Search

We present an improved determination of the proton structure functions $F_{2}$ and $xF_{3}$ from the CCFR $\nu $-Fe deep inelastic scattering (DIS) experiment. Comparisons to high-statistics charged-lepton scattering results for $F_{2}$ from the NMC, E665, SLAC, and BCDMS experiments, after correcting for quark-charge and heavy-target effects, indicate good agreement for $x>0.1$ but some discrepancy at lower x. The $Q^{2}$ evolution of the structure functions yields the quantum chromodynamics (QCD) scale parameter $\Lambda_{\bar{MS}}^{NLO,(4)}=337 \pm 28$(exp.) MeV. This corresponds to a value of the strong coupling constant at the scale of mass of the Z-boson of $\alpha _{S}(M_{Z}^{2})=0.119 \pm 0.002 (exp.) \pm 0.004 (theory)$ and is one of the most precise measurements of this quantity.

Previous energy measurements of cosmic ray muons have used magnetic spectrometers to measure the momentum of muons. Measurements using magnets fail for muons in the TeV range because at ultra-high muon energies, the measurement error in the angular deflection of muons by the spectrometer becomes comparable to the total angula deflection. A new method for measuring the energies of TeV muons is investigated, using a sample of cosmic ray muons accumulated parasitically (or synergistically) by the CCFR neutrino detector. The method infers the muon energy from measurements of the energy deposited by the muon in many layers of an iron-scintillator calorimeter. Muons in the TeV energy range lose energy stochastically through e+et - pai production. The distribution of muon energy loss is used t estimate the most likely muon energy. The analysis suggest that this new method for measuring cosmic ray muon energ may be applicable in future detectors such as MINOS an AMANDA.

We present limits on ${\ensuremath{\nu}}_{\ensuremath{\mu}}({\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}})\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}({\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}})$ and ${\ensuremath{\nu}}_{\ensuremath{\mu}}({\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}})\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}({\overline{\ensuremath{\nu}}}_{e})$ oscillations based on a study of inclusive $\ensuremath{\nu}N$ interactions performed using the CCFR massive coarse-grained detector in the Fermilab Tevatron Quadrupole Triplet neutrino beam. The sensitivity to oscillations is from the difference in the longitudinal energy deposition pattern of ${\ensuremath{\nu}}_{\ensuremath{\mu}}N$ vs ${\ensuremath{\nu}}_{\ensuremath{\tau}}N$ or ${\ensuremath{\nu}}_{e}N$ charged-current interactions. The ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ energies ranged from 30 to 500 GeV with a mean of 140 GeV. The minimum and maximum ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ flight lengths are 0.9 and 1.4 km, respectively. For ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ oscillations, the lowest 90% confidence upper limit in ${sin}^{2}2\ensuremath{\alpha}$ of 2.7 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$ is obtained at $\ensuremath{\Delta}{m}^{2}\ensuremath{\sim}50$ e${\mathrm{V}}^{2}$. This result is the most stringent limit to date for $25l\ensuremath{\Delta}{m}^{2}l90$ e${\mathrm{V}}^{2}$. For ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}$ oscillations, the lowest 90% confidence upper limit in ${sin}^{2}2\ensuremath{\alpha}$ of 1.9 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$ is obtained at $\ensuremath{\Delta}{m}^{2}\ensuremath{\sim}350$ e${\mathrm{V}}^{2}$. This result is the most stringent limit to date for $250l\ensuremath{\Delta}{m}^{2}l450$ e${\mathrm{V}}^{2}$, and also excludes at 90% confidence much of the high $\ensuremath{\Delta}{m}^{2}$ region favored by the recent LSND observation.

Results from the high-energy, high-statistics studies of neutrino nucleon interactions by the CCFR collaboration at the Fermilab Tevatron are described. Using a data sample of over 3.7 million events with energies up to 600 GeV, precision measurements are presented for the weak mixing angle, sin 2 θ w , the structure functions, F 2 ( χ, Q 2 ) and χ F 3 ( χ, Q 2 ), and the strange quark distribution, χs ( χ, Q 2 ). Comparisons of these measurements to those obtained in other processes are made in the context of global electroweak and QCD tests. Prospects for the next generation measurements by the NuTeV collaboration at Fermilab are also presented.

