Monday, April 30, 2007

Varadhan credits Indian education for success

``The winner of this year's Abel Prize in Mathematics, Indian American Professor Srinivasa S.R. Varadhan has said that his education in India provided him with the necessary foundation for success.''

For the entire story see this link.

Darwin and Pigeons ?

Continuing on the line of relieving you of heaviosity on this blog, here is a funny story on Darwin. It brings to mind one's own trials and tribulations with referees and editors. But should I be ashamed to speak of myself in the same breath as Darwin? Maybe I should. Any here goes: I now include an excerpt following the advice of Rahul Siddarthan and append an excerpt below and provide a link for the complete story

``The father of evolutionary theory, Charles Darwin, might have ended up being better known for his work on pigeon fancying if it was not for his publisher ignoring the advice of others.''

The link to the story is here.

Wednesday, April 25, 2007

Earth-like plant discovered

Here is a link for one of the interesting science stories on the discovery of earth-like planet. The story is reproduced below without permission, of course!

Scientists find most Earth-like planet yet
POSTED: 1335 GMT (2135 HKT), April 25, 2007

WASHINGTON (AP) -- European astronomers have found the most Earth-like planet outside our solar system, and here's what it might be like to live there:

The "sun" wouldn't burn brightly. It would hang close, large and red in the sky, glowing faintly like a charcoal ember. And it probably would never set if you lived on the sunny side of the planet.

You could have a birthday party every 13 days because that's how fast this new planet circles its sun-like star. But watch the cake -- you'd weigh a whole lot more than you do on Earth.

You might be able to keep your current wardrobe. The temperature in this alien setting will likely be a lot like Earth's -- not too hot, not too cold.

And that "just right" temperature is one key reason astronomers think this planet could conceivably house life outside our solar system. It's also as close to Earth-sized as telescopes have ever spotted. Both elements make it the first potentially habitable planet besides Earth or Mars.

Astronomers who announced the discovery of the new planet Tuesday say this puts them closer to answering the cosmic question: Are we alone?

"It's a significant step on the way to finding possible life in the universe," said University of Geneva astronomer Michel Mayor, one of 11 European scientists on the team that found the new body. "It's a nice discovery. We still have a lot of questions."

There's still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is learned about it. But as galaxies go, it's practically a neighbor. At only 120 trillion miles away, the red dwarf star that this planet circles is one of the 100 closest to Earth.

The results of the discovery have not been published but have been submitted to the journal Astronomy and Astrophysics.

Alan Boss, who works at the Carnegie Institution of Washington where a U.S. team of astronomers competed in the hunt for an Earth-like planet, called it "a major milestone in this business."

The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wavelengths. Those wobbles can reveal the existence of other worlds.

What they revealed is a planet circling the red dwarf star, Gliese 581. Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun. Until a few years ago, astronomers didn't consider these stars as possible hosts of planets that might sustain life.

The discovery of the new planet, named 581 c, is sure to fuel studies of planets circling similar dim stars. About 80 percent of the stars near Earth are red dwarfs.

The new planet is about five times heavier than Earth, and gravity there would be 1.6 times as strong as Earth's. Its discoverers aren't certain if it is rocky like Earth or if its a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 11/2 times bigger than our planet. If it is an iceball, as Mayor suggests, it would be even bigger.

Based on theory, 581 c should have an atmosphere, but what's in that atmosphere is still a mystery and if it's too thick that could make the planet's surface temperature too hot, Mayor said.

However, the research team believes the average temperature to be somewhere between 32 and 104 degrees and that set off celebrations among astronomers.

Until now, all 220 planets astronomers have found outside our solar system have had the "Goldilocks problem." They've been too hot, too cold or just plain too big and gaseous, like uninhabitable Jupiter.

The new planet seems just right -- or at least that's what scientists think.

"This could be very important," said NASA astrobiology expert Chris McKay, who was not part of the discovery team. "It doesn't mean there is life, but it means it's an Earth-like planet in terms of potential habitability."

Eventually astronomers will rack up discoveries of dozens, maybe even hundreds of planets considered habitable, the astronomers said. But this one -- simply called "c" by its discoverers when they talk among themselves -- will go down in cosmic history as No. 1.

Besides having the right temperature, the new planet is probably full of liquid water, hypothesizes Stephane Udry, the discovery team's lead author and another Geneva astronomer. But that is based on theory about how planets form, not on any evidence, he said.

