Search for magnetic monopoles produced via the Schwinger mechanism.

Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.

First Search for Dyons with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions.

The MoEDAL trapping detector consists of approximately 800 kg of aluminum volumes. It was exposed during run 2 of the LHC program to 6.46 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminum volumes comprising the detector through a superconducting quantum interference device (SQUID) magnetometer. The presence of a trapped dyon would be signaled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to five Dirac charges (5g_{D}) and an electric charge up to 200 times the fundamental electric charge for mass limits in the range 870-3120 GeV and also monopoles with magnetic charge up to and including 5g_{D} with mass limits in the range 870-2040 GeV.

Prospects for discovering supersymmetric long-lived particles with MoEDAL.

We present a study on the possibility of searching for long-lived supersymmetric partners with the MoEDAL experiment at the LHC. MoEDAL is sensitive to highly ionising objects such as magnetic monopoles or massive (meta)stable electrically charged particles. We focus on prospects of directly detecting long-lived sleptons in a phenomenologically realistic model which involves an intermediate neutral long-lived particle in the decay chain. This scenario is not yet excluded by the current data from ATLAS or CMS, and is compatible with astrophysical constraints. Using Monte Carlo simulation, we compare the sensitivities of MoEDAL versus ATLAS in scenarios where MoEDAL could provide discovery reach complementary to ATLAS and CMS, thanks to looser selection criteria combined with the virtual absence of background. It is also interesting to point out that, in such scenarios, in which charged staus are the main long-lived candidates, the relevant mass range for MoEDAL is compatible with a potential role of Supersymmetry in providing an explanation for the anomalous events observed by the ANITA detector.

Magnetic Monopole Search with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions Interpreted in Photon-Fusion and Drell-Yan Production.

MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

History of concussion is associated with higher head acceleration and reduced cervical muscle activity during simulated rugby tackle: An exploratory study.

OBJECTIVES: The objective of this study is to explore the effect of concussion history on head control during front on rugby tackles in non-professional male and female Rugby Union players. DESIGN: An observational cross-sectional design. SETTING: A laboratory-based study of simulated front on rugby tackles with a dynamic relatively-weighted (∼50% body-mass) tackle bag. PARTICIPANTS: 27 club Rugby Union players were recruited; 10 (7female) with no-concussion history, 10 (3female) within 12-months of concussion and 7 (3female) with 24 + months since last concussion. MAIN OUTCOME MEASURES: Linear and rotational head acceleration measured with a skin mounted CSx® triaxial accelerometer. Normalized Surface EMG amplitude of the bilateral sternocleidomastoid (Scm), upper trapezius (Trap) and splenius capitis (Spl). All outcome measures were synchronised with moment of impact with the tackle bag. RESULTS: A mixed-model analysis showed that players with 12-Month concussion history had the highest head acceleration (females = 48.6g, males = 68.3g, p < 0.05) with lower Trap (6.9-11.7%, p < 0.05) and Spl (3-12%, p < 0.05) amplitudes compared to athletes with No-concussion. CONCLUSIONS: These findings suggest probable disruption to neuromuscular control of the head in athletes with concussion history as a potential mechanism for recurrent concussion incidence.

Monopole production via photon fusion and Drell-Yan processes: MadGraph implementation and perturbativity via velocity-dependent coupling and magnetic moment as novel features.

In this work we consider point-like monopole production via photon-fusion and Drell-Yan processes in the framework of an effective U(1) gauge field theory obtained from conventional models describing the interaction of spin  magnetically-charged fields with ordinary photons, upon electric-magnetic dualisation. We present arguments based on such dualities which support the conjecture of an effective monopole-velocity-dependent magnetic charge. For the cases of spin- and spin-1 monopoles, we also include a magnetic-moment term κ , which is treated as a new phenomenological parameter and, together with the velocity-dependent coupling, allows for a perturbative treatment of the cross-section calculation. We discuss unitarity issues within these effective field theories, in particular we point out that in the spin-1 monopole case only the value κ = 1 may restore unitarity. However from an effective-field-theory point of view, this lack of unitarity should not be viewed as an impediment for the phenomenological studies and experimental searches of generic spin-1 monopoles, given that the potential appearance of new degrees of freedom in the ultraviolet completion of such models might restore it. The second part of the paper deals with an appropriate implementation of photon-fusion and Drell-Yan processes based on the above theoretical scenarios into MadGraph UFO models, aimed to serve as a useful tool in interpretations of monopole searches at colliders such as LHC, especially for photon fusion, given that it has not been considered by experimental collaborations so far. Moreover, the experimental implications of such perturbatively reliable monopole searches have been laid out.

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC.

MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

Analysis of different communication channels for promoting hygiene behaviour.