We report a precise measurement of the weak mixing angle from the ratio of neutral current to charged current inclusive cross-sections in deep-inelastic neutrino-nucleon scattering. The data were gathered at the CCFR neutrino detector in the Fermilab quadrupole-triplet neutrino beam, with neutrino energies up to 600 GeV. Using the on-shell definition, ${\rm sin ^2\theta_W} \equiv 1 - \frac{{\rm M_W} ^2}{{\rm M_Z} ^2}$, we obtain ${\rm sin ^2\theta_W} = 0.2218 \pm 0.0025 ({\rm stat.}) \pm 0.0036 ({\rm exp.\: syst.}) \pm 0.0040 ({\rm model})$., Comment: 10 pages, Nevis Preprint #1498 (Submitted to Phys. Rev. Lett.)

We have extracted the momentum dependence of the mean, the truncated mean and the most probable value of the energy deposited in a segmented, iron-scintillator, hadron calorimeter by high-energy muons. Data were drawn from a sample of momentum-analyzed, high-energy muons produced in charged-current neutrino interactions. The truncated mean energy deposition of high-energy muons traversing 20 calorimeter segments increases by approximately 16% per 100 GeV c increase in muon momentum over the range 25−125 GeV c ; the most probable energy deposition increases by approximately 7%. These results are important for experiments at high-energy colliders (e.g., Tevatron, SSC and LHC) which use the d E d x of high-energy muons to calibrate the response of electromagnetic and hadron calorimeters with tower geometry. The data are in qualitative agreement with GEANT3 (v3.15/308a) simulations.

We report energy and angle resolutions for hadron showers produced in the CCFR iron target-calorimeter. The measurements were made using drift chambers instrumented with FADC readout; showers were produced using a momentum-analyzed hadron test beam from the Fermilab Tevatron at energies of 40, 70, 100, 150, and 200 GeV. Shower energy measurements are compared to measurements using scintillation counters in the same target.

The CCFR Collaboration presents a measurement of scaling violations of the nonsinglet structure function and a comparison to the predictions of perturbative QCD. The value of [Lambda][sub QCD], from the nonsinglet evolution with [ital Q][sup 2][gt]15 GeV[sup 2] and in the modified minimal-subtraction renormalization scheme, is found to be 210[plus minus]28(stat)[plus minus]41(syst) MeV.

We present measurements of nucleon structure functions, F2(ϰ, Q2) and xFs(ϰ, Q2), from the high-statistics, high-energy neutrino-iron scattering experiment at the Fermilab Tevatron. The existing high-statistics xF3 determination by the CDHSW collaboration is compared to our data. The data presented here constitute the first corroboration of the QCD prediction of xF3 evolution at low-ϰ, and yields ΛMS=210±28±41 MeV, and a determination of the GLS sum rule at Q2 = 3 GeV2, SGLS = ∫ϰ1xFsϰ=2.50±0.018 (stat.)±0.078 (syst.). Our value of ΛMS yields α3(Mz) = .111 ± .002 ± .003 ± .003 (scale). Comparison of the neutrino determination of F2(ϰ, Q2) with that obtained from the charged-lepton (e or μ) scattering leads to a precise test of the mean-square charge prediction by the Quark Parton Model. The SLAC-CCFR and BCDMS structure function provide a consistent and precise set of structure functions over a large range of Q2.

We present the results of a preliminary determination of sin 2 θ W from a study of vFe scattering in the Lab E detector at Fermilab. The analysis is based on a sample of 5 × 10 5 events with a mean neutrino energy of 166 GeV. Our result, sin 2 θ W = 0.2242 ± 0.0044 expt . ± 0.0047 model , is the highest energy high statistics determination of the weak mixing angle using neutrino data.

