1,259 research outputs found
Orbiter CCTV video signal noise analysis
The amount of steady state and transient noise which will couple to orbiter CCTV video signal wiring is predicted. The primary emphasis is on the interim system, however, some predictions are made concerning the operational system wiring in the cabin area. Noise sources considered are RF fields from on board transmitters, precipitation static, induced lightning currents, and induced noise from adjacent wiring. The most significant source is noise coupled to video circuits from associated circuits in common connectors. Video signal crosstalk is the primary cause of steady state interference, and mechanically switched control functions cause the largest induced transients
Transitions in Family-dependent Models
We analyze flavor-changing-neutral-current (FCNC) effects in the
transitions that are induced by family non-universal gauge symmetries.
After systematically developing the necessary formalism, we present a
correlated analysis for the processes. We adopt a
model-independent approach in which we only require family-universal charges
for the first and second generations and small fermion mixing angles. We
analyze the constraints on the resulting parameter space from
mixing and the time-dependent CP asymmetries of the penguin-dominated decays. Our results indicate that the
currently observed discrepancies in some of these modes with respect to the
Standard Model predictions can be consistently accommodated within this general
class of models.Comment: 36 pages, 11 figure
The Impact of a 4th Generation on Mixing and CP Violation in the Charm System
We study D0-D0 mixing in the presence of a fourth generation of quarks. In
particular, we calculate the size of the allowed CP violation which is found at
the observable level well beyond anything possible with CKM dynamics. We
calculate the semileptonic asymmetry a_SL and the mixing induced CP asymmetry
eta_fS_f which are correlated with each other. We also investigate the
correlation of eta_fS_f with a number of prominent observables in other mesonic
systems like epsilon'/epsilon, Br(K_L -> pi0 nu nu), Br(K+ -> pi+ nu nu),
Br(B_s ->mu+ mu-), Br(B_d -> mu+ mu-) and finally S_psi phi in the B_s system.
We identify a clear pattern of flavour and CP violation predicted by the SM4
model: While simultaneous large 4G effects in the K and D systems are possible,
accompanying large NP effects in the B_d system are disfavoured. However this
behaviour is not as pronounced as found for the LHT and RSc models. In contrast
to this, sizeable CP violating effects in the B_s system are possible unless
extreme effects in eta_fS_f are found, and Br(B_s ->mu+ mu-) can be strongly
enhanced regardless of the situation in the D system. We find that, on the
other hand, S_psi phi > 0.2 combined with the measured epsilon'/epsilon
significantly diminishes 4G effects within the D system.Comment: 22 pages, 23 figures, v2 (references added
Phenomenology of a three-family model with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X
We study an extension of the gauge group SU(3)_c X SU(2)_L X U(1)_Y of the
standard model to the symmetry group SU(3)_c X SU(4)_L X U(1)_X (3-4-1 for
short). This extension provides an interesting attempt to answer the question
of family replication in the sense that models for the electroweak interaction
can be constructed so that anomaly cancellation is achieved by an interplay
between generations, all of them under the condition that the number of
families must be divisible by the number of colours of SU(3)_c. This method of
anomaly cancellation requires a family of quarks transforming differently from
the other two, thus leading to tree-level flavour changing neutral currents
(FCNC) transmitted by the two extra neutral gauge bosons and
predicted by the model. In a version of the 3-4-1 extension, which does not
contain particles with exotic electric charges, we study the fermion mass
spectrum and some aspects of the phenomenology of the neutral gauge boson
sector. In particular, we impose limits on the mixing angle and on the
mass scale of the corresponding physical new neutral gauge boson , and
establish a lower bound on the mass of the additional new neutral gauge boson
. For the analysis we use updated precision electroweak data at
the Z-pole from the CERN LEP and SLAC Linear Collider, and atomic parity
violation data. The mass scale of the additional new neutral gauge boson
is constrained by using updated experimental inputs from neutral meson mixing
in the analysis of the sources of FCNC in the model. The data constrain the
