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High Power Laser science and Engineering 2021年第2期9卷 168-173页

作者： Tina Ebert RenéHeber Torsten Abel Johannes bieker Gabriel schaumann and markus Roth Institut für Kernphysik Department of PhysicsTechnische Universität Darmstadt64289 DarmstadtGermany Integrierte mikro-Nano-systeme Department of Electrical Engineering and Information TechnologyTechnische Universität Darmstadt64283 DarmstadtGermany

Targets with microstructured front surfaces have shown great potential in improving high-intensity laser–matter interaction.We present cone-shaped microstructures made out of silicon and titanium created by ultrashort laser pulse processing with different characteristics.In addition,we illustrate a process chain based on moulding to recreate the laser-processed samples out of polydimethylsiloxane,polystyrol and copper.With all described methods,samples of large sizes can be manufactured,therefore allowing time-efficient,cost-reduced and reliable ways to fabricate large quantities of identical targets.

关键词： microstructured targets moulding particle acceleration ultrashort laser pulse processing X-ray generation

senescence-specific Alteration of Hydrogen Peroxide Levels in Arabidopsis thaliana and Oilseed Rape spring Variety Brassica napus L.cv.mozart

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Journal of Integrative Plant Biology 2012年第8期54卷 540-554页

作者： stefan bieker Lena Riester mark stahl Jürgen Franzaring Ulrike Zentgraf ZmBP (Center for Plant molecular Biology) University of TübingenAuf der Morgenstelle 2872076 Tübingen Germany Institute for Landscape and Plant Ecology kologiezentrum 2August-von-Hartmann-Str.370599 StuttgartGermany

In order to analyze the signaling function of hydrogen peroxide （H202） production in senescence in more detail, we manipulated intracellular H202 levels in Arabidopsis thaliala （L.） Heynh by using the hydrogen- peroxide-sensitive part of the Escherichia coil transcription regulator OxyR, which was directed to the cytoplasm as well as into the peroxisomes. H202 levels were lowered and senescence was delayed in both transgenic lines, but OxyR was found to be more effective in the cytoplasm. To transfer this knowledge to crop plants, we analyzed oilseed rape plants Brassica napus L. cv. mozart for H20~ and its scavenging enzymes catalase （CAT） and ascorbate peroxidase （APX） during leaf and plant development. H202 levels were found to increase during bolting and flowering time, but no increase could be observed in the very late stages of senescence. With increasing H202 levels, CAT and APX activities declined, so it is likely that similar mechanisms are used in oilseed rape and Arabidopsis to control H202 levels. Under elevated CO2 conditions, oilseed rape senescence was accelerated and coincided with an earlier increase in H202 levels, indicating that H202 may be one of the signals to inducing senescence in a broader range of Brassicaceae.

关键词： Arabidopsis thaliana Brassica napus E. coil Oxy-RD intracellular hydrogen peroxide senescence phenotype catalase ascorbatePeroxidase elevated CO2.

一种新型能量检测方法降低认知无线电网络中的主用户仿真攻击

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Journal of Central south University 2022年第5期29卷 1510-1520页

作者： shriraghavan mADBUsHI m.s.s.RUKmINI st.Vincent Pallotti College of Engineering&Technology NagpurMaharashtraIndia Vignan’s Foundation for science Technology and ResearchVadlamudiGuntur(Dist.)India

扩展频谱效率最有前途的解决方案是认知无线电(CR)技术。这种扩展是通过允许未经许可的辅助用户(sUs)访问许可的频段来实现的,不存在对许可的主用户(PUs)的干扰。这种在频谱感知中对CR网络的使用会导致脆弱的攻击,如主用户仿真(PUE)攻击... 详细信息

扩展频谱效率最有前途的解决方案是认知无线电(CR)技术。这种扩展是通过允许未经许可的辅助用户(sUs)访问许可的频段来实现的,不存在对许可的主用户(PUs)的干扰。这种在频谱感知中对CR网络的使用会导致脆弱的攻击,如主用户仿真(PUE)攻击,此时,PUs扮演了恶意用户的角色,不允许其他用户即使在他们不可用的情况下使用PUs通道。在传统的单阈值能量检测算法的基础上,在CR网络中建立一种改进的双阈值能量检测器,对检测概率、漏检概率、误报概率及其相互关系进行检测分析。提出一种改进的双阈值能量检测协同频谱传感技术,以缓解对主要用户的攻击。并对所提出的方法与现有的不考虑提示攻击的能量检测频谱传感方法基于性能方面进行对比评价。在mATLAB的仿真结果表明,所提出的能量检测协同频谱传感技术性能出色,显著减轻了对主用户的攻击。

关键词：认知无线电能量检测频谱检测检测率误报率漏检率

Abundant closed-form wave solutions to the simplified modified Camassa-Holm equation

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Journal of Ocean Engineering and science 2023年第3期8卷 238-245页

作者： s m Rayhanul Islam s m Yiasir Arafat Hanfeng Wang school of Civil Engineering Central South UniversityChangshaHunan 410075China Department of mathematics Pabna University of Science and TechnologyPabna 6600Bangladesh

The simplified modified Camassa-Holm (smCH) equation is an important nonlinear model equation for identifying various wave phenomena in ocean engineering and science. The new auxiliary equation (NAE) method has been applied to the smCH equation. Base on the method, we have obtained some novel an- alytical solutions such as hyperbolic, trigonometric, exponential, and rational function solutions of the smCH equation. For appropriate values of parameters, three dimensional (3D) and two dimensional (2D) graphs are designed by mathematica. The stability of the model is also discussed in this manuscript. The dynamic and physical behaviors of the solutions derived from the smCH equation have been ex- tensively discussed by these plots. All our solutions are indispensable for understanding the nonlinear phenomena of dispersive waves that are important in ocean engineering and science. In addition, our results are essential to clarify the various oceanographic applications containing ocean gravity waves, offshore rig in water, energy associated with a moving ocean wave and numerous other related phenom- ena. Finally, the obtained solutions are helpful for studying wave interactions in many new structures and high-dimensional models.

关键词： smCH equation NAE method Nonlinear physics Kink shape solitary wave

共流型和逆流型圆柱形锂离子电池组液基冷却系统分析

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Journal of Central south University 2023年第11期30卷 3617-3629页

作者： s.m.HAssANI s.H.mAZLOUmI m.KHOsHVAGHT-ALIABADI Department of Chemical Engineering Faculty of EngineeringFerdowsi University of MashhadIran Department of Chemical Engineering Shahrood BranchIslamic Azad UniversityShahroodIran school of mechanical Engineering Korea University145 Anam-roSeongbuk-guSeoul 02841Korea

随着电动汽车对锂离子电池组比能量密度要求的提高,解决电池在恶劣工况下的热稳定性问题在电池组的安全设计中变得越来越重要。这对于缓解里程焦虑和确保电动汽车的整体安全尤为重要。液体冷却系统是锂离子电池热管理的常用方法。本文... 详细信息

随着电动汽车对锂离子电池组比能量密度要求的提高,解决电池在恶劣工况下的热稳定性问题在电池组的安全设计中变得越来越重要。这对于缓解里程焦虑和确保电动汽车的整体安全尤为重要。液体冷却系统是锂离子电池热管理的常用方法。本文采用三维计算流体动力学模拟分析了圆柱电池组矩形通道水冷系统的性能。采用有限体积法,用实验数据验证了计算结果。首先,研究了通道的收敛和发散对所考虑的冷却系统热特性和水力特性的影响。然后,研究了冷却剂的共流型和逆流型策略。结果表明,与传统设计相比,通道的收敛使系统的努塞尔数提高了约21%。而沟道分流时,水力性能较好。散流冷却系统的摩擦损失减小约70%。研究还发现,流动模式对控制电池组的温度均匀性是相当有效的。通道的逆流模式提供了较低的温度,并且在发散通道的情况下,与共流模式的最大偏差约为5.2 K。

关键词：圆柱电池液冷系统不均匀的渠道温度均匀性性能指标

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广义混合流体中纤毛通过电渗透区的流动模拟

Journal of Central south University 2023年第4期30卷 1217-1230页

作者： s.IJAZ m.ABDULLAH H.sADAF s.NADEEm Department of mathematics Faculty of SciencesRawalpindi Women UniversityRawalpindi 44000Pakistan Department of Basic science and Humanities College of Electrical&Mechanical EngineeringNational University of Sciences and TechnologyIslamabad 46000Pakistan Department of mathematics Faculty of SciencesQuaid-e-Azam UniversityIslamabad 46000Pakistan

