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r17 - 13 Nov 2013 - 09:24:28 - VictoriaSanchezMartinezYou are here: TWiki >  Main Web  >  TWikiUsers > VictoriaSanchezMartinez > VictoriaDictionary

Victionary = Victoria's Dictionary


Physics:

Several important definitions and explanations.

  • ISR & FSR: Initial State Radiation & Final State Radiation.

  • Matching: agreement between ME (Matrix Element)) and PS (Parton Shower)) about who is the responsible for certain kinds of gluon radiation.
    • The ME is in charge of emissions with kT>xxx (hard gluons). PS is in charge of the remainder (soft gluons)). If we use the ME to compute the emission of additional gluons, there is some overlap with the emissions at PS.
    • There is two ways for simulating the soft gluon emission: at ME and at PS.

  • Inclusive measurement: it takes all the events, without distinguishing between ranges or mass intervals.

  • Unfolding: (is the correction of the measurement to the truth level) relation between a truth distribution Tj and the reconstructed distribution Sj (after detector simulation and event selection). This relationship is described by the response matrix Rij.
    • Si = SUMAT ( Rij * Tj )
    • probability Rij = P(observed in bin i | observed in bin j)
      The masured distributions of top and antitop rapidities are distorted by detector effects, event selection bias and the effects of finite sample statistics, and cannot be used to construct a charge asymmetry that can be directly compared to theoretical predictions. To correct for these distortions, the experimental distributions are first unfolded to a 'truth level' to obtain a charge asymmetry measurement that can be directly compared to theory.

  • Smearing: it refers to the application of a distortion at your measurement which typically represents an experimental effect.

  • scale factor = scaling factor: is a number which scales, or multiplies, some quantity. For example, in the equation y=Cx, C is the scale factor for x. At data analysis there are several kinds of SF: calibration sf, sf applied over real objects, e, mu, jets...

  • KFactor: scale factor which is applied only over MC. If there si no NLO calculations, you can approximate as LO*K in a concrete energy range.

  • fake/loose/tight lepton:
    • hay una serie de criterios que se usan para decir si un conjunto de señales en el inner detector + calorímetros+etc equivalen a un leptón o no. Si quieres estar muy seguro usas una selección "tight" que te asegura una muestra final muy pura pero con menos estadística. Si usas "loose" quiere decir que suavizas la selección para que entren más candidatos aunque la probabilidad de que alguno sea un "fake" es, en teoría, mayor.

  • jet energy scale:

  • slimming: reduce the number of BRANCHES in a file.root

  • skimming: remove the number of EVENTS in a file.root

  • Systematics:
    • Jet Energy Scale (JES):
    • Jet Mass Scale (JMS):
    • Jet Energy Resolution (JER):
    • Jet Mass Resolution (JMR):
    • Jet Reconstruction Efficiency (JRE):
    • Fatjet Mass Scale:
    • Fatjet pT Scale:
    • Fatjet d12 (kT splitting scale):
    • Electron Energy Resolution (eer):
    • Electron Energy Scale (ees):
    • Muon top-Id efficiency Scale Factor (muid):
    • Muon Momentum Scale (mums):
    • Muon Smearing Class (musc):
    • Modelling of the signal process:
    • MC sample sizes:
    • b-tagging efficiency:
    • Generator uncertainties:
    • PDF uncertainty:


Computing:

  • ES-ATLAS-T2: is a federated tier-2 formed by IFAE (Institut de Física d'Altes Energies de Barcelona), UAM (Iniversidad Autónoma de Madrid) and IFIC (Instituto de Física Corpuscular de Valencia).

  • LCG: the LHC Computing Grid.

  • MoU: Memorandum of Understanding.

  • HEP-SPEC06: is a HEP-wide benchmark for measuring CPU performance.

  • NREN: National Research and Education Network.

  • POPs: Point of Presence.

  • SAM: Service Available Monitoring.

  • Availability: is the ratio between the time the site is available over the total time.

  • Reliability: is the ratio between the time the site is available over the total time corrected by taking away the scheduled downtime.

  • Downtime: is the period in a known technical stop of a site aimed for system updates or for adding new hardware.

  • Throughput (performance): amount of data size transferred in function of time.

  • Transfer efficiency: transfer successes regarding the total number of transfers.

  • Space tokens: are reserved storage space for entity or puspose. ATLAS tier-2 space tokens:
    • DATADISK: where the official ATLAS data are stored, from the experiment or from de Monte Carlo production. Only users with production role can store in.
    • HOTDISK: files with frequently use are stored in, like database fi les. Nowadays, because of the database access has been changed by Squid system. Its use is the shortest of all the space tokens.
    • CALIBDISK: is the place booked for calibration operations of the ATLAS detector, only in some sites of tier-2, for instance the IFIC from ES-ATLAS-T2.
    • PRODDISK: is the speci c space for the les needed during the process of the ATLAS simulation production.
    • GROUPDISK: a space for ATLAS physics groups. Only users working in the physics group can store replicas under the approval of their conveners.
    • SCRATCHDISK: where all output analysis job les are stored when the process has nished. It is a temporal space, user must move the output les in less than one month. Every user has permission to use it.
    • LOCALGROUPDISK: is the space for local users of an institute or a Cloud. It is frequently a tier-3 storage subject to ATLAS pledges.

  • : .

  • : .


led-box-blue Victoria Sánchez Martínezled-box-blue
--- IFIC ---
Edificio Institutos de Investigación
Paterna, apartado 22085
E-46071 Valencia (Spain)

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