1,766 research outputs found

    Search for CP Violation in the Decay Z -> b (b bar) g

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    About three million hadronic decays of the Z collected by ALEPH in the years 1991-1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z -> b \bar{b} g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, h^b=h^AbgVbh^VbgAb{\hat{h}}_b = {\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab} and hb=h^Vb2+h^Ab2h^{\ast}_b = \sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}, limits of \hat{h}_b < 0.59and and h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Prevalence of emergency contraceptive pill use among Spanish adolescent girls and their family and psychological profiles

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    The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background:Adolescent girls’ family context and psychological characteristics play important roles in their sexual behavior, including the use of the emergency contraceptive pill (ECP). This study aims to (1) determine the prevalence of ECP use among girls who have had sexual intercourse and (2) comparatively analyze their family and psychological profiles according to whether they have used ECPs. Methods:The sample of 1735 Spanish girls aged 15 to 18 came from a representative sample of the 2014 edition of the Health Behaviour in School-aged Children (HBSC) study. Of this sample, 398 girls had sexual intercourse and reported their ECP use. Data collection for the HBSC study was performed through an online questionnaire to which adolescents responded anonymously in school. Data analyses were descriptive and bivariate and were performed with the statistical program IBM SPSS Statistics 23.Results:The results demonstrated that 30.65% of girls who had sexual intercourse used ECPs. Noticeable differences in paternal knowledge and communication with the father were observed between girls who used the ECP at least once and those who did not use it. In contrast, differences between girls who used the ECP once and those who used it twice or more were pronounced with regard to parental knowledge, communication with parents, maternal affection,life satisfaction, sense of coherence and depression. Conclusions:This work demonstrates a high prevalence of ECP use and a more positive family and psychological profile for girls who used ECP once compared with those who used it twice or more.Peer reviewedFinal Published versio

    Sleep Problems Are Related to a Worse Quality of Life and a Greater Non-Motor Symptoms Burden in Parkinson’s Disease

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    COPPADIS Study Group.[Introduction] The aim of the present study was to examine the frequency of self-reported sleep problems and their associated factors in a large cohort of PD patients.[Methods] PD patients and controls, recruited from 35 centers of Spain from the COPPADIS cohort were included in this cross-sectional study. Sleep problems were assessed by the Spanish version of the Parkinson’s disease Sleep Scale version 1 (PDSS-1). An overall score below 82 or a score below 5 on at least 1 item was defined as sleep problems.[Results] The frequency of sleep problems was nearly double in PD patients compared to controls: 65.8% (448/681) vs 33.5% (65/206) (p < 0.0001). Mean total PDSS score was lower in PD patients than controls: 114.9 ± 28.8 vs 132.8 ± 16.3 (p < 0.0001). Quality of life (QoL) was worse in PD patients with sleep problems compared to those without: PDQ-39SI, 19.3 ± 14 vs 13 ± 11.6 (p < 0.0001); EUROHIS-QoL8, 3.7 ± 0.5 vs 3.9 ± 0.5 (p < 0.0001). Non-motor symptoms burden (NMSS; OR = 1.029; 95%CI 1.015–1.043; p < 0.0001) and impulse control behaviors (QUIP-RS; OR = 1.054; 95%CI 1.009–1.101; p = 0.018) were associated with sleep problems after adjustment for age, gender, disease duration, daily equivalent levodopa dose, H&Y, UPDRS-III, UPDRS-IV, PD-CRS, BDI-II, NPI, VAS-Pain, VAFS, FOGQ, and total number of non-antiparkinsonian treatments.[Conclusion] Sleep problems were frequent in PD patients and were related to both a worse QoL and a greater non-motor symptoms burden in PD. These findings call for increased awareness of sleep problems in PD patients.Peer reviewe

    Diplopia Is Frequent and Associated with Motor and Non-Motor Severity in Parkinson’s Disease: Results from the COPPADIS Cohort at 2-Year Follow-Up

