104 research outputs found

    Electroweak Sudakov Logarithms and Real Gauge-Boson Radiation in the TeV Region

    Full text link
    Electroweak radiative corrections give rise to large negative, double-logarithmically enhanced corrections in the TeV region. These are partly compensated by real radiation and, moreover, affected by selecting isospin-noninvariant external states. We investigate the impact of real gauge boson radiation more quantitatively by considering different restricted final state configurations. We consider successively a massive abelian gauge theory, a spontaneously broken SU(2) theory and the electroweak Standard Model. We find that details of the choice of the phase space cuts, in particular whether a fraction of collinear and soft radiation is included, have a strong impact on the relative amount of real and virtual corrections.Comment: 20 pages, 4 figure

    Global Incidence and mortality of oesophageal cancer and their correlation with socioeconomic indicators temporal patterns and trends in 41 countries

    Get PDF
    Oesophageal cancers (adenocarcinomas [AC] and squamous cell carcinomas [SCC]) are characterized by high incidence/mortality in many countries. We aimed to delineate its global incidence and mortality, and studied whether socioeconomic development and its incidence rate were correlated. The age-standardized rates (ASRs) of incidence and mortality of this medical condition in 2012 for 184 nations from the GLOBOCAN database; national databases capturing incidence rates, and the WHO mortality database were examined. Their correlations with two indicators of socioeconomic development were evaluated. Joinpoint regression analysis was used to generate trends. The ratio between the ASR of AC and SCC was strongly correlated with HDI (r = 0.535 [men]; r = 0.661 [women]) and GDP (r = 0.594 [men]; r = 0.550 [women], both p < 0.001). Countries that reported the largest reduction in incidence in male included Poland (Average Annual Percent Change [AAPC] = −7.1, 95%C.I. = −12,−1.9) and Singapore (AAPC = −5.8, 95%C.I. = −9.5,−1.9), whereas for women the greatest decline was seen in Singapore (AAPC = −12.3, 95%C.I. = −17.3,−6.9) and China (AAPC = −5.6, 95%C.I. = −7.6,−3.4). The Philippines (AAPC = 4.3, 95%C.I. = 2,6.6) and Bulgaria (AAPC = 2.8, 95%C.I. = 0.5,5.1) had a significant mortality increase in men; whilst Columbia (AAPC = −6.1, 95%C.I. = −7.5,−4.6) and Slovenia (AAPC = −4.6, 95%C.I. = −7.9,−1.3) reported mortality decline in women. These findings inform individuals at increased risk for primary prevention

    Factorizing the hard and soft spectator scattering contributions for the nucleon form factor F_1 at large Q^2

    Full text link
    We investigate the soft spectator scattering contribution for the FF F1F_{1}. We focus our attention on factorization of the hard-collinear scale QΛ\sim Q\Lambda corresponding to transition from SCET-I to SCET-II. We compute the leading order jet functions and find that the convolution integrals over the soft fractions are logarithmically divergent. This divergency is the consequence of the boost invariance and does not depend on the model of the soft correlation function describing the soft spectator quarks. Using as example a two-loop diagram we demonstrated that such a divergency corresponds to the overlap of the soft and collinear regions. As a result one obtains large rapidity logarithm which must be included in the correct factorization formalism. We conclude that a consistent description of the factorization for F1F_{1} implies the end-point collinear divergencies in the hard and soft spectator contributions, i.e. convolution integrals with respect to collinear fractions are not well-defined. Such scenario can only be realized when the twist-3 nucleon distribution amplitude has specific end-point behavior which differs from one expected from the evolution of the nucleon distribution amplitude. Such behavior leads to the violation of the collinear factorization for the hard spectator scattering contribution. We suggest that the soft spectator scattering and chiral symmetry breaking provide the mechanism responsible for the violation of collinear factorization in case of form factor F1F_{1}.Comment: 25 pages, 6 figures, text is improved, few typos corrected, one figure added, statement about end-point behavior of the nucleon DA is formulated more accuratel

    Drell-Yan production at small q_T, transverse parton distributions and the collinear anomaly

    Full text link
    Using methods from effective field theory, an exact all-order expression for the Drell-Yan cross section at small transverse momentum is derived directly in q_T space, in which all large logarithms are resummed. The anomalous dimensions and matching coefficients necessary for resummation at NNLL order are given explicitly. The precise relation between our result and the Collins-Soper-Sterman formula is discussed, and as a by-product the previously unknown three-loop coefficient A^(3) is obtained. The naive factorization of the cross section at small transverse momentum is broken by a collinear anomaly, which prevents a process-independent definition of x_T-dependent parton distribution functions. A factorization theorem is derived for the product of two such functions, in which the dependence on the hard momentum transfer is separated out. The remainder factors into a product of two functions of longitudinal momentum variables and x_T^2, whose renormalization-group evolution is derived and solved in closed form. The matching of these functions at small x_T onto standard parton distributions is calculated at O(alpha_s), while their anomalous dimensions are known to three loops.Comment: 32 pages, 2 figures; version to appear in Eur. Phys. J.

