This Black Hole Keeps Its Own White Dwarf ‘Pet’

The most compact star-black hole binary has been discovered, but the star seems to be perfectly happy whirling around the massive singularity twice an hour.

Credits: X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.; Illustration: NASA/CXC/M.Weiss

A star in the globular cluster of 47 Tucanae is living on the edge of oblivion.

Located near a stellar-mass black hole at only 2.5 times the Earth-moon distance, the white dwarf appears to be in a stable orbit, but it’s still paying the price for being so intimate with its gravitational master. As observed by NASA’s Chandra X-ray Observatory and NuSTAR space telescope, plus the Australia Telescope Compact Array, gas is being pulled from the white dwarf, which then spirals into the black hole’s super-heated accretion disk.

47 Tucanae is located in our galaxy, around 14,800 light-years from Earth.

Eventually, the white dwarf will become so depleted of plasma that it will turn into some kind of exotic planetary-mass body or it will simply evaporate away. But one thing does appear certain, the white dwarf will remain in orbit and isn’t likely to get swallowed by the black hole whole any time soon.

“This white dwarf is so close to the black hole that material is being pulled away from the star and dumped onto a disk of matter around the black hole before falling in,” said Arash Bahramian, of the University of Alberta (Canada) and Michigan State University. “Luckily for this star, we don’t think it will follow this path into oblivion, but instead will stay in orbit.” Bahramian is the lead author of the study to be published in the journal Monthly Notices of the Royal Astronomical Society.

It was long thought that globular clusters were bad locations to find black holes, but the 2015 discovery of the binary system — called “X9” — generating quantities of radio waves inside 47 Tucanae piqued astronomers’ interest. Follow-up studies revealed fluctuating X-ray emissions with a period of around 28 minutes — the approximate orbital period of the white dwarf around the black hole.

So, how did the white dwarf become the pet of this black hole?

The leading theory is that the black hole collided with an old red giant star. In this scenario, the black hole would have quickly ripped away the bloated star’s outer layers, leaving a tiny stellar remnant — a white dwarf — in its wake. The white dwarf then became the black hole’s gravitational captive, forever trapped in its gravitational grasp. Its orbit would have become more and more compact as the system generated gravitational waves (i.e. ripples in space-time), radiating orbital energy away, shrinking its orbital distance to the configuration that it is in today.

It is now hoped that more binary systems of this kind will be found, perhaps revealing that globular clusters are in fact very good places to find black holes enslaving other stars.

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This Is Why NASA’s Space Station Bose-Einstein Experiment Will Be so Cool

An instrument capable of cooling matter to a smidgen above absolute zero is being readied for launch to the International Space Station, possibly uncovering new physics and answering some of our biggest cosmological questions.

NASA

This summer, a rather interesting experiment will arrive at the International Space Station. Called the Cold Atom Laboratory (CAL), this boxy instrument will be able to chill material down to unimaginably low temperatures — so low that it will become the coldest place in the known universe.*

At a temperature of a billionth of a degree above absolute zero, CAL will investigate a state of matter that cannot exist in nature. This strange state is known as a Bose-Einstein condensate (or BEC), which possesses qualities that, quite frankly, don’t make a lot of sense.

When a gas is sufficiently cooled and the subatomic particles (bosons) drop to their lowest energy state, “normal” physics start to break down and quantum mechanics — the physics that governs the smallest scales — starts to manifest itself throughout a material (on a macroscopic scale). When this occurs, a BEC is possible. And it’s weird.

BECs act as a “superfluid,” which means it has zero viscosity. Early experiments on supercooled helium-4 exhibited this trait, causing confusion at the time when this mysterious fluid was observed flowing up, against the force of gravity, and over the sides of its containing beaker. Now we are able to cool gases to sufficiently low temperatures, this superfluid trait dominates and gases move as one, apparently coherent, mass.

So far, BEC experiments have only been carried out in a gravitational environment and can only be observed for a very short period of time as gravity continually pulls the BEC particles to the bottom of its container, thereby limiting its stability. But remove gravity from the equation and we enter a brand new observational regime with the potential for brand new insights to fundamental physics, and this is why NASA built CAL — humanity’s first microgravity BEC laboratory that could unlock some of the universe’s biggest mysteries.

CAL works by trapping the BEC in magnetic containment and lasers will be used to cancel out energy in the gas, thereby cooling it (pictured top). The gas will then be further cooled through evaporative cooling (using a radio frequency “knife”) and adiabatic expansion. When sufficiently cooled, experiments can be carried out on the BEC — the first time a BEC has been tested in space. (The technical details behind CAL’s technology can be found on the experiment’s website.)

“Studying these hyper-cold atoms could reshape our understanding of matter and the fundamental nature of gravity,” said Robert Thompson, CAL Project Scientist from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., in a statement. “The experiments we’ll do with the Cold Atom Lab will give us insight into gravity and dark energy — some of the most pervasive forces in the universe.”

It is hoped that BECs will be observable inside CAL for five to twenty seconds and the ultra-low temperature technologies developed will allow for future experiments that could contain stable BECs for hundreds of times longer.

CAL isn’t a pure physics curiosity, even if it is pretty awesome just to observe quantum physics manifest itself across an entire mass of particles (in free-fall, no less). Producing stable BECs could have technical applications, such as in quantum computer development and improving the precision of quantum clocks. In addition, creating a stable BEC in a lab setting could, quite literally, give us new eyes on fundamental universal mysteries. Lower temperatures means more stability and more stability means boosted sensor precision. Astronomy is all about precision, so the spin-off technologies from the techniques developed in CAL could usher in a new generation of ultra-sensitive telescopes and detectors that could, ultimately, reveal the mechanisms behind dark energy and dark matter.

“Like a new lens in Galileo’s first telescope, the ultra-sensitive cold atoms in the Cold Atom Lab have the potential to unlock many mysteries beyond the frontiers of known physics,” said Kamal Oudrhiri, CAL deputy project manager also at JPL.

CAL is set for launch on a SpaceX resupply mission to the International Space Station in August and I can’t wait to see what new physics the instrument might uncover.

*Assuming there are no other intelligent lifeforms also playing with supercooled matter elsewhere in the universe, of course.

ALMA Reveals the True Nature of Hubble’s Enigmatic Ghost Spiral

Appearing as a ghostly apparition in deep space, the LL Pegasi spiral nebula signals the death of a star — and the world’s most powerful radio observatory has delved into its deeper meaning.

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Left: HST image of LL Pegasi publicized in 2010. Credit: ESA/NASA & R. Sahai. Right: ALMA image of LL Pegasi. Credit: ALMA (ESO/NAOJ/NRAO) / Hyosun Kim et al.

When the Hubble Space Telescope revealed the stunning LL Pegasi spiral for the first time, its ghostly appearance captivated the world.

Known to be an ancient, massive star, LL Pegasi is dying and shedding huge quantities of gas and dust into space. But this is no ordinary dying star, this is a binary system that is going out in style.

The concentric rings in the star system’s nebula are spiraling outwards, like the streams of water being ejected from a lawn sprinkler’s head. On initial inspection of the Hubble observation, it was assumed that the spiral must be caused by the near-circular orbit of two stars, one of which is generating the flood of gas. Judging by the symmetry of the rings, this system must be pointing roughly face-on, from our perspective.

Though these assumptions generally hold true, new follow-up observations by the Atacama Large Millimeter/submillimeter Array (ALMA) on the 5,000 meter-high Chajnantor plateau in Chile has added extra depth to the initial Hubble observations. Astronomers have used the incredible power of ALMA to see a pattern in the rings, revealing the complex orbital dynamics at play deep in the center of the spiral.

“It is exciting to see such a beautiful spiral-shell pattern in the sky. Our observations have revealed the exquisitely ordered three-dimensional geometry of this spiral-shell pattern, and we have produced a very satisfying theory to account for its details,” said Hyosun Kim, of the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan and lead researcher of this work.

Just as we read tree rings to understand the history of seasonal tree growth and climatic conditions, Kim’s team used the rings of LL Pegasi to learn about the nature of the binary star’s 800 year orbit. One of the key findings was the ALMA imaging of bifurcation in the rings; after comparing with theoretical models, they found that these features are an indicator that the central stars’ orbit is not circular — it’s in fact highly elliptical.

