Saturday, April 18, 2020
Strongest evidence yet that neutrinos explain how the universe exists
April 15, 2020
Imperial College London
New data throws more support behind the theory that neutrinos are the reason the universe is dominated by matter.
https://www.sciencedaily.com/releases/2020/04/200415133657.htm
New data throws more support behind the theory that neutrinos are the reason the universe is dominated by matter.
The current laws of physics do not explain why matter persists over antimatter -- why the universe is made of 'stuff'. Scientists believe equal amounts of matter and antimatter were created at the beginning of the universe, but this would mean they should have wiped each other out, annihilating the universe as it began.
Instead, physicists suggest there must be differences in the way matter and antimatter behave that explain why matter persisted and now dominates the universe. Each particle of matter has an antimatter equivalent, and neutrinos are no different, with an antimatter equivalent called antineutrinos.
They should be exact opposites in their properties and behaviour, which is what makes them annihilate each other on contact.
Now, an international team of researchers that make up the T2K Collaboration, including Imperial College London scientists, have found the strongest evidence yet that neutrinos and antineutrinos behave differently, and therefore may not wipe each other out.
Dr Patrick Dunne, from the Department of Physics at Imperial, said: "This result brings us closer than ever before to answering the fundamental question of why the matter in our universe exists. If confirmed -- at the moment we're over 95 per cent sure -- it will have profound implications for physics and should point the way to a better understanding of how our universe evolved."
Previously, scientists have found some differences in behaviour between matter and antimatter versions of subatomic particles called quarks, but the differences observed so far do not seem to be large enough to account for the dominance of matter in the universe.
However, T2K's new result indicates that the differences in the behaviour of neutrinos and antineutrinos appear to be quite large. Neutrinos are fundamental particles but do not interact with normal matter very strongly, such that around 50 trillion neutrinos from the Sun pass through your body every second.
Neutrinos and antineutrinos can come in three 'flavours', known as muon, electron and tau. As they travel, they can 'oscillate' -- changing into a different flavour. The fact that muon neutrinos oscillate into electron neutrinos was first discovered by the T2K experiment in 2013.
To get the new result, the team fired beams of muon neutrinos and antineutrinos from the J-PARC facility at Tokai, Japan, and detected how many electron neutrinos and antineutrinos arrived at the Super-Kamiokande detector 295km away.
They looked for differences in how the neutrinos or antineutrinos changed flavour, finding neutrinos appear to be much more likely to change than antineutrinos.
The available data also strongly discount the possibility that neutrinos and antineutrinos are as just likely as each other to change flavour. Dr Dunne said: "What our result shows is that we're more than 95 per cent sure that matter neutrinos and antineutrinos behave differently. This is big news in itself; however we do already know of other particles that have matter-antimatter differences that are too small to explain our matter-dominated universe.
"Therefore, measuring the size of the difference is what matters for determining whether neutrinos can answer this fundamental question. Our result today finds that unlike for other particles, the result in neutrinos is compatible with many of the theories explaining the origin of the universe's matter dominance."
While the result is the strongest evidence yet that neutrinos and antineutrinos behave differently, the T2K Collaboration is working to reduce any uncertainties and gather more data by upgrading the detectors and beamlines, including the new Hyper-Kamiokande detector to replace the Super-Kamiokande. A new experiment, called DUNE, is also under construction in the US. Imperial is involved in both.
Imperial researchers have been involved in the T2K Collaboration since 2004, starting with conceptual designs on whiteboards and research and development on novel particle detector components that were key to building this experiment, which was finally completed and turned on in 2010.
For the latest result, the team contributed to the statistical analysis of the results and ensuring the signal they observe is real, as well as including the effects of how neutrinos interact with matter, which is one of the largest uncertainties that go into the analysis.
Professor Yoshi Uchida said: "When we started, we knew that seeing signs of differences between neutrinos and antineutrinos in this way was something that could take decades, if they could ever be seen at all, so it is almost like a dream to have our result be celebrated on the cover of Nature this week."
Story Source:
Materials provided by Imperial College London. Original written by Hayley Dunning. Note: Content may be edited for style and length.
Related Multimedia:
Detection pattern for an electron neutrino; Inside the Super-Kamiokande detector
Journal Reference:
Abe, K., Akutsu, R., Ali, A. et al. Constraint on the matter–antimatter symmetry-violating phase in neutrino oscillations. Nature, 2020 DOI: 10.1038/s41586-020-2177-0
Is There Any Better Time Than Now For a General Strike?
Sonali Kolhatkar April 17, 2020
https://citizentruth.org/is-there-any-better-time-than-now-for-a-general-strike/
May Day offers a perfect opportunity to reshape labor relations during this pandemic.