"Liquid water is critical to life as we know it," co-author Xavier Delfosse of Grenoble University in France, said in a statement. "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."

Other astronomers cautioned it's too early to tell whether there is water.

"You need more work to say it's got water or it doesn't have water," said retired NASA astronomer Steve Maran, press officer for the American Astronomical Society. "You wouldn't send a crew there assuming that when you get there, they'll have enough water to get back."

The new planet's star system is a mere 20.5 light years away, making Gliese 581 one of the 100 closest stars to Earth. It's so dim, you can't see it without a telescope, but it's somewhere in the constellation Libra, which is low in the southeastern sky during the mid-evening in the Northern Hemisphere.

Even so, Maran noted, "We don't know how to get to those places in a human lifetime."

But, oh, the view, if you could. The planet is 14 times closer to the star it orbits. Udry figures the red dwarf star would hang in the sky at a size 20 times larger than our moon. And it's likely, but still not known, that the planet doesn't rotate, so one side would always be sunlit and the other dark.

Two teams of astronomers, one in Europe and one in the United States, have been racing to be the first to find a planet like 581 c outside the solar system.

The European team looked at 100 different stars using a tool called HARPS (High Accuracy Radial Velocity for Planetary Searcher) to find this one planet, said Xavier Bonfils of the Lisbon Observatory, one of the co-discoverers.

Much of the effort to find Earth-like planets has focused on stars like our sun with the challenge being to find a planet the right distance from the star it orbits. About 90 percent of the time, the European telescope focused its search more on sun-like stars, Udry said.

A few weeks before the European discovery earlier this month, a scientific paper in the journal Astrobiology theorized a few days that red dwarf stars were good candidates.

"Now we have the possibility to find many more," Bonfils said.

Black Hole Cluster...

Here is the link for the story on the black hole cluster.. The link was sent to me by my brother-in-law Pratyush. The story reads as follows:

Astronomers have spotted a giant cloud of superheated gas 6 million light years wide that might be generated by a cluster of supermassive black holes.

The plasma cloud, detailed in April 10 issue of Astrophysical Journal, might be the source of mysterious cosmic rays that permeate our universe.

"One of the most exciting aspects of the discovery is the new questions it poses," said study leader Philipp Kronberg of Los Alamos National Laboratories in New Mexico. "For example, what kind of mechanism could create a cloud of such enormous dimensions that does not coincide with any single galaxy or galaxy cluster? Is that same mechanism connected to the mysterious source of ultra high energy cosmic rays that come from beyond our galaxy?"

The plasma cloud is located about 300 million light years away and is spread across a vast region of space known to contain several galaxies with supermassive black holes, or active galactic nuclei (AGN), embedded at their centers. The cloud might be evidence that AGNs convert and transfer their enormous gravitational prowess, by a yet-unknown process, into magnetic fields and cosmic rays that spread across the universe.

The new finding could also help explain the unwanted and confusing "noise" scientists observe in the Cosmic Microwave Background (CMB), Kronberg said. The CMB is a ubiquitous radiation in the universe that is said to be a remnant of the Big Bang.

The plasma cloud was discovered using the Arecibo radio telescope in Puerto Rico and the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia.

Need for new agenda (The forgotten poor: Part II)

Here is the link for part 2 of the article on the forgotten poor. The article is also given below for your reading convenience.

Need for new agenda
By K N Hari Kumar
The final test for all development programmes would be to see how far they help the poor and the oppressed.

The real challenge before the media is how to attract the readers’/viewers’ attention to the small-scale, patient, unspectacular, not always wholly successful constructive work being done by ordinary individuals and organisations, like co-operatives, unions, parties, non-governmental organisations (NGOs), at the grassroots, but which may not instantly thrill the readers/viewers into paroxysms of excitement and amazement. Finally and perhaps most difficult in the current climate, they will have to reaffirm the relevance of Indian languages for communication at the grassroots and in bridging the ever-widening gulf between the haves and the have-nots, the powerful and the powerless within our society.

