2,640 research outputs found
Quark Loop Contributions to Neutron, Deuteron, and Mercury EDMs from Supersymmetry without R parity
We present a detailed analysis of the neutron, deuteron and mercury electric
dipole moment from supersymmetry without R parity, focusing on the quark-scalar
loop contributions. Being proportional to top Yukawa and top mass, such
contributions are often large. Analytical expressions illustrating the explicit
role of the R-parity violating parameters are given following perturbative
diagonalization of mass-squared matrices for the scalars. Dominant
contributions come from the combinations for which
we obtain robust bounds. It turns out that neutron and deuteron EDMs receive
much stronger contributions than mercury EDM and any null result at the future
deuteron EDM experiment or Los Alamos neutron EDM experiment can lead to
extra-ordinary constraints on RPV parameter space. Even if R-parity violating
couplings are real, CKM phase does induce RPV contribution and for some cases
such a contribution is as strong as contribution from phases in the R-parity
violating couplings.Hence, we have bounds directly on even if the RPV parameters are all real.
Interestingly, even if slepton mass and/or is as high as 1 TeV, it
still leads to neutron EDM that is an order of magnitude larger than the
sensitivity at Los Alamos experiment. Since the results are not much sensitive
to , our constraints will survive even if other observables tighten
the constraints on .Comment: 16 pages, 10 figures, accepted for publication in Physical Review
ASTROD, ASTROD I and their gravitational-wave sensitivities
ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) is a
mission concept with three spacecraft -- one near L1/L2 point, one with an
inner solar orbit and one with an outer solar orbit, ranging coherently with
one another using lasers to test relativistic gravity, to measure the solar
system and to detect gravitational waves. ASTROD I with one spacecraft ranging
optically with ground stations is the first step toward the ASTROD mission. In
this paper, we present the ASTROD I payload and accelerometer requirements,
discuss the gravitational-wave sensitivities for ASTROD and ASTROD I, and
compare them with LISA and radio-wave PDoppler-tracking of spacecraft.Comment: presented to the 5th Edoardo Amaldi Conference (July 6-11, 2003) and
submitted to Classical and Quantum Gravit
Decoherent Scattering of Light Particles in a D-Brane Background
We discuss the scattering of two light particles in a D-brane background. It
is known that, if one light particle strikes the D brane at small impact
parameter, quantum recoil effects induce entanglement entropy in both the
excited D brane and the scattered particle. In this paper we compute the
asymptotic `out' state of a second light particle scattering off the D brane at
large impact parameter, showing that it also becomes mixed as a consequence of
quantum D-brane recoil effects. We interpret this as a non-factorizing
contribution to the superscattering operator S-dollar for the two light
particles in a Liouville D-brane background, that appears when quantum D-brane
excitations are taken into account.Comment: 18 pages LATEX, one figure (incorporated
Timeless path integral for relativistic quantum mechanics
Starting from the canonical formalism of relativistic (timeless) quantum
mechanics, the formulation of timeless path integral is rigorously derived. The
transition amplitude is reformulated as the sum, or functional integral, over
all possible paths in the constraint surface specified by the (relativistic)
Hamiltonian constraint, and each path contributes with a phase identical to the
classical action divided by . The timeless path integral manifests the
timeless feature as it is completely independent of the parametrization for
paths. For the special case that the Hamiltonian constraint is a quadratic
polynomial in momenta, the transition amplitude admits the timeless Feynman's
path integral over the (relativistic) configuration space. Meanwhile, the
difference between relativistic quantum mechanics and conventional
nonrelativistic (with time) quantum mechanics is elaborated on in light of
timeless path integral.Comment: 41 pages; more references and comments added; version to appear in
CQ
Breast cancer–secreted factors perturb murine bone growth in regions prone to metastasis
Breast cancer frequently metastasizes to bone, causing osteolytic lesions. However, how factors secreted by primary tumors affect the bone microenvironment before the osteolytic phase of metastatic tumor growth remains unclear. Understanding these changes is critical as they may regulate metastatic dissemination and progression. To mimic premetastatic bone adaptation, immunocompromised mice were injected with MDA-MB-231–conditioned medium [tumor-conditioned media (TCM)]. Subsequently, the bones of these mice were subjected to multiscale, correlative analysis including RNA sequencing, histology, micro–computed tomography, x-ray scattering analysis, and Raman imaging. In contrast to overt metastasis causing osteolysis, TCM treatment induced new bone formation that was characterized by increased mineral apposition rate relative to control bones, altered bone quality with less matrix and more carbonate substitution, and the deposition of disoriented mineral near the growth plate. Our study suggests that breast cancer–secreted factors may promote perturbed bone growth before metastasis, which could affect initial seeding of tumor cells
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