First Particle Tracks at Prototype for DUNE Underground Neutrino Experiment

By Andre Salles 

The largest liquid-argon neutrino detector in the world has just recorded its first particle tracks, signaling the start of a new chapter in the story of the international Deep Underground Neutrino Experiment (DUNE).

The top of the steel cage for one of the two ProtoDUNE detectors is hoisted into position by crane. The prototype contains 800 tons of liquid argon: the final DUNE detector will be 20 times larger. Photo: CERN

Higgs Boson News: Decays to Bottom Quarks, Upholds Standard Model

Six years after its discovery, the Higgs boson has at last been observed decaying to fundamental particles known as bottom quarks. The finding, presented Aug. 28 at CERN by the ATLAS and CMS collaborations at the Large Hadron Collider (LHC), is consistent with the hypothesis that the all-pervading quantum field behind the Higgs boson also gives mass to the quarks. Both teams have submitted their results for publication.

The CMS detector catches a Higgs boson decaying to two bottom quarks (b) in association with a Z boson decaying to an electron (e-) and an antielectron (e+). (Image: CMS/CERN)

New Insights into Semiconductors for Spintronic Applications from Hard X-Ray Photoemission

“Spintronics” holds promise for new types of devices for information processing and data storage, with ones and zeros being stored in the spin state of electrons as well as their electric charge. Such devices could be faster and more energy efficient than current electronics.

Dilute magnetic semiconductors such as manganese-doped gallium arsenide are a promising material for spintronics, said Slavomir Nemsak, staff researcher at the Lawrence Berkeley National Laboratory and former postdoc in the UC Davis Department of Physics, working with Professor Charles Fadley and Adjunct Professor Claus Schneider. They have ferromagnetic properties but are not themselves metals. They are called “dilute” because the dopant makes up a small amount (a few percent) of the semiconductor material.

“Grit in the Gears” Costs Energy in Modular Information Systems

Digital information may appear to exist as abstract ones and zeroes, flipping effortlessly from one to another. But in fact there is a minimum amount of energy required to run any computation system, regardless of how “energy efficient” are its component parts. A recent paper from Jim Crutchfield and Alex Boyd at the UC Davis Complexity Sciences Center with Dibyendu Mandal at UC Berkeley shows that there is some inescapable friction, or “grit in the gears” between the levels of organization in an information system.

Piezomagnetic Material Changes Magnetic Properties When Stretched

Piezoelectric materials, which generate an electric current when compressed or stretched, are familiar and widely used: think of lighters that spark when you press a switch, but also microphones, sensors, motors and all kinds of other devices. Now a group of physicists has found a material with a similar property, but for magnetism. This “piezomagnetic” material changes its magnetic properties when put under mechanical strain.

Magnetic experiment

Top: A piece of BaFe2As2 is stretched while magnetic measurements are taken (the copper wire coil is part of the NMR device). Lower diagram shows atoms in a plane, with black arrows showing how magnetic spins lie in plane and point in opposite directions. Grey arrows show how the magnetic spin of atoms shifts as the material is stretched.

Italian Dark Matter Experiment Completes Run, Sets Stage for Next Experiment

The DarkSide-50 experiment at the Gran Sasso National Laboratory in Italy has completed its experimental run, the research collaboration announced today (Feb. 21). The experiment did not find any potential dark matter particles, but it did demonstrate that the technology could reject “false positive” signals from natural radioactivity or other sources. That will give researchers more confidence in data from the next, larger experiment, DarkSide-20k.

Dark Matter detector

Schematic of the DarkSide-50 detector. The cylinder is filled with liquid argon, which gives off a flash of light when a particle enters the chamber. This light is detected by photomultiplier tubes at top and bottom. (DarkSide-50 collaboration)

Swirling Quark-Gluon Plasma is the Swirliest Fluid Ever

STAR detector at Brookhaven

The Solenoidal Tracker at RHIC (STAR) detector is used to search for signatures of the quark-gluon plasma, a form of matter that filled the early universe. (Brookhaven National Laboratory)

The soup of fundamental particles called the quark-gluon plasma can swirl far faster than any known fluid – faster than the mightiest tornado or the superstorm that is Jupiter’s Great Red Spot.

The results, published Aug. 3 in the journal Nature, come from a new analysis of data from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory.

Deep Underground Neutrino Experiment Breaks Ground

A special groundbreaking was held today (July 21) deep underground in South Dakota. Scientists, engineers and guests turned the first shovelfuls of the 800,000 tons of rock that will be excavated to build the Long Baseline Neutrino Facility (LBNF) at the Sanford Underground Research Facility. The cavern will house a giant detector for the Deep Underground Neutrino Experiment (DUNE).

The goal of DUNE is to better understand neutrinos and their role in the evolution of the universe, including why our universe is made of matter and not antimatter. DUNE will also be able to detect neutrinos from deep space, emitted by supernovae or black holes.

SNO+ Neutrino Detector Gets Ready For Run

snowaterfill-1

SNO+ neutrino detector being filled with ultrapure water. The detector will search for neutrinos from distant supernovae and nuclear reactors. Credit: SNO+ Collaboration

 

Not a still from a science fiction movie, but the SNO+ neutrino detector being filled with very pure water prior to starting operations. Located over a mile underground in a mine in Ontario, Canada, the SNO+ detector consists of an acrylic sphere 12 meters in diameter filled with 800 tonnes of scintillation fluid, floating in a bath of ultrapure water surrounded by 10,000 photomultiplier tubes that will detect flashes of light from passing neutrinos.

Physics Nobel for topological phase transitions

The 2016 Nobel Prize for Physics will be shared by David Thouless, F. Duncan Haldane and J. Michael Kosterlitz for their work on peculiar states of matter under extreme conditions. The three used advanced mathematics — specifically topology, the study of shapes — to build theoretical models of matter. Their work has practical implications for understanding superconductors, superfluids and thin magnetic films, and ultimately for new types of devices and technologies.

“This year’s Laureates opened the door on an unknown world where matter can assume strange states,” according to the Nobel Prize citation.