Evolution of Non-Terrestrial Networks From 5G to 6G: A Survey

Non-terrestrial networks (NTNs) traditionally have certain limited applications. However, the recent technological advancements and manufacturing cost reduction opened up myriad applications of NTNs for 5G and beyond networks, especially when integrated into terrestrial networks (TNs). This article comprehensively surveys the evolution of NTNs highlighting their relevance to 5G networks and essentially, how it will play a pivotal role in the development of 6G ecosystem. We discuss important features of NTNs integration into TNs and the synergies by delving into the new range of services and use cases, various architectures, technological enablers, and higher layer aspects pertinent to NTNs integration. Moreover, we review the corresponding challenges arising from the technical peculiarities and the new approaches being adopted to develop efficient integrated ground-air-space (GAS) networks. Our survey further includes the major progress and outcomes from academic research as well as industrial efforts representing the main industrial trends, field trials, and prototyping towards the 6G networks

Evolution of Non-Terrestrial Networks From 5G to 6G: A Survey

Non-terrestrial networks (NTNs) traditionally have certain limited applications. However, the recent technological advancements and manufacturing cost reduction opened up myriad applications of NTNs for 5G and beyond networks, especially when integrated into terrestrial networks (TNs). This article comprehensively surveys the evolution of NTNs highlighting their relevance to 5G networks and essentially, how it will play a pivotal role in the development of 6G ecosystem. We discuss important features of NTNs integration into TNs and the synergies by delving into the new range of services and use cases, various architectures, technological enablers, and higher layer aspects pertinent to NTNs integration. Moreover, we review the corresponding challenges arising from the technical peculiarities and the new approaches being adopted to develop efficient integrated ground-air-space (GAS) networks. Our survey further includes the major progress and outcomes from academic research as well as industrial efforts representing the main industrial trends, field trials, and prototyping towards the 6G networks

Measurement of the WW Boson Mass

A measurement of the mass of the $W$ boson is presented based on a sample of 5982 $W \rightarrow e \nu$ decays observed in $p\overline{p}$ collisions at $\sqrt{s}$ = 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a fit to the transverse mass spectrum, combined with measurements of the $Z$ boson mass, the $W$ boson mass is measured to be $M_W = 80.350 \pm 0.140 (stat.) \pm 0.165 (syst.) \pm 0.160 (scale) GeV/c^2$.Comment: 12 pages, LaTex, style Revtex, including 3 postscript figures (submitted to PRL

A measurement of the W boson mass using large rapidity electrons

We present a measurement of the W boson mass using data collected by the D0 experiment at the Fermilab Tevatron during 1994--1995. We identify W bosons by their decays to e-nu final states where the electron is detected in a forward calorimeter. We extract the W boson mass, Mw, by fitting the transverse mass and transverse electron and neutrino momentum spectra from a sample of 11,089 W -> e nu decay candidates. We use a sample of 1,687 dielectron events, mostly due to Z -> ee decays, to constrain our model of the detector response. Using the forward calorimeter data, we measure Mw = 80.691 +- 0.227 GeV. Combining the forward calorimeter measurements with our previously published central calorimeter results, we obtain Mw = 80.482 +- 0.091 GeV

Direct Measurement of the Top Quark Mass at D0

We determine the top quark mass m_t using t-tbar pairs produced in the D0 detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar W^- final states with one W boson decaying to q-qbar and the other to e-nu or mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +- 5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +- 4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst) GeV/C^2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented.Comment: 43 pages, 53 figures, 33 tables. RevTeX. Submitted to Phys. Rev.

Search for Squarks and Gluinos in Events Containing Jets and a Large Imbalance in Transverse Energy

Using data corresponding to an integrated luminosity of 79 pb-1, D0 has searched for events containing multiple jets and large missing transverse energy in pbar-p collisions at sqrt(s)=1.8 TeV at the Fermilab Tevatron collider. Observing no significant excess beyond what is expected from the standard model, we set limits on the masses of squarks and gluinos and on the model parameters m_0 and m_1/2, in the framework of the minimal low-energy supergravity models of supersymmetry. For tan(beta) = 2 and A_0 = 0, with mu < 0, we exclude all models with m_squark < 250 GeV/c^2. For models with equal squark and gluino masses, we exclude m < 260 GeV/c^2.Comment: 10 pages, 3 figures, Submitted to PRL, Fixed typo on page bottom of p. 6 (QCD multijet background is 35.4 events

Search for Charged Higgs Bosons in Decays of Top Quark Pairs

We present a search for charged Higgs bosons in decays of pair-produced top quarks using 109.2 +- 5.8 pb^-1 of data recorded from ppbar collisions at sqrt{s} = 1.8 TeV by the D0 detector during 1992-96 at the Fermilab Tevatron. No evidence is found for charged Higgs production, and most parts of the [m(H+),tan(beta)] parameter space where the decay t -> bH+ has a branching fraction close to or larger than that for t -> bW+ are excluded at 95% confidence level. Assuming m(t) = 175 GeV and sigma(ppbar -> ttbar) = 5.5 pb, for m(H+) = 60 GeV, we exclude tan(beta) 40.9.Comment: 11 pages, 3 figures, submitted to PR

Limits on Anomalous WWgamma and WWZ Couplings

Limits on the anomalous WWgamma and WWZ couplings are presented from a simultaneous fit to the data samples of three gauge boson pair final states in pbar-p collisions at sqrt(s)=1.8 TeV: Wgamma production with the W boson decaying to enu or munu, W boson pair production with both of the W bosons decaying to enu or munu, and WW or WZ production with one W boson decaying to enu and the other W boson or the Z boson decaying to two jets. Assuming identical WWgamma and WWZ couplings, 95 % C.L. limits on the anomalous couplings of -0.30<Delta kappa<0.43 (lambda = 0) and -0.20<lambda<0.20 (Delta kappa = 0) are obtained using a form factor scale Lambda = 2.0 TeV. Limits found under other assumptions on the relationship between the WWgamma and WWZ couplings are also presented.Comment: 13 pages, 3 figures, submitted to Physical Review

Measurement of Dijet Angular Distributions and Search for Quark Compositeness

We have measured the dijet angular distribution in $\sqrt{s}$=1.8 TeV $p\bar{p}$ collisions using the D0 detector. Order $\alpha^{3}_{s}$ QCD predictions are in good agreement with the data. At 95% confidence the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV.Comment: 11 pages, Latex, 3 postscript figure