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Background: A point-prevalence survey that was conducted in the United States in 2011 showed that 4% of hospitalized patients had a health care-associated infection. We repeated the survey in 2015 to assess changes in the prevalence of health care-associated infections during a period of national attention to the prevention of such infections.Methods: At Emerging Infections Program sites in 10 states, we recruited up to 25 hospitals in each site area, prioritizing hospitals that had participated in the 2011 survey. Each hospital selected 1 day on which a random sample of patients was identified for assessment. Trained staff reviewed medical records using the 2011 definitions of health care-associated infections. We compared the percentages of patients with health care-associated infections and performed multivariable log-binomial regression modeling to evaluate the association of survey year with the risk of health care-associated infections.Results: In 2015, a total of 12,299 patients in 199 hospitals were surveyed, as compared with 11,282 patients in 183 hospitals in 2011. Fewer patients had health care-associated infections in 2015 (394 patients [3.2%; 95% confidence interval {CI}, 2.9 to 3.5]) than in 2011 (452 [4.0%; 95% CI, 3.7 to 4.4]) (P<0.001), largely owing to reductions in the prevalence of surgical-site and urinary tract infections. Pneumonia, gastrointestinal infections (most of which were due to Clostridium difficile [now Clostridioides difficile]), and surgical-site infections were the most common health care-associated infections. Patients' risk of having a health care-associated infection was 16% lower in 2015 than in 2011 (risk ratio, 0.84; 95% CI, 0.74 to 0.95; P=0.005), after adjustment for age, presence of devices, days from admission to survey, and status of being in a large hospital.Conclusions: The prevalence of health care-associated infections was lower in 2015 than in 2011. To continue to make progress in the prevention of such infections, prevention strategies against C. difficile infection and pneumonia should be augmented. (Funded by the Centers for Disease Control and Prevention.). [ABSTRACT FROM AUTHOR]

Purpose/objective(s): Meningiomas arising from the meningothelial lining of the central nervous system are the most common primary intracranial tumors, and a significant cause of neurologic morbidity and mortality. There are no effective medical therapies for meningioma patients, and new treatments have been encumbered by limited understanding of meningioma biology. The aim of this study was to understand the biology underlying meningioma DNA methylation groups, and identify novel therapeutic strategies to treat meningioma patients.Materials/methods: Illumina 850K DNA methylation profiling was performed on a discovery cohort of 200 meningiomas (median follow-up 6.3 years) and an external validation cohort of 365 meningiomas (median follow-up 5.3 years) from patients who were treated at 2 independent, international institutions from 1991 to 2019 (69% WHO grade 1, 25% WHO grade 2, 6% WHO grade 3). RNA sequencing was performed on the discovery cohort, and single-cell RNA sequencing was performed on 8 meningiomas to define the cellular architecture of meningiomas across DNA methylation groups. Targeted DNA sequencing (n = 65), H3K27ac ChIP sequencing (n = 25), whole exome sequencing (n = 25), and immunohistochemistry (n = 87) were used to validate novel biologic mechanisms underlying DNA methylation groups.Results: Unsupervised hierarchical clustering of DNA methylation profiles revealed 3 DNA methylation groups of meningioma with distinct clinical outcomes in the discovery cohort, which was validated in the external cohort using a multi-class support vector machine classifier. Merlin-intact meningiomas (34%) had the best outcomes and were distinguished by a novel tumor suppressor function of NF2/Merlin regulating glucocorticoid signaling and apoptosis. Immune-enriched meningiomas (38%) had intermediate outcomes and were distinguished by immune cell infiltration, HLA expression, and lymphatic vessels. Hypermitotic meningiomas (28%) had the worst outcomes and are distinguished by convergent genetic mechanisms misactivating the cell cycle, including CDKN2A/B loss, FOXM1 overexpression, and USF1 gain. Consistently, we found cell cycle inhibitors blocked Immune-enriched and Hypermitotic meningioma growth in cell culture, organoids, xenografts, and patients.Conclusion: Here we integrate genetic, epigenetic, transcriptomic, biochemical, and single-cell approaches to find that meningiomas are comprised of 3 DNA methylation groups with distinct clinical outcomes and biological drivers. We validate our results using mechanistic and functional studies in cells, organoids, xenografts, and patients to elucidate novel mechanisms and identify therapeutic vulnerabilities underlying the most common primary intracranial tumor. Our results establish a framework for understanding meningioma biology, and provide preclinical rationale for new meningioma treatments.Author Disclosure: A. Choudhury: None. S. Magill: None. C.D. Eaton: None. B.C. Prager: None. W.C. Chen: None. K. Seo: None. C. Lucas: None. J. Villanueva-Meyer: None. H. Vasudevan: Research Grant; Children's Tumor Foundation. Patent/License Fees/Copyright; Genentech, Eli Lilly. S.J. Liu: None. M.A. Cady: None. M.Y. Zhang: None. S.E. Braunstein: Advisory Board; Radiation Oncology Questions, LLC.N.A. Oberheim: None. A. Perry: None. D.A. Solomon: None. J. Costello: None. M.W. McDermott: None. J.N. Rich: None. D. Raleigh: None. [ABSTRACT FROM AUTHOR]

