1,423 research outputs found

    Yukawa unification in SO(10) with light sparticle spectrum

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    We investigate supersymmetric SO(10) GUT model with \mu<0. The requirements of top-bottom-tau Yukawa unification, correct radiative electroweak symmetry breaking and agreement with the present experimental data may be met when the soft masses of scalars and gauginos are non-universal. We show how appropriate non-universalities can easily be obtained in the SO(10) GUT broken to the Standard Model. We discuss how values of BR(b-->s \gamma) and (g-2)_\mu simultaneously in a good agreement with the experimental data can be achieved in SO(10) model with \mu<0. In the region of the parameter space preferred by our analysis there are two main mechanisms leading to the LSP relic abundance consistent with the WMAP results. One is the co-annihilation with the stau and the second is the resonant annihilation via exchange of the Z boson or the light Higgs scalar. A very interesting feature of SO(10) models with negative \mu is that they predict relatively light sparticle spectra. Even the heaviest superpartners may easily have masses below 1.5 TeV in contrast to multi-TeV particles typical for models with positive \mu.Comment: 23 pages, 5 figure

    Hadronic production of squark-squark pairs: The electroweak contributions

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    We compute the electroweak (EW) contributions to squark--squark pair production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Both tree-level EW contributions, of O(alpha_s alpha + alpha^2), and next-to-leading order (NLO) EW corrections, of O(alpha_s^2 alpha), are calculated. Depending on the flavor and chirality of the produced quarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO. We discuss the computational techniques and present an extensive numerical analysis for inclusive squark--squark production as well as for subsets and single processes. While the tree-level EW contributions to the integrated cross sections can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent.Comment: 36 pages, 18 figure

    Experimental Quantum Teleportation of a Two-Qubit Composite System

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    Quantum teleportation, a way to transfer the state of a quantum system from one location to another, is central to quantum communication and plays an important role in a number of quantum computation protocols. Previous experimental demonstrations have been implemented with photonic or ionic qubits. Very recently long-distance teleportation and open-destination teleportation have also been realized. Until now, previous experiments have only been able to teleport single qubits. However, since teleportation of single qubits is insufficient for a large-scale realization of quantum communication and computation2-5, teleportation of a composite system containing two or more qubits has been seen as a long-standing goal in quantum information science. Here, we present the experimental realization of quantum teleportation of a two-qubit composite system. In the experiment, we develop and exploit a six-photon interferometer to teleport an arbitrary polarization state of two photons. The observed teleportation fidelities for different initial states are all well beyond the state estimation limit of 0.40 for a two-qubit system. Not only does our six-photon interferometer provide an important step towards teleportation of a complex system, it will also enable future experimental investigations on a number of fundamental quantum communication and computation protocols such as multi-stage realization of quantum-relay, fault-tolerant quantum computation, universal quantum error-correction and one-way quantum computation.Comment: 16pages, 4 figure

    Quantum Communication

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    Quantum communication, and indeed quantum information in general, has changed the way we think about quantum physics. In 1984 and 1991, the first protocol for quantum cryptography and the first application of quantum non-locality, respectively, attracted a diverse field of researchers in theoretical and experimental physics, mathematics and computer science. Since then we have seen a fundamental shift in how we understand information when it is encoded in quantum systems. We review the current state of research and future directions in this new field of science with special emphasis on quantum key distribution and quantum networks.Comment: Submitted version, 8 pg (2 cols) 5 fig

    Foot pain and foot health in an educated population of adults: results from the Glasgow Caledonian University Alumni Foot Health Survey

