Forward jet production in deep inelastic ep scattering and low-x parton dynamics at HERA

Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector. Three phase-space regions have been selected in order to study parton dynamics where the effects of BFKL evolution might be present. The measurements have been compared to the predictions of leading-logarithm parton shower Monte Carlo models and fixed-order perturbative QCD calculations. In the forward region, QCD calculations at order alpha_s^1 underestimate the data up to an order of magnitude at low x. An improved description of the data in this region is obtained by including QCD corrections at order alpha_s^2, which account for the lowest-order t-channel gluon-exchange diagrams, highlighting the importance of such terms in parton dynamics at low x.Comment: 25 pages, 4 figure

Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.

The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.

Exclusive electroproduction of phi mesons at HERA

Exclusive electroproduction of phi mesons has been studied in e (+/-) p collisions at root s = 318 GeV with the ZEUS detector at HERA using an integrated luminosity of 65.1 pb(-l). The gamma*p crosssection is presented in the kinematic range 2 GeV(2) < Q(2) < 70 GeV(2), 35 GeV < W < 145 GeV and vertical bar t vertical bar < 0.6 GeV(2). The cross sections as functions of Q(2), W, t and helicity angle phi(h) are compared to cross sections for other vector mesons. The ratios R of the cross sections for longitudinally and transversely polarized virtual photons are presented as functions of Q2 and W. The data are also compared to predictions from theoretical models. (c) 2005 Elsevier B.V. All rights reserved

Search for pentaquarks decaying to &#926;&#960; in deep inelastic scattering at HERA

A search for pentaquarks decaying to Ξ-π- (Ξ-π+) and corresponding antiparticles has been performed with the ZEUS detector at HERA. The data sample consists of deep inelastic ep scattering events at centre-of-mass energies of 300 and 318 GeV, and corresponds to 121 pb -1 of integrated luminosity. A clear signal for Ξ0(1530) →Ξ-π+ was observed. However, no signal for any new baryonic state was observed at higher masses in either the Ξ-π- or Ξ-π+ channels. The searches in the antiparticle channels were also negative. Upper limits on the ratio of a possible Ξ3/2 - (Ξ3/20) signal to the Ξ0(1530) signal were set in the mass range 1650-2350 MeV. © 2005 Elsevier B.V. All rights reserved