Preliminary field observations on a large-scale multi-reef artificial reef system in Scotland indicated that the provision of artificial habitat of varying design alters the numbers and types of fishes present in areas where they were previously largely absent. These modifications could, in time, be highly beneficial to any programme of fishery enhancement, protection or restoration but only where the scale of habitat manipulation was relevant to the target fisheries. Ecosystem simulations provide a theoretical basis on which to conduct examinations of habitat manipulation at scales that could not be tested empirically. In the present study, a series of ecosystem models was constructed based on broad-scale simulations for the west coast of Scotland in order to examine the potential consequences to selected fisheries of different scales and types of intervention using artificial reefs. Initialized with a large-scale mass-balance model, a number of smaller-scale dynamic ecosystem simulations covered management situations that encompassed habitat type and reef design for open, restricted and closed fisheries. Spatial simulations examined the presence and absence of artificial habitat with natural reefs and marine protected areas (MPAs) under realistic environmental situations. The simulated trends supported preliminary field observations that artificial habitats would support similar biotic aggregations to natural reefs. Designs that maximized the reef edge as a function of the total reef volume were more productive for some of the functional groups examined compared with larger single deployments of identical area. Increasing the area of artificial habitat did result in improvements to some of the fisheries. The behaviour of some functional groups, however, highlighted the limitations of the broad-scale primary model to smaller-scale investigation. Future simulations used to inform management decision at the sub-regional level would require evidence-based revision to improve their relevance. [ABSTRACT FROM AUTHOR]

The osmolality and ionic composition of the blood of juvenile Atlantic cod Gadus morhua and their response to conditions of reduced temperature and salinity in summer- and winter-acclimated individuals was investigated. Haematocrit percentage was relatively stable throughout the experimental procedures. Summer-acclimated juvenile Atlantic cod had higher plasma osmolality than winter-acclimated fish in ambient conditions. Plasma Na+ levels were, however, higher in winter conditions, while Cl- did not vary between seasons. Temperature reduction (12, 9 and 6° C in summer and to 6 and 4° C in winter) induced a significant response in plasma osmolality and Na+ levels in summer, but only in Na+ levels in winter-acclimated fish. A pronounced effect was seen in the summer 6°C treatment. Salinity treatments (24, 16 and 8) had a significant effect on almost all the variables in both summer and winter and resulted generally in dilution of ionic and osmotic concentrations of the plasma. This effect was pronounced in the lowest temperature treatments, with the greatest reduction observed in the summer 6°C treatment. This could suggest that winter-acclimated fish are physiologically adapted to cope with lower seawater temperatures as opposed to summer-acclimated fish. [ABSTRACT FROM AUTHOR]

Fish assemblages on two inshore rocky subtidal sites on the west coast of Scotland, were studied using diver visual surveys on a monthly basis between September 1995 and December 1999. A total of 17 689 fishes and 26 species were recorded from the two sites, Saulmore Point (056°27′ N; 005°24′ W) near Oban and Davy''s Rock (055°46′ N; 004°53′ W) on the Isle of Great Cumbrae. The gobiidThorogobius eppiphiatus , dominated the Saulmore Point site; six fish species accounted for >93% of total abundance at that site. At Davy''s Rock four species contributed at least 93% of total fish abundance, and the dominant species was the labrid Ctenolabrus rupestris. Total abundance of the dominant species displayed a clear seasonal trend, and this was significantly related to recorded daily average seawater temperature. A maximum abundance of 4·9 fishes m−2 was recorded in November 1998 at Davy''s Rock and 2·5 fishes m−2 at Saulmore Point in October 1998. Multivariate analysis indicated a degree of variation in assemblage structure between winter and summer at both sites. A number of species showed some degree of interannual variation, in particular the gobiidGobiusculus flavescens whose abundance increased by over 300 times over a 5 month period in 1998. Correlation analysis showed that variation in annual winter seawater temperature could act as an indicator of interannual variation in abundance of some of the dominant species utilizing rocky subtidal habitats. Copyright 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved. [Copyright &y& Elsevier]

