3 research outputs found
General Minimal Flavor Violation
A model independent study of the minimal flavor violation (MFV) framework is
presented, where the only sources of flavor breaking at low energy are the up
and down Yukawa matrices. Two limits are identified for the Yukawa coupling
expansion: linear MFV, where it is truncated at the leading terms, and
nonlinear MFV, where such a truncation is not possible due to large third
generation Yukawa couplings. These are then resummed to all orders using
non-linear sigma-model techniques familiar from models of collective breaking.
Generically, flavor diagonal CP violating (CPV) sources in the UV can induce
O(1) CPV in processes involving third generation quarks. Due to a residual U(2)
symmetry, the extra CPV in B_d-\bar B_d mixing is bounded by CPV in B_s-\bar
B_s mixing. If operators with right-handed light quarks are subdominant, the
extra CPV is equal in the two systems, and is negligible in processes involving
only the first two generations. We find large enhancements in the up type
sector, both in CPV in D-\bar D mixing and in top flavor violation.Comment: 5 pages and no figure
The Pioneer Anomaly
Radio-metric Doppler tracking data received from the Pioneer 10 and 11
spacecraft from heliocentric distances of 20-70 AU has consistently indicated
the presence of a small, anomalous, blue-shifted frequency drift uniformly
changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was
interpreted as a constant sunward deceleration of each particular spacecraft at
the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of
the Newton's gravitational inverse-square law has become known as the Pioneer
anomaly; the nature of this anomaly remains unexplained. In this review, we
summarize the current knowledge of the physical properties of the anomaly and
the conditions that led to its detection and characterization. We review
various mechanisms proposed to explain the anomaly and discuss the current
state of efforts to determine its nature. A comprehensive new investigation of
the anomalous behavior of the two Pioneers has begun recently. The new efforts
rely on the much-extended set of radio-metric Doppler data for both spacecraft
in conjunction with the newly available complete record of their telemetry
files and a large archive of original project documentation. As the new study
is yet to report its findings, this review provides the necessary background
for the new results to appear in the near future. In particular, we provide a
significant amount of information on the design, operations and behavior of the
two Pioneers during their entire missions, including descriptions of various
data formats and techniques used for their navigation and radio-science data
analysis. As most of this information was recovered relatively recently, it was
not used in the previous studies of the Pioneer anomaly, but it is critical for
the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living
Reviews in Relativit