What is being suggested by the above analysis is that development journalists and activists need to go beyond the local, micro perspectives and address the larger, macro issues — political, economic, social — which impact the lives of all of us. They should resist the attempts of the private sector-oriented reformers to confine their development activities and role as relevant only to give small palliatives to the poor while the policy — and decision makers at the national and international levels address the larger economic and other issues facing the community of nations in an increasingly globalised world. They should question whether the model of economic development based on replicating the nature of the economies of the advanced western nations is appropriate for the very different society that we are today. More pertinently, they should dare to ask whether even those advanced societies have in fact achieved or are moving towards the desirable goals of poverty elimination, care for the sick, weak, disabled and old, empowerment of the common people, protection of the environment, sustainable development, social justice and a just world order, that they are preaching so insistently and loudly.

And, most importantly, to be effective, development journalists and activists have to pose an alternative. A workable, viable alternative to a society based on competition (as opposed to co-operation), greed and exploitation and disenfranchisement of the working people. Combining in equal measure micro and macro perspectives, they have to explore different social arrangements which can reflect their commitment to the common welfare. In seeking ways to transform society however, they cannot eschew the political.

Living in an interdependent world, they have to go beyond the nation-state and address and act with a global perspective and on global issues. They have to examine the nature of the society in which they live both nationally and globally, the nature of government policies and who benefits from them, the social forces which determine the vision of the policymakers and the decisions and actions of those in power. Without such a vision and analysis, and programmes and actions based on them, they will be restricted to the local and the grassroots and their transformative potential will be neutralised and defused.

In the context of today’s India, the additional task is to wean away the national agenda from empty grandiosity, megalomania and militarism. There was doubtless a certain ambition — political, economic and technological — in Jawaharlal Nehru’s vision, which could even be judged as excessive and, consequently, leading to failure, a loss of confidence and a sense of deflation. One consequence of this failure may have been the current compensatory vision and programme, which can be seen as a corruption of the original dream. But Nehru’s vision was always based firmly on deeply held values of humanism, social justice and self-respect. It was that of a proudly Independent India, subservient to and dependent upon none, but developing its own technology, industry and economy as far as possible by itself, and contributing as an equal in a community of equals to world peace on the basis of its moral influence. It was also based on an uncompromising refusal to accept the double standards and continuing injustice sought to be imposed in international affairs by the rich and powerful nations on those whom they have exploited and impoverished.

If the 21st century is to be India’s, it will have to be by virtue of our commitment to social justice within and between nations. Our nation will not be satisfied by accepting a subservient position of serving the interests of (rather than competing against) the companies of the developed economies like our much vaunted IT and IT-enabled service companies are doing today. Nor would it seek a “great power” label by becoming a willing tool of the great powers in our region of the globe. Rather, it would champion the cause of the underdeveloped nations globally based on their solidarity and common interests through the Non-Aligned Movement and other international groupings of those nations.

Through those associations, it will work towards sustainable economic development based on the real needs of the peoples of the world and a just economic order. Its commitment to world peace and disarmament will not be based on insincere rhetoric and time-bound plans, but shown by its deeds. It will lead by example, not military might. In spite of the derision and suspicion of motives that this gives rise to (“are you planning to enter politics?”), it is entirely appropriate that the final words should be those of the deified, but ignored father of the nation, Mahatma Gandhi. The yardstick proposed by him to measure and judge policies and actions by asking whether they will be helpful to the poorest, weakest and most oppressed, is more relevant than ever to the tasks on hand. And so is his very different kind of ambition “to wipe every tear from every eye”.


Virgin births in Komodo dragons

Lest you think everything in this blog is mind-boggling, heavy and/or too depressing for words, here is something for a change. I am doing this from outlook explorer because I am unable to get into blogger2 from my usual mozilla. In any case, the full story with pictures may be found here.. The text of the article reads:

CHESTER, England - Scientists unveiled five squirmy black and yellow Komodo dragons Wednesday that were the product of a virgin birth, predicting that the hatchlings offered hope for breeding the endangered species.

Flora, the Komodo dragon, has produced five hatchlings although a male has never been close to her, the proud staff at the Chester Zoo said.

“Flora is oblivious to the excitement she has caused, but we are delighted to say she is now a mum and dad,” said a delighted Kevin Buley, the zoo’s curator of lower vertebrates and invertebrates.

The shells began cracking last week, after an eight-month gestation period, which culminated with arrival on Tuesday of the fifth dragon. Two more eggs remained to be hatched.