Abstract: ZEUS inclusive diffractive-cross-section measurements have been used in a DGLAP next-to-leading-order QCD analysis to extract the diffractive parton distribution functions. Data on diffractive dijet production in deep inelastic scattering have also been included to constrain the gluon density. Predictions based on the extracted parton densities are compared to diffractive charm and dijet photoproduction data. [Copyright &y& Elsevier]

Abstract: Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of . Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges and for exchanged photon virtualities, , in the range and for invariant masses of the hadronic system . Differential cross sections are presented for inclusive isolated photon production as functions of , x, and . Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range. [Copyright &y& Elsevier]

Abstract: Differential cross sections for dijet photoproduction and this process in association with a leading neutron, , have been measured with the ZEUS detector at HERA using an integrated luminosity of 40 pb−1. The fraction of dijet events with a leading neutron was studied as a function of different jet and event variables. Single- and double-differential cross sections are presented as a function of the longitudinal fraction of the proton momentum carried by the leading neutron, , and of its transverse momentum squared, . The dijet data are compared to inclusive DIS and photoproduction results; they are all consistent with a simple pion-exchange model. The neutron yield as a function of was found to depend only on the fraction of the proton beam energy going into the forward region, independent of the hard process. No firm conclusion can be drawn on the presence of rescattering effects. [Copyright &y& Elsevier]

The production of charm and beauty quarks in ep interactions has been measured with the ZEUS detector at HERA for squared four-momentum exchange Q2>20 GeV2, using an integrated luminosity of 126 pb−1. Charm and beauty quarks were identified through their decays into muons. Differential cross sections were measured for muon transverse momenta $p_{T}^{\mu}>1.5\ \mbox{GeV}$ and pseudorapidities −1.6< η μ<2.3, as a function of $p_{T}^{\mu}$ , η μ, Q2 and Bjorken x. The charm and beauty contributions to the proton structure function F2 were also extracted. The results agree with previous measurements based on independent techniques and are well described by QCD predictions. [ABSTRACT FROM AUTHOR]

Abstract: The reduced cross sections for ep deep inelastic scattering have been measured with the ZEUS detector at HERA at three different centre-of-mass energies, 318, 251 and 225 GeV. From the cross sections, measured double differentially in Bjorken x and the virtuality, , the proton structure functions and have been extracted in the region and . [Copyright &y& Elsevier]

Subjet distributions were measured in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb−1. Jets were identified using the k T cluster algorithm in the laboratory frame. Subjets were defined as jet-like substructures identified by a reapplication of the cluster algorithm at a smaller value of the resolution parameter $y_{\rm cut}$. Measurements of subjet distributions for jets with exactly two subjets for $y_{\rm cut}=0.05$ are presented as functions of observables sensitive to the pattern of parton radiation and to the colour coherence between the initial and final states. Perturbative QCD predictions give an adequate description of the data. [ABSTRACT FROM AUTHOR]

Abstract: A search for events containing two or more high-transverse-momentum isolated leptons has been performed in ep collisions with the ZEUS detector at HERA using the full collected data sample, corresponding to an integrated luminosity of 480 pb−1. The number of observed events has been compared with the prediction from the Standard Model, searching for possible deviations, especially for multi-lepton events with invariant mass larger than 100 GeV. Good agreement with the Standard Model has been observed. Total and differential cross sections for di-lepton production have been measured in a restricted phase space dominated by photon–photon collisions. [Copyright &y& Elsevier]

