Monthly Archives: August 2019

Looking for neutralinos at the Large Hadron Collider

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first_img“We are looking at the heavens, and using the very biggest things to help up predict what will happen with the very smallest things,” David Toback tells PhysOrg.com. Toback is a professor at Texas A&M University in College Station, and he believes that there is a way to combine cosmology and particle physics in a way that can help us learn more about the universe. Explore further Tracking down dark matter Citation: Looking for neutralinos at the Large Hadron Collider (2008, July 9) retrieved 18 August 2019 from https://phys.org/news/2008-07-neutralinos-large-hadron-collider.htmlcenter_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. “We’re interested in the dark matter question,” Toback continues. “Our current best guess is that the particles we know and love only make up about four percent of the stuff in the universe. Twenty-three percent of the universe is dark matter. The rest is dark energy. But I’m interested in dark matter, which should be made of particles. We want to know the properties of the bulk of the matter in the universe. This is a question that interests both cosmologists and particle physicists.”Toback and his colleagues at Texas A&M, Richard Arnowitt, Bhaskar Dutta, Alfredo Gurrola, Teruki Kamon and Abram Krislock, have been working on a model that allows them to use information obtained from the Large Hadron Collider (LHC) to predict the amount of dark matter left over from the beginning of the universe. Their work is published in Physical Review Letters: “Determining the Dark Matter Relic Density in the Minimal Supergravity Stau-Neutralino Coannihilation Region at the Large Hadron Collider.”“Our goal is to see whether our understanding of particles in the universe, the theory of supersymmetry, is correct. If it is, it will explain one of the most important questions in particle physics and cosmology in one fell swoop,” Toback says.Supersymmetry is a theory that predicts that all elementary particles with spin are paired to other particles whose spin differs by half a unit. “One of the things that makes it special,” Toback says, “is that supersymmetry is a theory that predicts new particles. And one of the particles predicted is called a neutralino.” Neutralinos are thought to be heavy and stable, and they represent the leading candidate to explain the amount of cold dark matter indirectly detected in the universe. The problem is that no one has been able to measure dark matter directly yet. This is where the LHC comes in. This $6 billion project is scheduled to begin operation later this summer, smashing protons into each other. The LHC is the largest and highest energy particle accelerator in the world, and Toback thinks that there’s a good chance that neutralinos could be produced from the collisions between protons. The data produced by the LHC will be made available to scientists around the world, including the team at Texas A&M.“If our results are correct we now know much better where to look for this dark matter particle at the LHC,” Toback explains. “We’ve used precision data from astronomy to calculate what it would look like at the LHC, and how quickly we should be able to discover and measure it.” He and his colleagues have even gone so far to be show that with their measurements with LHC data they would be able to predict the amount of dark matter in the universe. This could be compared to what is seen from the WMAP satellite. “If we get the same answer,” he continues, “that would give us enormous confidence that the supersymmetry model is correct. If nature shows this, it would be remarkable.”Toback says that the work he is doing with his peers at Texas A&M could make a connection between particle physics and cosmology. “If this works out, we could do real, honest to goodness cosmology at the LHC. And we’d be able to use cosmology to make particle physics predictions.”Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.last_img read more

Research team finds way to simulate graphene Dirac points

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first_imgMovement of the Dirac points. Image (c) Nature, doi:10.1038/nature10871 Citation: Research team finds way to simulate graphene Dirac points (2012, March 15) retrieved 18 August 2019 from https://phys.org/news/2012-03-team-simulate-graphene-dirac.html In an interesting turn of events, another team taking a completely different approach has also managed to find a way to show the existence of Dirac points and to manipulate them as well by synthesizing a form of graphne and arranging it in the familiar chicken-wire lattice on top of a conducting substrate and then manipulating it with a tunneling microscope. They have also published their results in Nature.Finding ways to show how Dirac points can be manipulated will help to find ways of using graphene in real world applications that could result in new exotic materials with unique electronic properties, leading to end products that in some cases can’t even be imagined yet. Explore further The secrets of tunneling through energy barriers Now, Tilman Esslinger and his fellow researchers at the Institute for Quantum Optics at ETH Zurich have found a way to do just that by simulating graphene and its properties using a laser created lattice filled with potassium-40 atoms. They report on their findings in the journal Nature.The experiment began by cooling potassium-40 atoms, leaving them lethargic so they wouldn’t move away from within the lattice. Their role was to serve as stand-ins for electrons moving in graphene. Then, to create the lattice, the team fired one laser perpendicular to another causing the two to interfere with each other. A third laser beam with a slightly different wavelength was then added to create a standing wave. In this scenario, the square lattice that resulted could be adjusted by adjusting the third beam. The team then tested the lattice for Dirac points by speeding up the atoms and measuring their trajectories and found two of them by noting the momentum between the lattice cells didn’t slow, meaning there wasn’t any gap. Better yet, the team found that by adjusting the lattice they could manipulate the Dirac points, moving them around or even causing them to disappear completely. The density distribution of the potassium atoms measured after acceleration through Dirac points (left and centre), and without Dirac point (right). The upper row shows the corresponding regions of the calculated bandstructure. (Image: Tilman Esslinger’s Research Group / ETH Zurich)center_img © 2011 PhysOrg.com More information: Creating, moving and merging Dirac points with a Fermi gas in a tunable honeycomb lattice, Nature 483, 302–305 (15 March 2012) doi:10.1038/nature10871AbstractDirac points are central to many phenomena in condensed-matter physics, from massless electrons in graphene to the emergence of conducting edge states in topological insulators. At a Dirac point, two energy bands intersect linearly and the electrons behave as relativistic Dirac fermions. In solids, the rigid structure of the material determines the mass and velocity of the electrons, as well as their interactions. A different, highly flexible means of studying condensed-matter phenomena is to create model systems using ultracold atoms trapped in the periodic potential of interfering laser beams. Here we report the creation of Dirac points with adjustable properties in a tunable honeycomb optical lattice. Using momentum-resolved interband transitions, we observe a minimum bandgap inside the Brillouin zone at the positions of the two Dirac points. We exploit the unique tunability of our lattice potential to adjust the effective mass of the Dirac fermions by breaking inversion symmetry. Moreover, changing the lattice anisotropy allows us to change the positions of the Dirac points inside the Brillouin zone. When the anisotropy exceeds a critical limit, the two Dirac points merge and annihilate each other—a situation that has recently attracted considerable theoretical interest but that is extremely challenging to observe in solids10. We map out this topological transition in lattice parameter space and find excellent agreement with ab initio calculations. Our results not only pave the way to model materials in which the topology of the band structure is crucial, but also provide an avenue to exploring many-body phases resulting from the interplay of complex lattice geometries with interactions.Press release (PhysOrg.com) — As researchers continue to study graphene and its unique attributes, they find themselves fixated on different areas of its properties. One of those properties is that because of its lattice structure, graphene is a “zero-gap” semiconductor. This means that its conduction and electron valance bands actually touch each other at certain points, which means there is no energy gap between them, as is the case with current semiconductor materials. And this means that the momentum and energy association is very much like that of photons, which implies that electrons could move at speeds approaching the speed of light. These parts of graphene’s structure are known as Dirac points. Up until now though, no one has been able to see any real world evidence of such points, much less manipulate them. Journal information: Nature This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Electric Imp serves up plantsthirsty lightson control

