Recent measurements of CP violation at the B factories

Recent measurements of time dependent CP asymmetries at the B factories have led to substantial progress in our understanding of CP violation. In this article, I review some of these experimental results and discuss their implications in the Standard Model and their sensitivity to New Physics.Comment: 17 pages, 13 figures, to be published in Modern Physics Letters A. To be published in Modern Physics Letters

Directional detection of Dark Matter

Among the many experimental techniques available, those providing directional information have the potential of yielding an unambiguous observation of WIMPs even in the presence of insidious backgrounds. A measurement of the distribution of arrival direction of WIMPs can also discriminate between Galactic Dark Matter halo models. In this article, I will discuss the motivation for directional detectors and review the experimental techniques used by the various experiments. I will then describe one of them, the DMTPC detector, in more detail.Comment: 17 pages, 11 postscript figures, mini-review submitted to Modern Physics Letters A (MPLA). Submitted to Modern Physics Letters A (MPLA

Recent measurements of sin2b at BaBar

The angle beta is the most accurately measured quantity that determines the Unitarity Triangle. In this article I review the various measurements of this angle performed by the BaBar Collaboration, and discuss their implications in the search for new physics.Comment: 5 pages, 4 figures, contributed to the Proceedings of BEAUTY 200

Beyond CP violation: hadronic physics at BaBar

I report on recent studies of hadronic physics performed by the BaBar Collaboration. Emphasis is given to the measurement of the properties of newly discovered charmed hadrons and to the searches for light and heavy pentaquarks.Comment: 14 pages, 20 postscript figues, contributed to the Proceedings of the First APS Topical Group Meeting on Hadron Physics, Fermilab, Batavia, IL (October 24-26, 2004

The ABC130 barrel module prototyping programme for the ATLAS strip tracker

For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

Search for Production of Invisible Final States in Single-Photon Decays of Υ(1S)Υ(1S)

We search for single-photon decays of the $Υ(1S)$ resonance, $Υ→γ+$ invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson $A^0$, or a pair of dark matter particles, $χ\overline{χ}$. Both $A^0$ and χ are assumed to have zero spin. We tag $Υ(1S)$ decays with a dipion transition $Υ(2S)→π^{+}π^{−}Υ(1S)$ and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range $m_{A^{0}}≤9.2 GeV$ and $m_{χ}≤4.5 GeV$ in the sample of $98×10^{6} Υ(2S)$ decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.Physic

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements