# Tag Info

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The $\Delta$ is a quartet of particles with isospin 3/2: $$\Delta^-, \Delta^0, \Delta^+, \Delta^{++}$$ I would expect the anti-$\Delta$ to be written $\bar\Delta$, with the four isospin projections $$\bar\Delta^{--}, \bar\Delta^-, \bar\Delta^0, \bar\Delta^+$$ In this case the antiparticle of the $\Delta^+$ would be the $\bar\Delta^-$. If you'd like a ...

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Our Big Bang produced only matter. 2. Big Bangs can produce either only matter or only antimatter. 3. Many universes (only two will not do) were formed. One half of them contain only matter. The other half contains only antimatter. The formation of universes will continue. It has no known beginning nor a known end.

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The trapping technology used by the ALPHA group at CERN is described in this article, and specifically the trapping of the neutral anti-hydrogen is described here. The trapping is done by an Ioffe trap - I couldn't find a simple article describing how this works, but the search I've linked finds lots of related articles that are worth reading. In brief, the ...

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Since John is not addressing positrons one should know that positrons are easily created once a photon has more energy than twice the mass of the electron, in electron positron pairs. This can be seen clearly in this bubble chamber picture: where the positron is shown in purple on the right. One knows they are electrons (positrons) because of the ...

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Creating anti-protons is straightforward in principle because any high energy collision produces a shower of protons, antiprotons and various types of pions. The pions decay in a few nanoseconds, so you just have to wait for the pions to decay then separate the antiprotons from the protons. At Fermilab a 120GeV proton beam was collided with a nickel target ...

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The following has ben found via Wikipedia page “Gravitational interaction of antimatter”. Another experimental test has been provided by the supernova SN1987a (anti)neutrinos, and this has been published in two brief reports in Phys. Rev. D in 1988 [1] and 1989 [2]. After the explosion of this supernova, 19 antineutrinos have been detected at IMB and ...

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According to http://en.wikipedia.org/wiki/Antihydrogen, anti hydrogen has been produced - so the answer to your question is "yes, it is real".

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As well as the antihydrogen experiments, ALPHA, AEGIS and GBAR that were mentioned in other answers, there are a couple of other experiments, though they haven't had any results. In the 60's, they tried the obvious thing of dropping positrons down a metal tube (paper), but it didn't work, for the subtle reason that the electrons in the metal sag under ...

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There experiment which has measured the most stringent limit on neutron to anti-neutron oscillations (i.e. produce neutrons, let them fly for some time and then look if you find anti-neutrons) has used a 130 micrometer thick and 110 cm diameter carbon foil. This target had a probability greater than 99% for anti-neutrons to interact (and thus produce ...

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Detectors at particle colliders are layered like onions around the collision vertex. The CMS detector at CERN First there are charged particle sensitive detectors where charged particles leave tracks because of ionisation, but mass density is low so strong interactions do not happen often; their momentum can be measured by the curvature in the ...

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The only experiment I know of was done by the ALPHA team at CERN. The results are published in this paper. The error bounds are huge - all the team were able to say is that the upper limit for the gravitational mass of antihydrogen is no greater than 75 times its inertial mass! However I believe an updated version of the experiment, ALPHA2, is in progress ...

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In some normal matter there is the phenomenon of positron decay. That is, an unstable atom decays by the emission of an anti-electron. Presumably there is a mirror form of this where antimatter decays by electron emission.

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All of our observations in particle physics have led to the so called standard model of physics. The particles in the table are characterized with several quantum numbers, spin, lepton number, baryon number, charge and a mass This states that all particles of matter are made out of a basic number of elementary particles, with very specific rules ...

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I (a non particle physicist) believe the answer is no. The interaction has to conserve all quantum numbers, which are opposite between particles and their antiparticles. Thus, for example, anti-Silicon has 14 anti-protons, thus an electric charge of $-14\,e$ and carbon has $+6\,e$. It's the nucleusses that interact in any collision, so the nucleusses ...

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Antihelium has been observed: http://www.theguardian.com/science/2011/apr/24/antihelium-antimatter-brookhaven (sounds like just the nucleus, not a neutral atom). The AEgIS experiment http://aegis.web.cern.ch/aegis/research.html plans to make neutral antihydrogen atoms and measure their gravitational acceleration. Also, when an anti-hydrogen comes into ...

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Clumps of just anti-matter will have the same gravity field around them as clumps of matter. There was an experiment at either Fermilab or SLAC in the 1970s or early 1980s where the falling of a beam of anti-protons was measured. I was trying to look up details on this a couple years ago, and didn't find it. But I know I read about it long ago. Bottom ...

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So what about antimatter - since charges are opposite, perhaps it also clumps together to form anti-gravity superpositions. As Red Act says in a comment, gravity is too weak to be important on the scale of individual particles. However charge does group antiparticles together. For example an anti-proton and a positron will form an antihydrogen atom. In ...

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You clearly do a great deal of thinking with some lay understanding of physics. Yours is an intriguing idea, and I like the way you think. Since you don't give any info on your profile, so I'm going to guess you're at freshman level or have read many lay physics articles (perhaps like those in New Scientist) You seem to be describing an oscillation between ...

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