“The implications for conservation breeding programs are enormous because this opens up a new way that animals can potentially colonize an island,” Buley said. “A female could swim to a new island, lay a clutch of eggs, then mate with sons and be sexually producing normally within a generation.”

The dragons range from 16 inches to nearly 18 inches long (40 to 45 centimeters) and weigh between 3½ and 4½ ounces (100 to 125 grams), Buley said.

Eating crickets and locusts

The hatchlings were in good health and feeding on a diet of crickets and locusts.

When fully grown to 10 feet (3 meters) long and weighing about 300 pounds (135 kilograms), they’ll be capable of eating a whole pig or deer at one sitting, hooves and all.

That ravenous appetite explains why Flora isn’t allowed anywhere near her offspring.

“No maternal instincts exist in Komodos so it is perfectly natural to keep them as far apart as possible,” Buley said. “She would try to eat anything that comes in front of her.”

About 70 reptile species including snakes and lizards are known to reproduce asexually in a process known as parthenogenesis. But Flora’s virginal conception, and that of another Komodo dragon in April at the London Zoo, are the first documented in Komodo dragons.
The two virgin conceptions were announced in September in a scientific paper in the journal Nature.

Endangered lizardsKomodos are native to the arid volcanic Lesser Sunda Islands in Indonesia, and are named for the island where they were discovered in 1910.
The giant lizards are considered endangered, with fewer than 4,000 surviving in the wild and facing encroachment from humans.

Why Virginia Tech shootings happened - A statement from the IAC

I am attaching below this remarkable text from a message forwarded to me by my sister Padma. Needless to say, it is not that I particularly endorse the views here as I am not an expert on the subject of USA or what goes on there. However, this article here is very persuasive. Here is the article:

A Statement from the International Action Center
Why Virginia Tech shootings happened

Yet another rampage has occurred at a school, this time leaving 33 people dead at Virginia Tech-the worst such incident ever at a U.S. college campus.

The news media seem stunned and surprised, yet their coverage sounds so similar to the stories about Columbine eight years ago. They dwell on the personality of the young man the police say did the shooting, before killing himself. They talk about him being a "loner," depressed, perhaps angry at women.

But aren't there lonely and depressed people all over the world? Many countries have high suicide rates. Why is it that here some become mass murderers?

The U.S. is the world leader in seemingly random acts of violence by individuals. Why?

President George W. Bush rushed to Virginia to speak at a large convocation the day after the killings and tried to set the tone for what could be said about them. "It's impossible to make sense of such violence and suffering," he said.

Don't ask why, don't try to understand. It makes no sense. "Have faith" instead, was Bush's message.

But there ARE reasons these things happen here, and they are pretty clear to the rest of the world. It's just in the United States that no one is supposed to talk about the reasons.

What distinguishes this country from the rest of the world? It is neither the most affluent nor the poorest. It is neither the most secular nor the most religious. It is not the most culturally homogeneous nor is it the most diverse.

But in one area, it stands virtually alone. It has the biggest arsenal of high-tech weaponry in the world, way surpassing every other country. It has military bases spread all over; most countries have no troops outside their borders.

It is conducting two hot wars at the moment, in Iraq and Afghanistan, and has sent hundreds of thousands of troops abroad over the last few years. Every day, the public here is supposed to identify with soldiers who burst into homes in Baghdad, round up the people and take them away for "interrogation"-which everyone knows now can mean torture and indefinite detainment.

It also sends heavily armed "special ops" on secret missions to countless other countries, like the ones who just facilitated the invasion and bombing of Somalia, or the ones who have been trying to stir up opposition in Iran. This is documented in the news media.

The immense brutality of these colonial wars, as well as earlier ones, is praised from the White House on down as the best, the ONLY way to achieve what the political leaders and their influential, rich backers decide is necessary to protect their world empire. Do lots of people get killed? "Stuff happens," said former war secretary Donald Rumsfeld. "Collateral damage," says the Pentagon.

At home, the U.S. has the highest rate of incarceration in the world. Over 2 million people are locked up in the prison system each year, most of them people of color. When commercial armed security guards are also taken into consideration, the U.S. has millions of employees who use guns and other coercive paraphernalia in their jobs.

In the final analysis, the military and the police exist to perpetuate and protect this present unjust system of capitalist inequality, where a few can claim personal ownership over a vast economy built by the sweat and blood of hundreds of millions of workers.

