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.
No description provided.
No description provided.
No description provided.
The v and v nucleon total cross-sections have been determined as a function of energy using a sample of 2500 v and 950 v event. The results are compared with predictions of scaling and charge symmetry hypotheses.
Measured charged current total cross section.
Measured charged current total cross section.
Nucleon structure functions measured in neutrino-iron and antineutrinoiron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 Ge V. The structure functions $F_2$ and $xF_3$ are compared with the the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives NL0(4) . 2 value of $\Lambda^{NLO,(4)}_{\overline MS}$ = 337 ± 28 (exp.) MeV, which corresponds to $\alpha_s$ ($M^2_z$) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by $xG(x,Q^2_0 = 5 GeV^2$ ) = (2.22±0.34) x ($1-x)^{4.65 \pm 0.68}$
The cross sections are normalized to the world average of SIG(NUMU)/E/A = 0.677E-38 cm^2/GeV as no absolute flux measurement was made in this experiment.
These cross sections are normalized to the world average of SIG(NUMU)/E/A =0.677E-38 cm^2/GeV multiplied by the world average of SIG(NUMUBAR)/SIG(NUMU) i n c l u d i n g this experiment.
No description provided.
A new structure function analysis of CCFR deep inelastic nu-N and nubar-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x=0.0045 and Q^2=0.3 GeV^2. Comparisons to charged lepton scattering data from NMC and E665 experiments are made and the behavior of the structure function F2_nu is studied in the limit Q^2 -> 0.
F2 measurements.
We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared ($Q^{2}$), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for $1 < Q^2 < 15 GeV^2/c^2$. A comparison with the order $\alpha^{3}_{s}$ theoretical predictions yields a determination of $\alpha_{s}$ at the scale of the Z-boson mass of $0.114 \pm^{.009}_{.012}$. This measurement provides a new and useful test of perturbative QCD at low $Q^2$, because of the low uncertainties in the higher order calculations.
No description provided.
Total GLS integral and ALPHAS for each bin in Q2. Systematic errors are correlated in different Q2 bins. The second DSYS error in ALPHAS is due to the uncertainty in the theory.
ALPHAS extrapolated to the Z0 mass. The second DSYS error is due to the uncertainty in the theory.
Limits on $\nu_\mu (\overline{\nu}_\mu) \to \nu_e (\overline{\nu}_e)$ oscillations based on a statistical separation of $\nu_e N$ charged current interactions in the CCFR detector at Fermilab are presented. $\nu_e$ interactions are identified by the difference in the longitudinal shower energy deposition pattern of $\nu_e N \rightarrow eX$ versus $\nu_\mu N \to \nu_\mu X$ interactions. Neutrino energies range from 30 to 600 GeV with a mean of 140 GeV, and $\nu_\mu$ flight lengths vary from 0.9 km to 1.4 km. The lowest 90% confidence upper limit in $sin^2 2\alpha$ of $1.1 \times 10^{-3}$ is obtained at $\Delta m^2 \sim 300 eV^2$. For $sin^2 2\alpha = 1$, $\Delta m^2 > 1.6 eV^2$ is excluded, and for $\Delta m^2 \gg 1000 eV^2$, $sin^2 2\alpha > 1.8 \times 10^{-3}$ is excluded. This result is the most stringent limit to date for $\Delta m^2 > 25 eV^2$ and it excludes the high $\Delta m^2$ oscillation region favoured by the LSND experiment. The $\nu_\mu$-to-$\nu_e$ cross-section ratio was measured as a test of $\nu_\mu (\bar\nu_\mu) \leftrightarrow \nu_e (\bar\nu_e)$ universality to be $1.026 \pm 0.055$.
ALPHA is the neutrino mixing angle. The result for SIN(ALPHA)**2 from the fit at each Delta(M)**2 for NUMU -->NUE oscillations. The 90% CL upper limit is equal to the best fit SIN(ALPHA)**2 + 1.2*SIGMA.
No description provided.
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 ΛQCD, from the nonsinglet evolution with Q2>15 GeV2 and in the modified minimal-subtraction renormalization scheme, is found to be 210±28(stat)±41(syst) MeV.
The CONST(N=LAMBDA-QCD) is extracted from the measurement of scaling violations of the nonsinglet structure function.
A high-statistics study by the Columbia-Chicago-Fermilab-Rochester Collaboration of opposite-sign dimuon events induced by neutrino-nucleon scattering at the Fermilab Tevatron is presented. A sample of 5044 νμ and 1062 ν¯μ induced μ∓μ± events with Pμ1≥9 GeV/c, Pμ2≥5 GeV/c, 30≤Eν≤600 GeV, and 〈Q2〉=22.2 GeV2/c2 is observed. The data support the slow-rescaling model of charm production with a value of mc=1.31±0.24 GeV2/c2. The first measurement of the Q2 dependence of the nucleon strange quark distribution xs(x) is presented. The data yield the Cabibbo-Kobayashi-Maskawa matrix element ‖Vcd‖=0.209±0.012 and the nucleon fractional strangeness content ηs=0.064−0.007+0.008.
From joined NUMU and NUMUBAR statictics.
From joined NUMU and NUMUBAR statictics.
From joined NUMU and NUMUBAR statictics.
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.
Rate of dimuon production per charged current event.
Rate of dimuon production per charged current event.
We present results for the differential cross sections of neutrinos and antineutrinos on nucleons in the energy range E = 2−200 GeV, from the BEBC and Gargamelle experiments. The structure functions F 2 , 2 χF 1 and χF 3 have been evaluated as a function of χ and q 2 . Deviations are observed from Bjorken scaling, which are very similar to those found in electron and muon inelastic scattering. For the Callan-Gross ratio, we find 2χF 1 F 2 = 0.80 ± 0.12 and the corresponding value for 〈R〉 = 〈 σ S σ T 〉 = 0.15 ± 0.10 . Our results are consistent with the Gross-Llewellyn-Smith sum rule; we measure ⩾2.5 ± 0.5 valence quarks per nucleon. Quark and antiquark distributions are given. The Nachtmann moments of F 2 and χF 3 are quantitatively consistent with the predictions from QCD. The value of the strong interaction parameter is λ = 0.74 ± 0.05 GeV without corrections, and 0.66 ± 0.05 GeV including α S 2 corrections. The moments of the gluon distribution are found to be positive and indicate an χ distribution of gluons which is comparable with that of the valence quarks.
No description provided.
No description provided.
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