The LHCb experiment studies this phenomenon by observing the way B mesons decay into other particles. The new results reinforce earlier measurements from LHCb presented at last month’s European Physical Society conference in Grenoble, France, showing that the B meson decays so far measured by the collaboration are in full agreement with predictions from the Standard Model of particle physics, the theory physicists use to describe the behaviour of fundamental particles.
“This result shows that we’re now able to measure the finest details of the B meson system,” said LHCb spokesperson Pierluigi Campana, “which puts us right where we need to be to start finding cracks in the Standard Model, and explaining matter-antimatter asymmetry.”
Matter and antimatter are thought to have existed in equal amounts at the beginning of the universe, but as the universe expanded and cooled, an asymmetry developed between them, leaving a universe that appears to be composed entirely of matter. Heavy quarks provide a good place to investigate this phenomenon because the heavier the quark, the more ways it can decay, and all of these decays are described by the Standard Model. The Standard Model predicts matter-antimatter asymmetry, but at a level which is too small to explain the observed asymmetry in the Universe. Deviations from the predictions would bring an indication of new physics. B-quarks are produced copiously at the LHC, which makes them the particle of choice for studying matter-antimatter asymmetry in the laboratory. Quarks are never produced alone, but always travel in company: they are accompanied by another quark giving rise to the family of particles called B mesons. It is these that LHCb studies.
Earlier in the year, experiments at Fermilab presented results that hinted at a divergence from the Standard Model. Since then, however, the LHCb experiment has surpassed the Fermilab experiments’ precision, and sees no such divergence.
“These results suggest that the devil is in the detail,” said Campana, “and we’ve reached the point where we’re getting right down into the details. It’s not the devil we expect to find there, though, but new hints of deviations from the Standard Model.”
LHCb has been able to reach this level of precision so early in the operational lifetime of the LHC thanks to the excellent performance of the LHC, and the way that LHCb scientists have worked with LHC engineers to optimize the amount of data collected by the experiment. Unlike the large general-purpose detectors, ATLAS and CMS, the LHCb detector has not been constructed to record data at the maximum rate the LHC can deliver. LHCb contains very sensitive elements close to the beam that can measure the very short tracks left by B mesons before they decay. Reconciling the need to protect these devices from possible beam damage with maximizing beam intensity is the challenge these engineers and scientists have overcome.
“Collaboration with the accelerator people has been fantastic,” said Campana, “It’s allowing us to collect data much faster than expected, and bringing us closer to being able to understand where the antimatter went.”For more information:
India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.
James Gillies | Newswise Science News
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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