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A model to explain the angular distribution of J/Ψ and Ψ(2S) decay into ■ and ■

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Chinese Physics C 2019年第2期43卷 31-36页

作者： M.Alekseev A.Amoroso R.Baldini Ferroli I.Balossino M.Bertani D.Bettoni F.Bianchi J.Chai G.Cibinetto F.Cossio F.De Mori M.Destefanis R.Farinelli L.Fava G.Felici I.Garzia M.Greco L.Lavezzi C.Leng M.Maggiora A.Mangoni S.Marcello G.Mezzadri S.Pacetti P.Patteri A.Rivetti M.Da Rocha Rolo M.Savrié S.Sosio S.Spataro L.Yan Università di Torino infn sezione di Torino infn Laboratori Nazionali di Frascati infn sezione di Ferrara Institute of High Energy Physics Università di Ferrara Università del Piemonte Orientale Università di perugia INFN Sezione di Perugia

BESⅢ data show a particular angular distribution for the decay of J/Ψ and Ψ(2 S) mesons into ■ and Σ~0Σ~0 hyperons: the angular distribution of the decay Ψ(2 S) →Σ~0Σ~0 exhibits an opposite trend with respect to the other three channels: J/Ψ→■, J/Ψ→Σ~0Σ~0 and Ψ(2 S) →■. We define a model to explain the origin of this phenomenon.

关键词： J/ψandψ(2S)hadronic decays effective Lagrangian model polarization parameters

Alpha Magnetic Spectrometer (AMS02) experiment on the International Space Station (ISS)

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Nuclear Science and Techniques 2003年第3期14卷 182-194页

作者： Behcet ALPAT INFN Sezione di Perugia Via A.Pascoli06123PerugiaItaly

The Alpha Magnetic Spectrometer experiment is realized in two phases. A precursor flight (STS-91)with a reduced experimental configuration (AMS01) has successfully flown on space shuttle discovery in June 1998.The final version (AMS02) will be installed on the International Space Station (ISS) as an independent module inearly 2006 for an operational period of three years. The main scientific objectives of AMS02 include the searches forthe antimatter and dark matter in cosmic rays. In this work we will discuss the experimental details as well as the im-proved physics capabilities of AMS02 on ISS.

关键词： α磁分光仪国际空间站反物质暗物质

The HEPD particle detector of the CSES satellite mission for investigating seismo-associated perturbations of the Van Allen belts

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Science China(Technological Sciences) 2018年第5期61卷 643-652页

作者： AMBROSI Giovanni BARTOCCI Simona BASARA Laurent BATTISTON Roberto BURGER William J. CARFORA Luca CASTELLINI Guido CIPOLLONE Piero CONTI Livio CONTIN Andrea DE DONATO Cinzia DE SANTIS Cristian FOLLEGA Francesco M. GUANDALINI Cristina IONICA Maria IUPPA Roberto LAURENTI Giuliano LAZZIZZERA Ignazio LOLLI Mauro MANEA Christian MARCELLI Laura MASCIANTONIO Giuseppe MERGE Matteo OSTERIA Giuseppe PACINI Lorenzo PALMA Francesco PALMONARI Federico PANICO Beatrice PATRIZII Laura PERFETTO Francesco PICOZZA Piergiorgio POZZATO Michele PUEL Matteo RASHEVSKAYA Irina RICCI Ester RICCI Marco RICCIARINI Sergio Bruno SCOTTI Valentina SOTGIU Alessando SPARVOLI Roberta SPATARO Bruno VITALE Vincenzo Istituto Nazionale di Fisica Nucleare (infn) Sezione di Perugia Perugia 06123 Italy Uninettuno University Rome 00186 Italy Istituto Nazionale di Fisica Nucleare (infn) Sezione di Roma Tor Vergata Rome 00133 Italy Istituto Nazionale di Fisica Nucleare (infn) TIFPA Povo (TN) 38123 Italy dipartimento di Fisica Universita di Trento Povo (TN) 38123 Italy dipartimento di Fisica Universita di Roma Tor Vergata Rome 00133 Italy IFAC-CNR Sesto Fiorentino (FI) 50019 Italy dipartimento di Fisica e Astronomia Universita di Bologna Bologna 40127 Italy Istituto Nazionale di Fisica Nucleare (infn) Sezione di Bologna Bologna 40127 Italy Istituto Nazionale di Fisica Nucleare (infn) Sezione di Napoli Naples 80126 Italy Istituto Nazionale di Fisica Nucleare (infn) LNE Frascati (RM) 00044 Italy Agenzia Spaziale Italiana (ASI) SSDC Rome 00133 Italy