Abstract: The exclusive photoproduction reaction has been studied with the ZEUS experiment in ep collisions at HERA using an integrated luminosity of 468 pb−1. The measurement covers the kinematic range and , where W is the photon–proton centre-of-mass energy and is the photon virtuality. These results, which represent the analysis of the full ZEUS data sample for this channel, are compared to predictions based on perturbative QCD. [Copyright &y& Elsevier]

The production of D±- and D0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb−1. The measurements cover the kinematic range 5< Q2<1000 GeV2, 0.02< y<0.7, 1.5< p<15 GeV and | η D|<1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, $F_{2}^{c\bar{c}}$ , to the proton structure function, F2. [ABSTRACT FROM AUTHOR]

Measurements of the neutral current cross sections for deep inelastic scattering in e− p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections d σ/ dQ2, d σ/ dx and d σ/ dy and the double-differential cross sections in Q2 and x are measured in the kinematic region y<0.9 and Q2>185 GeV2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9 pb−1 taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions $x\tilde{F_{3}}$ and xF are determined by combining the e− p results presented in this paper with previously measured e+ p neutral current data. The asymmetry parameter A− is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model. [ABSTRACT FROM AUTHOR]

Abstract: The dissociation of virtual photons, , in events with a large rapidity gap between X and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities and centre-of-mass energies , with , where is the mass of the hadronic final state, X. Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex and Φ, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of and , the fraction of the proton''s momentum carried by the diffractive exchange, as well as β, the Bjorken variable defined with respect to the diffractive exchange. [Copyright &y& Elsevier]

Measurements of the cross sections for charged current deep inelastic scattering in e− p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb−1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections d σ/ dQ2, d σ/ dx and d σ/ dy are presented for Q2>200 GeV2. The double-differential cross-section d2 σ/ dxdQ2 is presented in the kinematic range 280< Q2<30 000 GeV2 and 0.015< x<0.65. The measured cross sections are compared with the predictions of the Standard Model. [ABSTRACT FROM AUTHOR]

The production of excited charm, D1(2420)0 and D(2460)0, and charm-strange, D s1(2536)±, mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb−1. Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D(2460)0 and D s1(2536)± branching fractions. A search for the radially excited charm meson, D*′(2640)±, was also performed. The results are compared with those measured previously and with theoretical expectations. [ABSTRACT FROM AUTHOR]

Abstract: A search for events with an isolated high-energy lepton and large missing transverse momentum has been performed with the ZEUS detector at HERA using a total integrated luminosity of 504 pb−1. The results agree well with Standard Model predictions. The cross section for production of single W bosons in electron–proton collisions with unpolarised electrons is measured to be . [Copyright &y& Elsevier]

Abstract: Deep inelastic scattering and its diffractive component, , have been studied at HERA with the ZEUS detector using an integrated luminosity of 52.4 pb−1. The method has been used to extract the diffractive contribution. A wide range in the centre-of-mass energy W (37–245 GeV), photon virtuality (20–450 GeV2) and mass (0.28–35 GeV) is covered. The diffractive cross section for rises strongly with W, the rise becoming steeper as increases. The data are also presented in terms of the diffractive structure function, , of the proton. For fixed and fixed , shows a strong rise as , where is the fraction of the proton momentum carried by the pomeron. For Bjorken-, shows positive scaling violations, while for negative scaling violations are observed. The diffractive structure function is compatible with being leading twist. The data show that Regge factorisation is broken. [Copyright &y& Elsevier]

Diffractive photoproduction of dijets was measured with the ZEUS detector at the ep collider HERA using an integrated luminosity of 77.2 pb-1. The measurements were made in the kinematic range Q2 < 1 GeV2, 0.207.5 and 6.5 GeV, respectively, and to lie in the pseudorapidity range -1.5<ηjet<1.5. Differential cross sections were compared to perturbative QCD calculations using available parameterisations of diffractive parton distributions of the proton. [ABSTRACT FROM AUTHOR]

Abstract: Three- and four-jet final states have been measured in photoproduction at HERA using the ZEUS detector with an integrated luminosity of . The results are presented for jets with transverse energy and pseudorapidity , in the kinematic region given by the virtuality of the photon and the inelasticity and in two mass regions defined as and , where is the invariant mass of the n-jet system. The four-jet photoproduction cross section has been measured for the first time and represents the highest-order process studied at HERA. Both the three- and four-jet cross sections have been compared with leading-logarithmic parton-shower Monte Carlo models, with and without multi-parton interactions. The three-jet cross sections have been compared to an perturbative QCD calculation. [Copyright &y& Elsevier]

