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.
204013563
KEKB beam collision stability at the picosecond timing and micron position resolution as observed with the Belle detector
Using the Belle detector we study the characteristics of beam collisions at the KEKB 3.5 GeV e+ on 8 GeV e− asymmetric energy collider. We investigate the collision timing tIP and its z-coordinate along the beam axis zIP as a function of the position of the colliding bunch in a beam train. The various tIP and zIP behaviors observed by Belle are attributed to beam loading effects in the radio frequency cavities that accelerate the beams with a beam abort gap. We report these results in detail and discuss the prospects for the SuperKEKB collider.
109454532
Online monitoring of laserpulses using the GPIB-interface of a Tektronix 2430 Digital Storage Oscilloscope
One of the monitoring aspects of holography at the 15 foot Bubble Chamber is the online checking of the lightoutput of the JK2000 ruby laser. Ideally the lightoutput should be a squared pulse in time. Spikes, pre- and postlasing (i.e., lasing before and after the squared pulse) can have a negative influence on the holograms. The scheme for monitoring the lightoutput is discussed in this paper as well as the programming codes and experimental setup necessary to enhance the holography. 1 fig.
119827566
Holography of particle tracks in the Fermilab 15-foot bubble chamber
123547474
The BELLE TOF system
Abstract The BELLE TOF system provides π/K separation for particle momentum below 1.2 GeV /c . A novel Time Stretcher TDC scheme is used to measure flight times with a 25 ps LSB in the high rate environment of KEKB. The TOF resolution is found to be 100 ps. The TOF system also provides precise event timing to the BELLE trigger system.
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.
124792007
A Measurement of $B$ Meson Oscillations Using Inclusive Leptons in $p\bar{p}$ Collisions at 1.8-TeV