CSES(China Seismo-Electromagnetic Satellite) is a mission developed by CNSA(Chinese National Space Administration) and ASI(Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle environment, for studying the seismo-associated disturbances in the ionosphere-magnetosphere transition zone. The anthropogenic and electromagnetic noise,as well as the natural non-seismic electromagnetic emissions is mainly due to tropospheric activity. In particular, the mission aims to confirming the existence of possible temporal correlations between the occurrence of earthquakes for medium and strong magnitude and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts with highenergy charged particles from the inner Van Allen belt. In this framework, the high energy particle detector(HEPD) of the CSES mission has been developed by the Italian LIMADOU Collaboration. HEPD is an advanced detector based on a tower of scintillators and a silicon tracker that provides good energy and angular resolution and a wide angular acceptance, for electrons of 3–100 Me V, protons of 30–200 Me V and light nuclei up to the oxygen. CSES satellite has been launched on February 2^(nd), 2018 from the Jiuquan Satellite Launch Center(China).

关键词：卫星发射中心粒子带子空间管理合作开发空间机构轻原子核意大利

General Relativity and the Tully-Fisher Relation for Rotating Galaxies

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Journal of Modern Physics 2022年第11期13卷 1452-1473页

作者： Yogendra Srivastava Giorgio Immirzi John Swain Orlando Panella Simone Pacetti Emeritus Professor of Physics Northeastern University Boston MA USA dipartimento di Fisica e Geologia Università di Perugia Perugia Italy Retired Dipartimento di Fisica e Geologia Università di Perugia Perugia Italy Physics Department Northeastern University Boston MA USA Istituto Nazionale di Fisica Nucleare INFN Sezione di Perugia Perugia Italy

The flat limit of rotational velocity (vφ) approximately equal to the “edge”-velocity of a galaxy is related to the baryonic mass (MB) via the T-F relationship with n ≈ 4. We explore the connection between mass and the limiting velocity in the framework of general relativity (GR) using the Weyl metric for axially-symmetric galaxies that are supported entirely by their rotational motion. While for small distances from the center, the Newtonian description is accurate as one moves beyond the (baryonic) edge of the galaxy, Lenz’s law and non-linearity of the gravitational field inherent in GR not only lead to a flat velocity (obviating its Keplerian fall), but also provide its tight log-log relationship with the enclosed (baryonic) mass.

关键词： GR Weyl Metric Rotating Galaxies Flat Rotation Curves TF Relation

Radioisotope production using lasers:From basic science to applications

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Matter and Radiation at Extremes 2024年第3期9卷 31-44页

作者： M.R.D.Rodrigues A.Bonasera M.Scisciò J.A.Pérez-Hernández M.Ehret F.Filippi P.L.Andreoli M.Huault H.Larreur D.Singappuli D.Molloy D.Raffestin M.Alonzo G.G.Rapisarda D.Lattuada G.L.Guardo C.Verona Fe.Consoli G.Petringa A.McNamee M.La Cognata S.Palmerini T.Carriere M.Cipriani G.di Giorgio G.Cristofari R.De Angelis G.A.P.Cirrone D.Margarone L.Giuffrida D.Batani P.Nicolai K.Batani R.Lera L.Volpe D.Giulietti S.Agarwal M.Krupka S.Singh Fa.Consoli cyclotron institute texas a&m universitycollege stationtexas 77840usa laboratori nazionali del sud istituto nazionale di fisica nucleare(lns-infn)cataniaitaly enea fusion and technologies for nuclear safety and security department-cfrascatiitaly centro de láseres pulsados(clpu) villamayorspain universidad de salamanca salamancaspain centre lasers intenses et applications(celia) universitéde bordeauxcnrsceatalencefrance hb11 energy holdings pty freshwaternew south walesaustralia school of mathematics and physics queen’s university belfastbelfastunited kingdom dipartimento di fisica e astronomia“5.majorana ”universitàdi cataniacataniaitaly facoltàdi ingegneria e architettura universitàdegli studi di enna“kore”ennaitaly dipartimento di ingegneria industriale universitàdi roma“tor vergata”romaitaly dipartimento di fisica e geologia universitàdegli studi di perugiaperugiaitaly istituto nazionale di fisica nucleare sezione di perugiaperugiaitaly eli beamlines facility the extreme light infrastructure ericdolni brezanyczech republic institute of plasma physics and laser microfusion(ipplm) warsawpoland 16etsiauniversidad politécnica de madridmadridspain ETSIA Universidad Politécnica de MadridMadridSpain dipartimento fisica “5.fermi”universitàdi pisa and infnpisaitaly fzu–institute of physics of czech academy of sciences pragueczech republic institute of plasma physics of czech academy of sciences pragueczech republic

The discovery of chirped pulse amplification has led to great improvements in laser technology,enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers.Protons with energies of tens of MeV can be accelerated using,for instance,target normal sheath acceleration and focused on secondary targets.Under such conditions,nuclear reactions can occur,with the production of radioisotopes suitable for medical application.The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators.In this paper,we study the production of^(67)Cu,^(63)Zn,^(18)F,and^(11)C,which are currently used in positron emission tomography and other applications.At the same time,we study the reactions^(10)B(p,α)^(7)Be and^(70)Zn(p,4n)^(67)Ga to put further constraints on the proton distributions at different angles,as well as the reaction^(11)B(p,α)^(8)Be relevant for energy production.The experiment was performed at the 1 PW laser facility at VegaⅢin Salamanca,Spain.Angular distributions of radioisotopes in the forward(with respect to the laser direction)and backward directions were measured using a high purity germanium detector.Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera[Nucl.Instrum.Methods Phys.Res.,Sect.A 637,164–170(2011)].

关键词： purity estimates backward

Comparison of Proton Shower Developments in the BGO Calorimeter of the Dark Matter Particle Explorer between GEANT4 and FLUKA Simulations

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Chinese Physics Letters 2020年第11期37卷 114-120页

作者：蒋维岳川崔明阳李翔袁强 Francesca Alemanno Paolo Bernardini Giovanni Catanzani 陈占方 Ivan De Mitri 董铁矿 Giacinto Donvito David Francois Droz Piergiorgio Fusco Fabio Gargano 郭东亚 dimitrios Kyratzis 雷仕俊刘杨 Francesco Loparco 马鹏雄 Giovanni Marsella Mario Nicola Mazziotta 潘旭彭文溪 Antonio Surdo Andrii Tykhonov 魏逸丰余玉洪藏京京张亚鹏张永杰张云龙 Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Gran Sasso Science Institute(GSSI) Viale F.Crispi 7I-67100L'AquilaItaly Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Gran SassoVia G.Acitelli 22I-67100AssergiL'AquilaItaly dipartimento di Matematica e Fisica E.De Giorgi Universitàdel SalentoI-73100 LecceItaly Istituto Nazionale di Fisica Nucleare(infn)-sezione di Lecce I-73100 LecceItaly infn Section of perugia I-06100 PerugiaItaly University of perugia I-06100 PerugiaItaly Istituto Nazionale di Fisica Nucleare(infn)-sezione di Bari I-70125BariItaly Department of Nuclear and Particle Physics University of GenevaCH-1211Switzerland dipartimento Interateneo“M.Merlin”dell'Universitàdegli Studi di Bari e del Politecnico di Bari I-70125BariItaly dipartimento di Fisica e Chimica“E.Segrè” via delle Scienze Edificio 17UniversitàDegli Studi di PalermoI-90128PalermoItaly Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The DArk Matter Particle Explorer(DAMPE)is a satellite-borne detector for high-energy cosmic rays and y-rays.To fully understand the detector performance and obtain reliable physical results,extensive simulations of the detector are necessary.The simulations are particularly important for the data analysis of cosmic ray nuclei,which relies closely on the hadronic and nuclear interactions of particles in the detector material.Widely adopted simulation softwares include the GEANT4 and FLUKA,both of which have been implemented for the DAMPE simulation tool.Here we describe the simulation tool of DAMPE and compare the results of proton shower properties in the calorimeter from the two simulation softwares.Such a comparison gives an estimate of the most significant uncertainties of our proton spectral analysis.

关键词： material. GEANT4 calorimeter

An algorithm to resolve γ-rays from charged cosmic rays with DAMPE

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Research in Astronomy and Astrophysics 2018年第3期18卷 25-36页

作者： Zun-Lei Xu Kai-Kai Duan Zhao-Qiang Shen Shi-Jun Lei Tie-Kuang Dong Fabio Gargano Simone Garrappa Dong-Ya Guo Wei Jiang Xiang Li Yun-Feng Liang Mario Nicola Mazziotta Maria Fernanda Munoz Salinas Meng Su Valerio Vagelli Qiang Yuan Chuan Yue Jing-Jing Zang Ya-Peng Zhang Yun-Long Zhang Stephan Zimmer Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China University of Chinese Academy of Sciences Beijing 100049 China Istituto Nazionale di Fisica Nucleare sezione di Bari I-70125 Bari Italy Istituto Nazionale di Fisica Nucleare sezione di perugia I-06123 Perugia Italy dipartimento di Fisica e Geologia Universita degli Studi di Perugia I-06123 Perugia Italy Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Department of Nuclear and Particle Physics University of Geneva CH- 1211 Switzerland School of Astronomy and Space Science University of Science and Technology of China Hefei 230026 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of China Hefei 230026 China

The DArk Matter Particle Explorer（DAMPE）,also known as Wukong in China,which was launched on 2015 December 17,is a new high energy cosmic ray and γ-ray satellite-borne observatory.One of the main scientific goals of DAMPE is to observe Ge V-Te V high energy γ-rays with accurate energy,angular and time resolution,to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays,it is challenging to identify γ-rays with sufficiently high efficiency,minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations,using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at～10 Ge V amounts to less than 1% of the selected sample.Finally,we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.

关键词： gamma rays general - instrumentation detectors - methods data analysis

Search for the doubly heavy baryons Ωbc~0 and Ξbc~0 decaying to Λc~+π~- and Ξc~+π~-

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Chinese Physics C 2021年第9期45卷 14-25页