A hygiene intervention study reduced diarrhoeal disease transmission in rural northeast Thailand by promoting hand-washing and dish-washing behaviour. Most of the target audience did not recognize a connection between these behaviours and diarrhoeal disease, and therefore a social marketing approach was used to develop a campaign promoting behaviours through a variety of communication channels keeping messages simple and in terms understood by the community. Overall, there was a strong correlation between the number of communication channels remembered by respondents and their knowledge score, with passive channels of printed media such as stickers, posters and leaflets associated with significantly higher scores than other channels. However, the same did not hold true for improvement in actual behaviour and only 'school children' were associated with significantly less fingertip contamination. In-depth interviews with conformers and non-conformers suggested that although most knew the intervention messages well enough, the importance they attached to them differed markedly. Thus dissemination of message knowledge was not consistent with the process of dissemination of actual practice. Where a strong sense of community spirit existed, friends, relatives and neighbours were more likely to discuss intervention activities with each other.

Measuring the effect of a hygiene behaviour intervention by indicators of behaviour and diarrhoeal disease.

A social marketing approach used both qualitative and quantitative methods to develop a hygiene behaviour intervention in rural north-east Thailand. Behaviours were preselected from a previous study and the intervention was designed to promote hand washing, especially before feeding a baby, cooking, eating, and after defaecation or cleaning a baby's bottom, and dish washing immediately after eating. A bacteriological indicator (enumerating faecal streptococci using a finger impression technique) was developed to measure changes in hand washing behaviour and observation (spot checks) of dirty dishes to indicate dish washing practice. There was a significant improvement in both behaviours and a significant reduction in diarrhoeal disease as a result of the intervention. Furthermore, both indicators were retrospectively found to be positively related to diarrhoeal disease incidence. However, receiving and being able to recall the intervention messages was not necessarily sufficient to ensure behaviour change, as some adults found it difficult to change old habits. Villages showing the greatest improvement tended to have a stronger sense of community than others and to have more people actively involved in the intervention.

Microbiological methods for assessing handwashing practice in hygiene behaviour studies.

Personal hygiene, especially handwashing, is frequently mentioned as an important aspect of diarrhoeal disease prevention in water and sanitation programmes. Handwashing practice is difficult to assess but the microbiological analysis of hands shows promise as an indicator of this behaviour. Most methods for isolating bacteria from the hands have been developed for use in hospitals in order to investigate the spread of nosocomial infections. However, reliable and inexpensive methods which need only limited expertise are needed for use in developing countries where diarrhoeal diseases remain a major health risk. Techniques for sampling hands and bacteriological analysis methods are discussed with special emphasis on practical considerations for conducting tests in developing countries. Several studies have used these methods successfully and have investigated hygiene behaviour and how living conditions affect behaviour and the role of hands in diarrhoeal disease transmission. We recommend the use of impression plates for isolating faecal indicator bacteria from the hands and also recommend faecal streptococci as an indicator of faecal contamination.

Seasonal effects on the reported incidence of acute diarrhoeal disease in northeast Thailand.

This paper examines the seasonal variation in the reported incidence of acute diarrhoea for selected areas in the northeast of Thailand. Charts are presented which show rainfall, temperature and reported incidence of acute diarrhoea for the period 1982 to 1987. Incidence of diarrhoea appears to be inversely related to a sharp decrease in temperature around January each year. Although rainfall does not appear to have a direct effect on the relative incidence of acute diarrhoea, there is always a consistent reduction during July or August, after the rains have begun. Seasonal changes in climate may be indirectly related to other factors which have an important bearing on diarrhoeal disease. Rainwater collection is an important water source in this region and the affect this has on water use is discussed in relation to faeco-oral disease transmission.

PIP: Researchers compared data on acute diarrhea incidence with data on rainfall and temperature of 10 provinces and 15 districts of Khon Kaen province in northeast Thailand to determine the link between seasonal weather patterns and reported incidence of acute diarrhea. The relative incidence of diarrhea decreased with age in the winter while it increased with age in the hot season and early in the rainy season. Indeed reported incidence of diarrhea peaked in January for children 2 years old. The researchers suggested that rotavirus was the leading causative agent in this age group since it is common in cooler months and in children 2 years old. Another peak occurred in April-June when temperatures are high and early in the rainy season. This peak involved mainly adults. The researchers believed enterotoxigenic Escherichia coli, Campylobacter jejuni, and Shigella were the leading causative agents. The researchers posed a possible explanation for this April-June peak. In the beginning of the wet season, households changed their water source from groundwater to rainwater and began to use it differently. Further, they often stored water separately from rainjars. It was more likely that this water was more contaminated than stored rainwater or groundwater. In addition, fecal bacteria transmitted by food preparation and utensil handling and the rising humidity fostered its growth. These events may have accounted for the increased incidence of diarrhea in the early rainy season. A steep reduction in diarrhea incidence occurred around the middle of the wet season (July and August). Research has shown that increased water quantity may be better in reducing diarrhea incidence than only improving water quality. Furthermore, it also demonstrated that bacteriological quality of water stored in rainjars was better than water from shallow wells.