118970720
Scaling Variable Distributions for Neutrino Proton Interactions in the Fermilab 15-ft. Bubble Chamber with External Muon Identifier
The Fermilab 15-ft. liquid hydrogen bubble chamber was exposed to a one-horn neutrino beam produced by 300 GeV/c protons. Data from 75,000 pictures yielding 343 events after cuts are analyzed here. Previous publications [1] have presented scaling variable (x and y) distribution from these same data analyzed without the use of auxilliary muon identification. These previous results depended upon the use of a purely kinematic method [2] for the identification of the muon in charged current events and thus for the separation of charged current (CC) and neutral current (NC) events. Since there might be important biases and backgrounds in the kinematic selection method, it is important to re-examine the data by means of a different selection method with different, and hopefully smaller, biases. The External Muon Identifier (EMI) mounted on the bubble chamber permits such an analysis.
122531862
The Design of the Magnetized Muon Shield for the Prompt Neutrino Facility
The main technical challenge in the design of the prompt neutrino beam is the magnetized muon shield. Two satisfactory alternate designs have been developed for such a shield during this past year and the background muon fluxes have been calculated by three independent programs at Columbia, Fermilab, and MIT. The background muon fluxes have been calculated to be satisfactory in all of the detectors that might use the beam. In Section III of this report we describe in detail the three Monte Carlo programs used in these calculations. In Section IV we give the details of the flux calculations for the E-613 shield and the comparisons with the observed fluxes with various configurations of that shield. In Section V we describe the designs that have been developed for the neutrino area shield. In Section VI we discuss the problem of proton beam transport losses and the associated muon fluxes. Finally, in Section VII a comparison of the two solutions is made which covers cost, effectiveness, schedule and responsiveness to future unknowns. We conclude that there are not overwhelming reasons for the choice of one design over the other. However, for a variety of secondary reasons the superconducting design offers advantages.more » We therefore propose the construction of the prompt neutrino facility with the superconducting magnet design.« less
118961337
Bubble-Chamber Study of Dimuon Production by Neutrinos Using the Phase-2 EMI and a Dichromatic Beam
118234753
Measurement of the amplitude ratio of $B^0 \to D^0K^{*0}$ and $B^0 \to \bar{D^0}K^{*0}$ decays with a model-independent Dalitz plot analysis using $D\to K_S^0\pi^+\pi^-$ decays
We report a measurement of the amplitude ratio $r_S$ of $B^0 \to D^0K^{*0}$ and $B^0 \to \bar{D^0}K^{*0}$ decays with a model-independent Dalitz plot analysis using $D\to K_S^0\pi^+\pi^-$ decays. Using the full data sample of $772\times10^6$ $B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at KEKB accelerator the upper limit is $r_S < 0.87$ at the 68 % confidence level. This result is the first measurement of $r_S$ with a model-independent Dalitz analysis, and is consistent with results from other analyses. The value of $r_S$ indicates the sensitivity of the decay to $\phi_3$ because the statistical uncertainty is proportional to $1/r_S$. The $r_S$ result is obtained from observables ($x_\pm$, $y_\pm$) \begin{eqnarray} x_- &=& +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} \pm0.0 \\ y_- &=& -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} \pm0.1 \\ x_+ &=& +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} \pm0.1 \\ y_+ &=& +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} \pm0.1 \\ , \end{eqnarray} where $x_\pm = r_S \cos(\delta_S \pm \phi_3)$, $y_\pm = r_S \sin(\delta_S \pm \phi_3)$ and $\phi_3 (\delta_S)$ are the weak (strong) phase difference between $B^0 \to D^0K^{*0}$ and $B^0 \to \bar{D^0}K^{*0}$. The first uncertainty is statistical, the second is the experimental systematic and the third is the systematic due to the uncertainties on $c_i$ and $s_i$ parameters measured by CLEO.
121721417
A track fitting method for particles in non-uniform magnetic fields
Abstract A new method of fitting particle trajectories in non-uniform magnetic fields is described. It is assumed that measured points in three-dimensional space have already been obtained. The trajectory is broken into segments within which the magnetic field may be regarded as a linear function, for which an approximate analytic form of the trajectory is derived. With this form and its derivatives, a Newton-Rapheson iteration is carried out to minimize the sum of the squares of deviations of observed points from the trajectory. The method described has been used in a spark chamber experiment investigating K e4 and K πee decays.
34597488
Left-right asymmetry in neutrino-produced hadron jets.
In an experiment (E546) to study interactions of {l angle}{ital E}{r angle}=100 GeV and {l angle}{ital Q}{sup 2}{r angle}=17 GeV{sup 2} neutrinos in the Fermilab 15-foot bubble chamber, we have looked for a left-right asymmetry in the azimuthal angle {phi} of individual hadrons about the direction of the lepton momentum transfer ({ital q} vector). Significant asymmetry is found for forward positive hadrons; for {ital x}{sub {ital F}}{gt}0.10, we find {l angle}cos{phi}{r angle}={minus}0.029{plus minus}0.008, where {ital x}{sub {ital F}} is the Feynman {ital x} variable. Negative hadrons with {ital x}{sub {ital F}}{gt}0.10 show no asymmetry, {l angle}cos{phi}{r angle}=0.004{plus minus}0.011. A model which includes parton intrinsic transverse momentum {ital k}{sub {ital t}} reproduces the asymmetry of combined positive and negative hadrons with {ital x}{sub {ital F}}{gt}0.10, {l angle}cos{phi}{r angle}={minus}0.018{plus minus}0.0065, if {l angle}{ital k}{sub {ital t}}{sup 2}{r angle}=0.065{plus minus}0.024 GeV{sup 2}/c{sup 2}. But the model predicts almost equal asymmetries for positive and negative hadrons. The model also agrees poorly with the observed dependence on the kinematic variables {ital x} and {ital Q}{sup 2} if the {ital k}{sub {ital t}} distribution is assumed to be independent of kinematic variables.
124792007
A Measurement of $B$ Meson Oscillations Using Inclusive Leptons in $p\bar{p}$ Collisions at 1.8-TeV
120780052
Radiation damage experience at CDF with SVX
Abstract The radiation damage experience of the silicon vertex detector used in the CDF experiment during the 1993–1995 collider run is described. The detector is single sided, AC coupled, FOXFET biased, and uses radiation hard readout chips. The detector's noise is seen to increase anomalously with radiation dose.