作者： R.Aaij C.Abellán Beteta T.Ackernley B.Adeva M.Adinolfi H.Afsharnia C.A.Aidala S.Aiola Z.Ajaltouni S.Akar J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche G.Alkhazov P.Alvarez Cartelle S.Amato Y.Amhis L.An L.Anderlini A.Andreianov M.Andreotti F.Archilli A.Artamonov M.Artuso K.Arzymatov E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista Leite R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay M.Becker F.Bedeschi I.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Bencivenni E.Ben-Haim A.Berezhnoy *** D.Berninghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker S.Bifani P.Billoir M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.Bj?rn M.P.Blago T.Blake F.Blanc S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev A.Bondar N.Bondar S.Borghi M.Borisyak M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M.J.Bradley S.Braun A.Brea Rodriguez M.Brodski J.Brodzicka A.Brossa Gonzalo D.Brundu A.Buonaura C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice L.Calero diaz S.Cali R.Calladine M.Calvi M.Calvo Gomez P.Camargo Magalhaes A.Camboni P.Campana A.F.Campoverde Quezada S.Capelli L.Capriotti A.Carbone G.Carboni R.Cardinale A.Cardini I.Carli P.Carniti L.Carus K.Carvalho Akiba A.Casais Vidal G.Casse M.Cattaneo G.Cavallero S.Celani J.Cerasoli A.J.Chadwick M.G.Chapman M.Charles Ph.Charpentier G.Chatzikonstantinidis C.A.Chavez Barajas M.Chefdeville C.Chen S.Chen A.Chernov V.Chobanova S.Cholak M.Chrzaszcz A.Chubykin V.Chulikov P.Ciambrone M.F.Cicala X.Cid Vidal G.Ciezarek P.E.L.Clarke M.Clemencic H.V.Cliff J.Closier J.L.Cobbledick V.Coco J.A.B.Coelho J.Cogan E.Cogneras L.Cojocariu P.Collins T.Colombo L.Congedo A.Contu N.Cooke G.Coombs G.Corti C.M.Costa Sobral B.Couturier D.C.Craik J.Crkovská M.Cruz Torres R.Currie C.L.Da Silva E.Dall’Occo J.Dalseno C.D’Amb AGH-University of Science and Technology Faculty of Computer Science Electronics and Telecommunications AGH-University of Science and Technology Faculty of Physics and Applied Computer Science Aix Marseille Univ CNRS/IN2P3 CPPM Budker Institute of Nuclear Physics (SB RAS) Cavendish Laboratory University of Cambridge Center for High Energy Physics Tsinghua University Centro Brasileiro de Pesquisas Físicas (CBPF) DS4DS La Salle Universitat Ramon Llull Departamento de Fisica Universidad Nacional de Colombia Department of Physics and Astronomy University of Manchester Department of Physics and Astronomy Uppsala University Department of Physics University of Oxford Department of Physics University of Warwick European Organization for Nuclear Research (CERN) Fakult?t Physik Technische Universit?t Dortmund Guangdong Provencial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University H.H. Wills Physics Laboratory University of Bristol Hangzhou Institute for Advanced Study UCAS Hanoi University of Science Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences Horia Hulubei National Institute of Physics and Nuclear Engineering I.Physikalisches Institut RWTH Aachen University ICCUB Universitat de Barcelona infn Laboratori Nazionali di Frascati infn sezione di Bari infn sezione di Bologna infn sezione di Cagliari infn sezione di Ferrara infn sezione di Firenze infn sezione di Genova infn sezione di Milano infn sezione di Milano-Bicocca INFN Sezione di Perugia infn sezione di Pisa infn sezione di Roma La Sapienza infn sezione di Roma Tor Vergata Imperial College London Institut für Physik Universit?t Rostock Institute Of High Energy Physics (IHEP) Institute for High Energy Physics NRC Kurchatov Institute (IHEP NRC KI) Institute for Nuclear Research of the National Academy of Sciences (KINR) Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) Institute of Nuclear Physics Moscow State University (SINP MSU) Institute of Part

The first search for the doubly heavy Ωbc~0 baryon and a search for the Ξbc~0 baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb-1.The baryons are reconstructed via their decays to ∧c~+π~-andΞc~+π~-.No significant excess is found for invariant masses between 6700 and 7300 MeV/c2,in a rapidity range from2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ωbc~0 andΞbc~0 production cross-section times the branching fraction to ∧c~+π~-(Ξc~+π~-) relative to that of the ∧b~0(Ξb~0) baryon,for different lifetime hypotheses,at 95% confidence level.The upper limits range from 0.5×10-4to 2.5×10-4for theΩbc~0→∧c~+π~-(Ξbc~0→∧c~+π~-) decay,and from 1.4×10-3to 6.9×10-3for the Ωbc~0→Ξc~+π~-(Ξbc~0→Ξc~+π~-) decay,depending on the considered mass and lifetime of the Ωbc~0(Ξbc~0) baryon.

关键词： B physics quarkonium spectroscopy heavy quark production

Search for the rare decays W^(+)→D_(s)^(+)γ and Z→D^(0)γ at LHCb

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中国物理C:英文版 2023年第9期47卷 14-26页

