Thermal and collisional history of Tishomingo iron meteorite: More evidence for early disruption of differentiated planetesimals

Tishomingo is a chemically and structurally unique iron with 32.5 wt.% Ni that contains 20% residual taenite and 80% martensite plates, which formed on cooling to between -75 and -200 °C, probably the lowest temperature recorded by any meteorite. Our studies using transmission (TEM) and scanning electron microscopy (SEM), X-ray microanalysis (AEM) and electron backscatter diffraction (EBSD) show that martensite plates in Tishomingo formed in a single crystal of taenite and decomposed during reheating forming 10-100 nm taenite particles with ∼50 wt.% Ni, kamacite with ∼4 wt.%Ni, along with martensite or taenite with 32 wt.% Ni. EBSD data and experimental constraints show that Tishomingo was reheated to 320-400 °C for about a year transforming some martensite to kamacite and to taenite particles and some martensite directly to taenite without composition change. Fizzy-textured intergrowths of troilite, kamacite with 2.7 wt.% Ni and 2.6 wt.% Co, and taenite with 56 wt.% Ni and 0.15 wt.% Co formed by localized shock melting. A single impact probably melted the sub-mm sulfides, formed stishovite, and reheated and decomposed the martensite plates. Tishomingo and its near-twin Willow Grove, which has 28 wt.% Ni, differ from IAB-related irons like Santa Catharina and San Cristobal that contain 25-36 wt.% Ni, as they are highly depleted in moderately volatile siderophiles and enriched in Ir and other refractory elements. Tishomingo and Willow Grove therefore resemble IVB irons but are chemically distinct. The absence of cloudy taenite in these two irons shows that they cooled through 250 °C abnormally fast at >0.01 °C/yr. Thus this grouplet, like the IVA and IVB irons, suffered an early impact that disrupted their parent body when it was still hot. Our noble gas data show that Tishomingo was excavated from its parent body about 100 to 200 Myr ago and exposed to cosmic rays as a meteoroid with a radius of ∼50-85 cm.

The effective Planck mass and the scale of inflation

Observable quantities in cosmology are dimensionless, and therefore independent of the units in which they are measured. This is true of all physical quantities associated with the primordial perturbations that source cosmic microwave background anisotropies such as their amplitude and spectral properties. However, if one were to try and infer an absolute energy scale for inflation—a priori, one of the more immediate corollaries of detecting primordial tensor modes—one necessarily makes reference to a particular choice of units, the natural choice for which is Planck units. In this note, we discuss various aspects of how inferring the energy scale of inflation is complicated by the fact that the effective strength of gravity as seen by inflationary quanta necessarily differs from that seen by gravitational experiments at presently accessible scales. The uncertainty in the former relative to the latter has to do with the unknown spectrum of universally coupled particles between laboratory scales and the putative scale of inflation. These intermediate particles could be in hidden as well as visible sectors or could also be associated with Kaluza–Klein resonances associated with a compactification scale below the scale of inflation. We discuss various implications for cosmological observables.

Automated NNLL + NLO resummation for jet-veto cross sections

In electroweak-boson production processes with a jet veto, higher-order corrections are enhanced by logarithms of the veto scale over the invariant mass of the boson system. In this paper, we resum these Sudakov logarithms at next-to-next-to-leading logarithmic accuracy and match our predictions to next-to-leading-order (NLO) fixed-order results. We perform the calculation in an automated way, for arbitrary electroweak final states and in the presence of kinematic cuts on the leptons produced in the decays of the electroweak bosons. The resummation is based on a factorization theorem for the cross sections into hard functions, which encode the virtual corrections to the boson production process, and beam functions, which describe the low-pT emissions collinear to the beams. The one-loop hard functions for arbitrary processes are calculated using the MadGraph5_aMC@NLO framework, while the beam functions are process independent. We perform the resummation for a variety of processes, in particular for W+W− pair production followed by leptonic decays of the W bosons.

A dispersive treatment of K ℓ 4 decays

Kℓ4 decays have several features of interest: they allow an accurate measurement of ππ-scattering lengths; they provide the best source for the determination of some low-energy constants of χPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of Kℓ4 decays that provides a resummation of ππ- and Kπ-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The matching to χPT at NLO and NNLO enables us to determine the LECs Lr1, Lr2 and Lr3. With recently published data from NA48/2, the LEC Lr9 can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.