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first_img Electric Imp designed the card to be inserted into a product, connecting to the cloud service and in turn allowing the device to talk to other devices and to communicate with the user and services via the Internet. The cards can be programmed to control or measure anything. They can be installed to devices using circuit boards sold by Electric Imp. The company is talking to manufacturers as well, for the purpose of getting slots pre-installed on various products.Costs for an imp card would be about $25 and circuit boards, would be between $10 and $25. Imp-enabled products will be available later this year from a number of vendors, say reports. The company notes that its patent-pending technology is available to license. Interactive media improved patients’ understanding of cancer surgery by more than a third Imp in Action A developer preview bundle will ship in late June. Electric Imp says the software uses drag-and-drop graphics to set up commands, and is easily programmed. Preview units will be available along with developer kits. In notes for developers, the company says software running on the Imp is written in Squirrel, a C-like language, with extensions to communicate with the hardware interfaces and the service.The release signifies a turning point in the Internet of Things, says the company, as Internet-connecting devices so far have been expensive and of limited user benefit. The idea for the Imp stems from one of the team members who wanted to remodel his bathroom and hook up a display under his bathroom cabinet to WiFi to display bits of ambient information, such as the weather forecast and share prices. Disappointed with the lack of tools available, he was convinced there must be a better way of doing something like this.Electric Imp plans to be at the Maker Faire in San Mateo, California, which runs from May 19 to May 20. Explore further More information: electricimp.com © 2012 Phys.Org (Phys.org) — Electric Imp wants to revive the dream of All Things Internet with its new device launched this week. Its Imp is able to connect devices to the Internet, where you can monitor and control information from your phone, mobile computer, or any other Imp-enabled devices. The Los Altos, California, company has essentially managed to come up with a cloud-based home automation unit. The Imp looks like any standard user-installable SD card and is equipped with embedded processor and Wi-Fi capability. The card’s WiFi radio supports 802.11b/g/n, and has an integrated antenna. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Electric Imp serves up plants-thirsty, lights-on control (2012, May 17) retrieved 18 August 2019 from https://phys.org/news/2012-05-electric-imp-plants-thirsty-lights-on.htmllast_img read more

Eastern Arctic Ocean found to be undergoing Atlantification

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first_img © 2017 Phys.org (Phys.org)—An international team of researchers has found that the eastern part of the Arctic Ocean is undergoing what they describe as “Atlantification”—in which the ocean is becoming more like the Atlantic Ocean. In their paper published in the journal Science, the group describes how they tracked ocean temperatures over a 15-year period and the changes they found. Citation: Eastern Arctic Ocean found to be undergoing ‘Atlantification’ (2017, April 7) retrieved 18 August 2019 from https://phys.org/news/2017-04-eastern-arctic-ocean-atlantification.html Journal information: Science Scientists report ocean data from under Greenland’s Petermann Glacier Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: Igor V. Polyakov et al. Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean, Science (2017). DOI: 10.1126/science.aai8204AbstractArctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline, and shoaling of intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin. The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching “atlantification” of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows. Recovery of mooring M6b north of Severnaya Zemlya on 30 August during NABOS 2015 cruise. Credit: © Ilona Goszczko The mooring M5 anchor with the Bottom Pressure Recorder BPR before deployment on 17 September 2013 during NABOS 2013 cruise. Credit: © Ilona Goszczko The Arctic Ocean has traditionally been different from the Atlantic or Pacific in a fundamental way—the water gets warmer as you go deeper (due to inflows from the Atlantic) rather than the other way around, as happens with the other two. But now, the researchers with this new effort have found that may be changing. They have been using tethered moorings to record ocean temperatures at different depths for approximately 15 years and have found that changes have taken place—sea ice is melting from below, not just from above due to warmer air temperatures.In studying the data from the moorings, the researchers found that warm water from the Atlantic, which has traditionally been separated from melting ice because of the halocline layer—a barrier that exists between deep salty water and fresher water closer to the surface—has been penetrating the barrier, allowing ice to melt from below. It has also led to the water becoming less stratified, like the Atlantic. They describe the changes as a “massive shift” in the ocean that has occurred over an extremely short time frame. These new findings may explain why the extent of ice coverage has been shrinking so dramatically—at a rate of 13 percent per decade.The result, the researchers report, is a feedback loop—as more ice melts due to warmer air, more vertical mixing occurs, allowing warmer water to move upwards, which causes melting from below. They also acknowledge that it is not yet clear what impact the change might have, but suggest it is likely to be substantial—from the biogeochemical to geophysical levels, basic components of the ocean will likely be altered, causing changes such as phytoplankton blooms in places where they have never been seen before. They also note that there is another factor to consider—the massive amounts of fresh water pouring into the ocean from rivers in Siberia as permafrost thaws.last_img read more

