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Could a Higgs Boson Announcement Be Imminent From the LHC?
Physicists at the Large Hadron Collider could be getting an early Christmas present: the Higgs boson. According to the latest rumors, scientists at the LHC are seeing a signal that could correspond to a Higgs particle with a mass of 125 GeV (a proton is slightly less than 1 GeV).
Public talks are scheduled to discuss the latest results from ATLAS and CMS, two of the main LHC experiments, on Dec. 13. This follows one day after a closed-door CERN council meeting where officials will get a short preview of the findings, whatever they may be.
“Chances are high (but not strictly 100%) that the talks will either announce a (de facto or de iure) discovery or some far-reaching exclusion that will be really qualitative and unexpected,” wrote theoretical physicist Lubos Motl on his blog.
#Science #News #Physics #Particle physics #Higgs Boson #LHC #Nature #Mass
One of the biggest unsolved problems in astrophysics is that galaxies and galaxy clusters rotate faster than expected, given the amount of existing baryonic (normal) matter. The fast orbits require a larger central mass than the nearby stars, dust, and other baryonic objects can provide, leading scientists to propose that every galaxy resides in a halo of (as yet undetectable) dark matter made of non-baryonic particles. As one of many scientists who have become somewhat skeptical of dark matter, CERN physicist Dragan Slavkov Hajdukovic has proposed that the illusion of dark matter may be caused by the gravitational polarization of the quantum vacuum.
“The key message of my paper is that dark matter may not exist and that phenomena attributed to dark matter may be explained by the gravitational polarization of the quantum vacuum,” Hajdukovic told PhysOrg.com. “The future experiments and observations will reveal if my results are only (surprising) numerical coincidences or an embryo of a new scientific revolution.”
Like his previous study featured on PhysOrg about a cyclic universe successively dominated by matter and antimatter, Hajdukovic’s paper on a dark matter alternative is also an attempt to understand cosmological phenomena without assuming the existence of unknown forms of matter and energy, or of unknown mechanisms for inflation and matter-antimatter asymmetry. In the case of the fast rotational curves of galaxies, he explains that there are currently two schools of understanding the phenomenon.
“The first school invokes the existence of dark matter, while the second school invokes modification of our law of gravity,” he said. “I suggest a third way, without introducing dark matter and without modification of the law of gravity.”
His ideas (like those in the previous paper) rest on the key hypothesis that matter and antimatter are gravitationally repulsive, which is due to the fact that particles and antiparticles have gravitational charge of opposite sign. (Though like matter, antimatter is gravitationally attractive with itself.) Currently, it is not known whether matter and antimatter are gravitationally repulsive, although a few experiments (most notably, the AEGIS experiment at CERN) are testing related concepts.
“Concerning gravity, mainstream physics assumes that there is only one gravitational charge (identified with the inertial mass) while I have assumed that, as in the case of electromagnetic interactions, there are two gravitational charges: positive gravitational charge for matter and negative gravitational charge for antimatter,” Hajdukovic explained.
matter and antimatter are gravitationally repulsive, then it would mean that the virtual particle-antiparticle pairs that exist for a limited time in the quantum vacuum are “gravitational dipoles.” That is, each pair forms a system in which the virtual particle has a positive gravitational charge, while the virtual antiparticle has a negative gravitational charge. In this scenario, the quantum vacuum contains many virtual gravitational dipoles, taking the form of a dipolar fluid.
“We can consider our universe as a union of two mutually interacting entities,” Hajdukovic said. “The first entity is our ‘normal’ matter (hence we do not assume the existence of dark matter and dark energy), immersed in the second entity, the quantum vacuum, considered as a sea of different kinds of virtual dipoles, including gravitational dipoles.”
He goes on to explain that the virtual gravitational dipoles in the quantum vacuum can be gravitationally polarized by the baryonic matter in nearby massive stars and galaxies. When the virtual dipoles align, they produce an additional gravitational field that can combine with the gravitational field produced by stars and galaxies. As such, the gravitationally polarized quantum vacuum could produce the same “speeding up” effect on the rotational curves of galaxies as either hypothetical dark matter or a modified law of gravity.
#cosmology #dark matter #particle physics #science #physics #astrophysics
Image of transverse energy in the electromagnetic calorimeter (ECAL) with a cut at 20 GeV. It is very clear in this image that there is energy being deposited in the whole detector.
Source: Beam Splash, Doug Berry’s blog, Notre Dame extended Research Community