Neutrino and antineutrino interactions with two muons in the final state have been studied by the CCFR collaboration in the Fermilab Tevatron neutrino beam. The rate of neutrino- and antineutrino-induced prompt same-sign dimuon production in steel was measured using a sample of 220 μ−μ− events and 15 μ+μ+ events with Pμ > 9 GeV/c, and energies between 30 GeV and 600 GeV. After background subtraction, the prompt rate of same-sign dimuon production is (0.53 ± 0.24) × 10−4 per νμ charged-current event and (0.52 ± 0.33) × 10 −4 per ν μ charged-current event. After demanding Pμ1 ≥ 9 GeV/c, Pμ2 ≥ 5 GeV/c and 30 ≤ Eν ≤ 600 GeV a sample of 5044 ν μ 1062 ν μ induced μ ∓ μ ± events are observed. The data support the slow rescaling model of charm production with a value of mc = 1.31 ± .24 GeV/c2. The CKM matrix element Vcd=.209±0.012 and the nucleon strangeness content, ηe=.064−0.00065+0.00075 are measured with the strange sea x distribution found to be softer than its non-strange counterpart. The first measurements of the Q2 dependence of the strange quark densities, ϰs(ϰ), are also presented.

The rate of neutrino- and antineutrino-induced prompt same-sign dimuon production in steel was measured using a sample of μ−μ− events and 25 μ+μ+ events withPμ>9 GeV/c, produced in 1.5 millionvμ and 0.3 million\(\overline {v_\mu }\) induced charged-current events with energies between 30 GeV and 600 GeV. The data were obtained with the Chicago-Columbia-Fermilab-Rochester (CCFR) neutrino detector in the Fermilab Tevatron Quadrupole Triplet Neutrino Beam during experiments E 744 and E 770. After background subtraction, the prompt rate of same-sign dimuon production is (0.53±0.24)×10−4 pervμ charged-current event and (0.52±0.33)×10−4 per\(\overline {v_\mu }\) charged-current event. The kinematic distributions of the same-sign dimuon events after background subtraction are consistent with those of the non-prompt background due to meson decays in the hadron shower of a charged-current event. Calculations ofc\(\bar c\) gluon bremsstrahlung, based on improved measurements of the charm mass parameter and nucleon structure functions by the CCFR collaboration, yield a prompt rate of (0.09±0.39)×10−4 pervμ charged-current event. In this case,c\(\bar c\) gluon bremsstrahlung is probably not an observable source of prompt same-sign dimuons.

We have measured the longitudinal particle punchthrough probability from shower cascades produced by hadrons incident on the iron-scintillator calorimeter of the CCFR neutrino detector and have compared them to a Monte Carlo simulation. Measurements of the dE/dx energy loss iron of high energy cosmic ray muons (up to 1 TeV) incident on the same detector are presented and are compared against calculations.

We report on muon spectrometry at the CCFR neutrino detector. The muon spectrometer and momentum-fitting analysis code are described, and results presented from the calibration of the spectrometer with test beams of momentum-analyzed muons.

Preliminary measurements of structure functions have been made from a sample of 1,281,000 ν μ and 270,000 ν μ charged current events with 30 GeV σ( ν μ )/σ(ν μ ) = .511 ± .002 ( stat ) ± .005 ( syst ) , and an analysis of the Q2 evolution of xF3.

We report an improved measurement of the inverse muon decay process, νμ+e→μ−+νe, at the Fermilab Tevatron. The rate of this reaction with respect to the νμ-N charged current interaction is measured to be (0.1245±0.0057(stat.)±0.0031 (sys.)) × 10−2. The measurement confirms the standard model predictions for the Lorentz structure of the weak current, the helicity of the neutrino, and the energy dependence of the cross section.