ALMA observation of the molecular gas around LL Pegasi. By comparing this gas distribution with theoretical simulations, the team concluded that the bifurcation of the spiral-shell pattern (indicated by a white box) is resulted from a highly elliptical binary system. Credit: ALMA (ESO/NAOJ/NRAO) / Hyosun Kim et al.

Probably most striking, however, was that Hubble was only able to image the 2D projection of what is in fact a 3D object, something that ALMA could investigate. By measuring the line-of-sight velocities of gas being ejected from the central star, ALMA was able to create a three-dimensional view of the nebula, with the help of numerical modeling. Watch the animation below:

“While the [Hubble Space Telescope] image shows us the beautiful spiral structure, it is a 2D projection of a 3D shape, which becomes fully revealed in the ALMA data,” added co-author Raghvendra Sahai, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in a statement.

This research is a showcase of the power of combining observations from different telescopes. Hubble was able to produce a dazzling (2D) picture of the side-on structure of LL Pegasi’s spirals, but ALMA’s precision measurements of gas outflow speed added (3D) depth, helping us “see” an otherwise hidden structure, while revealing the orbital dynamics of two distant stars.

A special thanks to Hyosun Kim for sending me the video of the LL Pegasi visualization!

So it Could be a ‘Supervoid’ That’s Causing the Mysterious CMB ‘Cold Spot’

Only last month I recorded a DNews video about the awesome possibilities of the “Cold Spot” that sits ominously in the cosmic microwave background (CMB) anisotropy maps (anisotropies = teenie tiny temperature variations in the CMB).

I still hold onto the hope that this anomalous low temperature region is being caused by a neighboring parallel universe squishing up against our own. But evidence is mounting for there actually being a vast low density region — known as a “supervoid” — between us and that Cold Spot.

And that’s crappy news for my dreams of cosmologists finding bona fide observational clues of the multiverse hypothesis any time soon. The Cold Spot could just be the frigid fingerprint of this supervoid etched into our observations of the CMB.

But as this supervoid could be as wide as 1.8 billion light-years, this discovery is still crazy cool — the supervoid could be the newest candidate for the largest structure ever discovered in the universe. Suck it, Sloan Great Wall.

Read more about this new research published today in the Monthly Notices of the Royal Astronomical Society in my Discovery News blog.

The Large Hadron Collider is Powering Back Up, What Next?

A segment of the Large Hadron Collider's super-cooled electromagnets. Credit: CERN/LHC
A segment of the Large Hadron Collider’s super-cooled electromagnets. Credit: CERN/LHC

After a 2 year hiatus for a significant upgrade, the Large Hadron Collider is being switched back on and, early on Sunday, the world’s most powerful particle accelerator saw the first circulation of protons around its 27 kilometer ring of superconducting electromagnets.

This is awesome news, especially as there was a minor electrical short last week that could have derailed this momentous occasion for weeks, or maybe months. In one of magnet segments, a metallic piece of debris from the upgrade work had become jammed in a diode box, triggering the short. Manual removal of the debris would have forced a lengthy warm up and then cool down back to cryogenic temperatures, but CERN engineers were able to find a quick fix — by passing an electrical current through the problem circuit the tiny piece of debris was burnt away, no warm-up required.

With this small hiccup out of the way, the complex task of circulating protons around the LHC began this weekend, resulting in two sparsely populated beams of protons speeding around the LHC in opposite directions. So far, so good, but the particle accelerator is far from being ready to recommence particle collisions.

“Bringing the LHC back on, from a complete shutdown to doing physics, is not a question of pushing a button and away you go,” Paul Collier, head of beams at CERN, told Nature News.

Sure, the LHC is circulating protons, but it is far from restarting high-energy collisions. In fact, over the coming weeks and months, engineers will be tuning the machine to finely collimate the counter-rotating beams of protons and gradually ramping-up their speed. The first collisions aren’t expected to begin until June at the earliest.

But seeing protons pump around the LHC for the first time since 2013 is an awesome sign that all the high-energy plumbing is in place and the electrical backbone of the accelerator appears to be working in synergy with the massive magnetic hardware.

Over the next 8 weeks, engineers will turn on the LHC’s acceleration systems, boosting the beam energy from 450 GeV to 6.5 TeV, gradually focusing the beams in preparation for the first collisions.

