A. Alton

Observation of an Anomalous Number of Dimuon Events in a High Energy Neutrino Beam

A search for long-lived neutral particles ( N0s) with masses above 2.2 GeV/c(2) that decay into at least one muon has been performed using an instrumented decay channel at the NuTeV experiment at Fermilab. Data were examined for particles decaying into the final states mumu, mu(e), and mu(pi). Three mumu events were observed over an expected standard model background of 0.069+/-0.010 events; no events were observed in the other modes.

Precision calibration of the NuTeV calorimeter

Abstract NuTeV is a neutrino–nucleon deep-inelastic scattering experiment at Fermilab. The detector consists of an iron-scintillator sampling calorimeter interspersed with drift chambers, followed by a muon toroidal spectrometer. We present determinations of response and resolution functions of the NuTeV calorimeter for electrons, hadrons, and muons over an energy range from 4.8 to 190xa0GeV. The absolute hadronic energy scale is determined to an accuracy of 0.43%. We compare our measurements to predictions from calorimeter theory and GEANT3 simulations.

Nuclear effects and the NuTeV sin2 θW measurement

Abstract NuTeV measures sin 2 θ W by comparing neutral and charged current cross-sections on a heavy nuclear target, and finds a value of sin 2 θ W (on-shell) = 0.2277 ± 0.0013(stat) ± 0.0009(syst), approximately 3σ from the predicted value. We discuss the possibility that nuclear effects on parton distribution functions or cross-sections may be responsible for the discrepancy.

High energy neutrino scattering results from NuTeV

The NuTeV experiment at Fermilab has obtained a unique high statistics sample of neutrino and antineutrino interactions using a novel high-energy sign-selected neutrino beam. Recent results from this sample are presented including a precision measurement of the electroweak parameter sin2≡W, which is observed to be three standard deviations above the standard model prediction.

Cross Section Measurements and Charm Production in the NuTeV Experiment

The NuTeV experiment at Fermilab obtained pure high statistics samples of neutrino and antineutrino interactions using its sign‐selected beam. Preliminary inclusive charged current differential cross sections of neutrino and antineutrino interactions on iron are presented, along with preliminary measurements of F2(x, Q2) and xF3(x, Q2). Preliminary results from the next‐to‐leading order QCD analysis of deep inelastic charged current dimuon data are also shown.

OBSERVATION OF ANOMALOUS DIMUON EVENTS IN THE NUTEV DECAY DETECTOR

A search for the decay of long-lived neutral particles has been performed using an instrumented decay channel at the E815 (NuTeV) experiment at Fermilab. The data were examined for particles decaying into the muonic final states μμ, μe, and μπ. Three μμ events were observed over an expected background of 0.040±0.009 events; no events were observed in the other modes. No Standard Model process appears to be consistent with this observation.

Evidence for diffractive charm production in {nu}{sub {mu}}Fe and {nu}(bar sign){sub {mu}}Fe scattering at the Fermilab Tevatron

We present evidence for the diffractive processes {nu}{sub {mu}}Fe{yields}{mu}{sup -}D{sub S}{sup +}(D{sub S}{sup *})Fe and {nu}(bar sign){sub {mu}}Fe{yields}{mu}{sup +}D{sub S}{sup -}(D{sub S}{sup *})Fe using the Fermilab SSQT neutrino beam and the Lab E neutrino detector. The data are consistent with standard model production of the neutrino trident reactions {nu}{sub {mu}}Fe{yields}{nu}{sub {mu}}{mu}{sup -}{mu}{sup +}Fe and {nu}(bar sign){sub {mu}}Fe{yields}{nu}(bar sign){sub {mu}}{mu}{sup +}{mu}{sup -}Fe. We see no evidence for neutral-current production of J/{psi} via either diffractive or deep inelastic scattering mechanisms. (c) 2000 The American Physical Society.

Recent QCD results from NuTeV/CCFR Collaboration

Abstract Fermilab experiments CCFR and its successor NuTeV study nucleon structure through deep inelastic scattering of neutrino beams off an iron target. We report on the most recent CCFR measurement of the νN differential cross section and resulting structure functions ΔxF 3 = xF ν 3 − xF ν 3 , and R long = σ L σ T , in the framework of massive charm quark. ΔxF3 in sensitive to strange and charm content of the nucleon. NuTeVs preliminary direct measurement of the strange sea, from dimuon charged-current production, and nucleon charm content probed by neutral-current νN interaction, are also presented.

Performance of the NuTeV Fe-scintillator sampling calorimeter and implications for thin calorimeters

NuTeV is a neutrino-nucleon deep inelastic scattering experiment at Fermilab. The NuTeV detector is a traditional heavy target neutrino detector which consists of an iron/liquid scintillator sampling calorimeter followed by a muon spectrometer. The calorimeter response to hadrons, muons and electrons has been measured in an in situ calibration beam over the energy range from 4.5 to 190 GeV. The small non-linearity of the response to hadrons is compared to the expectation from the measured ratio of responses between electrons and hadrons combined with the energy dependence of the fractional electromagnetic energy deposition in the form of neutral pions in hadronic showers fπ0(Eπ). The predictions use fπ0(Eπ) from the Monte Carlo simulations by GHEISHA, GFLUKA and GCALOR and also from the parameterizations of Wigmans and Groom. In addition, a study based on the NuTeV hadron calibration data of the effectiveness of a thin calorimeter is presented. The results of this study have important consequences for the energy resolution of calorimeters used in other applications; for example, measuring the cosmic ray flux in space or with balloon-based experiments.

Determination of sin2 θW from neutrino-nucleon scattering at NuTeV

We report the determination of sin2 θW in ν − N deep inelastic scattering from the NuTeV experiment. Using separate neutrino and anti-neutrino beams, NuTeV is able to extract sin2 θW with low systematic errors from the Paschos-Wolfenstein variable R−, a ratio of differences of neutrino and anti-neutrino neutral-current and charged-current cross-sections. NuTeV measures sin2 θW(on-shell) = 0.2253 ± 0.0019(stat) ± 0.0010(syst), which implies MW = 80.26 ± 0.11 GeV.