This paper reports on measurements of the total cross section for the inclusive reaction vμ+N, as a function of incident energy. Neutrinos and antineutrinos with energy in the range 30–300 GeV were produced in the 1982 Fermilab narrow-band neutrino beamline. A total of 35 000 neutrino and 7000 antineutrino interactions were recorded in the CCFR detector located in LabE. The incident neutrino flux was determined by methods similar to those used in previous experiments. The rate of increase with energy of the total cross section (σ/Ev) in the range 30 to 75 GeV was determined to be 0.659±0.005(stat)±0.039(syst)×10−38 cm2/GeV and 0.307±0.008(stat)±0.020(syst)×10−38 cm2/GeV for incident neutrinos and antineutrinos, respectively. The 5.9% systematic errors are due primarily to uncertainties in the flux intensity measurement. The energy dependence of the cross section in the regionEν=100–300 GeV was found to be linear, as determined by relative normalization techniques. A weighted average of our previous and present measurement for the total ν-N cross section yields: $$\begin{gathered} \sigma (vN) = 0.666 \pm 0.020(statistical \hfill \\ + systematic)E_v 10^{ - 38} cm^2 ; \hfill \\ \sigma (\bar vN) = 0.324 \pm 0.014(statistical \hfill \\ + systematic)E_v 10^{ - 38} cm^2 ; \hfill \\ \end{gathered} $$ .

The techniques used to calibrate and monitor the energy response of the CCFR (Lab E) iron-scintillator target calorimeter for a precision measurement of shower energies are described. Measurements on the energy response of the calorimeter to hadrons, electrons, and minimum ionizing muons (from range outs) are presented. The calorimeter's energy response and resolution for hadrons and electrons are obtained using a test beam with energies between 15 and 450 GeV.

We report on two recent measurements by the CCFR collaboration using the Fermilab Tevatron quad-triplet neutrino beam with neutrino energies up to 600 GeV. In a sample of 666,000 neutrino and 132,000 antineutrino events, 1151 inverse μ-decay events νμe− → μ−νe, were isolated corresponding to a rate with respect to ν μ-N charged current interactions of (0.125±.009 (stat.) ± .003 (sys.)) × 10−2. The data also contain 1522 νμ and 275 ν μ induced opposite sign dimuon events which are due predominantly to charm production at the hadronic vertex. Using this sample, we have measured the strange sea content of the nucleon, ηs = ∫ dχ(2χs(χ))/ ∫ dχ(χu(χ) + χd(χ)) = .057−0.008+0.012, the Cabbibo-KObayashi-Maskawa matrix element, |Vcd| = 0.220−.015+.018, and the slow-rescaling model charm mass parameter, mc = 1.3−0.5+0.6GeV. 0868

Data from the CCFR E770 neutrino deep inelastic scattering experiment at Fermilab contain events with a large Bjorken x (x>0.7) and high momentum transfer [Q{sup 2}>50 (GeV/c){sup 2}]. A comparison of the data with a model based on no nuclear effects at large x shows a significant excess of events in the data. The addition of Fermi gas motion of the nucleons in the nucleus to the model does not explain the excess. Adding a higher momentum tail due to the formation of ''quasi-deuterons'' makes some improvement. An exponentially falling F{sub 2}{proportional_to}e{sup -s(x-x{sub 0})} at large x, predicted by ''multi-quark clusters'' and ''few-nucleon correlations,'' can describe the data. A value of s=8.3{+-}0.7(stat){+-}0.7(syst) yields the best agreement with the data. (c) 2000 The American Physical Society.

We measure the energy loss of high-energy muons (up to 1 TeV) from cosmic-ray muons incident on the iron-scintillator calorimeter of the Chicago-Columbia-Fermilab-Rochester Collaboration (Lab E) neutrino detector at Fermilab. Measurements of the differential energy loss spectra in Fe and the average $\frac{\mathrm{dE}}{\mathrm{dx}}$ energy loss in Fe are presented as functions of muon energy and are compared against calculations. There is reasonable agreement between the measurements and calculations except in the region of small energy losses (under a few GeV) for 1-TeV muons, where the measurement is about 30% lower than the calculation. This level of agreement with theory implies that reliable simulations of the performance of muon detectors for future TeV colliders can be done.

We searched for candidates of neutral heavy lepton (NHL) production in a sample of 2.6 million neutrino interactions in the Columbia‐Chicago‐Fermilab‐Rochester (CCFR) neutrino detector. No evidence for a NHL was found in the charged current density channel, NHL→μ−+X. A NHL with mass between 0.5 and 3.0 GeV/c2 has been excluded (at 90% CL) for couplings to muons between 1×10−2 and 1±10−4 of the Fermi strength, depending on the NHL mass. The results of a search for a neutral heavy particle decaying via the neutral channel are also discussed.