mixing angle to a very small value of O(0.001), and the lower bounds on
and on are found to be of O(1 TeV) and of O(7 TeV),
repectively.Comment: 22 pages, 6 tables, 1 figure. To appear in J. Phys. G: Nuclear and
Particle Physic
Implications of large dimuon CP asymmetry in B_{d,s} decays on minimal flavor violation with low tan beta
The D0 collaboration has recently announced evidence for a dimuon CP
asymmetry in B_{d,s} decays of order one percent. If confirmed, this asymmetry
requires new physics. We argue that for minimally flavor violating (MFV) new
physics, and at low tan beta=v_u/v_d, there are only two four-quark operators
(Q_{2,3}) that can provide the required CP violating effect. The scale of such
new physics must lie below 260 GeV sqrt{tan beta}. The effect is universal in
the B_s and B_d systems, leading to S_{psi K}~sin(2beta)-0.15 and S_{psi
phi}~0.25. The effects on epsilon_K and on electric dipole moments are
negligible. The most plausible mechanism is tree-level scalar exchange. MFV
supersymmetry with low tan beta will be excluded. Finally, we explain how a
pattern of deviations from the Standard Model predictions for S_{psi phi},
S_{psi K} and epsilon_K can be used to test MFV and, if MFV holds, to probe its
structure in detail.Comment: 11 pages. v2: References adde
Intralimb coordination following obstacle clearance during running: the effect of obstacle height
The purpose of this study was to investigate the different coordination strategies used following obstacle clearance during running. Ten subjects ran over a level surface and over obstacles of six different heights (10, 12.5, 15, 17.5, 20 and 22.5% of their standing height). Analysis based upon the dynamical systems theory (DST) was used and the phasing relationships between lower extremity segments were examined. The results demonstrated that the increasing obstacle height elicited behavioral changes. The foot and the leg became more independent in their actions, while the leg and the thigh strengthened their already stable relationship. The 15% obstacle height seems to be a critical height for the observed changes
Symmetries and Asymmetries of B -> K* mu+ mu- Decays in the Standard Model and Beyond
The rare decay B -> K* (-> K pi) mu+ mu- is regarded as one of the crucial
channels for B physics as the polarization of the K* allows a precise angular
reconstruction resulting in many observables that offer new important tests of
the Standard Model and its extensions. These angular observables can be
expressed in terms of CP-conserving and CP-violating quantities which we study
in terms of the full form factors calculated from QCD sum rules on the
light-cone, including QCD factorization corrections. We investigate all
observables in the context of the Standard Model and various New Physics
models, in particular the Littlest Higgs model with T-parity and various MSSM
scenarios, identifying those observables with small to moderate dependence on
hadronic quantities and large impact of New Physics. One important result of
our studies is that new CP-violating phases will produce clean signals in
CP-violating asymmetries. We also identify a number of correlations between
various observables which will allow a clear distinction between different New
Physics scenarios.Comment: 56 pages, 18 figures, 14 tables. v5: Missing factor in eqs. (3.31-32)
and fig. 6 corrected. Minor misprints in eq. (2.10) and table A corrected.
Conclusions unchange
Emotion differentiation dissected: between-category, within-category, and integral emotion differentiation, and their relation to well-being
Lepton flavour violation in The Little Higgs model
Little Higgs models with T-parity have a new source of lepton flavour
violation. In this paper we consider the anomalous magnetic moment of the muon
\gmtwo and the lepton flavour violating decays \mutoeg and \tautomug in Little
Higgs model with T-parity \cite{Goyal:2006vq}. Our results shows that present
experimental constraints of \mutoeg is much more useful to constrain the new
sources of flavour violation which are present in T-parity models.Comment: LaTeX file with 13 eps figures (included
The impact of SuperB on flavour physics
This report provides a succinct summary of the physics programme of SuperB,
and describes that potential in the context of experiments making measurements
in flavour physics over the next 10 to 20 years. Detailed comparisons are made
with Belle II and LHCb, the other B physics experiments that will run in this
decade. SuperB will play a crucial role in defining the landscape of flavour
physics over the next 20 years.Comment: 20 pages, 6 figure
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