作者： R.Aaij A.S.W.Abdelmotteleb C.Abellan Beteta F.Abudinén T.Ackernley B.Adeva M.Adinolfi P.Adlarson H.Afsharnia C.Agapopoulou C.A.Aidala Z.Ajaltouni S.Akar K.Akiba J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche P.Alvarez Cartelle R.Amalric S.Amato J.L.Amey Y.Amhis L.An L.Anderlini M.Andersson A.Andreianov M.Andreotti D.Andreou D.Ao F.Archilli A.Artamonov M.Artuso E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back A.Bailly-reyre P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista de Souza Leite M.Barbetti R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay A.Beck M.Becker F.Bedeschi I.B.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Benane G.Bencivenni E.Ben-Haim A.Berezhnoy *** *** Andres D.Berninghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker N.V.Biesuz S.Bifani P.Billoir A.Biolchini M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.P.Blago T.Blake F.Blanc J.E.Blank S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev C.S.Bolognani R.Bolzonella N.Bondar F.Borgato S.Borghi M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M.J.Bradley S.Braun A.Brea Rodriguez J.Brodzicka A.Brossa Gonzalo J.Brown D.Brundu A.Buonaura L.Buonincontri A.T.Burke C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice S.Cali R.Calladine M.Calvi M.Calvo Gomez P.Campana D.H.Campora Perez A.F.Campoverde Quezada S.Capelli L.Capriotti A.Carbone G.Carboni R.Cardinale A.Cardini P.Carniti L.Carus A.Casais Vidal R.Caspary G.Casse M.Cattaneo G.Cavallero V.Cavallini S.Celani J.Cerasoli D.Cervenkov A.J.Chadwick M.G.Chapman M.Charles Ph.Charpentier C.A.Chavez Barajas M.Chefdeville C.Chen S.Chen A.Chernov S.Chernyshenko V.Chobanova S.Cholak M.Chrzaszcz A.Chubykin V.Chulikov P.Ciambrone M.F.Cicala X.Cid Vidal G.Ciezarek G.Ciullo P.E.L.Clarke M.Clemencic H.V.Cliff J.Closier J.L.Cobbledick V.Coco J.A.B.Coelho J.Cogan E.Cognera Centro Brasileiro de Pesquisas Físicas(CBPF) Rio de JaneiroBrazil Universidade Federal do Rio de Janeiro(UFRJ) Rio de JaneiroBrazil Center for High Energy Physics Tsinghua UniversityBeijingChina Institute Of High Energy Physics(IHEP) BeijingChina School of Physics State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijingChina University of Chinese Academy of Sciences BeijingChina Institute of Particle Physics Central China Normal UniversityWuhanHubeiChina Université Savoie Mont Blanc CNRSIN2P3-LAPPAnnecyFrance UniversitéClermont Auvergne CNRS/IN2P3LPCClermont-FerrandFrance Aix Marseille Univ CNRS/IN2P3CPPMMarseilleFrance UniversitéParis-Saclay CNRS/IN2P3IJCLabOrsayFrance Laboratoire Leprince-Ringuet CNRS/IN2P3Ecole PolytechniqueInstitut Polytechnique de ParisPalaiseauFrance LPNHE Sorbonne UniversitéParis Diderot Sorbonne Paris CitéCNRS/IN2P3ParisFrance I.Physikalisches Institut RWTH Aachen UniversityAachenGermany Fakultat Physik Technische Universitat DortmundDortmundGermany Max-Planck-Institut für Kernphysik(MPIK) HeidelbergGermany Physikalisches Institut Ruprecht-Karls-Universitat HeidelbergHeidelbergGermany School of Physics University College DublinDublinIreland infn sezione di Bari BariItaly infn sezione di Bologna BolognaItaly infn sezione di Ferrara FerraraItaly infn sezione di Firenze FirenzeItaly infn Laboratori Nazionali di Frascati FrascatiItaly infn sezione di Genova GenovaItaly infn sezione di Milano MilanoItaly infn sezione di Milano-Bicocca MilanoItaly infn sezione di Cagliari MonserratoItaly Universitàdegli Studi di Padova Universitàe INFNPadovaPadovaItaly infn sezione di Pisa PisaItaly infn sezione di Roma La Sapienza RomaItaly infn sezione di Roma Tor Vergata RomaItaly Nikhef National Institute for Subatomic Physics AmsterdamNetherlands Nikhef National Institute for Subatomic Physics and VU University Amsterdam AmsterdamNetherlands AGH-University of Science and Technology Faculty of Physics and Applied Computer Scienc

A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit.

关键词： W/Z boson rare decay upper limit of branching fraction