Ms. hebr. oct. 75 - Ḥidushim u-derushim

Vorbesitzer: Abraham Merzbacher

Dispersion relation for hadronic light-by-light scattering: theoretical foundations

In this paper we make a further step towards a dispersive description of the hadronic light-by-light (HLbL) tensor, which should ultimately lead to a data-driven evaluation of its contribution to (g − 2) μ . We first provide a Lorentz decomposition of the HLbL tensor performed according to the general recipe by Bardeen, Tung, and Tarrach, generalizing and extending our previous approach, which was constructed in terms of a basis of helicity amplitudes. Such a tensor decomposition has several advantages: the role of gauge invariance and crossing symmetry becomes fully transparent; the scalar coefficient functions are free of kinematic singularities and zeros, and thus fulfill a Mandelstam double-dispersive representation; and the explicit relation for the HLbL contribution to (g − 2) μ in terms of the coefficient functions simplifies substantially. We demonstrate explicitly that the dispersive approach defines both the pion-pole and the pion-loop contribution unambiguously and in a model-independent way. The pion loop, dispersively defined as pion-box topology, is proven to coincide exactly with the one-loop scalar QED amplitude, multiplied by the appropriate pion vector form factors.

Ms. Barth. 75 (Ausst. 32) - In primum et secundum Sententiarum

Vorbesitzer: Bartholomaeusstift Frankfurt am Main

There is a place for radical cystectomy and urinary diversion, including orthotopic bladder substitution, in patients aged 75 and older: Results of a retrospective observational analysis from a high-volume center

INTRODUCTION The incidence of cancer increases with age and owing to the changing demographics we are increasingly confronted with treating bladder cancer in old patients. We report our results in patients>75 years of age who underwent open radical cystectomy (RC) and urinary diversion. MATERIAL AND METHODS From January 2000 to March 2013, a consecutive series of 224 old patients with complete follow-up who underwent RC and urinary diversion (ileal orthotopic bladder substitute [OBS], ileal conduit [IC], and ureterocutaneostomy [UCST]) were included in this retrospective single-center study. End points were the 90-day complication rates (Clavien-Dindo classification), 90-day mortality rates, overall and cancer-specific survival rates, and continence rates (OBS). RESULTS Median age was 79.2 years (range: 75.1-91.6); 35 of the 224 patients (17%) received an OBS, 178 of the 224 patients (78%) an IC, and 11 of the 224 patients (5%) an UCST. The 90-day complication rate was 54.3% in the OBS (major: Clavien grade 3-5: 22.9%, minor: Clavien Grade 1-2: 31.4%), 56.7% in the IC (major: 27%, minor: 29.8%), and 63.6% in the UCST group (major: 36.4%, minor: 27.3%); P = 0.001. The 90-day mortality was 0% in the OBS group, 13% in the IC group, and 10% in the UCST group (P = 0.077). The Glasgow prognostic score was an independent predictor of all survival parameters assessed, including 90-day mortality. Median follow-up was 22 months. Overall and cancer-specific survivals were 90 and 98, 47 and 91, and 11 and 12 months for OBS, IC, and UCST, respectively. In OBS patients, daytime continence was considered as dry in 66% and humid in 20% of patients. Nighttime continence was dry in 46% and humid 26% of patients. CONCLUSION With careful patient selection, oncological and functional outcome after RC can be good in old patients. Old age as the sole criterion should not preclude the indication for RC or the option of OBS. In old patients undergoing OBS, satisfactory continence results can be achieved.

The coupling of non-linear supersymmetry to supergravity

We study the coupling of non-linear supersymmetry to supergravity. The goldstino nilpotent superfield of global supersymmetry coupled to supergravity is described by a geometric action of the chiral curvature superfield R subject to the constraint (R−λ)2=0 with an appropriate constant λ. This constraint can be found as the decoupling limit of the scalar partner of the goldstino in a class of f(R) supergravity theories.

Comparison of different lattice definitions of the topological charge

We present a comparison of different definitions of the topological charge on the lattice, using a small-volume ensemble with 2 flavours of dynamical twisted mass fermions. The investigated definitions are: index of the overlap Dirac operator, spectral projectors, spectral flow of the HermitianWilson- Dirac operator and field theoretic with different kinds of smoothing of gauge fields (HYP and APE smearings, gradient flow, cooling). We also show some results on the topological susceptibility.

Cosmogenic activation of xenon and copper

Rare event search experiments using liquid xenon as target and detection medium require ultra-low background levels to fully exploit their physics potential. Cosmic ray induced activation of the detector components and, even more importantly, of the xenon itself during production, transportation and storage at the Earth's surface, might result in the production of radioactive isotopes with long half-lives, with a possible impact on the expected background. We present the first dedicated study on the cosmogenic activation of xenon after 345 days of exposure to cosmic rays at the Jungfraujoch research station at 3470m above sea level, complemented by a study of copper which has been activated simultaneously. We have directly observed the production of 7Be, 101Rh, 125Sb, 126I and 127Xe in xenon, out of which only 125Sb could potentially lead to background for a multi-ton scale dark matter search. The production rates for five out of eight studied radioactive isotopes in copper are in agreement with the only existing dedicated activation measurement, while we observe lower rates for the remaining ones. The specific saturation activities for both samples are also compared to predictions obtained with commonly used software packages, where we observe some underpredictions, especially for xenon activation.

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.