Probing New Physics using top quark polarization in the e+e- -> t \bar{t} process at future Linear Colliders

We investigate the sensitivity to new physics of the process e+e- -> t bar{t} when the top polarization is analyzed using leptonic final states e+e- -> t \bar{t} -> l+l- b \bar{b} nu_l \bar{nu}_l. We first show that the kinematical reconstruction of the complete kinematics is experimentally tractable for this process. Then we apply the matrix element method to study the sensitivity to the Vt\bar{t} coupling (V being a vector gauge boson), at the tree level and in the narrow width approximation. Assuming the ILC baseline configuration, sqrt{S}=500 GeV, and a luminosity of 500 fb^{-1}, we conclude that this optimal analysis allows to determine simultaneously the ten form factors that parameterize the Vt\bar{t} coupling, below the percent level. We also discuss the effects of the next leading order (NLO) electroweak corrections using the GRACE program with polarized beams. It is found that the NLO corrections to different beam polarization lead to significantly different patterns of contributions.Comment: 14 pages, 4 figures, Proceedings for the TYL-FJPPL workshops on "Top Physics at ILC

Improving Object Detection in Medical Image Analysis through Multiple Expert Annotators: An Empirical Investigation

The work discusses the use of machine learning algorithms for anomaly detection in medical image analysis and how the performance of these algorithms depends on the number of annotators and the quality of labels. To address the issue of subjectivity in labeling with a single annotator, we introduce a simple and effective approach that aggregates annotations from multiple annotators with varying levels of expertise. We then aim to improve the efficiency of predictive models in abnormal detection tasks by estimating hidden labels from multiple annotations and using a re-weighted loss function to improve detection performance. Our method is evaluated on a real-world medical imaging dataset and outperforms relevant baselines that do not consider disagreements among annotators.Comment: This is a short version submitted to the Midwest Machine Learning Symposium (MMLS 2023), Chicago, IL, US

Statistical Analsysis to Evaluate Heavy Metal Pollution in the Air Obatained by Moss Technique in Hanoi and its Surrounding Region

The aim of this paper was the application of statistical analysis including principal component analysis to evaluate heavy metal pollution obtained by moss technique in the air of Ha Noi and its surrounding areas and to evaluate potential pollution sources. The concentrations of 33 heavy metal elements in 27 samples of Barbula Indica moss in the investigated region collected in December of 2016 in the investigated area have been examined using multivariate statistical analysis. Five factors explaining 80% of the total variance were identified and their potential sources have been discussed

Role of clusters in nuclear astrophysics with Cluster Nucleosynthesis Diagram (CND)

The role of nuclear clustering in stellar reactions is discussed, with Cluster Nucleosynthesis Diagram (CND) proposed before, for nucleosynthesis in stellar evolution and explosive stellar phenomena. Special emphasis is placed on α-induced stellar reactions. We report here the first experimental evidence that a cluster resonances dominate the (α,p) stellar reaction cross sections that is crucial for the vp-process in core-collapse supernovae

Coulomb breakup of secondary beams of neutron-rich nuclei

Secondary beams of unstable nuclei with kinetic energies of several hundred MeV per nucleon are produced at, GSI in fragment~ationr eactions followed by in-flight, isot,ope separat'ion. Results of studies of light) neutron-rich nuclei ranging from beryllium to oxygen including halo nuclei are presented. Interaction of the projectiles with lead targets leads to Coulomb breakup mediated t,hrough dipole excitabions into the continuum. Non-resonant excitat,ions near the neutron separat,ion threshold deliver information on ground-stat,e properties such as spect,roscopic factors