We present the results of a preliminary determination of sin2 θW from a study of νFe scattering in the Lab E detector at Fermilab. The analysis is based on a sample of 5×105 events with a mean neutrino energy of 166 GeV. Our result, sin2 θW=0.2242±0.0044expt.±0.0047model, is the highest energy high statistics determination of the weak mixing angle using neutrino data.

Neutrino and antineutrino interactions with two muons in the final state have been studied by the CCFR collaboration in the Fermilab Tevatron neutrino beam. The rate of neutrino‐ and antineutrino‐induced prompt same‐sign dimuon production in steel was measured using a sample of 220 μ−μ− events and 15 μ+μ+ events with Pμ≳9 GeV/c, and energies between 30 GeV and 600 GeV. In addition, a sample of 5044 νμ and 1062 νμ induced opposite‐sign (μ∓μ±) events was also observed with Pμ1≥9 GeV/c, Pμ2≥5 GeV/c, and 30≤Eθ≤600 GeV. The opposite‐sign data support the slow rescaling model of charm production with a value of mc=1.31±0.24 GeV/c2. The CKM matrix element Vcd=0.209±0.012 and the nucleon strangeness content, ηs=0.064+0.0075−0.0065 are also extracted from the data. The first measurements of the Q2 dependence of the strange quark densities, xs(x), are also presented.

We present preliminary results for nucleon structure functions measured in high energy neutrino interactions. Included are new results for the Gross‐Llewellyn Smith Sum Rule, ∫ 1/x xF3dx=2.66±0.03(stat)±0.08(syst), the ratio of cross‐sections, σν/σν=0.511±0.002(stat)±0.005(syst), and an analysis of the Q2 evolution of xF3.

We present a measurement of neutrino tridents, muon pairs induced by neutrino scattering in the Coulomb field of a target nucleus, in the Columbia-Chicago-Fermilab-Rochester neutrino experiment at the Fermilab Tevatron. The observed number of tridents after geometric and kinematic corrections, 37.0±12.4, supports the standard-model prediction of 45.3±2.3 events. This is the first demonstration of the W-Z destructive interference from neutrino tridents, and rules out, at 99% C.L., the V-A prediction without the interference.

We report on a measurement of inverse muon decay /nu//sub /mu//+e/r arrow//mu//sup /minus//+/nu//sub e/ at the Fermilab Tevatron. A sample of 1151 inverse-/mu/-decay events, produced by neutrinos with laboratory energy in the range 15/le//ital E//sub /nu///le/600 GeV, is extracted. We measure the rate of this reaction with respect to the /nu//sub /mu//-/ital N/ charged-current interaction to be (0.125/plus minus/0.009(stat)/plus minus/0.003(syst))/times/10/sup /minus/2/. The measurement supports /ital V/---/ital A/ structure of the weak current, left-handed two-component neutrinos, and a cross section rising linearly with respect to the center-of-mass energy.

The wide-band, high energy neutrino beam at the Fermilab Tevatron has made possible the observation of several electroweak processes with relatively high statistics. We present here measurements of v µ e- → µ- v e (inverse muon decay, IMD), v µ N → µ-Nµ+vµ (coherent trilepton production, CTP), and also a search for vµN → X N µ → X µ+µ-vµ (a particular case of neutral heavy lepton, NHL). These data are from a preliminary analysis of 670,000 neutrino- and 124,000 antineutrino scattering events, with visible energy in the range 30 – 600 GeV, observed by experiment FNAL E744, the CCFR Collaboration.

We report here on a new high energy neutrino scattering experiment (FNAL E744) by the CCFR Collaboration, and present a preliminary analysis of 1529 neutrino produced- and 284 antineutrino produced µ+µ- events. These dimuons, with visible energy in the range 30 – 600 GeV, are part of a sample of about 794,000 charged-current events. The events are used to extract the strange quark magnitude and shape, and the semileptonic branching ratio of charm.