The production of dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 61 pb-1. The dijet cross section has been measured for virtualities of the exchanged virtual photon, 5 < Q2 < 100 GeV2, and γ*p centre-of-mass energies, 100 < W < 250 GeV. The jets, identified using the inclusive kT algorithm in the γ*p frame, were required to have a transverse energy E* T,jet > 4 GeV and the jet with the highest transverse energy was required to have E* T,jet > 5 GeV. All jets were required to be in the pseudorapidity range -3.5<η* jet<0. The differential cross sections are compared to leading-order predictions and next-to-leading-order QCD calculations based on recent diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data. [ABSTRACT FROM AUTHOR]

Abstract: The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300–318 GeV using an integrated luminosity of 120 pb−1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range . The particle rates have been extracted and interpreted in terms of the coalescence model. The (anti)deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements. [Copyright &y& Elsevier]

Abstract: Inclusive dijet and trijet production in deep inelastic ep scattering has been measured for and low Bjorken x, . The data were taken at the HERA ep collider with centre-of-mass energy using the ZEUS detector and correspond to an integrated luminosity of . Jets were identified in the hadronic centre-of-mass (HCM) frame using the cluster algorithm in the longitudinally invariant inclusive mode. Measurements of dijet and trijet differential cross sections are presented as functions of , , jet transverse energy, and jet pseudorapidity. As a further examination of low- dynamics, multi-differential cross sections as functions of the jet correlations in transverse momenta, azimuthal angles, and pseudorapidity are also presented. Calculations at generally describe the trijet data well and improve the description of the dijet data compared to the calculation at . [Copyright &y& Elsevier]

Forward jet cross sections have been measured in neutral current deep inelastic scattering at low Bjorken-x with the ZEUS detector at HERA using an integrated luminosity of 81.8 pb-1. Measurements are presented for inclusive forward jets as well as for forward jets accompanied by a dijet system. The explored phase space, with jet pseudorapidity up to 4.3 is expected to be particularly sensitive to the dynamics of QCD parton evolution at low x. The measurements are compared to fixed-order QCD calculations and to leading-order parton-shower Monte Carlo models. [ABSTRACT FROM AUTHOR]

Abstract: Bose–Einstein correlations of charged and neutral kaons have been measured in deep inelastic scattering with an integrated luminosity of using the ZEUS detector at HERA. The two-particle correlation function was studied as a function of the four-momentum difference of the kaon pairs, , assuming a Gaussian shape for the particle source. The values of the radius of the production volume, r, and of the correlation strength, λ, were obtained for both neutral and charged kaons. The radii for charged and neutral kaons are similar and are consistent with those obtained at LEP. [Copyright &y& Elsevier]

Abstract: The production of energetic neutrons in ep collisions has been studied with the ZEUS detector at HERA. The neutron energy and distributions were measured with a forward neutron calorimeter and tracker in a sample of inclusive deep inelastic scattering (DIS) data and a sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data. [Copyright &y& Elsevier]

The distribution of the azimuthal angle of charged and neutral hadrons relative to the lepton plane has been studied for neutral current deep inelastic ep scattering using an integrated luminosity of 45 pb-1 taken with the ZEUS detector. The kinematic range is 100

Diffractive photoproduction of D*±(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb-1. The D* mesons were reconstructed in the kinematic range: transverse momentum pT(D*) > 1.9 GeV and pseudorapidity |η(D*)|<1.6, using the decay D*+→D0π+ s followed by D0→K-π+(+c.c.). Diffractive events were identified by a large gap in pseudorapidity between the produced hadronic state and the outgoing proton. Cross sections are reported for photon–proton centre-of-mass energies in the range 130 < W < 300 GeV and for photon virtualities Q2 < 1 GeV2, in two ranges of the Pomeron fractional momentum xIP<0.035 and xIP<0.01. The relative contribution of diffractive events to the inclusive D*±(2010) photoproduction cross section is about 6%. The data are in agreement with perturbative QCD calculations based on various parameterisations of diffractive parton distribution functions. The results are consistent with diffractive QCD factorisation. [ABSTRACT FROM AUTHOR]

