779 research outputs found
Charmonium production at neutrino factories
At existing and planned neutrino factories (high energy and high intensity
neutrino beam facilities) precision studies of QCD in neutrino-nucleon
interactions are a realistic opportunity. We investigate charmonium production
in fixed target neutrino experiments. We find that production in
neutrino-nucleon collision is dominated by the color octet NRQCD matrix
element in a neutral current process, which is not accessible in photo or
leptoproduction. Neutrino experiments at a future Muon Collider will acquire
sufficient event rate to accurately measure color octet matrix element
contributions. The currently running high energy neutrino experiments, NOMAD
and NuTeV could also observe several such events.Comment: 13 pages Latex, with five embedded eps figures. Cosmetic fixups in
the figures, otherwise unchange
Rate of Convergence Towards Semi-Relativistic Hartree Dynamics
We consider the semi-relativistic system of gravitating Bosons with
gravitation constant . The time evolution of the system is described by the
relativistic dispersion law, and we assume the mean-field scaling of the
interaction where and while fixed. In
the super-critical regime of large , we introduce the regularized
interaction where the cutoff vanishes as . We show that the
difference between the many-body semi-relativistic Schr\"{o}dinger dynamics and
the corresponding semi-relativistic Hartree dynamics is at most of order
for all , i.e., the result covers the sub-critical regime and
the super-critical regime. The dependence of the bound is optimal.Comment: 29 page
Limits on the monopole magnetic field from measurements of the electric dipole moments of atoms, molecules and the neutron
A radial magnetic field can induce a time invariance violating electric
dipole moment (EDM) in quantum systems. The EDMs of the Tl, Cs, Xe and Hg atoms
and the neutron that are produced by such a field are estimated. The
contributions of such a field to the constants, of the T,P-odd
interactions and are also estimated for the TlF, HgF and YbF molecules (where
() is the electron (nuclear) spin and is the molecular
axis). The best limit on the contact monopole field can be obtained from the
measured value of the Tl EDM. The possibility of such a field being produced
from polarization of the vacuum of electrically charged magnetic monopoles
(dyons) by a Coulomb field is discussed, as well as the limit on these dyons.
An alternative mechanism involves chromomagnetic and chromoelectric fields in
QCD.Comment: Uses RevTex, 16 pages, 4 postscript figures. An explanation of why
there is no orbital contribution to the EDM has been added, and the
presentation has been improved in genera
Time-reversal violating rotation of polarization plane of light in gas placed in electric field
Rotation of polarization plane of light in gas placed in electric field is
considered. Different factors causing this phenomenon are investigated. Angle
of polarization plane rotation for transition 6S_{1/2} - 7S_{1/2} in cesium
(lambda=539 nm) is estimated. The possibility to observe this effect
experimentally is discussed.Comment: 10 pages, Late
Measurement of the 6s - 7p transition probabilities in atomic cesium and a revised value for the weak charge Q_W
We have measured the 6s - 7p_{1/2,3/2} transition probabilities in atomic
cesium using a direct absorption technique. We use our result plus other
previously measured transition rates to derive an accurate value of the vector
transition polarizability \beta and, consequently, re-evaluate the weak charge
Q_W. Our derived value Q_W=-72.65(49) agrees with the prediction of the
standard model to within one standard deviation.Comment: 4 pages, 2 figure
Direct J/Psi hadroproduction in k_\perp-factorization and the color octet mechanism
The hadroproduction of direct J/Psi in the framework of the
k_\perp-factorization approach is studied. The color-singlet contribution is
essentially larger than in the collinear approach but is still an order of
magnitude below the data. The deficit may be well described by the color octet
contribution with the value of the matrix element
substantially decreased in comparison with the fits in the collinear
factorization. This should lead to a reduction of the large transverse
polarization, predicted in the collinear approach.Comment: 3 pages, LaTeX, 2 eps figures, final PRD versio
Gravitational hedgehog, stringy hedgehog and stringy sphere
We investigate the solutions of Einstein equations such that a hedgehog
solution is matched to different exterior or interior solutions via a spherical
shell. In the case where both the exterior and the interior regions are
hedgehog solutions or one of them is flat, the resulting spherical shell
becomes a stringy shell. We also consider more general matchings and see that
in this case the shell deviates from its stringy character.Comment: 11 page
Electric dipole moments of Hg, Xe, Rn, Ra, Pu, and TlF induced by the nuclear Schiff moment and limits on time-reversal violating interactions
We have calculated the atomic electric dipole moments (EDMs) induced in
^{199}Hg, ^{129}Xe, ^{223}Rn, ^{225}Ra, and ^{239}Pu by their respective
nuclear Schiff moments S. The results are (in units 10^{-17}S(e {fm}^{3})^{-1}e
cm): d(^{199}Hg)=-2.8, d(^{129}Xe)=0.38, d(^{223}Rn)=3.3, d(^{225}Ra)=-8.5,
d(^{239}Pu)=-11. We have also calculated corrections to the parity- and
time-invariance-violating (P,T-odd) spin-axis interaction constant in TlF.
These results are important for the interpretation of atomic and molecular
experiments on EDMs in terms of fundamental P,T-odd parameters.Comment: 16 page
Precise calculation of parity nonconservation in cesium and test of the standard model
We have calculated the 6s-7s parity nonconserving (PNC) E1 transition
amplitude, E_{PNC}, in cesium. We have used an improved all-order technique in
the calculation of the correlations and have included all significant
contributions to E_{PNC}. Our final value E_{PNC} = 0.904 (1 +/- 0.5 %) \times
10^{-11}iea_{B}(-Q_{W}/N) has half the uncertainty claimed in old calculations
used for the interpretation of Cs PNC experiments. The resulting nuclear weak
charge Q_{W} for Cs deviates by about 2 standard deviations from the value
predicted by the standard model.Comment: 24 pages, 8 figure
The role of proteomics in defining the human embryonic secretome
Non-invasive gamete and embryo assessment is considered an important focus in assisted reproductive technologies (ART). Currently, the selection of embryos for transfer is based on morphological indices. Though successful, the field of ART would benefit from a non-invasive quantitative method of viability determination. Omics technologies, including transcriptomics, proteomics and metabolomics, have already begun providing evidence that viable gametes and embryos possess unique molecular profiles with potential biomarkers that can be utilized for developmental and/or viability selection. Unlike the human genome that is relatively fixed and steady throughout the human body, the human proteome, estimated at over a million proteins, is more complex, diverse and dynamic. It is the proteins themselves that contribute to the physiological homeostasis in any cell or tissue. Of particular interest in ART is the secretome, those proteins that are produced within the embryo and secreted into the surrounding environment. Defining the human embryonic secretome has the potential to expand our knowledge of embryonic cellular processes, including the complex dialogue between the developing embryo and its maternal environment, and may also assist in identifying those embryos with the highest implantation potential. Advances in proteomic technologies have allowed the non-invasive profiling of the human embryonic secretome with ongoing research focused on correlation with outcome. From a clinical perspective, embryo selection based on morphological assessment and non-invasive analysis of the human embryonic secretome may improve IVF success and lead to routine single embryo transfers
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