And the more divided, the more polarized the society becomes, the higher the level of coercion and violence. Assault weapons are now everywhere in this society, as are Tasers, handcuffs, clubs and tear gas. They most often start out in the hands of the police, the military and other agents of the state, and can then turn up anywhere.

Violence is a big money maker in the mass culture. Television, films, pulp novels, Internet sites, video games-all dwell on "sociopaths" while glorifying the state's use of violence, often supplemented by a lone vigilante. By the time children reach their teens, they have already seen thousands of murders and killings on television. And these days even more suspense is added in countless programs that involve stalking and terror against women-and increasingly children.

As the Duke rape case and so many "escort service" ads show, women of color are particularly subject to exploitation and have little recourse to any justice. And as the murders along the border show, immigrants of color are fair game for racist killers.

The social soil of capitalism can alienate and enrage an unstable and miserable person who should be getting help but can't find it. If, as reports are saying, the young man accused of these killings was on anti-depressant medication, it is all the more evidence that, at a time when hospitals are closing and health care is unavailable for tens of millions, treating mental health problems requires more from society than just prescribing dubious chemicals.

Many liberal commentators are taking this occasion to renew the demand for tougher gun laws. Yes, assault weapons are horrible, but so are bunker buster bombs, helicopters that fire thousands of rounds a minute, and the ultimate-nuclear weapons. Disarming the people is not the answer, especially when the government is armed to the teeth and uses brutality and coercion daily.

The best antidote to these tragedies is to build a movement for profound social change, a movement directed at solving the great problems depressing so much of humanity today, whether they be wars or global climate change or the loneliness of the dog-eat-dog society.

International Action Center- 55 West 17th St, 5C, New York, NY 10011

* Contact us -
* Donate to help with organizing -
* Become an IAC intern -


'Execution by lethal injection ... has the same relationship to medicine that an executioner's axe has to surgery.'

found in an article on the impossibility of execution in a human manner. For more details see this article.

The forgotten poor - Part I

Anita drew my attention to an article that I had briefly noted in the Deccan Herald of April 23, 2007, which can be found here. It is good enough to be reproduced here, without permission, of course.

The forgotten poor

By K N Hari Kumar

The mass media has in recent years rarely focused on the problems and plight of the poor in India.

The need for development journalism, or journalism from the perspective of improving the living conditions of the poor, has acquired fresh urgency in recent years. For, in our country today the poor have been largely forgotten, ignored, sidelined and marginalised in the national reform agenda of liberalisation and globalisation adopted by our political leadership. Except when the latter have been hit where it hurts — as in the last general elections when it was perceived that the votes of the poor had led to the defeat of the ruling coalition in the Centre. But this challenge, by those who have got little, if any, of the much-touted benefits from the decade-and-a-half-old reform programme, has not been of such a nature as to lead to a radical transformation of the policies and actions of the government, or even those of most of the politicians and parties in the opposition. Besides a few gestures, including some handouts and much lip service, the basic programme of the nation remains unchanged. Hence, the interminable discussion day in and day out in the public sphere about the rates of growth (of Gross Domestic Product, industry, IT exports mostly) aimed at and achieved and strategies to increase, ignoring the alternative human development index which was developed to measure diverse aspects of the quality of life of the common people.

It is in this context that the mantra 2020, the avowed goal of which is to transform us into a developed nation by that year, should be seen. That objective is sought to be achieved by a variety of methods and strategies. Among these are, first, providing huge monetary incentives to the rich and super rich largely in the urban areas as an incentive to greater entrepreneurial initiative. Second, providing massive support to develop Indian multi-national companies (MNCs) in modern industry and services largely in the private sector, while neglecting agriculture and those sectors serving the poor and the rural areas. Third, motivating the young to become greedy entrepreneurs with a get-very-rich-quickly at-any-cost and by-any-method ambition and drive. Fourth, focusing almost exclusively on English even for the masses and in the rural areas as a passport to great global professional and business success to the neglect of Indian languages. Fifth, encouraging the citizenry to mimic the consumerist and ostentatious lifestyles of the advanced western societies. And, finally and rather incredibly, attempting to get advanced nuclear and other largely military technologies from the United States in particular, by toeing its line on major foreign policy issues, to the detriment of the nation’s longstanding commitment to an independent, non-aligned foreign policy.