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    Malaltia de Parkinson; Fenotip; TremolorEnfermedad de Parkinson; Fenotipo; TemblorParkinson’s disease; Phenotype; TremorBackground and objective: Diplopia is relatively common in Parkinson’s disease (PD) but is still understudied. Our aim was to analyze the frequency of diplopia in PD patients from a multicenter Spanish cohort, to compare the frequency with a control group, and to identify factors associated with it. Patients and Methods: PD patients who were recruited from January 2016 to November 2017 (baseline visit; V0) and evaluated again at a 2-year ± 30 days follow-up (V2) from 35 centers of Spain from the COPPADIS cohort were included in this longitudinal prospective study. The patients and controls were classified as “with diplopia” or “without diplopia” according to item 15 of the Non-Motor Symptoms Scale (NMSS) at V0, V1 (1-year ± 15 days), and V2 for the patients and at V0 and V2 for the controls. Results: The frequency of diplopia in the PD patients was 13.6% (94/691) at V0 (1.9% in controls [4/206]; p < 0.0001), 14.2% (86/604) at V1, and 17.1% (86/502) at V2 (0.8% in controls [1/124]; p < 0.0001), with a period prevalence of 24.9% (120/481). Visual hallucinations at any visit from V0 to V2 (OR = 2.264; 95%CI, 1.269–4.039; p = 0.006), a higher score on the NMSS at V0 (OR = 1.009; 95%CI, 1.012–1.024; p = 0.015), and a greater increase from V0 to V2 on the Unified Parkinson’s Disease Rating Scale–III (OR = 1.039; 95%CI, 1.023–1.083; p < 0.0001) and Neuropsychiatric Inventory (OR = 1.028; 95%CI, 1.001–1.057; p = 0.049) scores were independent factors associated with diplopia (R2 = 0.25; Hosmer and Lemeshow test, p = 0.716). Conclusions: Diplopia represents a frequent symptom in PD patients and is associated with motor and non-motor severity.Solano Vila B. has received honoraria for educational presentations and advice service by UCB, Zambon, Teva, Abbvie, Bia

    Diplopia is frequent and associated with motor and non-motor severity in parkinson's disease : Results from the COPPADIS cohort at 2-year follow-up

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    Background and objective: Diplopia is relatively common in Parkinson's disease (PD) but is still understudied. Our aim was to analyze the frequency of diplopia in PD patients from a multicenter Spanish cohort, to compare the frequency with a control group, and to identify factors associated with it. Patients and Methods: PD patients who were recruited from January 2016 to November 2017 (baseline visit; V0) and evaluated again at a 2-year ± 30 days follow-up (V2) from 35 centers of Spain from the COPPADIS cohort were included in this longitudinal prospective study. The patients and controls were classified as "with diplopia" or "without diplopia" according to item 15 of the Non-Motor Symptoms Scale (NMSS) at V0, V1 (1-year ± 15 days), and V2 for the patients and at V0 and V2 for the controls. Results: The frequency of diplopia in the PD patients was 13.6% (94/691) at V0 (1.9% in controls [4/206]; p < 0.0001), 14.2% (86/604) at V1, and 17.1% (86/502) at V2 (0.8% in controls [1/124]; p < 0.0001), with a period prevalence of 24.9% (120/481). Visual hallucinations at any visit from V0 to V2 (OR = 2.264; 95%CI, 1.269-4.039; p = 0.006), a higher score on the NMSS at V0 (OR = 1.009; 95%CI, 1.012-1.024; p = 0.015), and a greater increase from V0 to V2 on the Unified Parkinson's Disease Rating Scale-III (OR = 1.039; 95%CI, 1.023-1.083; p < 0.0001) and Neuropsychiatric Inventory (OR = 1.028; 95%CI, 1.001-1.057; p = 0.049) scores were independent factors associated with diplopia (R = 0.25; Hosmer and Lemeshow test, p = 0.716). Conclusions: Diplopia represents a frequent symptom in PD patients and is associated with motor and non-motor severity

    Identifying comorbidities and lifestyle factors contributing to the cognitive profile of early Parkinson's disease

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    Background: Identifying modifiable risk factors for cognitive impairment in the early stages of Parkinson's disease (PD) and estimating their impact on cognitive status may help prevent dementia (PDD) and the design of cognitive trials. Methods: Using a standard approach for the assessment of global cognition in PD and controlling for the effects of age, education and disease duration, we explored the associations between cognitive status, comorbidities, metabolic variables and lifestyle variables in 533 PD participants from the COPPADIS study. Results: Among the overall sample, 21% of participants were classified as PD-MCI (n = 114) and 4% as PDD (n = 26). The prevalence of hypertension, diabetes and dyslipidemia was significantly higher in cognitively impaired patients while no between-group differences were found for smoking, alcohol intake or use of supplementary vitamins. Better cognitive scores were significantly associated with regular physical exercise (p < 0.05) and cognitive stimulation (< 0.01). Cognitive performance was negatively associated with interleukin 2 (Il2) (p < 0.05), Il6 (p < 0.05), iron (p < 0.05), and homocysteine (p < 0.005) levels, and positively associated with vitamin B12 levels (p < 0.005). Conclusions: We extend previous findings regarding the positive and negative influence of various comorbidities and lifestyle factors on cognitive status in early PD patients, and reinforce the need to identify and treat potentially modifiable variables with the intention of exploring the possible improvement of the global cognitive status of patients with PD

    Observation of charmless hadronic B decays

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    Four candidates for charmless hadronic B decay are observed in a data sample of four million hadronic Z decays recorded by the ALEPH detector at LEP. The probability that these events come from background sources is estimated to be less than 10(-6). The average branching of weakly decaying B hadrons (a mixture of B-d(0), B-s(0) and Lambda(b) weighted by their production The average branching ratio of weakly decaying B hadrons (a mixture of B-d(0) cross sections and lifetimes, here denoted B) into two long-lived charged hadrons (pions, kaons or protons) is measured to be Br(B-->h(+)h(-))=(1.7(-0.7)(+1.0)+/-0.2)x10(-5). The relative branching fraction Br(B-d(s)(0)-->pi(+)pi(-)(K-))/Br(B-d(s)(0)-->h(+)h(-)) is measured to be 1.0(-0.3-0.1)(+0.0+0.0). In addition, branching ratio upper limits are obtained for a variety of exclusive charmless hadronic two-body decays of B hadrons

    Production of excited beauty states in Z decays

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    A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994, is used to make an inclusive selection of B~hadron events. In this event sample 4227 \pm 140 \pm 252 B^* mesons in the decay B^* \to B \gamma and 1944 \pm 108 \pm 161 B^{**} mesons decaying into a B~meson and a charged pion are reconstructed. For the well established B^* meson the following quantities areobtained: \Delta M = M_{B^*} - M_{B} = (45.30\pm 0.35\pm 0.87)~\mathrm{MeV}/c^2 and N_{B^*}/(N_B+N_{B^*}) = (77.1 \pm 2.6 \pm 7.0)\%. The angular distribution of the photons in the B^* rest frame is used to measure the relative contribution of longitudinal B^* polarization states to be \sigma_L/(\sigma_L + \sigma_T)= (33 \pm 6 \pm 5)\%. \\ Resonance structure in the M(B\pi)-M(B) mass difference is observed at (424 \pm 4 \pm 10)~\mathrm{MeV}/c^2. Its shape and position is in agreement with the expectation for B^{**}_{u,d} states decaying into B_{u,d}^{(*)} \pi^\pm. The signal is therefore interpreted as arising from them. The relative production rate is determined to be \frac{BR(Z \to b \to B_{u,d}^{**})}{BR(Z \to b \to B_{u,d})} = [27.9 \pm 1.6(stat) \pm 5.9(syst) \phantom{a}^{+3.9}_{-5.6}(model)]\%. where the third error reflects the uncertainty due to different production and decay models for the broad B_{u,d}^{**} states
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