Measurement of the Transverse Single Spin Asymmetry of pp + p↑p^\uparrow →\rightarrow η\eta + XX at s\sqrt{s} = 200 GeV

The measurement of transverse single spin asymmetries ($A_N$) provides insight into the structure of the nucleon. Several mechanisms have been proposed that attempt to explain $A_N$ based on QCD, and additional measurements of $A_N$ for different processes further constrain these models. Using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC), we study transversely polarized p+p collisions. Results from PHENIX and other experiments show significant asymmetries in the forward region, which could be due to contributions from both the Sivers and the Collins effects. Studying the species as well as the kinematic dependencies of these transverse single spin asymmetries will help to disentangle the origin of the observed asymmetries. Therefore, measurements of $A_N$ with inclusive $\eta$ mesons at forward rapidities are an important tool for the understanding of these asymmetries. In 2008, the PHENIX experiment collected 5.2 pb$^{-1}$ integrated luminosity in $p^\uparrow+p$ collisions at $\sqrt{s}$ = 200 GeV. The status of the asymmetry analysis of $\eta$ mesons at forward rapidity will be shown.Comment: 4 pages, 3 figure

Autobiography of Thaddeus Lafayette Adams

https://place.asburyseminary.edu/firstfruitsheritagematerial/1130/thumbnail.jp

Experimental data on the single spin asymmetry and their interpretations by the chromo-magnetic string model

An attempt is made to interpret the various existing experimental data on the single spin asymmetries in inclusive pion production by the polarized proton and antiproton beams. As the basis of analysis the chromo-magnetic string model is used. A whole measured kinematic region is covered. The successes and fails of such approach are outlined. The possible improvements of model are discussed.Comment: 17 pages, 3 figure

Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease

Analyzing powers in inclusive pion production at high energy and the nucleon spin structure

Analyzing powers in inclusive pion production in high energy transversely polarized proton-proton collisions are studied theoretically in the framework of the quark recombination model. Calculations by assuming the SU(6) spin-flavor symmetry for the nucleon structure disagree with the experiments. We solve this difficulty by taking into account the %We overcome this difficulty by taking into account the realistic spin distribution functions of the nucleon, which differs from the SU(6) expectation at large $x$, %but coincides with a perturbative QCD constraint on the ratio of the unpolarized valence distributions, $u/d \to 5$ as $x \to 1$. We also discuss the kaon spin asymmetry and find $A_N(K^+) = -A_N(K^0)$ in the polarized proton-proton collisions at large $x_F$.Comment: 13 pages, 4 figures, late

Physical disruption of intervertebral disc promotes cell clustering and a degenerative phenotype

© 2019, The Author(s). To test the hypothesis that physical disruption of an intervertebral disc disturbs cell-matrix binding, leading to cell clustering and increased expression of matrix degrading enzymes that contribute towards degenerative disc cell phenotype. Lumbar disc tissue was removed at surgery from 21 patients with disc herniation, 11 with disc degeneration, and 8 with adolescent scoliosis. 5 μm sections were examined with histology, and 30-µm sections by confocal microscopy. Antibodies were used against integrin α5beta1, matrix metalloproteinases (MMP) 1, MMP-3, caspase 3, and denatured collagen types I and II. Spatial associations were sought between cell clustering and various degenerative features. An additional, 11 non-herniated human discs were used to examine causality: half of each specimen was cultured in a manner that allowed free ‘unconstrained’ swelling (similar to a herniated disc in vivo), while the other half was cultured within a perspex ring that allowed ‘constrained’ swelling. Changes were monitored over 36 h using live-cell imaging. 1,9-Di-methyl methylene blue (DMMB) assay for glycosaminoglycan loss was carried out from tissue medium. Partially constrained specimens showed little swelling or cell movement in vitro. In contrast, unconstrained swelling significantly increased matrix distortion, glycosaminoglycan loss, exposure of integrin binding sites, expression of MMPs 1 and 3, and collagen denaturation. In the association studies, herniated disc specimens showed changes that resembled unconstrained swelling in vitro. In addition, they exhibited increased cell clustering, apoptosis, MMP expression, and collagen denaturation compared to ‘control’ discs. Results support our hypothesis. Further confirmation will require longitudinal animal experiments

Nantucket whalers and the Franklin-Folger chart of the Gulf Stream

Author Posting. © The Author(s), 2018. This article is posted here by permission of Nantucket Historical Association for personal use, not for redistribution. The definitive version was published in Historic Nantucket 68, no. 1 (2018): 17-24.Also includes: The search for the “lost” Franklin-Folger chart by Philip L. Richardso

The Impact of Isospin Breaking on the Distribution of Transition Probabilities

In the present paper we investigate the effect of symmetry breaking in the statistical distributions of reduced transition amplitudes and reduced transition probabilities. These quantities are easier to access experimentally than the components of the eigenvectors and were measured by Adams et al. for the electromagnetic transitions in ^{26}Al. We focus on isospin symmetry breaking described by a matrix model where both, the Hamiltonian and the electromagnetic operator, break the symmetry. The results show that for partial isospin conservation, the statistical distribution of the reduced transition probability can considerably deviate from the Porter-Thomas distribution.Comment: 16 pages, 8 figures, submitted to PR