    The combined role of MRI prostate and prostate health index in improving detection of significant prostate cancer in a screening population of Chinese men

    Get PDF
    Using prostate-specific antigen (PSA) for prostate cancer (PCa) screening led to overinvestigation and overdiagnosis of indolent PCa. We aimed to investigate the value of prostate health index (PHI) and magnetic resonance imaging (MRI) prostate in an Asian PCa screening program. Men aged 50-75 years were prospectively recruited from a community-based PSA screening program. Men with PSA 4.0-10.0 ng ml -1 had PHI result analyzed. MRI prostate was offered to men with PSA 4.0-50.0 ng ml -1. A systematic prostate biopsy was offered to men with PSA 4.0-9.9 ng ml -1 and PHI ≥35, or PSA 10.0-50.0 ng ml -1. Additional targeted prostate biopsy was offered if they had PI-RADS score ≥3. Clinically significant PCa (csPCa) was defined as the International Society of Urological Pathology (ISUP) grade group (GG) ≥2 or ISUP GG 1 with involvement of ≥30% of total systematic cores. In total, 12.8% (196/1536) men had PSA ≥4.0 ng ml -1. Among 194 men with PSA 4.0-50.0 ng ml -1, 187 (96.4%) received MRI prostate. Among them, 28.3% (53/187) had PI-RADS ≥3 lesions. Moreover, 7.0% (107/1536) men were indicated for biopsy and 94.4% (101/107) men received biopsy. Among the men received biopsy, PCa, ISUP GG ≥2 PCa, and csPCa was diagnosed in 42 (41.6%), 24 (23.8%), and 34 (33.7%) men, respectively. Compared with PSA/PHI pathway in men with PSA 4.0-50.0 ng ml -1, additional MRI increased diagnoses of PCa, ISUP GG ≥2 PCa, and csPCa by 21.2% (from 33 to 40), 22.2% (from 18 to 22), and 18.5% (from 27 to 32), respectively. The benefit of additional MRI was only observed in PSA 4.0-10.0 ng ml -1, and the number of MRI needed to diagnose one additional ISUP GG ≥2 PCa was 20 in PHI ≥35 and 94 in PHI &lt;35. Among them, 45.4% (89/196) men with PSA ≥4.0 ng ml -1 avoided unnecessary biopsy with the use of PHI and MRI. A screening algorithm with PSA, PHI, and MRI could effectively diagnose csPCa while reducing unnecessary biopsies. The benefit of MRI prostate was mainly observed in PSA 4.0-9.9 ng ml -1 and PHI ≥35 group. PHI was an important risk stratification step for PCa screening.</p

    Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

    Get PDF
    We present first measurements of the evolution of the differential transverse momentum correlation function, {\it C}, with collision centrality in Au+Au interactions at sNN=200\sqrt{s_{NN}} = 200 GeV. {\it C} exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of {\it C} with increasing centrality to estimate the ratio of the shear viscosity to entropy density, η/s\eta/s, of the matter formed in central Au+Au interactions. We obtain an upper limit estimate of η/s\eta/s that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.

    The trans-ancestral genomic architecture of glycemic traits

    Get PDF
    Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Diabetes mellitus: pathophysiological changes and therap

    Impact failure analysis of re-circulating mechanism in ball screw

    No full text
    A ball screw driven mechanism is a major component in high-speed/high-precision transmitting systems. In such a mechanism, the return tube has been designed to provide the path for a steel ball rolling in screw grooves. As the driven shaft in the mechanism operates at high rotating speed, forces caused by the impact activity between the steel ball and return tube may generate high stresses and cause damage to the return tube after some significant service times. In order to understand the fracture conditions in the return tube, an impact-contact formula is developed and the transient behavior is investigated based on the finite element method in this paper. From results obtained here, it is shown that the rotational speed of the ball screw may affect the service life of the return tube significantly. Factors that affect the service life of the re-circulating mechanism are then described in detail. Further suggestions for the improvement of the return tube in the design/fabrication processes are also proposed in the final part of this paper. (C) 2004 Elsevier Ltd. All rights reserved

    Oxygen diffusion and consumption in active aerobic granules of heterogeneous structure

    No full text
    10.1007/s00253-007-0847-6Applied Microbiology and Biotechnology753685-691AMBI
    corecore