Simple pleasures

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first_imgI fell in to sculpture,’ says Christine Margotin when we ask her about her stint with the art. Leaving behind the corporate world, Margotin started sculpting professionally from 2009. She quit her job, moved to India and then began her love affair with the beauty she saw all around her and that translated in to her art pieces.‘Once I came to India I had more time to meet people, more time to do what I loved,’ says Margotin explaining that earlier sculpting was just a hobby for her but with her time in India, she transformed it into a career. Also Read – ‘Playing Jojo was emotionally exhausting’Beauty Makes Us Happy is Margotin’s first solo exhibition that features 20 of her works in the national capital. Her works are figurative and she finds inspiration in everyday life.Her endeavour is to share these everyday moments without the need for articulation. She has selected moments and scenes drawn from daily life and endowed this ordinary ‘everydayness’.The works exhibited describe her journey from France to India – A journey resulted in amalgamation of the French and Indian culture in the form of this exhibition. Also Read – Leslie doing new comedy special with Netflix‘I saw beauty all around me and I wanted to bring those emotions out through what I create,’ says Margotin.So what has she planned next? ‘Nothing yet,’ says the artiste. But she points out that she has more moments captured in her mind that will soon transform into another body of work. ‘I store the moments in my head and work on them later,’ she adds.Clearly this lady is just allowing some more great art to gestate in her head and we can’t wait to see what she will create next!When: On till 21 NovemberWhere: Galerie Romain Rolland, Alliance Françaiselast_img read more

The comic nation comes alive

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first_imgThe 4th Annual Comic Con kicked off with a grand start on Friday, 7 February, with huge crowd hindering free movement. A comic and/or custom stuff lover’s way of socialising and finding more stuff which he/she will need, the fourth iteration is already a huge hit even though this is the first time it is being held outside their usual venue Delhi Haat. This time around, Comic Con has an exhibition of works of Charles M Schulz, the creator of Peanuts. The visitors are greeted by the exhibition gallery upon entering the venue. What more has changed is that now, the venue is divided in two zones, one being a display and engagement zone for introducing people to the new stuff. Sony has a stall here and has put up its latest console, the PlayStation 4 for the visitors to enjoy. There is also LAN gaming zone here. The second zone has all the merchandise stores and is the real crowd puller, like the previous three iterations. From comics to pillows and even slippers, everything that can accommodate a Batman or Superman is available for sale. Also Read – ‘Playing Jojo was emotionally exhausting’Not to forget, various visitors are here dressed as comic characters. Talk about Bleach, Naruto, Asterix, etc and you will see them all here. For those who want to see more, there is our desi SuperKudi too. Talk about India amongst the comic giants and there you go. The extravaganza is on from 7 to 9 February at Thyagraj Stadium near INA Colony. Do not miss this one. For those who have never been to one of these events, start now and make ‘history’. You will not regret being at this place at any hour, that is a promise.WHERE: Thyagraj StadiumWHEN: On till 9 Februarylast_img read more

Sky is the limit

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first_imgAll the adventure freaks have a chance to rejoice and cheer as Global Himalayan Expedition announces its second edition. The journey  from Delhi to Leh starts from 10 August.The 11 days expedition will be covered entirely on an electric powered vehicle (EV). The travel will include all kinds of action like setting-up a micro-grid in a Himalayan village, trekking, cycling and rafting in the mountains, to camping in some of the most picturesque locations in the world.  Also Read – ‘Playing Jojo was emotionally exhausting’The journey will be led by Robert Swan, UN Goodwill Ambassador and the first man to have walked to both the poles on earth. The electric vehicle will cover about 1300 kilometers between Delhi and Ladakh passing through Punjab, Himachal Pradesh and Jammu and Kashmir. Throughout the journey, the expedition team members, will reach out to people and raise awareness about clean energy, electric vehicle and its benefits. This awareness walk to the team will be a precursor to the Expedition, which would kick-off on the day when the electric vehicle reaches Leh. Also Read – Leslie doing new comedy special with NetflixSwan said, ‘This year the team wishes to further promote the idea of use of clean energy. We decided to undertake this journey as a display of how clean energy is an effective alternative to traditional fossil fuel based transportation systems. The team aims to show that if an electric vehicle can take on this challenge, then it can very well work anywhere. Once in Leh, the vehicle will be used to transport to help the students and people from the other parts of the city to reach the E-Base, built by the team during last year’s expedition, and work at the facility.’ In addition to the clean Himalayan journey, it will also focus on providing energy access to remote Himalayan regions. The team will also join forces with Ladakh Renewable Energy Development Agency for identification of villages across remote parts of Ladakh, where it will set up DC Solar Microgrids to provide basic lighting and charging facilities to the community. The region is suitable for yearlong solar energy generation, and can be used to refuel these EVs.last_img read more

