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118 个结果
  • 简介:UsingtheefectiveHamiltonianmethod,weanalyzetheB0-ˉB0mixingintheextensionofthestandardmodel(SM)wherebaryonnumberandleptonnumberarelocalgaugesymmetries.ThenumericalresultsindicatethecorrectionfromtheextraparticlestothemassdiferencemBissignificant.Thereisa60%enhancementcomparedtotheSMpredictionformBatmost,whichagreeswiththecurrentexperimentalresult.

  • 标签: 重子数 混合 轻子 有效哈密顿方法 标准模型 计算结果
  • 简介:Thereisagrowingsupportforthelowlyingscalarmesonsf0(500),f0(980),a0(980),and(800)tobegenerateddynamicallyfromtheinteractionofpseudoscalarmesons,whilethecaseofthenextsetofscalarresonancesathigherenergies,f0(1370),f0(1710),K0(1430)ismoreaquestionofdebate.Soisthecaseofthetensorresonancesf2(1270),f′2(1525),K2(1430).AnewperspectiveonthesestateshasbeenofferedinRef.[1]wherethef0(1370)andf2(1270)resonancesareshowntobegeneratedfromtheinteractionprovidedbythelocalhiddengaugeLagrangiansimplementingunitarization.Itisshownthattheideaofthenatureofthesestatesasvectormeson-vectormesoncompositestateshasbeentestedinmanyreactions.Yet,thepermanentdiscussionoftheissuedemandsextrachecksforotherobservablesand,inthissense,theweakdecaysbringanewsourceofvaluableinformationthatshouldservetotestdifferentmodels.

  • 标签: J/Ψ source case SENSE NEXT IDEA
  • 简介:Inthisarticle,wecalculatethecontributionfromthenonfactorizablesofthadronicmatrixelementtothedecayB~0→χc1~π~0withthelight-conequantumchromo-dynamic(QCD)sumrules.Thenumericalresultsshowthatitscontributionisratherlargeandshouldnotbeneglected.Thetotalamplitudesleadtoabranchingfractionwhichisinagreementwiththeexperimentaldatamarginally.

  • 标签: QCD求和规则 衰变 计算结果 强子矩阵元 实验数据 动力学
  • 简介:SAMisanetwork-distributeddatamanagementsystemdevelopedatFermilabforusewithRunIIdata,ItisbeingEmployedbytheD0Experimenttostore,manage,deliver,andtrackprocessingofalldata.Wedescribethedesignandfeaturesofthesystemincludingresourcemanagementanddatatransfermechanisms,WeshowtheoperationalexperienceD0hasaccumulatedtodateincludingdataacquisitionprocessing,andalllevelsofaccessanddelivery.Wepresentvariousconfigurationsofthesystemanddescribetheiruseinthecollaboration.

  • 标签: SAM 数据处理系统 D0实验
  • 简介:In2010,theBESCollaboration[1]foundaclearenhancementintheK0K0massdistributionintheJ=ψ!ηK0K0decay.SuchanenhancementisusuallyasignatureofanL=0resonancearoundthreshold,whichinthiscasewouldcorrespondstoanh1statewithquantumnumbersIG(JPC)=0??(1+??).Thish1statewaspredictedbytheChiralUnitarytheoryintheKKinteraction.Becauseoftheconversationlaw,thisstatecanonlydecaytoK0K0channel,andcanbestudiedefficientlyintheJ=ψ!ηK0K0decay.

  • 标签: SIGNATURE SIGNATURE QUANTUM CLEAR can BES
  • 简介:WereportonthefirstoperationsofthereconstructionfarmsfortheD0experiment.Datawerereadfromataperobotto50PC'srunningLinux,processed,spooledtoacentraldiskbufferformergingandthenwrittenbacktothetaperobot.Thefarmsarebeingusedsuccessfullytoreconstructthedataasitcomesin.Transferrateswelloverthe12.5MB/secneededforfulldatarateshavebeenachieved.

  • 标签: D0实验 探测器 软件开发
  • 简介:Oneofthekeycomponentsofanygridarchitectureismanagingcomputeandstorageresourcesandoptimizingtheirutilization.SAMhasimplementedfeaturesthatallowittoexercisea"fairshare"and"prioritized"policyamongmanygroupsofusers.Thegoalsareasfollows:1)implementthexperimentspoliciesforresourceusagebyresearchgroupandbydataaccessmode,and2)optimizetheresourceusagetomaximizetheoverallthroughputdefinedintermsofrealdataprocessingactivity,AtthelowestlevelofSAMarchitecture,calledthestation,theSAMsystemintegratesthedatadeliveryandcachemanagementwiththejobcontrolandschedulingofthebatchsystem.Atthesite-level,forexampleatFermilab,requestsfordatafromon-sitestationsaremanagedtooptimizeMassStorageSystemresourcesandnetworkthroughput,Managementofresourcesatavariousgeographiclevelsarediscussed.

  • 标签: 广域网 数据管理 数据存储 D0数据网格
  • 简介:IGUANA(InteractiveGraphicsforUserANAlysis)isaC++toolkitfordevelopinggraphicaluserinterfacesandhighperformance2-Dand3-Dgraphicsapplications,suchasdatabrowsersanddetectorandeventvisualisationprograms.TheIGUANAstrategyistousefreelyavailablesoftware(e.g.Qt,SoQt,OpenInventor,OpenGL,HEPVis)andpackageandextendittoprovideageneral-purposeandexperiment-independenttoolkit.WedescribetheevaluationandchoicesofpubliclyavailableGUI/graphicssoftwareandtheadditionalfunctionalitycurrentlyprovidedbyIGUANA.WedemonstratetheuseofIGUANAwithseveralapplicationsbuiltforCMSandD0.

  • 标签: 计算机图形学 交互图形 CMS DO CMS
  • 简介:TheimportanceoftheInternettomodernHighEnergyPhysicsCollaboratorsisclearlyimmense,andunderstandinghownewdevelopmentsinnetworktechnologyimpactnetworksiscriticaltothefuturedesignofexperiments.ThenextgenerationInternetProtocol(IPv6)isbeingdeployedontestbedsandproductionnetworksthroughouttheworld.Theprotocolhasbeendesignedtosolvetodaysinternetproblems,andmanyofthefeatureswillbecoreInternetservicesinthefuture.Inthistalkthefeaturesoftheprotocolwillbedescribed.DetailswillbegivenonthedeploymentatsitesimportanttoHighEnergyPhysicsResearchandthenetworkservicesoperatingatthesesites,InparticularIPv6deploymentontheU.S.EnergySciencesNetwork(ESnet)willbereviewed.TheconnectivityandperformancebetweenHighEnergyPhysicsLaboratories,UniversitiesandInstituteswillbediscussed.

  • 标签: 高能物理 国际互联网 合作实验
  • 简介:Aswellknown,iftheHiggsbosonwerenotobservedatLHC,thetechnicolormodelwouldbethemostfavorablecandidateresponsibleforthesymmetrybreaking.Toovercomesomedefectsinthepreviousmodel,someextendedversionshavebeenproposed.IntheTC2modeltypicalsignatureisexistenceofheavyH_(TC)andtechnipionП.Adirectproofofvalidityofthemodelistoproducethemataccelerator.Thuswestudytheproductionratesofe~+e~-→H_(TC)П~0ande~+e~-→П~+П~-atILCinthetopcolor-assistedtechnicolor(TC2)model.Infact,thereisafloodofmodelsbelongingtonewphysics,whichcanresultinproductswithcharacteristicssimilartoH_(TC)+ПoftheTC2model.ThereforetodistinguishthismodelfromothersonemayneedtoinvestigatesomedetailsbycalculatingthecrosssectiontoNLO.WeindeedfindthattheNLOcorrectionsaresignificant,namelytheratioδ2≡(σ_(NLO)-σ_(LO))/σ_(LO)ine~+e~-→H_(TC)П~0exceeds100%withinaplausibleparameterspace.

  • 标签: TECHNICOLOR模型 非线性光学 审判 国际 矫正 希格斯玻色子
  • 简介:ThespectrumoftheΣ(1193)excitedstates,Σ,withisospinI=1andstrangenessS=??1isoneofthemostimportantissuesinhadronicphysics.TheΣresonancesaremostlyproducedandstudiedinK-inducedreactions.ManyΣresonancesarenowcatalogedbytheParticleDataGroup[1].However,ourknowledgeoftheseresonancesisstillverypoor.Intheenergyregionbelow2GeV,onlyafewofthemarewellestablished,suchastheΣ(1385)ofspin-parityJP=3=2+,Σ(1670)ofJp=3=2??andΣ(1775)ofJp=5=2??.Theothersarenotwellestablishedandsomeofthemareevenoflargeuncertaintiesontheirexistence.Thus,thestudyoftheΣresonancewiththeavailableexperimentaldataisnecessary.

  • 标签: EXPERIMENTAL Π now OUR is
  • 简介:为了满足我国正在建设的白光中子源(whiteneutronsource,WNS)需求,设计了具有共性化架构的C6D6谱仪读出电子学系统。该系统基于波形数字化技术和PXIe平台,实现对γ能谱和中子飞行时间的测量。介绍了系统设计方案,详细阐述了信号调理模块、时间测量、PXIe平台及相关软件的设计与实现,并开展了系统性能测试和联调实验。测量结果表明:该系统能够正确获得测量数据,满足了白光中子源的首批实验需求。

  • 标签: C6D6探测器 波形数字化 信号调理 PXIe平台
  • 简介:在未采取预电离措施的情况下,研究了纯sf6气体及sf6/h29sf6/c2h6两种混合气体激光介质脉冲放电特性。实验结果表明,无预电离时SF68其混合气体介质可以实现自引发体放电,气体介质体放电维持电压主要由SF,;含量决定,C2H6具有抑制电弧的作用,可以有效延长体放电维持时间。分析认为,sf66体高折合场强E/P导致的放电通道电流密度受限和高电负度■引起的放电通道中负离子分解产生二次电子,是介质实现自引发体放电的重要机理。

  • 标签: HF激光 自引发 体放电 电弧放电