Jülich52425 Germany IKERBASQUE Basque Foundation for Science Bilbao48013 Spain Indian Institute of Science Education and Research Mohali SAS Nagar140306 India Indian Institute of Technology Bhubaneswar Satya Nagar751007 India Indian Institute of Technology Hyderabad Telangana502285 India Indian Institute of Technology Madras Chennai600036 India Indiana University BloomingtonIN47408 United States Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Institute for High Energy Physics Protvino142281 Russia Institute of High Energy Physics Vienna1050 Austria INFN - Sezione di Napoli Napoli80126 Italy INFN - Sezione di Torino Torino10125 Italy Advanced Science Research Center Japan Atomic Energy Agency Naka319-1195 Japan J. Stefan Institute Ljubljana1000 Slovenia Institut für Experimentelle

We present measurements of the branching fractions for the decays B → Kµ+µ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106 BB¯ events. The data were collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is 1.03+0−0.2824 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP -averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, dB/dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kµ±e decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+µ±e, and B0 → K0µ±e modes. Copyright © 2019, The Authors. All rights reserved.

关键词： Germanium alloys

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Optimal Selection of regularization parameter for ?1-based image restoration based on SURE

Optimal Selection of regularization parameter for ?1-based i...

引用

International Symposium on Optoelectronic technology and Application 2016(OTA 2016)——Conf.12 Infrared technology and Application

作者： Feng Xue Xin Liu Hongyan Liu Jiaqi Liu National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics

In real applications of infrared imaging and remote sensing, the observed images are often blurry and noisy due to the limitations of acquisition system. This degradation is often mathematically formu

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