lepton
554 Views

GC: n

CT: We present a feasibility study of top-quark mass measurement using the energy distribution of a lepton from a W boson in a top quark decay in pp collisions at the LHC. The proposed method requires only the lepton energy distribution at the parton level. The analysis is performed in the lepton + jets final state by using fast simulation data corresponding to an integrated luminosity of approximately 20 fb-1 at 14 TeV. Events with exactly one lepton, at least 3 jets and at least 1 b jet are selected. The lepton energy distribution at the parton level is obtained by applying the bin-by-bin unfolding technique. The study shows that the pole mass of the top quark can be measured within an uncertainty of 1 GeV.

S: RG – https://bit.ly/2AeeDJ2 (last access: 26 December 2018)

N: 1. 1948, from Greek leptos “small, slight, slender, delicate, subtle,” literally “peeled,” or “threshed out” (from lepein “to peel,” from PIE *lep- , a root which yields words for “peel” as well as “small shaving, scale (of a fish),” hence used of things fine, delicate, or weak; via the notion of “small shaving, flake, scale” (cognates: Latin lepidus “pleasant, charming, fine, elegant, effeminate,” lepos “pleasantness, agreeableness;” Old English læfer “rush, reed; metal plate;” Lithuanian lopas “patch, rag, cloth,” lepus “soft, weak, effeminate”)) + -on (subatomic particle suffix, from ion.). In Greek it was the name of a small coin, from neuter of leptos. Related: Leptonic.
2. A charged or an uncharged elementary particle (as a positron or a neutrino) having a mass of the same order as, or smaller than, that of the electron.
3. The standard model holds that all matter is made of two kinds of particle: quarks (which constitute protons, neutrons and many other particles) and leptons (among which are electrons).
4. Leptons do not appear to be made up of smaller units of matter and can either carry one unit of electric charge or be neutral. he charged leptons are the electrons, muons, and taus. Each of these types has a negative charge and a distinct mass.
5. All leptons, including the neutrinos, have antiparticles called antileptons. The mass of the antileptons is identical to that of the leptons, but all of the other properties are reversed.
6. A third characteristic feature of leptons, in addition to their charge and mass properties, is their intrinsic angular momentum, or spin. Leptons are classified within a larger group of subatomic particles, the fermions, which are characterized by half-integer values of their spin. The total number of leptons appears to remain the same in every particle reaction. Mathematically, total lepton number L (the number of leptons minus the number of antileptons) is constant.

S: 1. OED – https://bit.ly/2Lv6JiM ; https://bit.ly/2V3ZYsB; https://bit.ly/2BFMElA (last access: 20 December 2018). 2 & 3. TERMIUM PLUS – https://bit.ly/2CvYd03 (last access: 20 December 2018). 4, 5 & 6. EncBrit – https://bit.ly/2GzKNnJ (last access: 20 December 2018).

SYN:
S:

CR: atom, electron , gamma radiation, ion , muon , neutrino , nuclear energy, particle, quark , synchrotron.