The thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 microns

We report measurements of the thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 microns with the Spitzer Infrared Array Camera (IRAC). Our measured occultation depths are 0.510 +- 0.042 % and 0.41 +- 0.11 % at 4.5 and 8 microns, respectively. In addition to the CoRoT optical measurements, these planet/star flux ratios indicate a poor heat distribution to the night side of the planet and are in better agreement with an atmosphere free of temperature inversion layer. Still, the presence of such an inversion is not definitely ruled out by the observations and a larger wavelength coverage is required to remove the current ambiguity. Our global analysis of CoRoT, Spitzer and ground-based data confirms the large mass and size of the planet with slightly revised values (Mp = 3.47 +- 0.22 Mjup, Rp = 1.466 +- 0.044 Rjup). We find a small but significant offset in the timing of the occultation when compared to a purely circular orbital solution, leading to e cos(omega) = -0.00291 +- 0.00063 where e is the orbital eccentricity and omega is the argument of periastron. Constraining the age of the system to be at most of a few hundreds of Myr and assuming that the non-zero orbital eccentricity is not due to a third undetected body, we model the coupled orbital-tidal evolution of the system with various tidal Q values, core sizes and initial orbital parameters. For log(Q_s') = 5 - 6, our modelling is able to explain the large radius of CoRoT-2b if log(Q_p') <= 5.5 through a transient tidal circularization and corresponding planet tidal heating event. Under this model, the planet will reach its Roche limit within 20 Myr at most.Comment: 13 pages, 2 tables, 11 figures. Accepted for publication in Astronomy and Astrophysic

Interleukin-1 beta-converting enzyme-like protease cleaves DNA-dependent protein kinase in cytotoxic T cell killing.

Cytotoxic T cells (CTL) represent the major defense mechanism against the spread of virus infection. It is believed that the pore-forming protein, perforin, facilitates the entry of a series of serine proteases (particularly granzyme B) into the target cell which ultimately leads to DNA fragmentation and apoptosis. We demonstrate here that during CTL-mediated cytolysis the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an enzyme implicated in the repair of double strand breaks in DNA, is specifically cleaved by an interleukin (IL)-1 beta-converting enzyme (ICE)-like protease. A serine protease inhibitor, 3,4-dichloroisocoumarin (DCl), which is known to block granzyme B activity, inhibited CTL-induced apoptosis and prevented the degradation of DNA-PKcs in cells but failed to prevent the degradation of purified DNA-PKcs by CTL extracts. However, Tyr-Val-Ala-Asp-CH2Cl (YVAD-CMK) and other cysteine protease inhibitors prevented the degradation of purified DNA-PKcs by CTL extracts. Furthermore, incubation of DNA-PKcs with granzyme B did not produce the same cleavage pattern observed in cells undergoing apoptosis and when this substrate was incubated with either CTL extracts or the ICE-like protease, CPP32. Sequence analysis revealed that the cleavage site in DNA-PKcs during CTL killing was the same as that when this substrate was exposed to CPP32. This study demonstrates for the first time that the cleavage of DNA-PKcs in this intact cell system is exclusively due to an ICE-like protease

A binary merger origin for inflated hot Jupiter planets

We hypothesize that hot Jupiters with inflated sizes represent a separate planet formation channel,the merging of two low-mass stars. We show that the abundance and properties of W UMa stars and low mass detached binaries are consistent with their being possible progenitors. The degree of inflation of the transiting hot Jupiters correlates with their expected spiral-in life time by tidal dissipation, and this could indicate youth if the stellar dissipation parameter Q'* is sufficiently low. Several Jupiter-mass planets can form in the massive compact disk formed in a merger event. Gravitational scattering between them can explain the high incidence of excentric, inclined, and retrograde orbits. If the population of inflated planets is indeed formed by a merger process, their frequency should be much higher around blue stragglers than around T Tauri stars.Comment: Accepted for publication in A&

Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060^{\rm + 0.0000022 }_ days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_{\rm p} = 0.503^_ $M_{\rm J}$ and radius R_{\rm p} = 1.224^_ $R_{\rm J}$, resulting in a density $\rho_{\rm p} = 0.27 \pm 0.05$ $\rho_{\rm J}$. The mass and radius for the host star are M_\ast = 0.88^_ $M_\odot$ and R_\ast = 0.870^_ $R_\odot$. The non-zero orbital eccentricity e = 0.054^{\rm +0.018}_ that we measure suggests that the planet underwent a massive tidal heating ~1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis \beta = 11^_ deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk

WASP-31b: a low-density planet transiting a metal-poor, late-F-type dwarf star

We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.48 Jupiter masses and 1.55 Jupiter radii. It is in a 3.4-day orbit around a metal-poor, late-F-type, V = 11.7 dwarf star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass.Comment: 6 pages, 5 figures, 4 tables. As accepted for publication in A&A; bibcode = 2011A&A...531A..60

Measurement of the branching ratios of the Z0 into heavy quarks

We measure the hadronic branching ratios of the Z0 boson into heavy quarks: Rb=Gamma(Z0->bb)/Gamma(Z0->hadrons) and Rc=Gamma(Z0->cc/Gamma(Z0->hadrons) using a multi-tag technique. The measurement was performed using about 400,000 hadronic Z0 events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct bottom and charm hadron decay vertices with high efficiency and purity, which enables us to measure most efficiencies from data. We obtain, Rb=0.21604 +- 0.00098(stat.) +- 0.00073(syst.) -+ 0.00012(Rc) and, Rc= 0.1744 +- 0.0031(stat.) +- 0.0020(syst.) -+ 0.0006(Rb)Comment: 37 pages, 8 figures, to be submitted to Phys. Rev. D version 2: changed title to ratios, used common D production fractions for Rb and Rc and corrected Zgamma interference. Identical to PRD submissio

Direct Measurements of A_b and A_c using Vertex/Kaon Charge Tags at SLD

Exploiting the manipulation of the SLC electron-beam polarization, we present precise direct measurements of the parity violation parameters A_c and A_b in the Z boson - c quark and Z boson - b quark coupling. Quark/antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLD CCD vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996-98 sample of 400,000 Z decays, produced with an average beam polarization of 73.4%, we find A_c = 0.673 +/- 0.029 (stat.) +/- 0.023 (syst.) and A_b = 0.919 +/- 0.018 (stat.) +/- 0.017 (syst.).Comment: 11 pages, 2 figures, 2 tables, to be submitted to Physical Review Letters; version 2 reflects changes suggested by the refere

Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals

We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure