An energy deposition in a target's electronic degrees of freedom, as opposed to a nuclear recoil. gamma rays and beta decay can produce backgrounds in this channel. Detector discrimination is statistical because the measured light and charge distributions have finite widths.

A selected inner detector volume in which the response and background rejection meet specified criteria. Position cuts can suppress surface backgrounds, but the selected target mass and position-reconstruction uncertainty must be calibrated.

A reconstructed decay position measurably separated from the primary collision point. Its distribution constrains a particle's flight distance and lifetime, after correcting for boost, geometry, resolution and selection. It is one possible signature of a long-lived new particle.

The fraction of produced events falling within a detector's geometrical and kinematic selection. Reconstruction and trigger efficiencies are additional factors; conventions must state whether they are folded into the quoted acceptance. A changed decay spectrum can alter acceptance even at the same parent mass.

An event sample designed to constrain a background contribution to a signal region, while having little expected signal contamination. Changed particle-identification, kinematic or tagging requirements can isolate a process. The model must account for its relation to the signal sample, shared uncertainties and any signal leakage. A separate validation sample can test extrapolation without tuning the discovery selection.

A pre-specified region of reconstructed event space selected for sensitivity to a hypothesized signal. Observed events are compared with a background prediction constrained by particle-physics control regions and other measurements. A blind analysis can hide this region while choices and uncertainty estimates are finalized.

An additional active detector region or system whose correlated signal identifies events to reject from a signal sample. Its efficiency, time window, dead time and accidental coincidences must be measured. It can reject some backgrounds without proving that every unvetoed event is signal.

Additional collisions overlapping an event in the same beam crossing or detector response window. Extra tracks and calorimeter deposits affect particle-jet reconstruction, isolation and missing transverse momentum. Vertex association, subtraction and response calibration reduce the effect but leave uncertainties that depend on collision conditions.

A paleontologist studies past life through fossils. The work can include field collection, reconstruction of anatomy, measurement of chemical remains and testing of evolution relationships. A paleontologist must also assess taphonomy, because what survives burial is an incomplete transformation of the original organism.

Study of processes between an organism's death and observation of its remains, including transport, decay, burial and preservation. These processes bias the fossil and archaeological record.

A Georgian archaeological and fossil locality with evidence of early Pleistocene human occupation. The earliest archaeological levels and the hominin-bearing deposits have different stratigraphic positions. ^[ref]

An Israeli cave locality with a maxilla attributed to Homo sapiens dated to approximately 177–194 thousand years ago. ^[ref]

Skhul is a Levantine cave locality with early Homo sapiens remains. Together with Qafzeh, it is important for testing the timing and complexity of early human dispersal. A local occurrence does not by itself demonstrate continuous occupation across the entire interval between that deposit and later populations.

Qafzeh is a cave locality in the Levant with early Homo sapiens remains. Its importance lies in the evidence it supplies for human presence outside Africa before the later widespread expansion of living human populations. Anatomical identification, the age of the enclosing deposits and evidence about occupation are separate observations that must be combined when reconstructing dispersal.

A Greek cave locality whose incomplete human crania have generated debated reconstructions, dates and taxonomic assignments. ^[ref]

The preserved and recovered evidence of past life. First observed occurrences supply minimum ages; uneven preservation and sampling prevent interpreting every absence as a biological absence.

The final geological period preceding the Cambrian. Its fossil communities provide evidence of animal complexity before the conspicuous Cambrian radiation.

A geological period beginning approximately 539 million years ago, with exceptional deposits documenting diverse early animals, including early vertebrates. Increased fossil visibility and biological diversification must be distinguished.

The Devonian is a geological period after the Silurian and before the Carboniferous. Its fossil record is especially important for studying early jawed vertebrates, the origin of tetrapod limbs and the diversification of land plants.

The pectoral fin of Tiktaalik combines fish-like features with structures informative about the origin of a weight-supporting vertebrate limb. Such a character combination supports reconstruction of a transition without requiring that the sampled individual was itself a direct ancestor.^[ref]

The Silurian is a geological period between the Ordovician and the Devonian. Its rocks preserve evidence relevant to the diversification of jawed vertebrates and early terrestrial ecosystems.

A Silurian placoderm with marginal jaw bones resembling those of Osteichthyes illustrates its evolutionary importance: a fossil's combination of characters can challenge a simple sequence in which each major group acquires a wholly separate body plan.^[ref]