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    Abstract Background Foot pain is common amongst the general population and impacts negatively on physical function and quality of life. Associations between personal health characteristics, lifestyle/behaviour factors and foot pain have been studied; however, the role of wider determinants of health on foot pain have received relatively little attention. Objectives of this study are i) to describe foot pain and foot health characteristics in an educated population of adults; ii) to explore associations between moderate-to-severe foot pain and a variety of factors including gender, age, medical conditions/co-morbidity/multi-morbidity, key indicators of general health, foot pathologies, and social determinants of health; and iii) to evaluate associations between moderate-to-severe foot pain and foot function, foot health and health-related quality-of-life. Methods Between February and March 2018, Glasgow Caledonian University Alumni with a working email address were invited to participate in the cross-sectional electronic survey (anonymously) by email via the Glasgow Caledonian University Alumni Office. The survey was constructed using the REDCap secure web online survey application and sought information on presence/absence of moderate-to-severe foot pain, patient characteristics (age, body mass index, socioeconomic status, occupation class, comorbidities, and foot pathologies). Prevalence data were expressed as absolute frequencies and percentages. Multivariate logistic and linear regressions were undertaken to identify associations 1) between independent variables and moderate-to-severe foot pain, and 2) between moderate-to-severe foot pain and foot function, foot health and health-related quality of life. Results Of 50,228 invitations distributed, there were 7707 unique views and 593 valid completions (median age [inter-quartile range] 42 [31–52], 67.3% female) of the survey (7.7% response rate). The sample was comprised predominantly of white Scottish/British (89.4%) working age adults (95%), the majority of whom were overweight or obese (57.9%), and in either full-time or part-time employment (82.5%) as professionals (72.5%). Over two-thirds (68.5%) of the sample were classified in the highest 6 deciles (most affluent) of social deprivation. Moderate-to-severe foot pain affected 236/593 respondents (39.8%). High body mass index, presence of bunions, back pain, rheumatoid arthritis, hip pain and lower occupation class were included in the final multivariate model and all were significantly and independently associated with moderate-to-severe foot pain (p < 0.05), except for rheumatoid arthritis (p = 0.057). Moderate-to-severe foot pain was significantly and independently associated lower foot function, foot health and health-related quality of life scores following adjustment for age, gender and body mass index (p < 0.05). Conclusions Moderate-to-severe foot pain was highly prevalent in a university-educated population and was independently associated with female gender, high body mass index, bunions, back pain, hip pain and lower occupational class. Presence of moderate-to-severe foot pain was associated with worse scores for foot function, foot health and health-related quality-of-life. Education attainment does not appear to be protective against moderate-to-severe foot pain

    Charged-Lepton Flavour Physics

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    This writeup of a talk at the 2011 Lepton-Photon symposium in Mumbai, India, summarises recent results in the charged-lepton flavour sector. I review searches for charged-lepton flavour violation, lepton electric dipole moments and flavour-conserving CP violation. I also discuss recent progress in tau-lepton physics and in the Standard Model prediction of the muon anomalous magnetic moment.Comment: Presented at Lepton-Photon 2011, Mumbai, India; 23 pages, 14 figure

    Comparison of breast and bowel cancer screening uptake patterns in a common cohort of South Asian women in England

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    Background: Inequalities in uptake of cancer screening by ethnic minority populations are well documented in a number of international studies. However, most studies to date have explored screening uptake for a single cancer only. This paper compares breast and bowel cancer screening uptake for a cohort of South Asian women invited to undertake both, and similarly investigates these women's breast cancer screening behaviour over a period of fifteen years. Methods: Screening data for rounds 1, 2 and 5 (1989-2004) of the NHS breast cancer screening programme and for round 1 of the NHS bowel screening pilot (2000-2002) were obtained for women aged 50-69 resident in the English bowel screening pilot site, Coventry and Warwickshire, who had been invited to undertake breast and bowel cancer screening in the period 2000-2002. Breast and bowel cancer screening uptake levels were calculated and compared using the chi-squared test. Results: 72,566 women were invited to breast and bowel cancer screening after exclusions. Of these, 3,539 were South Asian and 69,027 non-Asian; 18,730 had been invited to mammography over the previous fifteen years (rounds 1 to 5). South Asian women were significantly less likely to undertake both breast and bowel cancer screening; 29.9% (n = 1,057) compared to 59.4% (n = 40,969) for non-Asians (p < 0.001). Women in both groups who consistently chose to undertake breast cancer screening in rounds 1, 2 and 5 were more likely to complete round 1 bowel cancer screening. However, the likelihood of completion of bowel cancer screening was still significantly lower for South Asians; 49.5% vs. 82.3% for non-Asians, p < 0.001. South Asian women who undertook breast cancer screening in only one round were no more likely to complete bowel cancer screening than those who decided against breast cancer screening in all three rounds. In contrast, similar women in the non-Asian population had an increased likelihood of completing the new bowel cancer screening test. The likelihood of continued uptake of mammography after undertaking screening in round 1 differed between South Asian religio-linguistic groups. Noticeably, women in the Muslim population were less likely to continue to participate in mammography than those in other South Asian groups. Conclusions: Culturally appropriate targeted interventions are required to reduce observed disparities in cancer screening uptakes

    Long distance quantum teleportation of qubits from photons at 1300 nm to photons at 1550 nm wavelength

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    Elementary 2-dimensional quantum states (qubits) encoded in 1300 nm wavelength photons are teleported onto 1550 nm photons. The use of telecommunication wavelengths enables to take advantage of standard optical fibre and permits to teleport from one lab to a distant one, 55 m away, connected by 2 km of fibre. A teleportation fidelity of 81.2 % is reported. This is large enough to demonstrate the principles of quantum teleportation, in particular that entanglement is exploited. This experiment constitutes a first step towards a quantum repeater.Comment: 7 pages, 5 figures, Extended version of Nature lette

    An Alternative Yukawa Unified SUSY Scenario

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    Supersymmetric SO(10) Grand Unified Theories with Yukawa unification represent an appealing possibility for physics beyond the Standard Model. However Yukawa unification is made difficult by large threshold corrections to the bottom mass. Generally one is led to consider models where the sfermion masses are large in order to suppress these corrections. Here we present another possibility, in which the top and bottom GUT scale Yukawa couplings are equal to a component of the charged lepton Yukawa matrix at the GUT scale in a basis where this matrix is not diagonal. Physically, this weak eigenstate Yukawa unification scenario corresponds to the case where the charged leptons that are in the 16 of SO(10) containing the top and bottom quarks mix with their counterparts in another SO(10) multiplet. Diagonalizing the resulting Yukawa matrix introduces mixings in the neutrino sector. Specifically we find that for a large region of parameter space with relatively light sparticles, and which has not been ruled out by current LHC or other data, the mixing induced in the neutrino sector is such that sin22Θ231sin^2 2\Theta_{23} \approx 1, in agreement with data. The phenomenological implications are analyzed in some detail.Comment: 32 pages, 22 Figure

    Increasing boys' and girls' intention to avoid teenage pregnancy: a cluster randomised control feasibility trial of an interactive video drama based intervention in post-primary schools in Northern Ireland

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    Background: Adolescent men have a vital yet neglected role in reducing unintended teenage pregnancy (UTP). There is a need for gender-sensitive educational interventions. Objectives: To determine the value and feasibility of conducting an effectiveness trial of the If I Were Jack Relationship and Sexuality Education (RSE) intervention in a convenience quota sample of post-primary schools in Northern Ireland. Secondary objectives were to assess acceptability to schools, pupils (male/female, aged 14–15 years) and parents/guardians; to identify optimal delivery structures and systems; to establish participation rates and reach, including equality of engagement of different socioeconomic and religious types; to assess trial recruitment and retention rates; to assess variation in normal RSE practice; to refine survey instruments; to assess differences in outcomes for male and female pupils; to identify potential effect sizes that might be detected in an effectiveness trial and estimate appropriate sample size for that trial; and to identify costs of delivery and pilot methods for assessing cost-effectiveness. Design: Cluster randomised Phase II feasibility trial with an embedded process and economic evaluation. Intervention: A teacher-delivered classroom-based RSE resource – an interactive video drama (IVD) with classroom materials, teacher training and an information session for parents – to immerse young people in a hypothetical scenario of Jack, a teenager whose girlfriend is unintentionally pregnant. It addresses gender inequalities in RSE by focusing on young men and is designed to increase intentions to avoid UTP by encouraging young people to delay sexual intercourse and to use contraception consistently in sexual relationships. Main outcome measures: Abstinence from sexual intercourse (delaying initiation of sex or returning to abstinence) or avoidance of unprotected sexual intercourse (consistent correct use of contraception). Secondary outcomes included Knowledge, Attitudes, Skills and Intentions. Results: The intervention proved acceptable to schools, pupils and parents, as evidenced through positive process evaluation. One minor refinement to the parental component was required, namely the replacement of the teacher-led face-to-face information session for parents by online videos designed to deliver the intervention to parents/guardians into their home. School recruitment was successful (target 25%, achieved 38%). No school dropped out. Pupil retention was successful (target 85%, achieved 93%). The between-group difference in incidence of unprotected sex of 1.3% (95% confidence interval 0.55% to 2.2%) by 9 months demonstrated an effect size consistent with those reported to have had meaningful impact on UTP rates (resulting in an achievable sample size of 66 schools at Phase III). Survey instruments showed high acceptability and reliability of measures (Cronbach’s alpha: 0.5–0.7). Economic evaluation at Phase III is feasible because it was possible to (1) identify costs of delivering If I Were Jack (mean cost per pupil, including training of teachers, was calculated as £13.66); and (2) develop a framework for assessing cost-effectiveness. Conclusion: Trial methods were appropriate, and recruitment and retention of schools and pupils was satisfactory, successfully demonstrating all criteria for progression to a main trial. The perceived value of culture- and gender-sensitive public health interventions has been highlighted. Future work: Progression to a Phase III effectiveness trial. Trial registration: Current Controlled Trials ISRCTN99459996. Funding: This project was funded by the NIHR Public Health Research programme and will be published in full in Public Health Research; Vol. 5, No. 1. See the NIHR Journals Library website for further project information
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