862 research outputs found

    Boosting Higgs CP properties via VH Production at the Large Hadron Collider

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    We consider ZH and WH production at the Large Hadron Collider, where the Higgs decays to a bb pair. We use jet substructure techniques to reconstruct the Higgs boson and construct angular observables involving leptonic decay products of the vector bosons. These efficiently discriminate between the tensor structure of the HVV vertex expected in the Standard Model and that arising from possible new physics, as quantified by higher dimensional operators. This can then be used to examine the CP nature of the Higgs as well as CP mixing effects in the HZZ and HWW vertices separately.Comment: 5 pages, 3 figures. v2: two references added and typo correcte

    Quest for new materials: Inorganic chemistry plays a crucial role

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    There is an endless quest for new materials to meet the demands of advancing technology. Thus, we need new magnetic and metallic/semiconducting materials for spintronics, new low-loss dielectrics for telecommunication, new multi-ferroic materials that combine both ferroelectricity and ferromagnetism for memory devices, new piezoelectrics that do not contain lead, new lithium containing solids for application as cathode/anode/electrolyte in lithium batteries, hydrogen storage materials for mobile/transport applications and catalyst materials that can convert, for example, methane to higher hydrocarbons, and the list is endless! Fortunately for us, chemistry - inorganic chemistry in particular - plays a crucial role in this quest. Most of the functional materials mentioned above are inorganic non-molecular solids, while much of the conventional inorganic chemistry deals with isolated molecules or molecular solids. Even so, the basic concepts that we learn in inorganic chemistry, for example, acidity/basicity, oxidation/reduction (potentials), crystal field theory, low spin-high spin/inner sphere-outer sphere complexes, role of d-electrons in transition metal chemistry, electron-transfer reactions, coordination geometries around metal atoms, Jahn-Teller distortion, metal-metal bonds, cation-anion (metal-nonmetal) redox competition in the stabilization of oxidation states - all find crucial application in the design and synthesis of inorganic solids possessing technologically important properties. An attempt has been made here to illustrate the role of inorganic chemistry in this endeavour, drawing examples from the literature as well as from the research work of my group

    Jet substructure and probes of CP violation in Vh production

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    We analyse the hVV (V = W, Z) vertex in a model independent way using Vh production. To that end, we consider possible corrections to the Standard Model Higgs Lagrangian, in the form of higher dimensional operators which parametrise the effects of new physics. In our analysis, we pay special attention to linear observables that can be used to probe CP violation in the same. By considering the associated production of a Higgs boson with a vector boson (W or Z), we use jet substructure methods to define angular observables which are sensitive to new physics effects, including an asymmetry which is linearly sensitive to the presence of CP odd effects. We demonstrate how to use these observables to place bounds on the presence of higher dimensional operators, and quantify these statements using a log likelihood analysis. Our approach allows one to probe separately the hZZ and hWW vertices, involving arbitrary combinations of BSM operators, at the Large Hadron Collider.Comment: 37 pages, 17 figures; v3 matches published versio

    Sensors in Unmanned Robotic Vehicle

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    Unmanned tracked vehicles are developed for deployment in dangerous zones that are notsafe for human existence. These vehicles are to be fitted with various sensors for safe manoeuvre.Wide range of sensors for vehicle control, vision, and navigation are employed. The main purposeof the sensors is to infer the intended parameter precisely for further utilisation. Software isinseparable part of the sensors and plays major role in scaling, noise reduction, and fusion.Sensor fusion is normally adapted to enhance the decision-making. Vehicle location  andorientation can be sensed through global positioning system, accelerometer, gyroscope, andcompass. The unmanned vehicle can be navigated with the help of CCD camera, radar, lidar,ultrasonic sensor, piezoelectric sensor, microphone, etc.  Proximity sensors like capacitive andRF proximity detectors can detect obstacles in close vicinity.  This paper presents an overviewof sensors normally deployed in unmanned tracked vehicles