The ultimate goal of all this is said to be to transform our nation into a global economic, political and military superpower. By thinking and acting big, even gigantic, it is said, we can become big and great. And eventually we can join the club of the rich and the powerful and sit at their table and discuss issues and influence decisions affecting the destiny of nations and all of mankind. All this is sought to be encapsulated in the much-proclaimed slogan — the 21st century will be India’s. To what end is not clear. It could be surmised that the protagonists of such fantastic ambitions are the urban propertied and professional elite, whose income and wealth the reform programme has increased vastly, as well as those who really feel that by their getting to sit around the table in the rich man’s club they may actually be doing something worthwhile.

Following this lead, the mass media also has in recent years rarely, if at all focused on the problems and plight of the poor and the damage to their means of livelihood and the environment under the new policy regime. Nor has it deliberated on the need for initiatives and programmes to improve their condition and enable them to take control of their lives. Rather, reflecting perhaps its ownership and readership which has largely been the educated and propertied elite, it has only been expending large amounts of energy in enthusiastically exaggerating stories of great business successes in the domestic arena. It has been even more enthusiastic in devoting vast amounts of paper, words and pictures to hype the real and putative success stories of Indians, living in India and abroad, even those with foreign passports, in professional and entrepreneurial roles and in R and D, in the advanced western nations, especially in the US. These men and women, including sportspersons who have achieved greater and lesser international success, are the heroes of the new reform agenda and the values, ideology and perspective on which it is based. They are seen to have, almost miraculously, succeeded where their compatriots back home have tried and failed. They are being sought to be promoted as models to inspire the nation, especially its youth, to greater ambition and endeavour. Their successes are seen to give confidence to a nation that has lost faith in itself. They are evidence for our belief that we as a nation can, indeed, do it.

In trying to swim against what has lately become the mainstream of Indian opinion and policy, and focus attention on the plight of the poor, powerless and oppressed — their needs and hopes, their troubles and obstacles, their frustrations and demands, development journalists face an uphill task. For, it is not enough to divert readers/viewers away from juicy stories glorifying the successes of Indian and Indian-origin buccaneers in the national and global arena and celebrating their vulgar and gross conspicuous consumption and ostentatious lifestyles. (Amazingly, the national public outrage led by the media at the extravagantly ostentatious wedding celebration in Mumbai of a fabulously rich diamond merchant family from Antwerp just two decades ago has completely faded from memory). It also has to contend with the cheap titillation and voyeurism of the stories, photos and videos of the rich, famous and successful of diverse varieties, but especially youthful and nubile models and film stars, that have now become the staple of the media.

( The above essay was published in the second edition of Samparka Sethu, the Karnataka Directory of Development Writers. The writer thanks the publishers, Communication for Development and Learning for allowing its republication)

(To be concluded)

Tuesday, April 24, 2007

My article on meson scattering

I wrote an article on low energy meson scattering at high precision. It is posted on the arxiv with an abstract that reads:

A fascinating new generation of experiments has determined certain meson scattering parameters at high precision. A confluence of highly sophisticated theory as well as new experimental ideas have led to this state of affairs, which sheds important light on the properties of the strong interactions. A brief review of the experiments and the theory is presented.

It has been published in Current science and here is the the link.

Neutral-pion lifetime

Just as I thought that I had blogged enough, came this news about the neutral pion lifetime. The central value translates to a width of 7.83 eV. In my paper with Bachir Moussallam, we gave a central value of 8.06 eV. I am waiting to hear from him in this regard. In any case here is the entire story from this web-site:

The Lifetime of the Chargeless Pion

The lifetime of the chargeless pion, the lightest particle made of quark-antiquark pairs, has been determined to higher levels of precision in a new experiment at Jefferson Laboratory in Virginia. According to experimentalist Liping Gan (Univ of North Carolina-Wilmington), speaking at the APS meeting, the neutral pion lifetime is one of the few quantities that can be directly calculated (to about 1% precision) in quantum chromodynamics (QCD), the theory of the strong force, which holds together quarks and quark-containing objects.

In Jefferson Lab’s Primakoff Experiment, the researchers aim a gamma-ray beam at nuclei, which perpetually has a cloud of photons around it. Through a phenomenon known as the Primakoff effect, two photons (one from the target nucleus and another from the photon beam) interact and make a chargeless pion, which decays into two daughter photons.

