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Water probes the dynamics in young stellar objects (YSOs) effectively, especially shocks in molecular outflows. It is a key molecule for exploring whether the physical properties of low-mass protostars can be extrapolated to massive YSOs. As part of the WISH key programme, we investigate the dynamics and the excitation conditions of shocks along the outflow cavity wall as function of source luminosity. Velocity-resolved Herschel-HIFI spectra of the H2O 988, 752, 1097 GHz and 12CO J=10-9, 16-15 lines were analysed for 52 YSOs with bolometric luminosities (L_bol) ranging from <1 to >10^5 L_sun. The profiles of the H2O lines are similar, indicating that they probe the same gas. We see two main Gaussian emission components in all YSOs: a broad component associated with non-dissociative shocks in the outflow cavity wall (cavity shocks) and a narrow component associated with quiescent envelope material. More than 60% of the total integrated intensity of the H2O lines (L_H2O) comes from the cavity shock component. The H2O line widths are similar for all YSOs, whereas those of 12CO 10-9 increase slightly with L_bol. The excitation analysis of the cavity shock component, performed with the non-LTE radiative transfer code RADEX, shows stronger 752 GHz emission for high-mass YSOs, likely due to pumping by an infrared radiation field. As previously found for CO, a strong correlation with slope unity is measured between log(L_H2O) and log(L_bol), which can be extrapolated to extragalactic sources. We conclude that the broad component of H2O and high-J CO lines originate in shocks in the outflow cavity walls for all YSOs, whereas lower-J CO transitions mostly trace entrained outflow gas. The higher UV field and turbulent motions in high-mass objects compared to their low-mass counterparts may explain the slightly different kinematical properties of 12CO 10-9 and H2O lines from low- to high-mass YSOs., Comment: Abridged abstract, 31 pages, 18 figures, 12 tables, accepted in Astronomy & Astrophysics

In this addendum to Phys. Rev. D 88, no. 1, 013009 (2013), we give results for the electroweak Sudakov corrections in gauge-boson production at large transverse momentum p_T at proton colliders. In order for the results to be easily usable, we provide a simple and accurate parameterization of the corrections as a function of p_T and the center-of-mass energy \sqrt{s}. Additionally, we also discuss the dependence of the electroweak corrections on the rapidity of the produced boson, and comment on the complications that arise in the photon-production case due to isolation requirements, Comment: 4 pages, 4 figures

Intermediate mass protostarsprovide a bridge between theories of low- and high-mass star formation. Emerging molecular outflows can be used to determine the influence of fragmentation and multiplicity on protostellar evolution through the correlation of outflow forces of intermediate mass protostars with the luminosity. The aim of this paper is to derive outflow forces from outflows of six intermediate mass protostellar regions and validate the apparent correlation between total luminosity and outflow force seen in earlier work, as well as remove uncertainties caused by different methodology. By comparing CO 6--5 observations obtained with APEX with non-LTE radiative transfer model predictions, optical depths, temperatures, densities of the gas of the molecular outflows are derived. Outflow forces, dynamical timescales and kinetic luminosities are subsequently calculated. Outflow parameters, including the forces, were derived for all sources. Temperatures in excess of 50 K were found for all flows, in line with recent low-mass results. However, comparison with other studies could not corroborate conclusions from earlier work on intermediate mass protostars which hypothesized that fragmentation enhances outflow forces in clustered intermediate mass star formation. Any enhancement in comparison with the classical relation between outflow force and luminosity can be attributed the use of a higher excitation line and improvement in methods; They are in line with results from low-mass protostars using similar techniques. The role of fragmentation on outflows is an important ingredient to understand clustered star formation and the link between low and high-mass star formation. However, detailed information on spatial scales of a few 100 AU, covering all individual members is needed to make the necessary progress., Comment: 14 pages, accepted for publication in A&A; changed a few boldface text left in

Top quark production in the process $e^+e^- \to t\bar{t}$ at a future linear electron positron collider with polarised beams is a powerful tool to determine indirectly the scale of new physics. The presented study, based on a detailed simulation of the ILD detector concept, assumes a centre-of-mass energy of $\sqrt{s}=500\,$GeV and a luminosity of $\mathcal{L}=500\,{\rm fb}^{-1}$ equally shared between the incoming beam polarisations of $\mathcal{P}_{e^-}, \mathcal{P}_{e^+} =\pm0.8,\mp0.3$. Events are selected in which the top pair decays semi-leptonically and the cross sections and the forward-backward asymmetries are determined. Based on these results, the vector, axial vector and tensorial $CP$ conserving couplings are extracted separately for the photon and the $Z^0$ component. With the expected precision, a large number of models in which the top quark acts as a messenger to new physics can be distinguished with many standard deviations. This will dramatically improve expectations from e.g. the LHC for electro-weak couplings of the top quark., Comment: This work is an update of arXiv:1307.8102, minor changes w.r.t. v1 (typos, wrong grammar, incomplete sentences etc.)

We analyze transverse thrust in the framework of Soft Collinear Effective Theory and obtain a factorized expression for the cross section that permits resummation of terms enhanced in the dijet limit to arbitrary accuracy. The factorization theorem for this hadron-collider event-shape variable involves collinear emissions at different virtualities and suffers from a collinear anomaly. We compute all its ingredients at the one-loop order, and show that the two-loop input for next-to-next-to-leading logarithmic accuracy can be extracted numerically, from existing fixed-order codes., Comment: 47 pages, 12 figures. v2: journal version

Context: Outflows are an important part of the star formation process as both the result of ongoing active accretion and one of the main sources of mechanical feedback on small scales. Water is the ideal tracer of these effects because it is present in high abundance in various parts of the protostar. Method: We present \textit{Herschel} HIFI spectra of multiple water-transitions towards 29 nearby Class 0/I protostars as part of the WISH Survey. These are decomposed into different Gaussian components, with each related to one of three parts of the protostellar system; quiescent envelope, cavity shock and spot shocks in the jet and at the base of the outflow. We then constrain the excitation conditions present in the two outflow-related components. Results: Water emission is optically thick but effectively thin, with line ratios that do not vary with velocity, in contrast to CO. The physical conditions of the cavity and spot shocks are similar, with post-shock H$_{2}$ densities of order 10$^{5}-$10$^{8}$\,cm$^{-3}$ and H$_{2}$O column densities of order 10$^{16}-$10$^{18}$\,cm$^{-2}$. H$_{2}$O emission originates in compact emitting regions: for the spot shocks these correspond to point sources with radii of order 10-200\,AU, while for the cavity shocks these come from a thin layer along the outflow cavity wall with thickness of order 1-30\,AU. Conclusions: Water emission at the source position traces two distinct kinematic components in the outflow; J shocks at the base of the outflow or in the jet, and C shocks in a thin layer in the cavity wall. Class I sources have similar excitation conditions to Class 0 sources, but generally smaller line-widths and emitting region sizes. We suggest that it is the velocity of the wind driving the outflow, rather than the decrease in envelope density or mass, that is the cause of the decrease in H$_{2}$O intensity between Class 0 and I., Comment: Abstract is abridged. Accepted to Astronomy & Astrophysics. 50 pages (21 excluding appendices), 15 figures and 7 tables in the main paper, 18 figures and 10 tables in the appendices. Table 4 updated to Corrigendum version

We present an update of our determination of the strong coupling alpha_s from the quantum chromodynamics static energy. This updated analysis includes new lattice data, at smaller lattice spacings and reaching shorter distances, the use of better suited perturbative expressions to compare with data in a wider distance range, and a comprehensive and detailed estimate of the error sources that contribute to the uncertainty of the final result. Our updated value for alpha_s at the Z-mass scale, M_Z, is alpha_s(M_Z)=0.1166^{+0.0012}_{-0.0008}, which supersedes our previous result., Comment: 20 pages, 23 figures. v2: Minor changes. Journal version. v3: Misprint corrected in Eq.(11), results unchanged

The spectrum of electrons from muons decaying in an atomic bound state is significantly modified by their interaction with the nucleus. Somewhat unexpectedly, its first measurement, at the Canadian laboratory TRIUMF, differed from basic theory. We show, using a combination of techniques developed in atomic, nuclear, and high-energy physics, that radiative corrections eliminate the discrepancy. In addition to solving that outstanding problem, our more precise predictions are potentially useful for interpreting future high-statistics muon experiments that aim to search for exotic interactions at $10^{-16}$ sensitivity., Comment: 6 pages, 4 figures, Alberta Thy 7-14 v2: Expanded discussion. Journal version

This report summarizes the proceedings of the 2014 Mainz Institute for Theoretical Physics (MITP) scientific program on "High precision fundamental constants at the TeV scale". The two outstanding parameters in the Standard Model dealt with during the MITP scientific program are the strong coupling constant $\alpha_s$ and the top-quark mass $m_t$. Lacking knowledge on the value of those fundamental constants is often the limiting factor in the accuracy of theoretical predictions. The current status on $\alpha_s$ and $m_t$ has been reviewed and directions for future research have been identified., Comment: 57 pages, 24 figures, pdflatex

In this paper we explore the effect of $\delta$-ray emission, fluctuations in th e signal deposition on the detection of charged particles in silicon-based detec tors. We show that these two effects ultimately limit the resolution that can be achieved by interpolation of the signal in finely segmented position-sensitive solid-state devices., Comment: 5 pages

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly-coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments., Comment: 246 pp, around 128 figures; v2 adds material, references, and corrections suggested by readers of v1 -- to be submitted to EPJC

We briefly review some of the lower-energy constraints to the perturbative behaviour of the strong coupling $\alpha_s$, with some emphasis on the determination coming from the energy between two static sources calculated on the lattice., Comment: 4 pages, 1 figure. Contribution to the proceedings of MENU2013

(Abridged) We study the response of the gas to energetic processes associated with high-mass star formation and compare it with studies on low- and intermediate-mass young stellar objects (YSOs) using the same methods. The far-IR line emission and absorption of CO, H$_2$O, OH, and [OI] reveals the excitation and the relative contribution of different species to the gas cooling budget. Herschel-PACS spectra covering 55-190 um are analyzed for ten high-mass star forming regions of various luminosities and evolutionary stages at spatial scales of ~10^4 AU. Radiative transfer models are used to determine the contribution of the envelope to the far-IR CO emission. The close environments of high-mass YSOs show strong far-IR emission from molecules, atoms, and ions. Water is detected in all 10 objects even up to high excitation lines. CO lines from J=14-13 up to typically 29-28 show a single temperature component, Trot~300 K. Typical H$_2$O temperatures are Trot~250 K, while OH has Trot~80 K. Far-IR line cooling is dominated by CO (~75 %) and to a smaller extent by OI (~20 %), which increases for the most evolved sources. H$_2$O is less important as a coolant for high-mass sources because many lines are in absorption. Emission from the envelope is responsible for ~45-85 % of the total CO luminosity in high-mass sources compared with only ~10 % for low-mass YSOs. The highest-J lines originate most likely from shocks, based on the strong correlation of CO and H$_2$O with physical parameters of the sources from low- to high-masses. Excitation of warm CO is very similar for all mass regimes, whereas H$_2$O temperatures are ~100 K higher for high-mass sources than the low-mass YSOs. Molecular cooling is ~4 times more important than cooling by [OI]. The total far-IR line luminosity is about 10$^{-3}$ and 10$^{-5}$ times lower than the dust luminosity for the low- and high-mass YSOs., Comment: 23 pages, 19 figures, 6 Tables. Accepted to Astronomy and Astrophysics