    Barriers to Health among IDPs in Kabul, Afghanistan: a qualitative study

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    Background: Forced displacement is a significant problem for regions experiencing prolonged humanitarian crises due to armed conflict. Afghanistan, having experienced over four decades of conflict, has an estimated 1.2 million internally displaced persons (IDPs), a majority of which are concentrated in urban centers. IDPs have limited resources and face challenges accessing health services through traditional channels, leading to a disproportionate burden of morbidity and mortality. Health care facilities created for and existing within IDP camps also face numerous challenges. We aim to understand the structural factors that negatively impact health and the specific barriers to healthcare access for IDPs using qualitative methods. Methods: A brief qualitative study was done to assess the barriers to health faced by IDPs and to understand the experience of providers caring for IDPs. We conducted open-ended interviews using a semi-structured interview guide across three IDP camps in Kabul, Afghanistan between May and June 2017. Participants were interviewed in focus groups, interviewing a total of 37 IDP ag 18 and older. In addition, two former health care providers were interviewed. We used grounded theory to code interviews using a priori and emergent coding, from which several themes and sub-themes emerged. Two independent readers coded the data and discrepancies were resolved by consensus. Results: Human security, water access, limited livelihood and employment, poor housing infrastructure and environmental factors significantly impacted IDP health. Closure of clinics within the camps caused substantial limitations to healthcare service access. Accessing existing health care infrastructure was limited by cost, distance, discrimination, and limited access to medication and vaccinations, particularly for children. Key informant interviews identified healthcare funding and vaccination delivery to be priority problems. Across all focus groups and key informant interviews, there appeared to be a solid and trusted patient-provider relationship. Conclusion Structural factors that negatively impact health coupled with new barriers to healthcare access for IDPs in Kabul are a source of serious concern. Our study identified structural factors that exacerbate poor health and new challenges to healthcare access resulting from the discontinuation of in-camp health services. Further research should be done on the barriers and facilitators of transition from emergency humanitarian response to long-term care for IDPs, as well as on the ability of local health systems to absorb vulnerable populations after humanitarian crises

    Hybrid Evolutionary Computing Assisted Irregular-Shaped Patch Antenna Design for Wide Band Applications

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    A novel optimization concept for modeling irregular-shaped patch antenna with high bandwidth and efficient radiation attributes is proposed in this paper, along with the ability to accomplish the design at a reduced computational and cost burden. A revolutionary computing perception is established with Gravitational Search Algorithm (GSA) and Quantum Based Delta Particle Swarm Optimization (QPSO), now known as GSA-QPSO. The suggested model employed the GSA-QPSO algorithm strategically interfaced with a high-frequency structure simulator (HFSS) software through a Microsoft Visual Basic script to enhance irregular-shaped antenna design while maintaining wide bandwidth with suitable radiation efficiency over the target bandwidth region. The optimally designed microstrip patch antenna is fabricated on an FR-4 substrate with a surface area of 30×30×1.6 mm 3 . The evaluated outcome shows 96 % supreme radiation efficacy at 2.4 GHz whereas overall effectiveness is above 84% over the entire frequency range, with a nearly omnidirectional radiation pattern. In terms of impedance bandwidth, the suggested antenna offers 126.6 % over the operational frequency range from 2.34 GHz to 10.44 GHz. Fabrication and measurement results are also used to validate the simulated results. It exhibits the proficiency of the offered antenna design to be used for real-world wideband (WB) communication drives

    Elastocapillary driven assembly of particles at free-standing smectic-A films

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    Colloidal particles at complex fluid interfaces and within films assemble to form ordered structures with high degrees of symmetry via interactions that include capillarity, elasticity, and other fields like electrostatic charge. Here we study microparticle interactions within free-standing smectic-A films, in which the elasticity arising from the director field distortion and capillary interactions arising from interface deformation compete to direct the assembly of motile particles. New colloidal assemblies and patterns, ranging from 1D chains to 2D aggregates, sensitive to the initial wetting conditions of particles at the smectic film, are reported. This work paves the way to exploiting LC interfaces as a means to direct spontaneously formed, reconfigurable, and optically active materials.Comment: 8 pages, 6 figures. Supplementary Materials: 3 pages, 3 figure