本文建立了一个广义纳米流体流动模型,研究磁流体中纤毛毯在通过电渗透通道时对其运输的作用,并对混合纳米流体的特性进行解释。通过假设长波长和低雷诺数估计,将流体的流动分析方程转换为无量纲形式;用数学解法得到速度分布、压力梯度... 详细信息

本文建立了一个广义纳米流体流动模型,研究磁流体中纤毛毯在通过电渗透通道时对其运输的作用,并对混合纳米流体的特性进行解释。通过假设长波长和低雷诺数估计,将流体的流动分析方程转换为无量纲形式;用数学解法得到速度分布、压力梯度和流函数的解析解;用图表表明相关物理参数的影响。该模型具有重要的应用价值,可应用于生物运输过程、人工纤毛设计和其他机械装置的操作等领域。

关键词：电渗透效应纤毛边界辐射影响混合纳米流体现象

Y^(3+) substituting-adjusted mechanical,dielectric,and impedance properties of cobalt copper zinc nanoferrites for high frequency applications

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Journal of Rare Earths 2023年第10期41卷 1597-1605,I0005页

作者： s.F.mansour N.s.Al-Bassami m.Afifi m.A.Abdo Physics Department Faculty of ScienceZagazig UniversityZagazigEgypt General studies Department Jubail Industrial CollegeJubail Industrial CitySaudi Arabia Faculty of Nanotechnology for Postgraduate studies Cairo UniversityEl-Sheikh Zayed12588Egypt

Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic devices.This paper reports the mechanical and dielectric properties of Co_(0.5)Cu_(0.25)Zn_(0.25)Y_(x)Fe_(2-x)O_(4)ferrite nanoparticles labeled as CCZYF#0,CCZYF#1,CCZYF#2,CCZYF#3,CCZYF#4 and CCZYF#5 for x=0.***.0.02,0.04,0.06,0.08,and 0.1,respectively.The frequency and temperature dependence of dielectric parameters and co nductivity of all CCZYF nanoferrites are well discussed.The nanoferrite CCZYF#5 has the highest dielectric constant(enhancing ratio 170%)and the highest conductivity(enhancing ratio 7125.81%)compared with the undoped sample.Nyquist plots of all CCZYF nano ferrites manifest two arcs;the main reasons for the dielectric process are the grain boundaries and bulk grains.All impedance parameters were determined,which showed the effective role of Y^(3+)ions on their values.The nanoferrite CCZYF#5 has the highest grain boundaries capacitance(with enhancing ratio of 59.40%)and the highest grains capacitance(with enhancing ratio of 22.53%)with a relaxation time decrement efficiency of 62.51%.An ultrasonic flaw detector was utilized to determine the elastic moduli of all CCZYF nanoferrites.The nanoferrite CCZYF#5 has the highest longitudinal modulus(with enhancing ratio of 20.95%),the highest shear modulus(with enhancing ratio of48.72%),highest Young's modulus(with enhancing ratio of 88.47%),the highest bulk modulus(with enhancing ratio 13.27%)and the highest micro hardness(with enhancing ratio 77.77%).Hence,Y3+tuned Co-Cu-Zn nanoferrites possess new opportunities for high-frequency and storage applications.

关键词： Nanoferrites Rare arth ions mechanical properties Dielectric parameters Impedance spectroscopy

Background removal from global auroral images:Data-driven dayglow modeling

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Earth and Planetary Physics 2024年第1期8卷 247-257页

作者： A.Ohma m.madelaire K.m.Laundal J.P.Reistad s.m.Hatch s.Gasparini s.J.Walker Birkeland Centre for space science Department of Physics and TechnologyUniversity of BergenBergenNorway

