LHC

Measurements of normalized differential cross-sections for top-quark pair production are presented as a function of the top-quark transverse momentum, and of the mass, transverse momentum, and
rapidity of the tt system, in proton–proton collisions at a center-of-mass energy of √s = 7 TeV. The dataset corresponds to an integrated luminosity of 4.6 fb−1, recorded in 2011 with the ATLAS detector
at the CERN Large Hadron Collider. Events are selected in the lepton+jets channel, requiring exactly one lepton and at least four jets with at least one of the jets tagged as originating from a b-quark.
The measured spectra are corrected for detector efficiency and resolution effects and are compared to several Monte Carlo simulations and theory calculations. The results are in fair agreement with the predictions in a wide kinematic range. Nevertheless, data distributions are softer than predicted for higher values of the mass of the tt system and of the top-quark transverse momentum. The
measurements can also discriminate among different sets of parton distribution functions.

We present, for the first time, a set of next-to-next-to-leading order (NNLO) fragmentation functions (FFs) describing the production of charmed-meson D * + from partons. Exploiting the univer-sality and scaling violations of FFs, we extract the NLO and NNLO FFs through a global fit to all relevant data sets from single-inclusive e + e − annihilation. The uncertainties for the resulting FFs as well as the corresponding observables are estimated using the Hessian approach. We evaluate the quality of the SKM18 FFs determined in this analysis by comparing with the recent results in literature and show how they describe the available data for single-inclusive D * +-meson production in electron-positron annihilation. As a practical application, we apply the extracted FFs to make our theoretical predictions for the scaled-energy distributions of D * +-mesons inclusively produced in top quark decays. We explore the implications of SKM18 for LHC phenomenology and show that our findings of this study can be introduced as a channel to indirect search for top-quark properties.

Physicists believe that such dark matter is composed of (as yet undefined) elementary particles that stick together thanks to gravitational force. In a study recently published in EPJ C, scientists from the CRESST-II research project use the so-called phonon-light technique to detect dark matter. [16] A team of researchers at MIT has succeeded in creating a double film coating that is able to convert infrared light at modest intensities into visible light. In their paper published in the journal Nature Photonics, the team describes their film, how well it works and the possible uses for it. [15] Before the Hawaii-bound storm Julio strengthened into a hurricane, a NASA satellite spotted a high-energy flash of "dark lightning" coming from the swirling clouds. [14] Researchers may have uncovered a way to observe dark matter thanks to a discovery involving X-ray emissions. [13] Between 2009 and 2013, the Planck satellite observed relic radiation, sometimes called cosmic microwave background (CMB) radiation. Today, with a full analysis of the data, the quality of the map is now such that the imprints left by dark matter and relic neutrinos are clearly visible. [12] The gravitational force attracting the matter, causing concentration of the matter in a small space and leaving much space with low matter concentration: dark matter and energy. There is an asymmetry between the mass of the electric charges, for example proton and electron, can understood by the asymmetrical Planck Distribution Law. This temperature dependent energy distribution is asymmetric around the maximum intensity, where the annihilation of matter and antimatter is a high probability event. The asymmetric sides are creating different frequencies of electromagnetic radiations being in the same intensity level and compensating each other. One of these compensating ratios is the electron-proton mass ratio. The lower energy side has no compensating intensity level, it is the dark energy and the corresponding matter is the dark matter. The Weak Interaction changes the temperature dependent Planck Distribution of the electromagnetic oscillations and changing the non-compensated dark matter rate, giving the responsibility to the sterile neutrino.