The production of the neutral strange hadrons K0 S, Λ and Λ̄ has been measured in ep collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, Λ (Λ̄) asymmetry and polarization have been measured in three kinematic regions: Q2 > 25 GeV2; 5 < Q2 < 25 GeV2; and in photoproduction (Q2≃0). In photoproduction the presence of two hadronic jets, each with at least 5 GeV transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at e+e- colliders, except for an enhancement of baryon relative to meson production in photoproduction. [ABSTRACT FROM AUTHOR]

Abstract: The production of mesons in scattering in the range of exchanged photon virtuality has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb−1. The decay channels with and corresponding antiparticle decay were used to identify mesons and the ZEUS beampipe calorimeter was used to identify the scattered electron. Differential cross sections as functions of , inelasticity, y, transverse momentum of the meson, , and pseudorapidity of the meson, , have been measured in the kinematic region , and . The measured differential cross sections are in agreement with two different NLO QCD calculations. The cross sections are also compared to previous ZEUS measurements in the photoproduction and DIS regimes. [Copyright &y& Elsevier]

Abstract: Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb−1. Jets were identified in the Breit frame using the cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of and the jet transverse energy, . The dependence on R of the inclusive-jet cross section has been measured for and and found to be linear with R in the range studied. Next-to-leading-order QCD calculations give a good description of the measurements for . A value of has been extracted from the measurements of the inclusive-jet cross section with for : . The variation of with is in a good agreement with the running of as predicted by QCD. [Copyright &y& Elsevier]

Abstract: Mean values and differential distributions of event-shape variables have been studied in neutral current deep inelastic scattering using an integrated luminosity of 82.2 pb−1 collected with the ZEUS detector at HERA. The kinematic range is and , where is the virtuality of the exchanged boson and x is the Bjorken variable. The data are compared with a model based on a combination of next-to-leading-order QCD calculations with next-to-leading-logarithm corrections and the Dokshitzer–Webber non-perturbative power corrections. The power-correction method provides a reasonable description of the data for all event-shape variables studied. Nevertheless, the lack of consistency of the determination of and of the non-perturbative parameter of the model, , suggests the importance of higher-order processes that are not yet included in the model. [Copyright &y& Elsevier]

The production of beauty quarks with a $D^{\ast\pm}$ and a muon in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. Low transverse-momentum thresholds for the muon and D* meson allow for a measurement of beauty production closer to the production threshold than previous measurements. The beauty signal was extracted using the charge correlations and angular distributions of the muon with respect to the D* meson. Cross sections for photoproduction and deep inelastic scattering are somewhat higher than, but compatible with, next-to-leading-order QCD predictions, and compatible with other measurements. [ABSTRACT FROM AUTHOR]

A search for stop production in R-parity-violating supersymmetry has been performed in e+p interactions with the ZEUS detector at HERA, using an integrated luminosity of 65 pb-1. At HERA, the R-parity-violating coupling λ’ allows resonant squark production, $e^+d\to\tilde{q}$ . Since the lowest-mass squark state in most supersymmetry models is the light stop, $\tilde{t}$ , this search concentrated on production of $\tilde{t}$ , followed either by a direct R-parity-violating decay, or by the gauge decay to $b\tilde{\chi}^+_{1}$ . No evidence for stop production was found and limits were set on λ’131 as a function of the stop mass in the framework of the minimal supersymmetric standard model. The results have also been interpreted in terms of constraints on the parameters of the minimal supergravity model. [ABSTRACT FROM AUTHOR]

The photoproduction of dijet events, where the two jets with the highest transverse energy are separated by a large gap in pseudorapidity, have been studied with the ZEUS detector using an integrated luminosity of 39 pb-1. Rapidity-gap events are defined in terms of the energy flow between the jets, such that the total summed transverse energy in this region is less than some value ET CUT. The data show a clear excess over the predictions of standard photoproduction models. This is interpreted as evidence for a strongly interacting exchange of a color-singlet object. Monte Carlo models which include such a color-singlet exchange are able to describe the data. [ABSTRACT FROM AUTHOR]

