CERN’s ALPHA experiment measures charge of antihydrogen

(a) A schematic of the antihydrogen production and trapping region of the ALPHA apparatus, showing the cryogenically cooled cylindrical Penning–Malmberg trap electrodes, and the mirror and octupole magnet coils. Our positron source (not shown) is towards the right, and the antiproton decelerator (not shown) is towards the left. (b) The on-axis magnetic field B as a function of z. (c) The on-axis electrostatic potentials V used to establish the Bias-Right (red dashed line) and Bias-Left (blue solid line) configurations. (d) Normalized histograms of the experimental z positions of the annihilations in the Bias-Right (red dashed line) and Bias-Left (blue solid line) configurations. The error bars show the expected deviation of the distribution based on the number of observed antiatoms in each bin.

(a) A schematic of the antihydrogen production and trapping region of the ALPHA apparatus, showing the cryogenically cooled cylindrical Penning–Malmberg trap electrodes, and the mirror and octupole magnet coils. Our positron source (not shown) is towards the right, and the antiproton decelerator (not shown) is towards the left. (b) The on-axis magnetic field B as a function of z. (c) The on-axis electrostatic potentials V used to establish the Bias-Right (red dashed line) and Bias-Left (blue solid line) configurations. (d) Normalized histograms of the experimental z positions of the annihilations in the Bias-Right (red dashed line) and Bias-Left (blue solid line) configurations. The error bars show the expected deviation of the distribution based on the number of observed antiatoms in each bin.

Geneva, 3 June 2014.
In a paper published in the journal Nature Communications today, the ALPHA experiment at CERN’s Antiproton Decelerator (AD) reports a measurement of the electric charge of antihydrogen atoms, finding it to be compatible with zero to eight decimal places. Although this result comes as no surprise, since hydrogen atoms are electrically neutral, it is the first time that the charge of an antiatom has been measured to high precision.
“This is the first time we have been able to study antihydrogen with some precision,” said ALPHA spokesperson Jeffrey Hangst. “We are optimistic that ALPHA’s trapping technique will yield many such insights in the future. We look forward to the restart of the AD program in August, so that we can continue to study antihydrogen with ever increasing accuracy.” Continue reading CERN’s ALPHA experiment measures charge of antihydrogen

Sonata in LHCb: The sound of antimatter

In a recent paper the LHCb collaboration at CERN observed two particles changing from matter into antimatter and back again. Now the collaboration has turned that data into sound, so that you can listen to the music of antimatter.

For every fundamental particle, there is a corresponding antiparticle. Antimatter particles share the same mass as their matter counterparts, but qualities such as electric charge are opposite. Though most particles exist as either matter or antimatter, some particles can switch between the two.
B0 and B0s are such particles. They oscillate between their matter and antimatter equivalents up to 3 million million times per second. If that frequency were converted directly into the pitch of a musical note, it would be much too high for the human ear to hear. So the LHCb collaboration has slowed down the frequency millions of times so that we can enjoy the oscillation as detectable sound.
In the video below, a blue box moves from left to right across the screen, depicting the area of the graph you can hear. At first you hear only white noise – random background fluctuations of particles in the LHCb detector. But the two peaks on the graph come from the B0 and B0s particles. First you hear the loud tone of B0 – B0 oscillations, then background noise followed by the tone of the  B0s –  B0s oscillations. The higher frequency B0s – B0s oscillations are experimentally more difficult to observe, which is why their tone is not as loud

So sit back, relax, and enjoy the music of particles switching to antimatter and back millions of times per second.
Now that’s vibrato.
Check out this explanation video of the data sonification from LHCb:

Read more at http://phys.org/news/2013-08-sonata-lhcb-antimatter-video.html

ALPHA weighs in on antimatter

Description and first application of a new technique to measure the gravitational mass of antihydrogen

The Alpha experiment's antimatter chamber uses magnetic fields to sequester antihydrogen atoms

The Alpha experiment’s antimatter chamber uses magnetic fields to sequester antihydrogen atoms

Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen >75 at a statistical significance level of 5%; worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regime….
Read more: http://www.nature.com/ncomms/journal/v4/n4/full/ncomms2787.html

Read also: Antigravity gets first test at Cern’s Alpha experiment

Observing Matter-Antimatter Oscillations

D-mesons are the fourth in a quartet of neutral mesons to be observed oscillating into their antiparticle partners
MATTER_ANTIMATTER
While quantum mechanics is by now a well-established theory, it nonetheless still fascinates both newcomers and experts alike with unusual phenomena. The paradox of Schrödinger’s cat and the subtleties of the two-slit interference are timeless classics. Another less-familiar quantum effect, the oscillations of neutral mesons (bound states of a quark and an antiquark), has also intrigued legions of physicists for nearly sixty years [1]. These mesons oscillate back and forth between particle and antiparticle states. The theoretical ideas underlying this behavior involve concepts that are woven deeply into the history of particle physics. In Physical Review Letters, the LHCb Collaboration has now reported [2] the first significant single-measurement observation of oscillations in the neutral D-meson system…
Read more at: http://physics.aps.org/articles/v6/26

Measuring g with a beam of antihydrogen

AEgIS is a physics experiment that takes place at the european laboratory CERN, using the antiprotons delivered by the AD accelerator. AEgIS is a collaboration of physicists from all around the world.
The primary scientific goal of the AEgIS experiment is the direct measurement of the Earth’s gravitational acceleration g on antihydrogen. In the first phase of the experiment, a gravity measurement with 1% precision will be carried out by sending an antihydrogen beam through a classical Moire deflectometer coupled to a position sensitive detector. This will represent the first direct measurement of a gravitational effect on an antimatter system. aegis.web.cern.ch

Why We Already Know that Antihydrogen is Almost Certainly NOT Going to Fall “Up”

Scott Menary
The ALPHA collaboration (of which I am a member) has made great strides recently in trapping antihydrogen[1, 2] and starting down the path of making spectroscopic measurements[3].
The primary goal of the experiment is to test CPT invariance but there is also interest in testing another fundamental issue – the gravitational interaction between matter and antimatter (the so-called question of “antigravity”).
As well as the other antihydrogen trapping experiments – ASACUSA[4] and ATRAP[5] – there is also a new experiment in the Antiproton Decelerator hall at CERN called AEGIS[6] which is dedicated to testing the gravitional interaction between antihydrogen and the Earth. It was claimed in [7] that there “is no compelling evidence or theoretical reason to rule out such a difference (i.e., between g and ¯g) at the 1% level.
I argue in this short paper that bending of light by the sun provides a more stringent limit than this2….

Read more: http://arxiv.org/pdf/1207.7358v1.pdf