    The Origin of Nitrogen on Jupiter and Saturn from the 15^{15}N/14^{14}N Ratio

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    The Texas Echelon cross Echelle Spectrograph (TEXES), mounted on NASA's Infrared Telescope Facility (IRTF), was used to map mid-infrared ammonia absorption features on both Jupiter and Saturn in February 2013. Ammonia is the principle reservoir of nitrogen on the giant planets, and the ratio of isotopologues (15^{15}N/14^{14}N) can reveal insights into the molecular carrier (e.g., as N2_2 or NH3_3) of nitrogen to the forming protoplanets, and hence the source reservoirs from which these worlds accreted. We targeted two spectral intervals (900 and 960 cm1^{-1}) that were relatively clear of terrestrial atmospheric contamination and contained close features of 14^{14}NH3_3 and 15^{15}NH3_3, allowing us to derive the ratio from a single spectrum without ambiguity due to radiometric calibration (the primary source of uncertainty in this study). We present the first ground-based determination of Jupiter's 15^{15}N/14^{14}N ratio (in the range from 1.4×1031.4\times10^{-3} to 2.5×1032.5\times10^{-3}), which is consistent with both previous space-based studies and with the primordial value of the protosolar nebula. On Saturn, we present the first upper limit on the 15^{15}N/14^{14}N ratio of no larger than 2.0×1032.0\times10^{-3} for the 900-cm1^{-1} channel and a less stringent requirement that the ratio be no larger than 2.8×1032.8\times10^{-3} for the 960-cm1^{-1} channel (1σ1\sigma confidence). Specifically, the data rule out strong 15^{15}N-enrichments such as those observed in Titan's atmosphere and in cometary nitrogen compounds. To the extent possible with ground-based radiometric uncertainties, the saturnian and jovian 15^{15}N/14^{14}N ratios appear indistinguishable, implying that 15^{15}N-enriched ammonia ices could not have been a substantial contributor to the bulk nitrogen inventory of either planet, favouring the accretion of primordial N2_2 from the gas phase or as low-temperature ices.Comment: 33 pages, 19 figures, manuscript accepted for publication in Icaru

    Higgs Physics at the Large Hadron Collider

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    In this talk I will begin by summarising the importance of the Higgs physics studies at the LHC. I will then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at the LHC. In addition to the material covered in the presented talk, I have included in the writeup, a critical appraisal of the theoretical uncertainties in the Higgs cross-sections at the Tevatron as well as a discussion of the recent experimental results from the LHC which have become available since the time of the workshop.Comment: LateX, 12 figures, 15 pages, Presented at the XIth Workshop on High Energy Physics Phenomenology, 2010, Ahmedabad, Indi

    The Istanbul Protocol: A global stakeholder survey on past experiences, current practices and additional norm setting

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    Introduction: The Istanbul Protocol (IP) principles and guidelines have served as international norms for the effective investigation and documentation of torture and ill-treatment since 1999. Given the widespread use of the IP and recent calls to update or enhance its norms, we conducted a large-scale study among stakeholders to understand current practices as well as opinions on additional IP norm setting. Methods: Between February 20, 2017 and April 7, 2017, we conducted an online survey of IP users using a combination of criterion and chain sampling. The survey instrument included the following domains of inquiry: 1) respondent characteristics (demographics, anti-torture work, country conditions, and IP training); 2) IP use, importance and practices, and; 3) opinions on additional IP norm setting. Results: The survey was distributed to 177 individuals and 250 organizational representatives with response rates of 78% and 47% respectively. The respondents came from a variety of clinical, legal, academic, and advocacy disciplines from around the world. The respondents indicated that they use the IP for a wide range of anti-torture activities: investigation and documentation, advocacy, training and capacity building, policy reform, prevention, and treatment and rehabilitation of torture survivors. The vast majority (94% of individual respondents and 84% of organizations) reported that the IP is important to their anti-torture work. A majority of individual (60%) and organizational (59%) respondents reported that updating or adding clarifications to the IP would help to address the challenges they face and provided specific suggestions. However, 41% of individuals and 21% of organizational respondents also reported concerns that additional IP norm setting could have negative consequences. Discussion: The IP provides critical guidance for a wide range of torture prevention, accountability, and redress activities and can be enhanced through the development of additional updates and clarifications to respond to the current needs of torture survivors and stakeholders
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