Properties of the DsJ states

Recent measurements involving the newly discovered D_sJ particles are reported. The results of D_sJ production and decay branching fraction measurements are shown. Possible spin-parity and quark content assignments of D_sJ mesons are discussed. The results are based on a large data sample recorded by the Belle detector at the KEKB e^+ e^- collider.Comment: 4 pages, 3 figures, proceedings to the talk given on behalf of the Belle Collaboration at the First Meeting of the APS Topical Group on Hadron Physic

Intensity-Frontier Antiproton Physics with The Antiproton Annihilation Spectrometer (TAPAS) at Fermilab

The Fermilab Antiproton Source is the world's most intense source of antimatter. With the Tevatron program now behind us, this unique facility can help make the case for Fermilab's continued accelerator operations. The Antiproton Source can be used for unique, dedicated antimatter studies, including medium-energy {bar p}-annihilation experiments. We propose to assemble a powerful, yet cost-effective, solenoidal magnetic spectrometer for antiproton-annihilation events, and to use it at the Fermilab Antiproton Accumulator to measure the charm production cross section, study rare hyperon decays, search for hyperon CP asymmetry, precisely measure the properties of several charmonium and nearby states, and make the first measurements of the Drell-Yan continuum in medium-energy antiproton annihilation. Should the charm production cross section be as large as some have proposed, we will also be able to measure D{sup 0}-{bar D}{sup 0} mixing with high precision and discover (or sensitively limit) charm CP violation. The observation of charm or hyperon CP violation would be evidence for physics beyond the Standard Model, with possible implications for the origin of the baryon asymmetry of the universe - the question of what happened to all the antimatter that must have been produced in the Big Bang. The experiment will be carried out by an international collaboration and will require some four years of running time. As possibly the sole hadron experiment in progress at Fermilab during that time, it will play an important role in maintaining a broad particle physics program at Fermilab and in the U.S. It will thus help us to continue attracting creative and capable young people into science and technology, and introducing them to the important technologies of accelerators, detectors, and data acquisition and analysis - key roles in society that accelerator-based particle physics has historically played

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of $\sqrt s =1.96$ TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is $A_{\mathrm{FB}}^{t\bar{t}} = 0.128 \pm 0.025$. The combined inclusive and differential asymmetries are consistent with recent standard model predictions

Observation of a new Bs π state

We report the observation of a narrow structure, X(5568), in the decay sequence X(5568) &rarr; Bs &pi;&plusmn;, Bs &rarr; J/&psi; ϕ, J/&psi; &rarr; &mu;+&mu;&minus;, ϕ &rarr; K+K&minus;. This is the first observation of a hadronic state with valence quarks of four different flavors. The mass and natural width of the new state are measured to be m = 5567.8 &plusmn; 2.9 (stat) +0.9&minus;1.9 (syst) MeV and &Gamma; = 21.9 &plusmn; 6.4 (stat) +5.0&minus;2.5 (syst) MeV, and the significance including look-elsewhere effect and systematic uncertainties is 5.1&sigma;. The observation is based on10.4 fb&minus;1 of ppbar collision data at 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider.</p

International linear collider: the next mega-scale particle collider

The International Linear Collider (ILC) is a mega-scale, technically complex project, requiring large financial resources and cooperation of thousands of scientists and engineers from all over the world. Such a big and expensive project has to be discussed publicly, and the planned goals have to be clearly formulated. This book advocates for the demand for the project, motivated by the current situation in particle physics. The natural and most powerful way of obtaining new knowledge in particle physics is to build a new collider with a larger energy. In this approach, the Large Hadron Collider (LHC) was created and is now operating at the world record center of-mass energy of 13 TeV. Although the design of colliders with a larger energy of 50-100 TeV has been discussed, the practical realization of such a project is not possible for another 20-30 years. Of course, many new results are expected from LHC over the next decade. However, we must also think about other opportunities, and in particular, about the construction of more dedicated experiments. There are many potentially promising projects, however, the most obvious possibility to achieve significant progress in particle physics in the near future is the construction of a linear e+e- collider with energies in the range (250-1000) GeV. Such a project, the ILC, is proposed to be built in Kitakami, Japan. This book will discuss why this project is important and which new discoveries can be expected with this collider