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Adams, Todd

Publications and source records attributed to Adams, Todd.

60 records · Page 4
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DOE OSTI2010

Search for sneutrino production in $e\mu$ final states in 5.3 fb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt(s) =1.96$ TeV

We report the results of a search for R parity violating (RPV) interactions leading to the production of supersymmetric sneutrinos decaying into e{mu} final states using 5.3 fb{sup -1} of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Having observed no evidence for production of e{mu} resonances, we set direct bounds on the RPV couplings {lambda}{prime}{sub 311} and {lambda}{sub 312} as a function of sneutrino mass.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Search for Randall-Sundrum Gravitons in the Dielectron and Diphoton Final States with 5.4 fb{sup -1} of Data from pp Collisions at {radical}(s)=1.96 TeV

Using 5.4 fb{sup -1} of integrated luminosity from pp collisions at {radical}(s)=1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider, we search for decays of the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model to ee and {gamma}{gamma}. We set 95% C.L. lower limits on the mass of the lightest graviton between 560 and 1050 GeV for values of the coupling k/M{sub Pl} between 0.01 and 0.1.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Measurement of the normalized $Z/\gamma^* -> \mu^+\mu^-$ transverse momentum distribution in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

We present a new measurement of the Z/{gamma}* transverse momentum distribution in the range 0-330 GeV, in proton anti-proton collisions at {radical}s = 1.96 TeV. The measurement uses 0.97 fb{sup -1} of integrated luminosity recorded by the D0 experiment and is the first using the Z/{gamma}* {yields} {mu}{sup +}{mu}{sup -} + X channel at this center-of-mass energy. This is also the first measurement of the Z/{gamma}* transverse momentum distribution that presents the result at the level of particles entering the detector, minimizing dependence on theoretical models. As any momentum of the Z/{gamma}* in the plane transverse to the incoming beams must be balanced by some recoiling system, primarily the result of QCD radiation in the initial state, this variable is an excellent probe of the underlying process. Tests of the predictions of QCD calculations and current event generators show they have varied success in describing the data. Using this measurement as an input to theoretical predictions will allow for a better description of hadron collider data and hence it will increase experimental sensitivity to rare signals.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Measurement of the $WZ\rightarrow \ell\nu\ell\ell$ cross section and limits on anomalous triple gauge couplings in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV

The standard model (SM) of particle physics has been extensively tested in the past three decades and is found to be in excellent agreement with experimental observations. It is widely assumed, however, that the SM is only a low energy approximation of a more general theory. Therefore, any significant deviation from the SM predictions yields information on the nature of a more fundamental theory. Production of WZ pairs is the least studied diboson process within the SM, as it is a charged final state and can only be produced at hadron colliders. A detailed study of this process probes the electroweak sector of the SM. In addition, searches for new phenomena in the production of heavy gauge boson pairs are interesting, as many extensions of the SM predict 1-4 additional heavy gauge bosons that can decay into a WZ boson pairs.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Search for flavor changing neutral currents in single top quark production using 2.3 fb$^-1$ of $p\bar{p}$ collisions

We present a search for flavor changing neutral currents via quark-gluon couplings in a sample of single top quark final states corresponding to 2.3 fb{sup -1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. We select events containing a single top quark candidates with an additional jet, and obtain separation between signal and background using Bayesian neural networks. We find consistency between background expectation and observed data, and set limits on avor changing neutral current gluon couplings of the top quark to up quarks (tgu) and charm quarks (tgc). The cross section limits at the 95% C.L. are {sigma}{sub tgu} < 0.20 pb and {sigma}{sub tgc} < 0.27 pb. These correspond to limits on the top quark decay branching fractions of B(t {yields} gu) < 2.0 x 10{sup -4} and B(t {yields} gc) < 3.9 x 10{sup -3}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