According to Nature, the re-started LHC will slam 1 billion pairs of protons together every second inside the various detectors dotted around the accelerator ring with a collision energy of 13 TeV, boosting the LHC’s energy into a whole new regime. During the LHC’s first run, the maximum energy recorded was 8 TeV.

This makes for a curious time in cutting-edge particle physics.

Before the LHC was fully commissioned in 2008, its clear task was to track down, discover and characterize the Higgs boson, the last remaining piece of the Standard Model. Having achieved the Higgs discovery in 2012 — resulting in the 2013 Nobel Prize being awarded to Peter Higgs and François Englert — physicists have been combing through the reams of data to understand the new particle’s characteristics. Although a lot still needs to be learnt about the famous boson that endows all matter with mass, Run 2 of the LHC has a rather vague mission. But “vague” certainly doesn’t mean dull, we could be entering into a new era of physics discovery.

I always imagine that powering up the LHC is like this... completely inaccurate, mind you.
I always imagine that powering up the LHC is like this… completely inaccurate, mind you.

We’ve never seen collision energies this high before, and with the Standard Model all but tied up, physicists are on the lookout for phenomena with an “exotic” flavor. Exotic, in this case, means the production of quantum effects that cannot be easily explained or may be driven by mechanics that have, until now, been considered pure speculation.

Personally, I’m excited that the LHC may generate a signature that we cannot explain. I’m also trilled by the possibility of micro-black holes, the discovery of dark matter particles, potential hints of supersymmetry and quantum gravity. But I’m doubly-thrilled by the prospect of something popping out of the collision debris that doesn’t make any sense.

As the LHC will now slam protons (and, later, ions) at energies nearly double of what it was previously capable of, we are in uncharted territory. Physicists are recreating the conditions of the Big Bang, condensing primordial particles and forces from the concentrated energy of colliding beams of charged particles. So far, after only 7 years since the LHC was first powered up, it has already confirmed the existence of a Standard Model Higgs boson. So now, without a single ultimate goal, the LHC will do what physics does best, discovery-driven science that could answer many quantum mysteries and, hopefully, create many more.

We Are The 4.9%

The AMS attached to the space station's exterior (NASA)
The AMS attached to the space station’s exterior (NASA)

This month is Global Astronomy Month (GAM2013) organized by my friends Astronomers Without Borders (AWB). There is a whole host of events going on right this moment to boost astronomy throughout the international community, and as a part of GAM2013, AWB are hosting daily blogs from guest astronomers, writers, physicists and others with a background in space. Today (April 11) was my turn, so I wrote a blog about the fascinating first results to be announced on the International Space Station instrument the Alpha Magnetic Spectrometer — or AMS for short.

Although the AMS’ most recent findings suggest positrons with a signature energy indicative of the annihilation of dark matter — particularly hypothetical weakly interaction massive particles (WIMPS) — it isn’t final proof of dark matter (despite what the tabloid press might’ve told you). But still, it’s exciting and another component of our enduring search for 95.1% of the mass-energy of the universe that is locked in the mysterious and perplexing dark matter and dark energy.

You can read my blog on the AWB website: “Dark Matter: We Are The 4.9%

Intercontinental Travel Is Impossible…

(Imagine an island long, long ago, in an ocean far, far away…)

“Intercontinental travel will never happen. The nearest shore is thousands of miles away. This means that even if we had the ability to row five miles per day from our little island, it would take years to get there!

To rub (sea) salt into the wound, the nearest shoreline is probably not a place we’d want to visit anyway. We’ve heard that beasts of unimaginable horror lurk over the horizon. Even worse, what if that undiscovered country is a desert-like place, or a disease-ridden tropic? Perhaps water doesn’t even flow as a liquid! Imagine trying to live in a land covered with ice. What a thought!

To put it bluntly, our little island is quarantined from the rest of the world. But it’s not a quarantine where we are locked inside an impenetrable room, we’re quarantined by a mind-bogglingly vast expanse of ocean. We live here with only a rowing boat for transportation — you can do some laps around the island in that rowing boat, but that’s all.

