We present new measurements of the CMB polarization from the final season of CAPMAP. The data set was obtained in winter 2004-2005 with the 7 m antenna in Crawford Hill, New Jersey, from 12 W-band ...(84-100 GHz) and four Q-band (36-45 GHz) correlation polarimeters with 3.3 super(image ) and 6.5 super(image ) beam sizes, respectively. After selection criteria were applied, 956 (939) hr of data survived for analysis of W-band (Q-band) data. Two independent and complementary pipelines produced results in excellent agreement with each other. A broad suite of null tests, as well as extensive simulations, showed that systematic errors were minimal, and a comparison of the W-band and Q- band sky maps revealed no contamination from galactic foregrounds. We report the E-mode and B-mode power spectra in seven bands in the range image, extending the range of previous measurements to higher image. The E-mode spectrum, which is detected at 11 capital sigma significance, is in agreement with cosmological predictions and with previous work at other frequencies and angular resolutions. The BB power spectrum provides one of the best limits to date on B-mode power at 4.8 muK super(2) (95% confidence).
The Fermilab KTeV experiment has searched for lepton-flavor-violating decays of the K(L) meson in three decay modes. We observe no events in the signal region for any of the modes studied, and we set ...the following upper limits for their branching ratios at the 90% C.L.: BR(K(L) --> pi(0) micro(+/-) e(-/+)) <7.6 x 10(-11); BR(K(L) --> pi(0)pi(0) micro(+/-) e(-/+)) <1.7 x 10(-10); BR(pi(0) --> micro(+/-) e(-/+)) <3.6 x 10(-10). This result represents a factor of 82 improvement in the branching ratio limit for K(L) --> pi(0) micro(+/-) e(-/+) and is the first reported limit for K(L) --> pi(0)pi(0) micro(+/-) e(-/+).
We present a new determination of the parity of the neutral pion via the double Dalitz decay pi0-->e+e-e+e-. Our sample, which consists of 30,511 candidate decays, was collected from KL-->pi0pi0pi0 ...decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative pi0 parity and place a limit on scalar contributions to the pi0-->e+e-e+e- decay amplitude of less than 3.3% assuming CPT conservation. The pi0gamma*gamma* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase-space distribution. Additionally, we have measured the branching ratio of this mode to be B(pi0-->e+e-e+e-)=(3.26+/-0.18)x10(-5).
Using the complete KTeV data set of 5,241 candidate K(L)--> pi(+) pi(-) e(+) e(-) decays (including an estimated background of 204 +/- 14 events), we have measured the coupling g(CR)= 0.163 +/- ...0.0149(stat) +/- 0.023(syst) of the CP conserving charge radius process and from it determined a K(0) charge radius of <r(2)(K(0))> = -0.077 +/- 0.007(stat) +/- 0.011(syst)fm(2). We have determined a first experimental upper limit of 0.04 (90% C.L.) /g(e1)/ / /g(M1)/ of the couplings for the E1 and M1 direct photon emission processes. We also report the measurement of /g(M1)/ including a vector form factor /g(M1)/(1 + (a(1)/a(2))/((M(2)(p)-(M(2)(k))= 2M(K)E(gamma*)), where vector /g(M1)/= 1.11+/- 0.12(stat) +/- 0.08(syst) and a(1)/a(2) = -0.744 +/- 0.027(stat) +/- 0.032(syst) GeV(2)/c(2). Finally, a CP-violating asymmetry of 13.6 +/- 1.4(stat) +/- 1.5(syst)% in the CP and T odd angle phi between the decay planes of the e(+) e(-) and pi(+) pi(-) pairs in the K(L) center of mass is reported.
The Princeton IQU Experiment (PIQUE) and the Cosmic Anisotropy Polarization Mapper (CAPMAP) are experiments designed to measure the polarization of the cosmic microwave background (CMB) on sub-degree ...scales in an area within 1 degree of the North Celestial Pole using heterodyne correlation polarimeters and off-axis telescopes located in central New Jersey. PIQUE produced the tightest limit on the CMB polarization prior to its detection by DASI, while CAPMAP has recently detected polarization at l similar to 1000. The experimental methods and instrumentation for these two projects are described in detail with emphasis on the particular challenges involved in measuring the tiny polarized component of the CMB.
The photon detection inefficiency of electromagnetic calorimeters due to photonuclear reactions has been studied at photon energies below 1
GeV using a tagged-photon beam at the KEK-Tanashi 1.3-GeV ...electron synchrotron. Photonuclear reactions are identified by detecting low-energy neutrons with liquid scintillation counters surrounding the sample calorimeter. For a Cesium Iodide (CsI) calorimeter with a detection threshold of 10
MeV, the inefficiency due to photonuclear reactions is
10
-
4
at
E
γ
=
100
MeV
, and decreases to
2
×
10
-
7
at
E
γ
=
1
GeV
. For a lead-scintillator sampling calorimeter, the inefficiency is larger than the above values by a factor of 2–3, reflecting the sampling effect after photonuclear reactions. By decreasing the detection threshold down to 1
MeV, the inefficiencies are reduced by a factor of 10 for both types of calorimeters.
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