The COVID-19 pandemic has brought into stark relief the inequalities baked into the U.S.’s capitalist system—one that deems nurses and grocery workers “essential,” but leaves them with just as few rights and privileges as they had before the crisis struck. The scenario before us, where society depends more than ever on the bottom rung of the working class, offers a perfect storm for these “essential workers” to use their leverage and demand better protections for themselves now and in the future. This perfect storm may well unfold on May 1—a day with historic roots in the U.S., marked by workers all around the world to demand their labor rights.
For those of us considered “non-essential workers,” May 1, 2020, also offers an opportunity to say a resounding “no” to President Donald Trump, who is desperate to salvage his flagging shot at reelection and demanding that people return to work at the beginning of May. Trump has made clear that his needs are more important than ours in defying health experts who agree that May 1 is far too early to return to “normal.” He has claimed “total” authority over lifting state and citywide quarantines during the pandemic. A general strike on May 1 would lay waste to his wishful thinking for totalitarianism.
Kali Akuno, the co-founder and co-director of Cooperation Jackson, laid out his organization’s call for a May Day strike this year and shared with me in an interview that, “we are calling on all workers to come as one, in particular the essential workers to strike for their lives.” He explained that, “If Trump is calling for businesses to return to normal, if that is allowed to proceed without the personal protective gear being in place for every single one of our essential workers, we’re just going to create a calamity and keep this crisis going further.”
Akuno also sees the pandemic as a turning point where workers can send a message of refusing to “go back to business-as-usual”—the status quo where a massive underclass of working people are living paycheck-to-paycheck without adequate health care, paid leave, childcare for their dependents, or decent wages is no longer acceptable. “It was business-as-usual that allowed this to roll out in the way that it has,” he said.
Workers deemed “essential” have been forced to work in order to keep their jobs but offered little recompense or even protection from the virus. A supermarket worker at Tem’s Food Market in Macon, Mississippi, found my personal mask-making project on social media and begged me to make 20 masks for her colleagues and her. In the early days of the crisis, not only were grocery workers like her not provided with protective gear, but many were also stunningly not allowed to wear their own safety equipment such as masks and gloves. My own cousin, a grocery store manager in Boston, Massachusetts, responded to my worried queries about his health and safety saying that upper management was not permitting him and others to wear masks at work until recently. This was corroborated by supermarket analyst Phil Lempert who told the Washington Post, “One of the biggest mistakes supermarkets made early on was not allowing employees to wear masks and gloves the way they wanted to.”
It is no wonder that the workers we rely on to feed and care for us are falling ill from the virus and dying. Thousands of grocery workers have already tested positive for COVID-19 and as of mid-April more than 40 have died. Although such “essential workers” are naturally terrified of catching the virus in their workplace, their vulnerable socioeconomic status also means they cannot afford to quit. The pressure to conform and fall in line with the demands of corporate America are all too real as workers face a choice between accepting their oppression or being fired. More than 16 million Americans have already lost their jobs, and beyond a $1,200 payout from the federal government and hard-to-access unemployment benefits, there is little else to compensate them.
Still, in the face of such an untenable situation, workers are already agitating for their rights with walkouts and protests. The New York Times’ labor writer Steven Greenhouse explained that, “Fearing retaliation, American workers are generally far more reluctant to stick their necks out and protest working conditions than are workers in other industrial countries.” However, now, “with greater fear of the disease than of their bosses, workers have set off a burst of walkouts, sickouts and wildcat strikes.” Whole Foods workers had planned an action for May Day but moved up their “sick out” to March 31 to demand better conditions and pay. Amazon workers at a warehouse in Staten Island, New York, organized a walkout, but the world’s largest retail giant simply fired the organizer. The person ultimately responsible for overseeing workers at Whole Foods and Amazon is Jeff Bezos, the world’s richest man who personally racked up an extra $24 billion this year alone largely as a result of the pandemic. Bezos’s wealth and power, when contrasted with the harsh conditions under which his employees work, are an appropriate symbol for a general strike on May Day as the best chance for workers to demand their rights.
On its website, Akuno’s organization Cooperation Jackson spells out the demands it is making for May Day in encouraging workers to not show up for their jobs, and for all Americans to collectively refuse to shop for a day. These include not only short-term demands for personal protective equipment for all essential workers, but also long-term demands for a Universal Basic Income, health care for all, housing rights, and a Green New Deal.
Americans are perhaps more receptive to the idea of a general strike than they have been in a century. Alongside the hashtag #NotDying4WallStreet are calls on social media for a #GeneralStrike2020. High-profile left thinkers like Naomi Klein have already embraced the idea of a general strike. But Akuno admits that a strike will not work if only small numbers of Americans participate, saying, “we need to reach people in the hundreds of millions,” and “we have to organize in such a way where we change the fundamental dynamics of labor, how it’s valued, how it’s treated.” In other words, there is the potential for transformative change in this crisis—but only if we can seize the moment.
Friday, April 17, 2020
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