Track A Basic Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd

Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

This is the pre-print version of the Published Article, which can be accessed from the link below - Copyright @ 2010 Springer VerlagResults on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle (phi). Short-range correlations in Delta(eta), which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in eta (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 inverse nb data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate transverse momentum of 1-3 GeV/c, 2.0< |Delta(eta)| <4.8 and Delta(phi) near 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or p p-bar collisions

Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle (phi). Short-range correlations in Delta(eta), which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in eta (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb(-1) data set at 7TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate p(T) of 1-3 GeV/c, 2.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape : A Large-Scale Genome-Wide Interaction Study

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age-and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to similar to 2.8M SNPs with BMI and WHRadjBMI in four strata (men 50y, women 50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR= 50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may providefurther insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.Peer reviewe

Recycling of foliatons during folding

Bedding on the limbs of early-formed regional folds generally lies oblique to the major directions of bulk shortening in the crust, that is, the horizontal and vertical. During subsequent deformations, matrix foliations on at least one limb of these folds may start to form but then be destroyed by reactivation of the bedding causing decrenulation and rotation into parallelism with the compositional layering. Consequently, the schistosity parallel to bedding (S0//S1) in multiply deformed rocks contains the relics of many deformation events, and the 2 or 3 oblique foliations record only the very youngest history. This lengthy early history is preserved as inclusion trails within porphyroblasts. Recycling of foliations depends on the shear sense acting on any newly developing foliation and the orientation of this foliation relative to S0//S1. For some orientations and combinations of shear senses, both limbs of a pre-existing fold can be reactivated from the commencement of a new deformation event. This can result in the decrenulation and obliteration of a new foliation that is beginning to form before it shows any significant degree of development. For other combinations, one limb of a pre-existing fold will behave in this manner whereas a new foliation does develop fully on the other limb. However, subsequent phases of deformation switch which limb shears versus develops an oblique new cleavage rotating the earlier formed oblique foliation into parallelism with S0//S1

Partitioning of deformation along an orogen and its effects on porphyroblast growth during orogenesis

An identical succession of foliation inflection/intersection axis trends in porphyroblasts (FIAs) is present in three separate areas affected by Acadian deformation and metamorphism along 130 kms of the Appalachians from East Central Vermont to North Central Massachusetts. The FIAs trend successively NW-SE, SW-NE, W-E, NNW-SSE and SSW-NNE and appear to have formed during the same succession of deformations, which have been dated in SE Vermont as follows; not yet dated, pre-425 Ma, 425 to 404 Ma, 404 to 385 Ma, and 385 to 360 Ma, respectively. The two areas that are furthest apart, in east central Vermont and north central Massachusetts, have strikingly similar total distributions of FIAs in garnet porphyroblasts that show a somewhat inverse relationship to those observed in the Chester-Athens dome area of SE Vermont that separates them. That is, the number of samples containing the first formed FIA set is greatest for the two regions lying furthest apart and decreases in younger sets, whereas the number of samples containing the first FIA set is the least in the central region and increases for more recently developed sets. Partitioning of deformation into zones of progressive shearing and shortening has been demonstrated to control the sites of development of differentiated crenulation cleavage versus porphyroblast growth and sites of porphyroblast growth on one limb of a regional fold versus the other. We argue that partitioning of the deformation around competent feldspathic gneiss bodies at an orogen scale produced the variation in the number of samples containing the various FIA sets between the central and outer areas described above.\ud Porphyroblasts most commonly grew during SW-NE directed shortening to the north and south of the Chester-Athens dome region of the Appalachians, but only rarely grew in the latter region. This suggests that deformation at this time partitioned around an outlier of competent basement feldspathic gneiss that underlies the Chester-Athens dome region, and this protected the rocks above and in the strain shadow to the NW and SE from the effects of the great bulk of the deformation that occurred over the period of time during which NW-SE trending FIAs formed. We attribute the increase in the number of samples containing progressively younger FIAs in the Chester-Athens dome area during subsequent periods of NW-SE-, N-S-, WSW-ENE-, and WNW-ESE-directed shortening to the rise in temperature and pressure recorded in the rocks above the Chester-Athens dome with peak conditions occurring during the development of the NNW-SSE oriented FIA set between 404 and 385 Ma. As the temperature and pressure increased, the gneiss below would have become less competent, allowing the deformation associated with the succession of FIA sets to partition more pervasively through the dome core. This provided more sites for porphyroblast nucleation and growth and hence the number of samples recording these FIA sets increased. The concomitant decrease in the number of samples in which porphyroblasts grew in the rock within the areas to the north and south with successive FIAs possibly resulted from a progressive increase in competency of these rocks as the number of porphyroblasts increased. \u

On the development of gneiss domes

The New England Appalachians contain some of the first documented gneiss domes. The classic domes of SE Vermont are typical of these structures in that they appear to have formed by doming of both the gneissosity in basement gneisses and the dominant matrix schistosity in the overlying rocks, after these foliations had formed. However, the three matrix foliations (other than bedding) present in these rocks, which include the one parallel to all compositional layering, post date dome development. The domes formed as upright anticlines after deposition of the overlying Lower Palaeozoic sediments and volcanics on a PreCambrian granitic or gneissic basement. This occurred during orogenesis driven by horizontally directed compressional forces with interspersed periods of relatively coaxial gravitational collapse, rather than through early nappe development followed by folding or diapiric granite emplacement, or crustal extension and upwards bowing of a necked portion of the crust. In spite of numerous subsequent deformations, the domes are very old structures that have been little modified at the level of current crustal exposure. The dominant process during each deformation was reactivation of the compositional layering or gneissosity on at least one limb of the dome. This destroyed earlier developed crenulation cleavages that lay oblique to the compositional layering and commonly prevented new ones from developing. Consequently, a schistosity parallel to bedding in the overlying rocks, and the gneissosity below, formed and was intensified by reactivation on at least one limb of the dome during all subsequent deformations. Nappe development, which has commonly been proposed as the origin of foliation parallel to bedding in the rocks overlying gneiss domes, is not necessary and there is no evidence for such a deformation history preserved within either the bedding or matrix foliations that have been folded around the Chester and Athens domes of SE Vermont. Sub-horizontally dipping foliations that formed during collapse stages of orogenesis have mainly been the product of relatively coaxial deformation rather than the highly non-coaxial deformation that accompanies nappe development. The fold to the west of the Chester and Athens domes, which has classically been regarded as the nose of the major nappe, formed with an upright rather than shallowly dipping axial plane

The works for preventing the salt-water at Cua Lac

Design of an closure dam and ancillary works at the upstream end of the Tam Giang estuary, Hue province. The main purpose of the works is to prevent salt intrusion. Report in English and Vietnamese