Friday, August 22, 2014

[1408.4805] Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

[1408.4805] Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC:



 "The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on 4.9×1010 events recorded between June 2013 and February 2014 shows anisotropy at the 10−4 level on angular scales of about 10∘. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to ℓ=15 contribute significantly to the excesses."



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Russia Moves Artillery Units Into Ukraine, NATO Says - NYTimes.com

Russia Moves Artillery Units Into Ukraine, NATO Says - NYTimes.com:



 "WASHINGTON — The Russian military has moved artillery units manned by Russian personnel inside Ukrainian territory in recent days and is using them to fire at Ukrainian forces, NATO officials said on Friday."



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Air strikes? Talk of God? Barack Obama is following the jihadists’ script after James Foley beheading

Robert Fisk:

The “caliphate” has some pretty tough theatrical producers. They write a bleak and savage script. Our job is now to respond to each line, and they understand us well enough to know just what we’ll say. So they beheaded James Foley and threatened to do the same to one of his colleagues, and what do we do? Exactly what I predicted 24 hours ago: turn Foley’s murder into a further reason to go on bombing the Isis “caliphate”. And what else did they provoke from us – or at least from America’s vacationing President? A battle on strictly religious terms, which is exactly what they wanted.

Yes, Barack Obama – before he headed back to the golf links – informed the world that “No just God would stand for what they [Isis] did yesterday, and for what they do every single day.” So there you have it: Obama turned the “caliphate’s” savagery into an inter-religious battle of rival Gods, “ours” [ie the West’s] against “theirs” [the Muslim God, of course]. This was the nearest Obama has yet come in rivalling George W Bush’s gormless reaction to 9/11 in which he said that “we” are going to go on a “Crusade”.

Now of course, Obama didn’t mean the Muslim God, any more than Bush intended to send thousands of horse-mounted Christian warriors to the Biblical lands of the Middle East: indeed, Bush only sent tank-mounted and helicopter-borne warriors to those lands. No, Obama was also announcing that the “caliphate’s” victims are “overwhelmingly Muslim” – ie that the “Caliphate” wasn’t Muslim at all – although his enthusiasm to intervene earlier this month was not caused by his sympathy for these thousands of poor Muslims, but by the persecution of Christians and Yazidis. And of course the danger to potential American victims – a fact which Abu Bakr al-Baghdadi’s men understood all too well.

That’s why they slaughtered poor James Foley. Not because he was a journalist , but because he was an American, indeed one of the Americans Obama was promising to defend in Iraq. Whether or not Obama forgot about US hostages in Syria – the US military’s attempt to rescue them at least proved they knew Foley was in Syria. But why is Isis in Syria? To overthrow the Assad regime, of course, which is what we too are trying to do, is it not?

What on earth made Obama believe he could tell Muslims about what a “just God” would or would not do? For a President who regrets the Bush war in Iraq, does he not realise that millions of Muslims in Iraq believe that “no just God” would stand for the American invasion of Iraq in 2003, nor for the tens of thousands of Iraqis massacred because of the lies of Bush and Blair? I was amazed to hear Obama announce that “one thing we [sic] can all agree on” was that “a group like Isil has no place in the 21st century”.

This is the same claptrap which that old scallywag Bill Clinton used when he addressed the Jordanian parliament after King Hussein’s unpopular peace treaty with Israel: that those Muslim groups who opposed it were “yesterday’s men”. For some reason, we really think that the Muslims of the Middle East need us to tell them their history, what is good for them, what is bad for them. Muslims who agreed that Foley’s murder was a revolting crime against humanity will have been insulted by being told by a Christian what a “just God” would approve or disapprove of. And those who supported such a crime will have been further convinced that America was a justified enemy of all Muslims.

As for the sinister British executioner “John”, I rather think he may have lived in Newcastle-upon-Tyne or Gateshead, because – having spent time on Tyneside – I thought he seemed to have just a hint of the Geordie accent. But “John” could have been French or Russian or Spanish. It’s not what went wrong in his mind, but what phenomena have afflicted so many other young men, in their thousands to do the same. How, for example, did an Australian apparently allow his young son to pose with the head of a decapitated Syrian soldier (a soldier serving, of course, in the army of the Assad regime we have all sworn to overthrow)?

And how have our security “services” responded to this? With the usual nonsense about how merely looking at such gruesome execution videotapes may be a terrorist crime. What is this tosh? Personally, I find it equally offensive to film – and show on television – the mass killing of human beings by US aircraft. But we do show them, don’t we? We are repeatedly invited to observe on our television screens the targeting of supposed Isis fighters and imagine their fate in the bubble of fire that consumes their pick-up trucks. Because we can’t see their faces doesn’t make this any less obscene. Of course, their activities are the opposite of what James Foley stood for. But were they all actually fighters? We haven’t yet heard that outrageous linguistic curse “collateral damage”, but I bet we will.

So are our security bosses going to make the viewing of US military target videos a terrorist crime? I doubt it – unless, of course, the film shows us massacring lots of civilians. Then they could claim – rightly – that such viewing might encourage “terrorism”. And we’d all have to give up covering the war.