Forget about it. Don’t look at those distant shores and think that some day we’ll be able to build an engine for that rowing boat. A little outboard motor wouldn’t get you very far — you’d likely run out of gas before the island is out of sight! Heck, you’ll probably starve before then anyway.

Just go home. Why are you still planning on building a big boat — that sci-fi notion of a metal-hulled “ship” no less! — when you should be worrying more about your little island? We have problems here! Our resources are dwindling, people are starving! Your dreams mean nothing in our everyday lives.”

What am I talking about? Read my Discovery News op-ed to find out…

Plasmaloopalicious!

The magnetic loop containing hydrogen and nitrogen plasma evolves over 4 micro-seconds. Credit: Bellan & Stenson, 2012
The magnetic loop containing hydrogen and nitrogen plasma evolves over 4 micro-seconds. Credit: Bellan & Stenson, 2012

There’s no better method to understand how something works than to build it yourself. Although computer simulations can help you avoid blowing up a city block when trying to understand the physics behind a supernova, it’s sometimes just nice to physically model space phenomena in the lab.

So, two Caltech researchers have done just that in an attempt to understand a beautifully elegant, yet frightfully violent, solar phenomenon: coronal loops. These loops of magnetism and plasma dominate the lower corona and are particularly visible during periods of intense solar activity (like, now). Although they may look nice and decorative from a distance, these loops are wonderfully dynamic and are often the sites of some of the most energetic eruptions in our Solar System. Coronal loops spawn solar flares and solar flares can really mess with our hi-tech civilization.

A coronal loop as seen by NASA's Transition Region and Coronal Explorer (TRACE). Credit: NASA
A coronal loop as seen by NASA’s Transition Region and Coronal Explorer (TRACE). Credit: NASA

In an attempt to understand the large-scale dynamics of a coronal loop, Paul Bellan, professor of applied physics at Caltech, and graduate student Eve Stenson built a dinky “coronal loop” of their own (pictured top). Inside a vacuum chamber, the duo hooked up an electromagnet (to create the magnetic “loop”) and then injected hydrogen and nitrogen gas into the two “footpoints” of the loop. Then, they zapped the whole thing with a high-voltage current and voila! a plasma loop — a coronal loop analog — was born.

Although coronal loops on the sun can last hours or even days, this lab-made plasma loop lasted a fraction of a second. But by using a high-speed camera and color filters, the researchers were able to observe the rapid expansion of the magnetic loop and watch the plasma race from one footpoint to the other. Interestingly, the two types of plasma flowed in opposite directions, passing through each other.

The simulation was over in a flash, but they were able to deduce some of the physics behind their plasma loop: “One force expands the arch radius and so lengthens the loop while the other continuously injects plasma from both ends into the loop,” Bellan explained. “This latter force injects just the right amount of plasma to keep the density in the loop constant as it lengthens.” It is hoped that experiments like these will ultimately aid the development of space weather models — after all, it would be useful if we could deduce which coronal loops are ripe to erupt while others live out a quiescent existence.

It’s practical experiments like these that excite me. During my PhD research, my research group simulated steady-state coronal loops in the hope of explaining some of the characteristics of these fascinating solar structures. Of particular interest was to understand how magnetohydrodynamic waves interact with the plasma contained within the huge loops of magnetism. But all my research was based on lines of code to simulate our best ideas on the physical mechanisms at work inside these loops. Although modelling space phenomena is a critical component of science, it’s nice to compare results with experiments that aim to create analogs of large-scale phenomena.

The next test for Bellan and Stenson is to create two plasma loops inside their vacuum chamber to see how they interact. It would be awesome to see if they can initiate reconnection between the loops to see how the plasma contained within reacts. That is, after all, the fundamental trigger of explosive events on the Sun.

Read more in my Discovery News article: “Precursors to Solar Eruptions Created in the Lab

After Historic Discovery, Higgs Flies Economy

Real superstars: Peter Higgs congratulates ATLAS experiment spokesperson Fabiola Gianotti after she announced her collaboration's discovery of a Higgs-like particle (CERN/ATLAS/Getty)
Real superstars: Peter Higgs congratulates ATLAS experiment spokesperson Fabiola Gianotti after she announced her collaboration’s discovery of a Higgs-like particle. Credit: CERN/ATLAS/Getty

I am endlessly baffled by modern society.

