5,455 research outputs found

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

    Development of Hexapod Robot with Manoeuvrable Wheel

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    The necessity to utilize the usage of the robot cannot be denied since there are a lot of natural disasters occur everywhere around the world. The robot that can be used in this situation may be a remotely controlled by human or moves autonomously. Hexapod robot is one of the robots used in this situation because of its stability and flexibility during the motion on any type of surface. Hexapod robot is a robot that has six legs to walk or move. Since the robot has many legs, the robot is easily programmed to move around because it can be configured to many types of gait such as alternating tripod, quadruped and crawl. There are various designs of hexapod with certain function and advantages. In this research, a hexapod robot with manoeuvrable wheel is designed and developed. The purpose of the hexapod robot with manoeuvrable wheel is to ease the movement either on the flat surface or on the inclined surface. On the flat surface, the robot will move using the manoeuvrable wheel while on incline surface, the robot will climb using its legs. The decisions for the robot to use either wheel or legs are based on the sensory devices and algorithm develops at the controller attached to the robot
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