CM condoles death of budding cricketer

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first_imgKolkata: Chief Minister Mamata Banerjee condoled the death of promising cricketer Debabrata Pal, who was killed after lightning struck him on Sunday.The incident happened when the 21-year-old all-rounder went for practice at Vivekananda Park ground. He was a resident of Serampore in Hooghly. While addressing the felicitation programme of toppers from different boards of examination, Chief Minister said: “I am saddened due to the tragic death of the budding cricketer.” Also Read – Heavy rain hits traffic, flightsAroop Biswas, the Youth Services and Sports minister along with Laxmi Ratan Shukla, Minister of State for Youth Services and Sports department, went to SSKM Hospital on Monday. The post-mortem of Debabrata’s body was carried out at SSKM. Shukla said: “We are shocked. It is a big loss for the family and Bengal. I pray to God that it should not happen with anyone else.” It may be mentioned that the lightning struck when he was about to enter a shade. Others, who were also busy in their practice along with him, had already gone under it as soon as the rain started pouring. He was last of the lot. Other players came out when he fell on the ground and rushed him to hospital where he was declared brought dead. Calcutta Cricket Academy will remain closed for 3 days as a mark of respect.last_img read more

Met forecasts heavy rain in South Bengal

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first_imgKolkata: The Met department today forecast heavy to very heavy rain in the districts of south Bengal owing to a well-marked low pressure in north-west Bay of Bengal. Heavy to very heavy rain have been forecast in districts of south Bengal, with the intensity likely to be more in the coastal districts of East Midnapore, South 24 Parganas and North 24 Parganas. The well-marked low pressure area over northwest Bay of Bengal and adjoining West Bengal and Odisha coasts is likely to concentrate into a depression during the next two days, regional Met director G K Das said. Also Read – Rain batters Kolkata, cripples normal life Fishermen have been advised not to venture into the sea till July 22. The metropolis, which has been experiencing sweltering heat for the last few days, is likely to receive heavy rain tomorrow and a few spells of rain thereafter, Das said. Kolkata recorded the day’s highest temperature at 36.1 degree Celsius yesterday, which is three notches above normal, while the minimum temperature was two counts above average at 28.5 degree Celsius.last_img read more

Firstborn kids more likely to be nearsighted

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first_imgFirst-born children run higher risk of becoming nearsighted later in life, compared with their later-born siblings, a study says.Parents pushing the eldest kid to do better in studies may be partly blamed for the higher myopia risk among the first-borns, the researcher found.“Our study provides an extra piece of evidence linking education and myopia, consistent with the very high prevalence of myopia in countries with intensive education from an early age,” study author Jeremy Guggenheim, of Cardiff University in Britain, was quoted as saying. Also Read – ‘Playing Jojo was emotionally exhausting’For the study, researchers examined birth order and nearsightedness in about 89,000 people, aged 40 to 69, in Britain. First-borns were 10 per cent more likely to be nearsighted and 20 per cent more likely to be severely nearsighted than their subsequent siblings, the findings showed, the study said.Reduced parental investment in education of children with later birth order may be partly responsible, the researchers said. Also Read – Leslie doing new comedy special with NetflixEducation accounted for about 25 per cent of the link between birth order and the risk of nearsightedness.However, in addition to education, there may be other, unmeasured factors that could partially mediate the relationship between birth order and one’s risk of nearsightedness, Live Science reported.The study was published in the journal JAMA Ophthalmology.last_img read more