Global images of auroras obtained by cameras on spacecraft are a key tool for studying the near-Earth environment.However,the cameras are sensitive not only to auroral emissions produced by precipitating particles,but also to dayglow emissions produced by photoelectrons induced by sunlight.Nightglow emissions and scattered sunlight can contribute to the background signal.To fully utilize such images in space science,background contamination must be removed to isolate the auroral signal.Here we outline a data-driven approach to modeling the background intensity in multiple images by formulating linear inverse problems based on B-splines and spherical harmonics.The approach is robust,flexible,and iteratively deselects outliers,such as auroral emissions.The final model is smooth across the terminator and accounts for slow temporal variations and large-scale asymmetries in the dayglow.We demonstrate the model by using the three far ultraviolet cameras on the Imager for magnetopause-to-Aurora Global Exploration(ImAGE)mission.The method can be applied to historical missions and is relevant for upcoming missions,such as the solar wind magnetosphere Ionosphere Link Explorer(smILE)mission.

关键词： aurora dayglow modeling global auroral images far ultraviolet images dayglow removal

■^(−)_(b)→J/ψΛK^(−)衰变中一个J/ψΛ结构的迹象与■^(−)激发态的发现

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science Bulletin 2021年第13期66卷 1278-1287,M0003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 s.Baker 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 E.Bertholet 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.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 s.-G.Chitic 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’ 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 school of Physics state Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijingChina University of Chinese Academy of sciences BeijingChina Institute Of High Energy Physics(IHEP) BeijingChina Institute of Particle Physics Central China Normal UniversityWuhanHubeiChina Univ.Grenoble Alpes Univ.Savoie Mont BlancCNRSIN2P3-LAPPAnnecyFrance UniversitéClermont Auvergne CNRS/IN2P3LPCClermont-FerrandFrance Aix marseille Univ CNRS/IN2P3CPPMMarseilleFrance UniversitéParis-saclay CNRS/IN2P3IJCLabOrsayFrance Laboratoire Leprince-ringuet(llr) PalaiseauFrance LPNHE Sorbonne UniversitéParis Diderot Sorbonne Paris CitéCNRS/IN2P3ParisFrance I.Physikalisches Institut RWTH Aachen UniversityAachenGermany Fakultät Physik Technische Universität DortmundDortmundGermany max-Planck-Institut für Kernphysik(mPIK) HeidelbergGermany Physikalisches Institut Ruprecht-Karls-Universität 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-Bicocca MilanoItaly INFN sezione di milano MilanoItaly INFN sezione di Cagliari MonserratoItaly Universita degli studi di Padova Universita e INFNPadovaPadovaItaly INFN sezione di Pisa PisaItaly INFN sezione di Roma Tor Vergata RomaItaly INFN sezione di Roma La sapienza RomaItaly Nikhef National Institute for subatomic Physics AmsterdamNetherlands Nikhef National Institute for subatomic Physics and VU University Amsterdam AmsterdamNetherlands Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of sciences KrakówPoland AGH-University of science and Techno

夸克和胶子组成的粒子统称强子,其中包含4个或以上组分夸克的强子被称为奇异强子.目前实验上发现的奇异强子最多包含5个夸克,称为五夸克态.对五夸克态的深入研究可以检验对强相互作用的理解.利用质心能量为7、8和13 TeV,总积分亮度9 fb^... 详细信息

夸克和胶子组成的粒子统称强子,其中包含4个或以上组分夸克的强子被称为奇异强子.目前实验上发现的奇异强子最多包含5个夸克,称为五夸克态.对五夸克态的深入研究可以检验对强相互作用的理解.利用质心能量为7、8和13 TeV,总积分亮度9 fb^(−1)的质子-质子对撞数据,大型强子对撞机底夸克实验(LHCb)采用全谱分析的方法,研究了■^(−)_(b)→J/ψΛK^(−)衰变过程中的共振态结构.实验发现J/ψΛ系统中存在质量约为4.46 meV/c^(2)的共振结构存在的迹象,其显著程度为3.1倍标准偏差,性质与五夸克态相符.这是实验上首次观测到包含奇异夸克的五夸克态的存在证据,为五夸克态的理论研究和后续的实验探索提供了重要的依据.除此之外,实验还精细测量了ΛK−系统中部分共振态的共振参数,精度远高于当前世界平均值,这对加深传统重子谱学的认识有着重要的意义.

关键词：大型强子对撞机强相互作用五夸克态共振结构奇异夸克强子组分夸克重子谱

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