Measuring the daughter photons reconstructs the details of the decay and provides lifetime information about the pions. The new experiment is more precise than past Primakoff effect experiments because the incident photons (produced from the deceleration of Jlab’s electron beam) are "tagged," meaning that the researchers can keep track of the numbers of incoming photons hitting the nuclear targets, as well as their energies.

When the photons emerge from the decay, an advanced calorimeter (called HyCal) is able to measure the daughter photons' trajectories and energies to high precision. Ashot Gasparian of North Carolina A&T State University said the calculated lifetime of the pion is 82 attoseconds with about a 2.9% error [(8.20+/-0.24)x10^-17 sec].

The new, preliminary result is two times more precise than the present value published in particle data tables [8.4+/-(0.6)x10^-17s], and the precision can potentially double as researchers analyze all of their data and finalize their result.

Monday, April 23, 2007

Physics stories of the last 3 months

Here are the links to some of the great happenings in the elementary particle physics world, with a few comments in my own words.

Here is the link to the story on the mixing of neutral D mesons. This was already observed a long time ago in the K and B meson systems. Mesons are particles with one quark and anti-quark. Quarks come in 6 flavours: up, down, strange, charm, b and top, given in order of increasing mass. K mesons have strange and a light quark, D mesons have a strange and a light quark, B have a b and a light quark. The effect is highly suppressed in the D meson systems and the BELLE experiment at KEK in Japan had a huge number of D mesons that they used to find the effect.

It is the BELLE experiment which also saw quantum entanglement in B-mesons. It is reported here in this preprint. The idea of entanglement was first given by Einstein, Rosen and Podolsky. I don't know much more about this.

The other great story is the result from the MiniBoone experiment. The AIP press release is entitled ``One Neutrino Anomaly is Resolved.'' Neutrino oscillations have been established beyond doubt in the last decade, first by the Sudbury Neutrino Observatory and by the Super Kamiokande experiment in Japan. There were contradictory experimental findings from a Los Alamos Experiment which now seem to have been repudiated by the MiniBoone experiment.

Sunday, April 22, 2007

Where have I been?

To my horror I see that it is almost three months since my last post. In fact, that post was on the morning of our visit to Madras, or should I say Chennai, for tourism. The denizens of that great city were probably surprised to know that anyone could think of their home as a tourist destination, but I certainly am one of them. Although I was sick as a dog on the train journey and on the first day of our holiday, and could not visit the Parthasarathi Koil, Kapaleshwarar Koil or Radha Silks with the family, I did manage to go to the beach and the next day to IIT, Mahabalipuram and Dakshina Chitra, and on the way back home we stopped at the University campus. Much water has flowed under various bridges since then. I was in Bombay early February to give a talk at the Tata Institute to honour Shasanka Mohan Roy and l'il ole me was asked to talk about the famous Roy equations of pion scattering. There were two other speakers, Virendra Singh, former director of TIFR who talked about their long collaboration stretching over decades and Anil Gangal who talked about the man. If you think I have not been doing anything, try again. I wrote an article on high precision meson scattering for Current Science which has now appeared inspired by my preparation for this talk. I also wrote a book review on a recent volume of Annual Reviews of Nuclear and Particle Science for Current Science. I was also busy with trying to wrap up some projects, and writing manuscripts. I will soon provide links to all of these with a small precis of each of the contributions. I have also been writing for Lokrajsangathan which may be found there.

So what has happened in the great world of science? First, I read that quantum entanglement has been seen in B-meson systems. I will try and do a post on this. Then some experiments have seen mixing of neutral D mesons for the first time. D mesons contain a charm quark. Such mixing has been seen in B meson systems long ago. I will try and say something about this. Then there is the important news on the MiniBoone experiment from Fermilab which does not see the neutrino anomaly reported by the Los Alamos experiment LSND. So that is a relief. Maybe I will do a post on this as well. Then there was the news that some of the magnets at the LHC have failed. So this may set back the LHC by some time, but I hope it is not serious. Is there anything else that I missed? I saw something about clusters of supermassive black holes. Maybe I should write something about this. Then there was an article on virgin births amongs Komodo dragons. I think that is enough science for 3 months. So, do not despair and keep watching this space.