116 research outputs found
Arthritis as a presentation of paraneoplastic syndrome: A case report
Paraneoplastic syndrome includes symptoms that occur far from the primary tumor, and despite unclear pathogenesis, these conditions are thought to be caused by substances secreted by the neoplasm or by the effect of antibodies directed at the tumor, which cross- react with other tissues
Measurement of the muon anomaly to high and even higher precision
Our recent series of measurements at Brookhaven National Laboratory
determined the muon anomalous magnetic moment \amu to a precision of 0.5 ppm.
The final result--representing the average of five running periods using both
positive and negative muons--is \amu ^\pm = 11 659 208(6) \times 10^{-10}. It
lies 2.7 standard deviations above the standard model expectation, which is
based on updates given at this Workshop. Importantly, only the
annihilation and new KLOE radiative return data are used for the hadronic
vacuum polarization input. Because the systematic limit has not been reached in
the experiment, a new effort has been proposed and approved with the highest
scientific priority at Brookhaven. The goal is an experimental uncertainty of
0.2 ppm, a 2.5-fold reduction in the overall experimental uncertainty. To do so
will require a suite of upgrades and several qualitative changes in the
philosophy of how the measurement is carried out. I discuss the old and new
experiments with a particular emphasis on the technical matters that require
change for the future.Comment: 10 pages, Proceedings of the 8th International Workshop on Tau-Lepton
Physic
Why do we need the new BNL muon g-2 experiment now?
New final results from the CMD-2 and SND e+e- annihilation experiments,
together with radiative return measurements from BaBar, lead to recent
improvements in the standard model prediction for the muon anomaly. The
uncertainty at 0.48 ppm--a largely data-driven result--is now slightly below
the experimental uncertainty of 0.54 ppm. The difference, a_mu(expt)- a_mu(SM)
= (27.6 +/- 8.4) x 10^-10, represents a 3.3 standard deviation effect. At this
level, it is one of the most compelling indicators of physics beyond the
standard model and, at the very least, a major constraint for speculative new
theories such as SUSY or extra dimensions. Others at this Workshop detailed
further planned standard model theory improvements to a_mu. Here I outline how
BNL E969 will achieve a factor of 2 or more reduction in the experimental
uncertainty. The new experiment is based on a proven technique and track
record. I argue that this work must be started now to have maximal impact on
the interpretation of the new physics anticipated to be unearthed at the LHC.Comment: Invited Talk, Tau-06 Workshop, 10 pages, 5 figure
A nonsupersymmetric resolution of the anomalous muon magnetic moment
The recent result from the E821 experiment at BNL on the anomalous magnetic
moment of the muon shows a distinct discrepancy with the Standard Model
predictions. We calculate the additional correction that the anomalous magnetic
moment receives in a model with scalar leptoquarks. We find that such models
can account for the deviation from the SM value even for small leptoquark
couplings.Comment: 7 pages LaTex, 4 postscript figure
News from the Muon (g-2) Experiment at BNL
The magnetic moment anomaly a_mu = (g_mu - 2) / 2 of the positive muon has
been measured at the Brookhaven Alternating Gradient Synchrotron with an
uncertainty of 0.7 ppm. The new result, based on data taken in 2000, agrees
well with previous measurements. Standard Model evaluations currently differ
from the experimental result by 1.6 to 3.0 standard deviations.Comment: Talk presented at RADCOR - Loops and Legs 2002, Kloster Banz,
Germany, September 8-13 2002, to be published in Nuclear Physics B (Proc.
Suppl.); 5 pages, 3 figure
Sensitive Search for a Permanent Muon Electric Dipole Moment
We are proposing a new method to carry out a dedicated search for a permanent
electric dipole moment (EDM) of the muon with a sensitivity at a level of
10^{-24} e cm. The experimental design exploits the strong motional electric
field sensed by relativistic particles in a magnetic storage ring. As a key
feature, a novel technique has been invented in which the g-2 precession is
compensated with radial electric field. This technique will benefit greatly
when the intense muon sources advocated by the developers of the muon storage
rings and the muon colliders become available.Comment: 16 pages, 3 figures. Submitted for publication in Proceedings of the
International Workshop on High Intensity Muon Sources (HIMUS99), KEK, Japan,
December 1-4 199
The Role of Ontogenetic Development in Fish Scale Shape Change
Fish scale investigation has been used in many ways. Recently several speciesâ scale shape was used to differentiate species, populations or stocks. Effects of allometric growth on scale shape proved to be a common phenomenon in case of numerous species, however there is no information regarding the impact of temporal (ontogenetic timescale) changes. In this study the effect of intrapopulation age distribution on the scale shape was tested. Seven age groups of a gibel carp (Carassius gibelio) population were identified and analyzed using landmark-based geometric morphometric methods. The results indicated a clear trend of ontogenetic-driven shape change of gibel carp scales: the adult fish specific scale shape occurs at the age of 3+, along with sexual maturation, the alterations among the older age classes show no significant differences. These results suggest that the asymmetric age distribution of fish populations should be taken into consideration during scale morphometric analyses
Final Report of the Muon E821 Anomalous Magnetic Moment Measurement at BNL
We present the final report from a series of precision measurements of the
muon anomalous magnetic moment, a_mu = (g-2)/2. The details of the experimental
method, apparatus, data taking, and analysis are summarized. Data obtained at
Brookhaven National Laboratory, using nearly equal samples of positive and
negative muons, were used to deduce a_mu(Expt) = 11 659 208.0(5.4)(3.3) x
10^-10, where the statistical and systematic uncertainties are given,
respectively. The combined uncertainty of 0.54 ppm represents a 14-fold
improvement compared to previous measurements at CERN. The standard model value
for a_mu includes contributions from virtual QED, weak, and hadronic processes.
While the QED processes account for most of the anomaly, the largest
theoretical uncertainty, ~0.55 ppm, is associated with first-order hadronic
vacuum polarization. Present standard model evaluations, based on e+e- hadronic
cross sections, lie 2.2 - 2.7 standard deviations below the experimental
result.Comment: Summary paper of E821 Collaboration measurements of the muon
anomalous magnetic moment, each reported earlier in Letters or Brief Reports;
96 pages, 41 figures, 16 tables. Revised version submitted to PR
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