Abstract: Inclusive-jet and dijet differential cross sections have been measured in neutral current deep inelastic ep scattering for exchanged boson virtualities with the ZEUS detector at HERA using an integrated luminosity of 82 pb−1. Jets were identified in the Breit frame using the cluster algorithm. Jet cross sections are presented as functions of several kinematic and jet variables. The results are also presented in different regions of . Next-to-leading-order QCD calculations describe the measurements well. Regions of phase space where the theoretical uncertainties are small have been identified. Measurements in these regions have the potential to constrain the gluon density in the proton when used as inputs to global fits of the proton parton distribution functions. [Copyright &y& Elsevier]

The photoproduction of prompt photons, together with an accompanying jet, has been studied in ep collisions at a centre-of-mass energy of 318 GeV with the ZEUS detector at HERA using an integrated luminosity of 77 pb-1. Cross sections were measured for the transverse energy of the photon and the jet larger than 5 and 6 GeV, respectively. The differential γ+jet cross sections were reconstructed as functions of the transverse energy, pseudorapidity and xγ obs, the fraction of the incoming photon momentum taken by the photon-jet system. Predictions based on leading-logarithm parton-shower Monte Carlo models and next-to-leading-order (NLO) QCD generally underestimate the cross sections for the transverse energies of prompt photons below 7 GeV, while the kT-factorisation QCD calculation agrees with the data better. When the minimum transverse energy of prompt photons is increased to 7 GeV, both NLO QCD and the kT-factorisation calculations are in good agreement with the data. [ABSTRACT FROM AUTHOR]

A new method is employed to measure the neutral current cross section up to Bjorken-x values of one with the ZEUS detector at HERA using an integrated luminosity of 65.1 pb-1 for e+p collisions and 16.7 pb-1 for e-p collisions at $\sqrt{s}=318\,\mathrm{GeV}$ and 38.6 pb-1 for e+p collisions at $\sqrt{s}=300\,\mathrm{GeV}$ . Cross sections have been extracted for Q2≥648 GeV2 and are compared to predictions using different parton density functions. For the highest x bins, the data have a tendency to lie above the expectations using recent parton density function parametrizations. [ABSTRACT FROM AUTHOR]

Abstract: The cross sections for charged and neutral current deep inelastic scattering in collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an integrated luminosity of 23.8 pb−1 at , are given for both charged current and neutral current deep inelastic scattering for both positive and negative values of the longitudinal polarisation of the positron beam. Single differential cross sections are presented for the kinematic region . The measured cross sections are compared to the predictions of the Standard Model. A fit to the data yields , which is consistent within two standard deviations with the absence of right-handed charged currents in the Standard Model. [Copyright &y& Elsevier]

Abstract: Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 38.7 pb−1. The jets have been identified using the cluster algorithm in the longitudinally invariant inclusive mode in the laboratory frame; they have been selected with jet transverse energy, above 6 GeV and jet pseudorapidity, , between −1 and 3. Measurements of cross sections as functions of , Björken x and the photon virtuality, , are presented. Three phase-space regions have been selected in order to study parton dynamics from the most global to the most restrictive region of forward-going (close to the proton-beam direction) jets at low x, 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 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, which account for the lowest-order -channel gluon-exchange diagrams, highlighting the importance of such terms in the parton dynamics at low x. [Copyright &y& Elsevier]

Abstract: Inclusive jet cross sections in photoproduction for events containing a meson have been measured with the ZEUS detector at HERA using an integrated luminosity of . The events were required to have a virtuality of the incoming photon, , of less than 1 GeV2, and a photon–proton centre-of-mass energy in the range . The measurements are compared with next-to-leading-order (NLO) QCD calculations. Good agreement is found with the NLO calculations over most of the measured kinematic region. Requiring a second jet in the event allowed a more detailed comparison with QCD calculations. The measured dijet cross sections are also compared to Monte Carlo (MC) models which incorporate leading-order matrix elements followed by parton showers and hadronisation. The NLO QCD predictions are in general agreement with the data although differences have been isolated to regions where contributions from higher orders are expected to be significant. The MC models give a better description than the NLO predictions of the shape of the measured cross sections. [Copyright &y& Elsevier]

Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities $10 < Q^{2} < 5000\;{\text{GeV}}^{2} $. The data were taken at the ep collider HERA with centre-of-mass energy $\sqrt{s} = 318 \hbox{GeV}$ using the ZEUS detector and correspond to an integrated luminosity of $82.2 \hbox{pb}^{-1}$. Jets were identified in the Breit frame using the k T cluster algorithm in the longitudinally invariant inclusive mode. Measurements of differential dijet and trijet cross sections are presented as functions of jet transverse energy ( $E_{T,B}^{\rm jet}$), pseudorapidity ( $\eta_{\rm LAB}^{\rm jet}$) and Q2 with $E^{{{\text{jet}}}}_{{T,B}} > 5\;{\text{GeV}}$ and $- 1 < \eta ^{{{\text{jet}}}}_{{{\text{LAB}}}} < 2.5$. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant $\alpha_s(M_Z)$, determined from the ratio of the trijet to dijet cross sections, is $\alpha_s(M_Z) = 0.1179 \pm 0.0013 \rm (stat.)^{ + 0.0028}_{-0.0046} \rm (exp.)^{ + 0.0064}_{-0.0046} \rm (th.)$. [ABSTRACT FROM AUTHOR]

The inelastic production of $J/\psi$ mesons in ep collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of $109{ \text{pb}^{-1}}$. The $J/\psi$ mesons were identified using the decay channel $J/\psi\to\mu^{ + }\mu^{-}$. The measurements were performed in the kinematic range $2 < Q^2 < 80 {\rm GeV}^2$, $50 < W < 250 \text{GeV}$, 0.2 < z < 0.9 and $-1.6 < Y_{\text{lab}} < 1.3$, where Q2 is the virtuality of the exchanged photon, W is the photon-proton centre-of-mass energy, z is the fraction of the photon energy carried by the $J/\psi$ meson in the proton rest frame and $Y_{\text{lab}}$ is the rapidity of the $J/\psi$ in the laboratory frame. The measured cross sections are compared to theoretical predictions within the non-relativistic QCD framework including colour-singlet and colour-octet contributions, as well as to predictions based on the k T-factorisation approach. Calculations of the colour-singlet process generally agree with the data, whereas inclusion of colour-octet terms spoils this agreement. [ABSTRACT FROM AUTHOR]

Abstract: Exclusive electroproduction of ϕ mesons has been studied in collisions at with the ZEUS detector at HERA using an integrated luminosity of . The cross section is presented in the kinematic range , and . The cross sections as functions of , W, t and helicity angle 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 and W. The data are also compared to predictions from theoretical models. [Copyright &y& Elsevier]

The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e + and e- beams, together with differential cross-section data on inclusive jet production in e + p scattering and dijet production in $\gamma p$ scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the proton. The input of jet-production data constrains the gluon and allows an accurate extraction of $\alpha_s(M_Z)$ at NLO; $\alpha _{s} {\left( {M_{Z} } \right)} = 0.1183 \pm 0.0028{\left( {\exp .} \right)} \pm 0.0008{\left( {{\text{model}}} \right)}.$ An additional uncertainty from the choice of scales is estimated as $\pm 0.005$. This is the first extraction of $\alpha_s(M_Z)$ from HERA data alone. [ABSTRACT FROM AUTHOR]

Abstract: Deep inelastic scattering and its diffractive component, , have been studied at HERA with the ZEUS detector using an integrated luminosity of . The measurement covers a wide range in the c.m. energy W (37–245 GeV), photon virtuality Q 2 (2.2–80 GeV2) and mass (0.28–35 GeV). The diffractive cross section for rises strongly with W; the rise is steeper with increasing Q 2. The latter observation excludes the description of diffractive deep inelastic scattering in terms of the exchange of a single pomeron. The ratio of diffractive to total cross section is constant as a function of W, in contradiction to the expectation of Regge phenomenology combined with a naive extension of the optical theorem to scattering. Above of 8 GeV, the ratio is flat with Q 2, indicating a leading-twist behaviour of the diffractive cross section. The data are also presented in terms of the diffractive structure function, , of the proton. For fixed β, the Q 2 dependence of changes with in violation of Regge factorisation. For fixed , rises as , the rise accelerating with increasing Q 2. These positive scaling violations suggest substantial contributions of perturbative effects in the diffractive DIS cross section. [Copyright &y& Elsevier]

Abstract: A search for pentaquarks decaying to () 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 was observed. However, no signal for any new baryonic state was observed at higher masses in either the or channels. The searches in the antiparticle channels were also negative. Upper limits on the ratio of a possible () signal to the signal were set in the mass range 1650–2350 MeV. [Copyright &y& Elsevier]