Inelastic Diffraction and Spectroscopy of Very Weakly Bound Clusters

We study the coherent inelastic diffraction of very weakly bound two body clusters from a material transmission grating. We show that internal transitions of the clusters can lead to new separate peaks in the diffraction pattern whose angular positions determine the excitation energies. Using a quantum mechanical approach to few body scattering theory we determine the relative peak intensities for the diffraction of the van der Waals dimers (D_2)_2 and H_2-D_2. Based on the results for these realistic examples we discuss the possible applications and experimental challenges of this coherent inelastic diffraction technique.Comment: 15 pages + 5 figures. J. Phys. B (in press

Photo- and Electroproduction of Eta Mesons

Eta photo- and electroproduction off the nucleon is investigated in an effective lagrangian approach that contains Born terms and both vector meson and nucleon resonance contributions. In particular, we review and develop the formalism for coincidence experiments with polarization degrees of freedom. The different response functions appearing in single and double polarization experiments have been studied. We will present calculations for structure functions and kinematical conditions that are most sensitive to details of the lagrangian, in particular with regard to contributions of nucleon resonances beyond the dominant $S_{11}$(1535) resonance.Comment: 24 pages RevTeX/LaTeX2.09, NFSS1, 13 figures (in separate file (tar,gzip and uue)), accepted for publication in Z. Phys.

To Separate or Not to Separate Investment from Commercial Banking? An Empirical Analysis of Attention Distortion Under Multiple Tasks

In the wake of the 2008/2009 financial crisis, a number of policy reports (Vickers, Liikanen, Volcker) proposed to separate investment banking from commercial banking to increase financial stability. This paper empirically examines one theoretical justification for these proposals, namely attention distortion under multiple tasks as in Holmstrom and Milgrom (1991). Universal banks can be viewed as combining two different tasks (investment banking and commercial banking) in the same organization. We estimate pay-performance sensitivities for different segments within universal banks and for pure investment and commercial banks. We show that the pay-performance sensitivity is higher in investment banking than in commercial banking, no matter whether it is organized as part of a universal bank or in a separate institution. Next, the paper shows that relative pay-performance sensitivities of investment and commercial banking are negatively related to the quality of the loan portfolio in universal banks. Depending on the specification, we obtain a reduction in problem loans when investment banking is removed from commercial banks of up to 12 percent. We interpret the evidence to imply that the higher pay-performance sensitivity in investment banking directs the attention of managers away from commercial banking within universal banks, consistent with Holmstrom and Milgrom (1991). Separation of investment banking and commercial banking may indeed be associated with a reduction in risk in commercial banking

The Impact of Social Support Networks on Maternal Employment: A Comparison of West German, East German and Migrant Mothers of Pre-School Children

Given shortages in public child care in Germany, this paper asks whether social support with child care and domestic work by spouses, kin and friends can facilitate mothers' return to full-time or part-time positions within the first six years after birth. Using SOEP data from 1993-2009 and event history analyses for competing risks, the author compares the employment transitions of West German, East German and migrant mothers of pre-school children. The results indicate that West German and migrant mothers return to work sooner if they have access to kin, and that kinship support is particularly important when public child care is unavailable. Furthermore, West German and migrant mothers are more likely to work full-time if their spouses partipate in domestic work. In contrast, social support does not affect employment transitions in East Germany where public child care is more easily accessible and continuous female employment is a prevalent social norm

The Macroeconomic Effects of the Euro Area's Fiscal Consolidation 2011-2013: A Simulation-Based Approach

We simulate the Euro Area's fiscal consolidation between 2011 and 2013 by employing two DSGE models used by the ECB and the European Commission, respectively. The cumulative multiplier amounts to 0.7 and 1.0 in the baseline, but increases to 1.3 with a reasonably calibrated financial accelerator and a crisis-related increase of the share of liquidity constrained households. In the latter scenario, fiscal consolidation would be largely responsible for the decline in the output gap from 2011-2013. Postponing the fiscal consolidation to a period of unconstrained monetary policy (until after the economic recovery) would have avoided most of these losses.Wir simulieren die Haushaltskonsolidierung im Euroraum im Zeitraum 2011 bis 2013 mit Hilfe von zwei DSGE Modellen der EZB und der Europäischen Kommission. Der kumulative Multiplikator beträgt 0.7 bzw. 1.0 in der Basislinie, steigt aber auf 1.3, wenn die Modelle um einen plausibel kalibrierter Finanzakzelerator erweitert und der Anteil liquiditätsbeschränkter Haushalte krisenbedingt erhöht wird. Im letzteren Szenario trägt die Haushaltskonsolidierung die maßgebliche Verantwortung für die Verschlechterung der Produktionslücke im Zeitraum 2011 bis 2013. Wäre die Haushaltskonsolidierung erst in einer Phase mit uneingeschränktem geldpolitischen Handlungsspielraum vorgenommen worden (d.h. nach der Erholung der Wirtschaft) hätte der Großteil der BIP-Verluste verhindert werden können

Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector

Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. A measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and pp collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of 208 mu b(-1) and 38 mu b(-1), respectively, and pp data with a sampled integrated luminosity of 1.17 pb(-1) were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in pp collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval vertical bar eta vertical bar < 2. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The bottom muon results are the most precise measurement of b quark nuclear modification at low transverse momentum where reconstruction of B hadrons is challenging. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays

A search for an unexpected asymmetry in the production of e+μ− and e−μ+ pairs in proton-proton collisions recorded by the ATLAS detector at root s = 13 TeV

This search, a type not previously performed at ATLAS, uses a comparison of the production cross sections for e(+)mu(-) and e(-)mu(+) pairs to constrain physics processes beyond the Standard Model. It uses 139 fb(-1) of proton-proton collision data recorded at root s = 13 TeV at the LHC. Targeting sources of new physics which prefer final states containing e(+)mu(-) and e(-)mu(+), the search contains two broad signal regions which are used to provide model-independent constraints on the ratio of cross sections at the 2% level. The search also has two special selections targeting supersymmetric models and leptoquark signatures. Observations using one of these selections are able to exclude, at 95% confidence level, singly produced smuons with masses up to 640 GeV in a model in which the only other light sparticle is a neutralino when the R-parity-violating coupling lambda(23)(1)' is close to unity. Observations using the other selection exclude scalar leptoquarks with masses below 1880 GeV when g(1R)(eu) = g(1R)(mu c) = 1, at 95% confidence level. The limit on the coupling reduces to g(1R)(eu) = g(1R)(mu c) = 0.46 for a mass of 1420 GeV