Search for Doubly-Charged Higgs Bosons Decaying to Dileptons in proton anti-proton Collisions at s**(1/2) = 1.96 TeV

We present the results of a search for doubly charged Higgs bosons (H±±) decaying to dileptons (ll′) using ≈240  pb-1 of pp̅ collision data collected by the CDF II experiment at the Fermilab Tevatron. In our search region, given by same-sign ll′ mass mll′>80  GeV/c2 (100  GeV/c2 for ee channel), we observe no evidence for H±± production. We set limits on σ(pp̅ →H++H--→l+l′+l-l′-) as a function of the mass of the H±± and the chirality of its couplings. Assuming exclusive same-sign dilepton decays, we derive lower mass limits on HL±± of 133, 136, and 115  GeV/c2 in the ee, μμ, and eμ channels, respectively, and a lower mass limit of 113  GeV/c2 on HR±± in the μμ channel, all at the 95% confidence level

Search for quark-lepton compositeness and a heavy W boson using the ev channel in pp(overbar) collisions at (square root)s = 1.8 TeV

We present searches for quark-lepton compositeness and a heavy W′ boson at high electron-neutrino transverse mass. We use ∼110pb-1 of data collected in pp̅ collisions at √s = 1.8TeV by the CDF Collaboration during 1992–1995. The data are consistent with standard model expectations. Limits are set on the quark-lepton compositeness scale Λ, the ratio of partial cross sections σ(W′→eν)/σ(W→eν), and the mass of a W′ boson with standard model couplings. We exclude Λ<2.81TeV and a W′ boson with mass below 754GeV/c2 at the 95% confidence level. Combining with our previously published limit obtained using the muon channel, we exclude a W′ boson with mass below 786GeV/c2 at the 95% confidence level

Search for neutral supersymmetric Higgs bosons in pp(overbar) collisions at (square root)s = 1.8 TeV

We present the results of a search for neutral Higgs bosons produced in association with b quarks in pp̅ →bb̅ ϕ→bb̅ bb̅ final states with 91±7pb-1 of pp̅ collisions at √s = 1.8TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tanβ values in excess of 35

Production of Xc1 and Xc2 in pp(overbar) collisions at (square root)s = 1.8 TeV

We have measured the ratio of prompt production rates of the charmonium states χc1 and χc2 in 110pb-1 of pp̅ collisions at √s = 1.8TeV. The photon from their decay into J/ψγ is reconstructed through conversion into e+e- pairs. The energy resolution this technique provides makes the resolution of the two states possible. We find the ratio of production cross sections σχc2/σχc1 = 0.96±0.27(stat)±0.11(syst) for events with pT(J/ψ)>4.0GeV/c, |η(J/ψ)|1.0GeV/c

Dusty Planetary Systems

Extensive photometric stellar surveys show that many main sequence stars show emission at infrared and longer wavelengths that is in excess of the stellar photosphere; this emission is thought to arise from circumstellar dust. The presence of dust disks is confirmed by spatially resolved imaging at infrared to millimeter wavelengths (tracing the dust thermal emission), and at optical to near infrared wavelengths (tracing the dust scattered light). Because the expected lifetime of these dust particles is much shorter than the age of the stars (>10 Myr), it is inferred that this solid material not primordial, i.e. the remaining from the placental cloud of gas and dust where the star was born, but instead is replenished by dust-producing planetesimals. These planetesimals are analogous to the asteroids, comets and Kuiper Belt objects (KBOs) in our Solar system that produce the interplanetary dust that gives rise to the zodiacal light (tracing the inner component of the Solar system debris disk). The presence of these "debris disks" around stars with a wide range of masses, luminosities, and metallicities, with and without binary companions, is evidence that planetesimal formation is a robust process that can take place under a wide range of conditions. This chapter is divided in two parts. Part I discusses how the study of the Solar system debris disk and the study of debris disks around other stars can help us learn about the formation, evolution and diversity of planetary systems by shedding light on the frequency and timing of planetesimal formation, the location and physical properties of the planetesimals, the presence of long-period planets, and the dynamical and collisional evolution of the system. Part II reviews the physical processes that affect dust particles in the gas-free environment of a debris disk and their effect on the dust particle size and spatial distribution.Comment: 68 pages, 25 figures. To be published in "Solar and Planetary Systems" (P. Kalas and L. French, Eds.), Volume 3 of the series "Planets, Stars and Stellar Systems" (T.D. Oswalt, Editor-in-chief), Springer 201

Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands

"© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)