Thursday, August 21, 2014

Drought Said to Claim Trillions of Gallons - NYTimes.com

Drought Said to Claim Trillions of Gallons - NYTimes.com:



 "About 63 trillion gallons of groundwater have been lost across the West since the start of last year because of a severe drought, a study found. The loss is not only forcing farmers to drill deeper wells, it has caused the crust of the earth in the region to rise. A study from the Scripps Institution of Oceanography at the University of California, San Diego, found that the earth’s crust, which is normally weighed down by groundwater, had risen 0.15 inches over the last two years. The rise was most drastic in the California mountains, which have risen more than half an inch. The study was first published in the journal Science on Thursday."



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Hawks Crying Wolf - NYTimes.com

Hawks Crying Wolf - NYTimes.com:



 "According to a recent report in The Times, there is dissent at the Fed: “An increasingly vocal minority of Federal Reserve officials want the central bank to retreat more quickly” from its easy-money policies, which they warn run the risk of causing inflation. And this debate, we are told, is likely to dominate the big economic symposium currently underway in Jackson Hole, Wyo."



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Wednesday, August 20, 2014

Clashes Erupt as Liberia Imposes Quarantine to Curb Ebola - NYTimes.com

Clashes Erupt as Liberia Imposes Quarantine to Curb Ebola - NYTimes.com:



"MONROVIA, Liberia — Liberia’s halting efforts to contain the Ebola outbreak spreading across parts of West Africa quickly turned violent on Wednesday when angry young men hurled rocks and stormed barbed-wire barricades, trying to break out of a neighborhood here that had been cordoned off by the government."



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Neanderthals in Europe Died Out Thousands of Years Sooner Than Some Thought, Study Says - NYTimes.com

Neanderthals in Europe Died Out Thousands of Years Sooner Than Some Thought, Study Says - NYTimes.com:



"Neanderthals, our heavy-browed relatives, spread out across Europe and Asia about 200,000 years ago. But when did they die out, giving way to modern humans?"



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Tuberculosis Is Newer Than What Was Thought, Study Says - NYTimes.com

Tuberculosis Is Newer Than What Was Thought, Study Says - NYTimes.com:



"After a remarkable analysis of bacterial DNA from 1,000-year-old mummies, scientists have proposed a new hypothesis for how tuberculosis arose and spread around the world."



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Tuesday, August 19, 2014

It's Confirmed: Black Holes Do Come in Medium Sizes

It's Confirmed: Black Holes Do Come in Medium Sizes:



"Black holes do indeed come in three sizes: small, medium and extra large, a new study suggests."



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Middle Mass Black Holes

A 400-solar-mass black hole in the galaxy M82 : Nature : Nature Publishing Group

A 400-solar-mass black hole in the galaxy M82 : Nature : Nature Publishing Group:



 "M82 X-1, the brightest X-ray source in the galaxy M82, has been thought to be an intermediate-mass black hole (100 to 10,000 solar masses) because of its extremely high luminosity and variability characteristics1, 2, 3, 4, 5, 6, although some models suggest that its mass may be only about 20 solar masses3, 7. The previous mass estimates were based on scaling relations that use low-frequency characteristic timescales which have large intrinsic uncertainties8, 9. For stellar-mass black holes, we know that the high-frequency quasi-periodic oscillations (100–450 hertz) in the X-ray emission that occur in a 3:2 frequency ratio are stable and scale in frequency inversely with black hole mass with a reasonably small dispersion10, 11, 12, 13, 14, 15. The discovery of such stable oscillations thus potentially offers an alternative and less ambiguous means of mass determination for intermediate-mass black holes, but has hitherto not been realized. Here we report stable, twin-peak (3:2 frequency ratio) X-ray quasi-periodic oscillations from M82 X-1 at frequencies of 3.32 ± 0.06 hertz and 5.07 ± 0.06 hertz. Assuming that we can extrapolate the inverse-mass scaling that holds for stellar-mass black holes, we estimate the black hole mass of M82 X-1 to be 428 ± 105 solar masses. In addition, we can estimate the mass using the relativistic precession model, from which we get a value of 415 ± 63 solar masses."



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[1308.1682] Can the 62 day X-ray period of the Ultraluminous X-ray source M82 X-1 be due to a precessing accretion disk?

[1308.1682] Can the 62 day X-ray period of the Ultraluminous X-ray source M82 X-1 be due to a precessing accretion disk?:



 "We have analyzed all archival RXTE/PCA monitoring observations of the ultraluminous X-ray source (ULX) M82 X-1 in order to study the properties of its 62 day X-ray period (Kaaret & Feng 2007). Based on its high coherence it has been argued that the observed period is the orbital period of the binary. Utilizing a much longer data set than in previous studies we find: (1) The phase-resolved X-ray (3-15 keV) spectra -- modeled with a thermal accretion disk and a power-law -- suggest that the accretion disk's contribution to the total flux is strongly modulated with phase. (2) Suggestive evidence for a sudden phase shift--of approximately 0.4 in phase (25 days)-- between the first and the second halves of the light curve separated by roughly 1000 days. If confirmed, the implied timescale to change the period is ~ 10 yrs, which is exceptionally fast for an orbital phenomenon. These two independent pieces of evidence are consistent with the periodicity being due to a precessing accretion disk, similar to the super-orbital periods observed in systems like Her X-1, LMC X-4, and SS433. However, the timing evidence for a change in the period needs to be confirmed with additional observations. This should be possible with further monitoring of M82 with instruments such as the Swift X-ray telescope (XRT)."



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[1312.1228] Determination of $|V_{us}|$ from a lattice-QCD calculation of the $K\to\pi\ell\nu$ semileptonic form factor with physical quark masses

[1312.1228] Determination of $|V_{us}|$ from a lattice-QCD calculation of the $K\to\pi\ell\nu$ semileptonic form factor with physical quark masses:



 "We calculate the kaon semileptonic form factor f+(0) from lattice QCD, working, for the first time, at the physical light-quark masses. We use gauge configurations generated by the MILC collaboration with Nf=2+1+1 flavors of sea quarks, which incorporate the effects of dynamical charm quarks as well as those of up, down, and strange. We employ data at three lattice spacings to extrapolate to the continuum limit. Our result, f+(0)=0.9704(32), where the error is the total statistical plus systematic uncertainty added in quadrature, is the most precise determination to date. Combining our result with the latest experimental measurements of K semileptonic decays, one obtains the Cabibbo-Kobayashi-Maskawa matrix element |Vus|=0.22290(74)(52), where the first error is from f+(0) and the second one is from experiment. In the first-row test of Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from |Vus| is now comparable to that from |Vud|."



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[1401.6298] The Green Function for the BFKL Pomeron and the Transition to DGLAP Evolution

[1401.6298] The Green Function for the BFKL Pomeron and the Transition to DGLAP Evolution:



"We consider the (process-independent) Green function for the BFKL equation in the next-to-leading order approximation, with running coupling, and explain how, within the semi-classical approximation, it is related to Green function of the Airy equation. The unique Green function is obtained from a combination of its required ultraviolet behaviour compatible with asymptotic freedom and an infrared limit phase imposed by the non-perturbative sector of QCD. We show that at sufficiently large gluon transverse momenta the corresponding gluon density matches that of the DGLAP analysis, whereas for relatively small values of the gluon transverse momentum the gluon distribution is sensitive to the Regge poles, whose positions are determined both by the non-pertubative QCD dynamics and physics at large transverse momenta."



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Monday, August 18, 2014

A World of Creatures That Hide in the Open - NYTimes.com

A World of Creatures That Hide in the Open - NYTimes.com:



 "Sönke Johnsen scuba dives in the middle of the ocean, far from land, miles above the seafloor. There are no shipwrecks to explore, no reefs to admire, just a disorienting oasis of blue."



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Julian Assange Says He Will Leave Embassy ‘Soon’ - NYTimes.com

Julian Assange Says He Will Leave Embassy ‘Soon’ - NYTimes.com:



 "LONDON — Julian Assange, the founder of WikiLeaks, who was given asylum in the Ecuadorean Embassy here two years ago, said Monday that he “will be leaving the embassy soon,” but he provided no specifics."



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Saturday, August 16, 2014

[1401.7848] Realizing three generations of the Standard Model fermions in the type IIB matrix model

[1401.7848] Realizing three generations of the Standard Model fermions in the type IIB matrix model:



"We discuss how the Standard Model particles appear from the type IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. In particular, we are concerned with a constructive definition of the theory, in which we start with finite-N matrices and take the large-N limit afterwards. In that case, it was pointed out recently that realizing chiral fermions in the model is more difficult than it had been thought from formal arguments at N=infinity and that introduction of a matrix version of the warp factor is necessary. Based on this new insight, we show that two generations of the Standard Model fermions can be realized by considering a rather generic configuration of fuzzy S^2 and fuzzy S^2 * S^2 in the extra dimensions. We also show that three generations can be obtained by squashing one of the S^2's that appear in the configuration. Chiral fermions appear at the intersections of the fuzzy manifolds with nontrivial Yukawa couplings to the Higgs field, which can be calculated from the overlap of their wave functions."



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Friday, August 15, 2014

Four dimensional supersymmetric Yang-Mills quantum mechanics with three colors

The D=4 supersymmetric Yang-Mills quantum mechanics with SU(2) and SU(3) gauge symmetry groups is studied. A numerical method to find finite matrix representation of the Hamiltonian is presented in detail. It is used to find spectrum of the theory. In the SU(2) case there are bound states in all channels with definite total number of fermions and angular momentum. For 2,3,4 fermions continuous and discrete spectra coexist in the same range of energies. These results are confirmation of earlier studies. With SU(3) gauge group, the continuous spectrum is moved to sectors with more fermions. Supersymmetry generators are used to identify supermultiplets and determine the level of restoration of supersymmetry for a finite cutoff. For both theories, with SU(2) and SU(3) symmetry, wavefunctions are studied and different behavior of bound and scattering states is observed.

arXiv

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