We have reality TV stars whose only talent is to shock and annoy, and yet inexplicably have millions of adoring fans. We also have sports superstars who get paid tens of millions of dollars to play a game they love, and yet they still get elevated to God-like status.

And then there’s Professor Peter Higgs, arguably the biggest science superstar of recent years.

The 83-year-old retired theoretical physicist was one of six scientists who, in the 1960s, assembled the framework behind the Higgs boson — the almost-unequivocally-discovered gauge particle that is theorized to carry the Higgs field, thereby endowing matter with mass. The theory behind the Higgs boson and all the high-energy physics experiments pursuing its existence culminated in a grand CERN announcement from Geneva, Switzerland, on Wednesday. With obvious emotion and nerves, lead scientist of the Large Hadron Collider’s CMS detector Joe Incandela announced what we’ve all been impatiently waiting for: “We have observed a new boson.

So, we now have evidence for the existence of the Higgs boson — or a Higgs boson — to a high degree of statistical certainty, ultimately providing observational evidence for a critical piece of the Standard Model. This story began half a century ago with Prof. Higgs’ theoretical team, and it culminated on July 4, 2012, when results from a $10 billion particle accelerator were announced.

After the historic events of the last few days, one would think Peter Higgs would have been at least treated to a First Class flight back to his home in Scotland. But true to form, Higgs had other ideas:

Later, Higgs’s friend and colleague Alan Walker recounted the low-key celebration they held after learning of the breakthrough, one of the most important scientific discoveries of recent years.

Walker said he and Higgs were flying home from CERN in Geneva this week on budget airline easyJet when he offered Higgs a glass of Prosecco sparkling wine so they could toast the discovery.

Higgs replied: “‘I’d rather have a beer’ and popped a can of London Pride,” Walker said.

via Discovery News

In a world where “celebrities” are hailed as superhuman, to hear that potential Nobel Prize candidate Peter Higgs took a budget airline home, after history had been made, typifies the humble nature of a great scientist and puts the world of celebrity to shame. Money and fame matters little to the people who are unraveling the fabric of the Universe.

On a different (yet related) note, Motherboard interviewed people on the streets of Brooklyn and asked them if they knew what the Higgs boson is. Most had never heard of it, let alone understood it (which, let’s face it, isn’t a surprise — many science communicators still have problems explaining the Higgs mechanism). But I wonder if the same group of people were asked if they knew what a “Snookie” was; I’m guessing they’d have no problem answering.

People may not read the news, but they sure have an innate knowledge of who’s in the gossip columns.

Higgs Boson-like Particle Discovered in CMS and ATLAS Data!

The CMS detector at the LHC (CERN)
The CMS detector at the LHC (CERN)

Yes, the Higgs boson has been discovered… or, to put it more accurately, something that looks like a Higgs boson has been discovered. But is it a Higgs boson? There’s a very high probability that it is, but in the world where theory meets high-energy physics, it pays to be completely sure about what you’re looking at.

Prof. Peter Higgs, theoretical theorist, receives applause at the CERN event.
Prof. Peter Higgs, theoretical theorist, receives applause at the CERN event.

But for the ATLAS and CMS collaborations at the Large Hadron Collider in CERN, near Geneva, Switzerland, who held a rapturous conference at CERN and in Australia this morning, they’re pretty damned sure they are looking at a bona fide Higgs boson discovery.

“We have observed a new boson,” said CMS lead scientist Joe Incandela.

“We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV,” confirmed ATLAS lead scientist Fabiola Gianotti.

“I think we have it,” said CERN Director-General Rolf Heuer. “We have discovered a particle that is consistent with a Higgs boson.”

Why all the certainty? Well, it all comes down to statistics, and all the statistics seem to show a defined “bump” in the CMS and ATLAS data around the mass-energy of 125-126 GeV/c2 — to a statistical certainty of 4.9 and 5 sigma. 125-126 GeV/c2 just so happens to be one of the theorized masses of a Higgs boson — placing the Higgs’ mass at 133 times that of a proton. This particular boson is therefore the most massive boson ever detected.

For more news on this incredible discovery, check out my Discovery News blog “Particle ‘Consistent’ With Higgs Boson Discovered