早期社会的复杂化进程是文明起源的核心课题，是近些年来考古学研究的一个热点。岭南地区是中华文明“多元一体”格局中的重要组成部分，探索这一地区早期社会的演进过程对推进当前正在开展的中华文明起源和早期国家的形成这一研究课题具有重要的意义。从新石器时代末期至秦统一中国的这一历史阶段是岭南地区社会复杂化和区域文明起源的关键时期。本文在前人研究成就的基础上，通过对岭南先秦考古学文化内涵、墓葬和遗物等资料的梳理和分析，考察这一时空经济形态和社会组织结构的演变状况，探讨先秦时期岭南复杂化社会的演进过程。 本文共分为六个部分： 第一章为绪论，回顾岭南早期社会发展进程研究的学术史，并论述本文的研究目的和研究思...The topic on process of social complexity is a core subject in research which is ahout origin of civilization . Recently,it has become a hot spot in archaeological academy. Lingnan is an important part in the pluralistic but unitive framework of Chinese civilization. Searching the evolutionary process of ancient society in Lingnan is meaningful to push the research of the origins of Chinese civili...学位：历史学硕士院系专业：人文学院历史学系_考古学及博物馆学学号：1032006115009

程玲

Xiamen University Institutional Repository

The Evolution of Complex Society of Lingnan in Pre-Qin Period

W and Z bosons will be produced at high rates at the LHC. The understanding of these processes will be very important for all the LHC physics program. We discuss the ATLAS and CMS detectors potential for an early measurement of W and Z inclusive cross sections and lepton asymmetries, the prospects for the precision measurement of the W boson mass and for the study of di-bosons production processes

Malberti, M

CERN Document Server

Available on CMS information server CMS CR -2009/164The Compact Muon Solenoid ExperimentMailing address: CMS CERN, CH-1211 GENEVA 23, SwitzerlandConference Report08 June 2009 (v4, 24 June 2009)W and Z at the LHCM. Malberti on the behalf of the ATLAS and CMS CollaborationsAbstractW and Z bosons will be produced at high rates at the LHC. The understanding of these processeswill be very important for all the LHC physics program. We discuss the ATLAS and CMS detectorspotential for an early measurement of W and Z inclusive cross sections and lepton asymmetries, theprospects for the precision measurement of the W boson mass and for the study of di-bosons produc-tion processes.Presented at IFAE 2009 Incontri di Fisica delle Alte Energie - VIII Edizione,15-17 April 2009,Bari,Italy,30/06/2009IL NUOVO CIMENTO Vol. ?, N. ? ?W and Z at the LHCM. Malberti (1) on the behalf of the ATLAS and CMS collaborations(1) INFN Milano-Bicocca, Piazza della Scienza 3, 20126, Milano, ItalySummary. — W and Z bosons will be produced at high rates at the LHC. Theunderstanding of these processes will be very important for all the LHC physicsprogram. We discuss the ATLAS and CMS detectors potential for an early mea-surement of W and Z inclusive cross sections and lepton asymmetries, the prospectsfor the precision measurement of the W boson mass and for the study of di-bosonsproduction processes.PACS 14.70.Fm – W bosons.PACS 14.70.Hp – Z bosons.1. – IntroductionW and Z bosons will be abundantly produced at the LHC. The W(Z) productioncross sections at√s=14 TeV is 20 nb(2 nb), i.e. about seven times larger than at theTevatron. These processes are theoretically well understood and the decays into leptons(namely electrons and muons) provide an extremely clear experimental signature. Allthese features make their study very important in the early LHC running for detector un-derstanding and calibration/alignment purposes and for the first physics measurements,while increased integrated luminosities will give access also to the precision measurementof fundamental electroweak parameters (e.g. W mass). An overview of the ATLAS [1]and CMS [2] potential for some selected measurements with W and Z bosons is presented.2. – Inclusive W/Z cross section measurementsZ → ll are selected by requiring two isolated and well reconstructed leptons of op-posite charge, with high transverse momentum (typically pT > 20-25 GeV) and with aninvariant mass in a window about MZ . The resulting samples is very pure, with residualbackgrounds (W+jets, Z → ττ , tt¯, di-jets) at the level of 0.1% (fig. 1-left).The selection of W → lν events is based on the requirement of one isolated lepton;moreover, a cut on the missing transverse energy due to the neutrino and/or on thetransverse mass (MT ) is applied, as it is very useful in rejecting most of the QCD back-ground (fig. 1-right). A detailed discussion of the events selection can be found in [3],[4] and [5].c© Societa` Italiana di Fisica 12 M. MALBERTI ON THE BEHALF OF THE ATLAS AND CMS COLLABORATIONSFig. 1. – Invariant mass distribution of Z → ee events (left) and transverse mass distribution ofW → eν events (right).The W/Z inclusive cross section measurement will be one of the very first physicsmeasurements (with 10-50 pb−1) at the LHC. The cross section is given by the followingrelation:σ =Nsignal −NbkgǫA∫Ldt(1)where Nsignal and Nbkg are the number of signal and background events, A is thegeometrical/kinematic acceptance, ǫ is the efficiency and∫Ldt is the integrated lumi-nosity. The measurement will be dominated by the luminosity uncertainty (3-7%, 10%at the start-up). The statistical uncertainty is expected to be ∼1% with about 10 pb−1.The uncertainty on the acceptance gives a contribution of about 2% [5]. Experimen-tal uncertainties related to the trigger efficiency and lepton reconstruction/identificationefficiencies will be a few % at the beginning, but are expected to improve with the statis-tics as they are planned to be measured from Z → ll samples with the “tag-and-probe”method. Data-driven approaches will also be applied to estimate the residual backgroundfrom jets faking leptons, that is the most uncertain source of background and is not reli-ably predictable by means of Monte Carlo simulations. The control samples are definedby relaxing one of the lepton identification requirements in order to get a QCD enrichedsample to model the background in the signal region.3. – Lepton charge asymmetry in W eventsThe measurement of differential rapidity distributions and lepton asymmetries willbe also feasible with initial luminosities and provide a useful tool to constrain PartonDistribution Functions.For example, the lepton charge asymmetry in W events, defined asσ =dσ/dη(l+)− dσ/dη(l−)dσ/dη(l+) + dσ/dη(l−),(2)W AND Z AT THE LHC 3is directly sensitive to the u and d quarks PDFs. For leptons within the detectorsacceptance, it varies between 10% and 20% as a function of the lepton pseudorapid-ity. Being most of the uncertainties reduced in the ratio, this measurement is expectedto provide constraints on the PDFs already with integrated luminosities of about 100pb−1 [6].Fig. 2. – Muon charge asymmetry as a function of the muon pseudorapidity for∫Ldt = 10 pb−1(left) and∫Ldt = 100 pb−1 (right). The blue band corresponds to the PDF uncertainty.4. – W mass measurementThe measurement of the W boson mass (MW ) is an example of precision measure-ment of a fundamental electroweak parameter. An improved measurement of MW willallow to set strong indirect constraints on the Higgs boson mass. The aimed precision of15 MeV at the LHC (to be compared to the current 25 MeV) will be achieved combiningchannel and experiments.The approaches for such a precision measurement are different. One, studied by the AT-LAS collaboration, is the traditional approach used at hadron colliders and consists infitting W data (lepton pT , MT ) with Z tuned Monte Carlo samples generated at differ-ent values of MW . An excellent modelling of the both of the physics and of the detectorperformances is needed. A recent review of the performances expected by ATLAS is dis-cussed in [5] for a luminosity of about 15 pb−1. With such luminosity, the measurementis dominated by statistical and experimental systematic uncertainties (O(100) MeV) and,although it is not competitive, it will be extremely important for an early commissioningof the method. An uncertainty of about 20 MeV with 10 fb−1 can be foreseen in eachleptonic channel [1].An alternative approach, explored by CMS, is the use of templates built from the datathemselves using Z → ll: the experimental distributions scaled to the boson mass in Wevents are predicted from the corresponding distributions measured from Z → ll alongwith the theoretical ratio between W and Z differential cross sections, that can be re-liably calculated using perturturbative QCD. The advantage of this second approach isthat many of the common uncertainties between W and Z are reduced in the ratio. With10 fb−1, a statistical uncertainty of 15 MeV is foreseen for each leptonic channel and anexperimental systematic uncertainty of about 20 MeV is expected from the measurementfrom the electron pT spectrum, however with precision requirements much looser than4 M. MALBERTI ON THE BEHALF OF THE ATLAS AND CMS COLLABORATIONSthose needed by the Monte Carlo template one [7].5. – Di-bosons productionThe study of di-bosons production at the TeV scale constitutes a unique opportunityto test the Standard Model (SM) at the highest possible energies: any deviation of themeasured production cross section or of the Triple Gauge Couplings (TGCs) from theSM predictions will be an indication of New Physics. These processes are moreoverbackgrounds to other searches (Higgs, Susy...). The production cross sections for all di-boson processes (WZ, ZZ, WW, Wγ and Zγ) are relatively large and these processes areexpected to be observed already with luminosities of a few hundreds inverse picobarnsat the LHC (fig. 3). With higher integrated luminosities, an improvement on the limitson the TGCs will be possible.Fig. 3. – Left: Z candidate invariant mass from a WZ samples for all four channels combined,normalized to integrated luminosity of 300 pb−1 [8]. Right: transverse momentum distributionof lepton pairs in WW events, normalized to 1 fb−1 [5].REFERENCES[1] ATLAS Collaboration, The ATLAS experiment at the CERN LHC, JINST 3:S08003 (2008).[2] CMS Collaboration, The CMS experiment at the CERN LHC, JINST 3:S08004 (2008)[3] CMS Collaboration, Towards a Measurement of the Inclusive W → µν and Z → µ+µ−Cross Sections in pp Collisions at√s = 14 TeV, CMS PAS EWK-07-002 (2007)[4] CMS Collaboration, Towards a Measurement of the Inclusive W → eν and Z → e+e−Cross Sections in pp Collisions at√s = 14 TeV, CMS PAS EWK-08-005 (2008)[5] ATLAS Collaboration, Expected Performance of the ATLAS Experiment Detector, Triggerand Physics, CERN-OPEN-2008-020 (December 2008)[6] CMS Collaboration, Measurement of the Muon Charge Asymmetry in the pp→W +X →µν process at√s = 14 TeV, CMS PAS EWK-08-002 (2008)[7] V. Bu¨ge, A. Ghezzi, C. Jung, M. Malberti, G. Quast and T. Tabarelli de Fatis, Prospectsfor the precision measurement of the W mass with the CMS detector at the LHC, J. Phys.G: Nucl. Part. Phys., 34 (2007) N193N220[8] CMS Collaboration, Study of the process pp → WZ0 → l±νl+l−(l = e, µ) at CMS, CMSPAS EWK-08-003 (2008)

W and Z at the LHC

W and Z bosons will be produced at high rates at the LHC. The understanding of these processes will be very important for all the LHC physics program. We discuss the ATLAS and CMS detectors potential for an early measurement of W and Z inclusive cross-sections and lepton asymmetries, the prospects for the precision measurement of the W boson mass and for the study of di-bosons production processes

Malberti, M.

Scientific Open-access Literature Archive and Repository

DOI 10.1393/ncc/i2009-10447-yColloquia: IFAE 2009IL NUOVO CIMENTO Vol. 32 C, N. 3-4 Maggio-Agosto 2009W and Z at the LHCM. Malberti on behalf of the ATLAS and CMS CollaborationsINFN Milano-Bicocca - Piazza della Scienza 3, 20126 Milano, Italy(ricevuto il 19 Settembre 2009; pubblicato online il 5 Novembre 2009)Summary. — W and Z bosons will be produced at high rates at the LHC. Theunderstanding of these processes will be very important for all the LHC physicsprogram. We discuss the ATLAS and CMS detectors potential for an early mea-surement of W and Z inclusive cross-sections and lepton asymmetries, the prospectsfor the precision measurement of the W boson mass and for the study of di-bosonsproduction processes.PACS 14.70.Fm – W bosons.PACS 14.70.Hp – Z bosons.1. – IntroductionW and Z bosons will be abundantly produced at the LHC. The W(Z) productioncross-sections at√s = 14TeV is 20 nb (2 nb), i.e. about seven times larger than atthe Tevatron. These processes are theoretically well understood and the decays intoleptons (namely electrons and muons) provide an extremely clear experimental signa-ture. All these features make their study very important in the early LHC running fordetector understanding and calibration/alignment purposes and for the first physics mea-surements, while increased integrated luminosities will give access also to the precisionmeasurement of fundamental electroweak parameters (e.g., W mass). An overview of theATLAS [1] and CMS [2] potential for some selected measurements with W and Z bosonsis presented.2. – Inclusive W/Z cross-section measurementsZ → ll are selected by requiring two isolated and well-reconstructed leptons of op-posite charge, with high transverse momentum (typically pT > 20–25GeV) and with aninvariant mass in a window about MZ . The resulting sample is very pure, with residualbackgrounds (W+jets, Z → ττ , tt¯, di-jets) at the level of 0.1% (fig. 1 left).The selection of W → lν events is based on the requirement of one isolated lepton;moreover, a cut on the missing transverse energy due to the neutrino and/or on thetransverse mass (MT ) is applied, as it is very useful in rejecting most of the QCDbackground (fig. 1 right). A detailed discussion of the events selection can be foundin [3, 4] and [5].c© Societa` Italiana di Fisica 8990 M. MALBERTI on behalf of the ATLAS and CMS COLLABORATIONSFig. 1. – Invariant mass distribution of Z → ee events (left) and transverse mass distribution ofW → eν events (right).The W/Z inclusive cross-section measurement will be one of the very first physicsmeasurements (with 10–50 pb−1) at the LHC. The cross-section is given by the followingrelation:(1) σ =Nsignal −NbkgA∫Ldt,where Nsignal and Nbkg are the number of signal and background events, A is the geo-metrical/kinematic acceptance,  is the efficiency and∫Ldt is the integrated luminosity.The measurement will be dominated by the luminosity uncertainty (3–7%, 10% at thestart-up). The statistical uncertainty is expected to be ∼ 1% with about 10 pb−1. Theuncertainty on the acceptance gives a contribution of about 2% [5]. Experimental uncer-tainties related to the trigger efficiency and lepton reconstruction/identification efficien-cies will be a few % at the beginning, but are expected to improve with the statistics asthey are planned to be measured from Z → ll samples with the “tag-and-probe” method.Data-driven approaches will also be applied to estimate the residual background fromjets faking leptons, that is the most uncertain source of background and is not reliablypredictable by means of Monte Carlo simulations. The control samples are defined byrelaxing one of the lepton identification requirements in order to get a QCD enrichedsample to model the background in the signal region.3. – Lepton charge asymmetry in W eventsThe measurement of differential rapidity distributions and lepton asymmetries willbe also feasible with initial luminosities and provide a useful tool to constrain PartonDistribution Functions.For example, the lepton charge asymmetry in W events, defined as(2) σ =dσ/dη(l+)− dσ/dη(l−)dσ/dη(l+) + dσ/dη(l−),is directly sensitive to the u and d quarks PDFs. For leptons within the detectors accep-tance, it varies between 10% and 20% as a function of the lepton pseudorapidity (fig. 2).W AND Z AT THE LHC 91Fig. 2. – (Colour on-line) Muon charge asymmetry as a function of the muon pseudorapidity forRLdt = 10pb−1 (left) andRLdt = 100 pb−1 (right). The blue band corresponds to the PDFuncertainty.Being most of the uncertainties reduced in the ratio, this measurement is expected to pro-vide constraints on the PDFs already with integrated luminosities of about 100 pb−1 [6].4. – W mass measurementThe measurement of the W boson mass (MW ) is an example of precision measurementof a fundamental electroweak parameter. An improved measurement of MW will allow toset strong indirect constraints on the Higgs boson mass. The aimed precision of 15MeVat the LHC (to be compared to the current 25MeV) will be achieved combining channeland experiments.The approaches for such a precision measurement are different. One, studied by theATLAS Collaboration, is the traditional approach used at hadron colliders and consists infitting W data (lepton pT , MT ) with Z tuned Monte Carlo samples generated at differentvalues of MW . An excellent modelling of the both of the physics and of the detectorperformances is needed. A recent review of the performances expected by ATLAS isdiscussed in [5] for a luminosity of about 15 pb−1. With such luminosity, the measurementis dominated by statistical and experimental systematic uncertainties (O(100)MeV) and,although it is not competitive, it will be extremely important for an early commissioningof the method. An uncertainty of about 20MeV with 10 fb−1 can be foreseen in eachleptonic channel [1].An alternative approach, explored by CMS, is the use of templates built from thedata themselves using Z → ll: the experimental distributions scaled to the boson massin W events are predicted from the corresponding distributions measured from Z → llalong with the theoretical ratio between W and Z differential cross-sections, that can bereliably calculated using perturturbative QCD. The advantage of this second approach isthat many of the common uncertainties between W and Z are reduced in the ratio. With10 fb−1, a statistical uncertainty of 15MeV is foreseen for each leptonic channel and anexperimental systematic uncertainty of about 20MeV is expected from the measurementfrom the electron pT spectrum, however with precision requirements much looser thanthose needed by the Monte Carlo template one [7].92 M. MALBERTI on behalf of the ATLAS and CMS COLLABORATIONSFig. 3. – Left: Z candidate invariant mass from a WZ samples for all four channels combined,normalized to integrated luminosity of 300 pb−1 [8]. Right: transverse momentum distributionof lepton pairs in WW events, normalized to 1 fb−1 [5].5. – Di-bosons productionThe study of di-bosons production at the TeV scale constitutes a unique opportunityto test the Standard Model (SM) at the highest possible energies: any deviation of themeasured production cross-section or of the Triple Gauge Couplings (TGCs) from theSM predictions will be an indication of New Physics. These processes are moreoverbackgrounds to other searches (Higgs, Susy, . . . ). The production cross-sections for alldi-boson processes (WZ, ZZ, WW, Wγ and Zγ) are relatively large and these processesare expected to be observed already with luminosities of a few hundred inverse picobarnsat the LHC (fig. 3). With higher integrated luminosities, an improvement on the limitson the TGCs will be possible.REFERENCES[1] ATLAS Collaboration, The ATLAS experiment at the CERN LHC, JINST, 3 (2008)S08003.[2] CMS Collaboration, The CMS experiment at the CERN LHC, JINST, 3 (2008) S08004.[3] CMS Collaboration, Towards a Measurement of the Inclusive W → μν and Z → μ+μ−Cross Sections in pp Collisions at√s = 14TeV, CMS PAS EWK-07-002 (2007).[4] CMS Collaboration, Towards a Measurement of the Inclusive W → eν and Z → e+e−Cross Sections in pp Collisions at√s = 14TeV, CMS PAS EWK-08-005 (2008).[5] ATLAS Collaboration, Expected Performance of the ATLAS Experiment Detector,Trigger and Physics, CERN-OPEN-2008-020 (December 2008).[6] CMS Collaboration, Measurement of the Muon Charge Asymmetry in the pp→W+X →μν process at√s = 14TeV, CMS PAS EWK-08-002 (2008).[7] Bu¨ge V., Ghezzi A., Jung C., Malberti M., Quast G. and Tabarelli de Fatis T.,Prospects for the precision measurement of the W mass with the CMS detector at the LHC,J. Phys. G: Nucl. Part. Phys., 34 (2007) N193N220.[8] CMS Collaboration, Study of the process pp→WZ0 → l±νl+l−(l = e, μ) at CMS, CMSPAS EWK-08-003 (2008).

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The Evolution of Complex Society of Lingnan in Pre-Qin Period

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