Lessons from crossing symmetry at large N

20 pages, v2: Assumptions stated more clearly, version published in JHEPWe consider the four-point correlator of the stress tensor multiplet in N=4 SYM. We construct all solutions consistent with crossing symmetry in the limit of large central charge c ~ N^2 and large g^2 N. While we find an infinite tower of solutions, we argue most of them are suppressed by an extra scale \Delta_{gap} and are consistent with the upper bounds for the scaling dimension of unprotected operators observed in the numerical superconformal bootstrap at large central charge. These solutions organize as a double expansion in 1/c and 1/\Delta_{gap}. Our solutions are valid to leading order in 1/c and to all orders in 1/\Delta_{gap} and reproduce, in particular, instanton corrections previously found. Furthermore, we find a connection between such upper bounds and positivity constraints arising from causality in flat space. Finally, we show that certain relations derived from causality constraints for scattering in AdS follow from crossing symmetry.Peer reviewe

Test-retest reliability of capability measurement in the UK general population

Although philosophically attractive, it may be difficult, in practice, to measure individuals' capabilities (what they are able to do in their lives) as opposed to their functionings (what they actually do). To examine whether capability information could be reliably self-reported, we administered a measure of self-reported capability (the Investigating Choice Experiments Capability Measure for Adults, ICECAP-A) on two occasions, 2 weeks apart, alongside a self-reported health measure (the EuroQol Five Dimensional Questionnaire with 3 levels, EQ-5D-3L). We found that respondents were able to report capabilities with a moderate level of consistency, although somewhat less reliably than their health status. The more socially orientated nature of some of the capability questions may account for the difference. © 2014 The Authors Health Economics Published by John Wiley & Sons Ltd

Large spin systematics in CFT

20 pages; v2: version published in JHEPUsing conformal field theory (CFT) arguments we derive an infinite number of constraints on the large spin expansion of the anomalous dimensions and structure constants of higher spin operators. These arguments rely only on analiticity, unitarity, crossing-symmetry and the structure of the conformal partial wave expansion. We obtain results for both, perturbative CFT to all order in the perturbation parameter, as well as non-perturbatively. For the case of conformal gauge theories this provides a proof of the reciprocity principle to all orders in perturbation theory and provides a new "reciprocity" principle for structure constants. We argue that these results extend also to non-conformal theories.Peer reviewe

What works for wellbeing in culture and sport? Report of a DELPHI process to support coproduction and establish principles and parameters of an evidence review

Aims: There is a growing recognition of the ways in which culture and sport can contribute to wellbeing. A strong evidence base is needed to support innovative service development and a 3-year research programme is being undertaken to capture best evidence of wellbeing impacts and outcomes of cultural and sporting activities in order to inform UK policy and practice. This article provides an overview of methods and findings from an initial coproduction process with key stakeholders that sought to explore and agree principles and parameters of the evidence review for culture, sport and wellbeing (CSW). Methods: A two-stage DELPHI process was conducted with a purposeful sample of 57 stakeholders between August and December 2015. Participants were drawn from a range of culture and sport organisations and included commissioners and managers, policy makers, representatives of service delivery organisations (SDOs) and scholars. The DELPHI 1 questionnaire was developed from extensive consultation in July and August 2015. It explored definitions of wellbeing, the role of evidence, quality assessment, and the culture and sport populations, settings and interventions that are most likely to deliver wellbeing outcomes. Following further consultation, the results, presented as a series of ranked statements, were sent back to participants (DELPHI 2), which allowed them to reflect on and, if they wished, express agreement or disagreement with the emerging consensus. Results: A total of 40 stakeholders (70.02%) responded to the DELPHI questionnaires. DELPHI 1 mapped areas of agreement and disagreement, confirmed in DELPHI 2. The exercise drew together the key priorities for the CSW evidence review. Conclusion: The DELPHI process, in combination with face-to-face deliberation, enabled stakeholders to engage in complex discussion and express nuanced priorities while also allowing the group to come to an overall consensus and agree outcomes. The results will inform the CSW evidence review programme until its completion in March 2018

Outcomes in Economic Evaluations of Public Health Interventions in Low- and Middle-Income Countries: Health, Capabilities and Subjective Wellbeing.

Public health programmes tend to be complex and may combine social strategies with aspects of empowerment, capacity building and knowledge across sectors. The nature of the programmes means that some effects are likely to occur outside the healthcare sector; this breadth impacts on the choice of health and non-health outcomes to measure and value in an economic evaluation. Employing conventional outcome measures in evaluations of public health has been questioned. There are concerns that such measures are too narrow, overlook important dimensions of programme effect and, thus, lead to such interventions being undervalued. This issue is of particular importance for low-income and middle-income countries, which face considerable budget constraints, yet deliver a large proportion of health activities within public health programmes. The need to develop outcome measures, which include broader measures of quality of life, has given impetus to the development of a variety of new, holistic approaches, including Sen's capability framework and measures of subjective wellbeing. Despite their promise, these approaches have not yet been widely applied, perhaps because they present significant methodological challenges. This paper outlines the methodological challenges for the identification and measurement of broader outcomes of public health interventions in economic evaluation in low-income and middle-income countries

Simplifying instanton corrections to N=4 SYM correlators

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited

Constraining compressed supersymmetry using leptonic signatures

We study the impact of the multi-lepton searches at the LHC on supersymmetric models with compressed mass spectra. For such models the acceptances of the usual search strategies are significantly reduced due to requirement of large effective mass and missing E_T. On the other hand, lepton searches do have much lower thresholds for missing E_T and p_T of the final state objects. Therefore, if a model with a compressed mass spectrum allows for multi-lepton final states, one could derive constraints using multi-lepton searches. For a class of simplified models we study the exclusion limits using ATLAS multi-lepton search analyses for the final states containing 2-4 electrons or muons with a total integrated luminosity of 1-2/fb at \sqrt{s}=7 TeV. We also modify those analyses by imposing additional cuts, so that their sensitivity to compressed supersymmetric models increase. Using the original and modified analyses, we show that the exclusion limits can be competitive with jet plus missing E_T searches, providing exclusion limits up to gluino masses of 1 TeV. We also analyse the efficiencies for several classes of events coming from different intermediate state particles. This allows us to assess exclusion limits in similar class of models with different cross sections and branching ratios without requiring a Monte Carlo simulation.Comment: 18 pages, 5 figure

Infant and young child feeding in emergencies:Organisational policies and activities during the refugee crisis in Lebanon

Appropriate infant and young child feeding (IYCF) is key to reducing mortality amongst children aged under 2. Facilitating adherence to recommended IYCF practices during emergencies includes having relevant policies to support breastfeeding and complementary feeding as well as regulating the distribution of breast milk substitutes. In the current crisis, more than 1.2 million Syrian refugees are in Lebanon and it is timely to examine organisational IYCF policies and programmes. One hundred and thirty-five non-governmental organisations providing humanitarian aid in Lebanon were invited to participate in an online survey about organisational policies and programmatic activities on IYCF. Responses were obtained from 54 organisations: 29 International Non-Governmental Organisations (INGOs) and 25 Local Non-Governmental Organisations (LNGOs). In total, 8 (15%) reported having a written policy on IYCF, but only 1 policy (in draft format) was available for inspection. Twelve (8 INGOs and 4 LNGOs) indicated endorsing an external IYCF policy, but only 6 listed a valid policy. Four organisations (3 INGOs and 1 LNGO) had programme objectives that indicate protection, promotion, and support of IYCF. Three LNGOs reported receiving infant formula donations and 5 organisations (2 INGOs and 3 LNGOs) indicated distributing infant formula; 2 (1 INGO and 1 LNGO) did so in accordance with international and national policies. Few organisations violated IYCF guidance but organisational policies and activities on IYCF are not well established. In order to improve response in the current refugee crisis in Lebanon, there is a need to ensure policies are in place and implemented so that interventions support, promote, and protect IYCF.</p

Temperature and Density Effects on the Nucleon Mass Splitting

The finite temperature and finite density dependence of the neutron-proton mass difference is analysed in a purely hadronic framework where the $\rho-\omega$ mixing is crucial for this isospin symmetry breakdown. The problem is handled within Thermo Field Dynamics. The present results, consistent with partial chiral and charge symmetry restoration, improve the experimental data fit for the energy difference between mirror nuclei.Comment: 17 pages, revtex fil

Development of a self-report measure of capability wellbeing for adults: the ICECAP-A

Purpose The benefits of health and social care are not confined to patient health alone and therefore broader measures of wellbeing may be useful for economic evaluation.\ud This paper reports the development of a simple measure of capability wellbeing for adults (ICECAP-A).\ud Methods In-depth, informant-led, interviews to identify the attributes of capability wellbeing were conducted with 36 adults in the UK. Eighteen semi-structured, repeat interviews were carried out to develop a capability-based descriptive system for the measure. Informants were purposively selected to ensure variation in socio-economic status, age, sex, ethnicity and health. Data analysis was carried out inductively and iteratively alongside interviews, and findings were used to shape the questions in later interviews.\ud Results Five over-arching attributes of capability wellbeing were identified for the measure: ‘‘stability’’,‘‘attachment’’, ‘‘achievement’’, ‘‘autonomy’’ and ‘‘enjoyment’’. One item, with four response categories, was developed for each attribute for the ICECAP-A descriptive system.\ud Conclusions The ICECAP-A capability measure represents a departure from traditional health economics outcome measures, by treating health status as an influence over broader attributes of capability wellbeing. Further work is required to value and validate the attributes and test the sensitivity of the ICECAP-A to healthcare interventions