QCD analysis of charged-current structure functions
The structure functions F 2 ( x , Q 2 ) and xF 3 ( x , Q 2 ) measured in high-energy neutrino charged-current interactions on nuclei are compared with QCD predictions. Solutions to the moment equations of QCD are found which are in good agreement with the data and yield simple parametrisations of the structure functions. For the scale parameter Λ we find Λ = 0.5 ± 0.2 GeV. The analysis also results in values for the width of the gluon distribution as a function of Q 2 . We find 〈 x 〉 gluons = 0.16 ± 0.03 for Q 2 = 10 GeV 2 .

title: Production of excited beauty states inZ decays
abstract: AbstractA data sample of about 3.0 million hadronicZ decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of B hadron events. In this event sample 4227±140±252B* mesons in the decayB*→Bγ and 1944±108±161B**u,d mesons decaying into a B meson and a charged pion are reconstructed. Here and in the followingB**u,d denotes the eightL=1(bū) and (bd) states and their charge conjugate.For the well establishedB* meson the following quantities are obtained:ΔM=MB*−MB=(45.30±0.35±0.87) MeV/c2 andNB*/(NB+NB*)=(77.1±2.6±7.0)%. The angular distribution of the photons in theB* rest frame is used to measure the relative contribution of longitudinalB* polarization states to beσL/(σL+σT)=(33±6±5)%.In theM(Bπ)−M(B) mass difference resonance structure is observed at (424±4±10) MeV/c2, for which the shape and position is consistent with the expectation forB**u,d states decaying intoB(*)π±. The relative production rate is determined to be
$$\begin{gathered} \frac{{BR(Z \to b \to B_{u,d}^{ * * } )}}{{BR(Z \to b \to B_{u,d} )}} \hfill \\ = [27.9 \pm 1.6(stat) \pm 5.9(syst) {}_{ - 5.6}^{ + 3.9} (model)]\% \hfill \\ \end{gathered} $$
 where the third error reflects the uncertainty due to different production and decay models for the broadB**u,d states.

title: First measurement of the quark-to-photon fragmentation function
abstract: Earlier measurements at LEP of isolated hard photons in hadronic Z decays, attributed to radiation from primary quark pairs, have been extended in the ALEPH experiment to include hard photon productioninside hadron jets. Events are selected where all particles combine democratically to form hadron jets, one of which contains a photon with a fractional energyz≥0.7. After statistical subtraction of non-prompt photons, the quark-to-photon fragmentation function,D(z), is extracted directly from the measured 2-jet rate. By taking into account the perturbative contributions toD(z) obtained from anO(ααs) QCD calculation, the unknown non-perturbative component ofD(z) is then determined at highz. Provided due account is taken of hadronization effects nearz=1, a good description of the other event topologies is then found.

title: Studies of quantum chromodynamics with the ALEPH detector
abstract: Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons.

title: Charged particle pair production associated with a lepton pair in Z decays. indication of an excess in the tau channel
abstract: In a sample of 200 000 Z decays, events with two leptons and an additional pair of charged particles are studied. The 35 events found show a possible excess in the tau channel compared with the expectation from electroweak processes. The features of the events are consistent with radiation of virtual photons.

title: A measurement of the ratio of longitudinal and transverse structure functions in neutrino interactions between 30 and 200 GeV
abstract: A new measurement of the ratio R = σ L / σ T of longitudinal and transverse structure functions in neutrino interactions on iron between 30 and 190 GeV neutrino energy is reported. The result is given as a function of the scale parameter x and the inelasticity ν of the interaction. The average value is R = 0.10 ± 0.07 around ν ≈ 50 GeV and is in accordance with a prediction from the QCD theory.

title: CHARACTERIZATION OF THE PIEZO BLADE TUNER FOR SUPERCONDUCTING RF CAVITIES
abstract: Cavity tuners are mechanical devices designed to precisely match the resonant frequency of a superconducting (SC) cavity to the RF frequency synchronous with the beam. The blade tuner is mounted coaxially to the cavity and changes the resonator frequency by varying its length. A high tuning range is desired together with small mechanical hysteresis, to allow for easy and reproducible resonator setup operations. A high stiffness of the tuner system is also necessary both to ensure mechanical stability and to mitigate the frequency instabilities induced by perturbations. In high gradient SC resonators, the main sources of resonant frequency instability are the Lorentz Force Detuning (LFD) under pulsed mode operation, and the microphonic noise, in continuous wave (CW) with high loaded quality factors. Piezoelectric ceramic (piezo) elements add a dynamic tuning capability to the system, allowing fast compensation of these instabilities with the help of feedforward and feedback loops. The piezo blade tuner has been extensively tested assembled on a TESLA type cavity in its final configuration. Tests were done both at room temperature and under cryogenic conditions. This paper presents the summary of the complete characterization tests.

title: STATUS OF THE BERLINPRO OPTICS DESIGN
abstract: Following the funding approval late 2010, HelmholtzZentrum Berlin officially started the realization of the Berlin Energy Recovery Linac Project BERLinPro in January 2011. The goal of this compact ERL is to develop the accelerator physics and technology required to accelerate a high-current (100 mA) and low emittance (1 mm·mrad normalized) beam, as desired by future large scale facilities based on ERLs, e.g ERL-based synchrotron light sources. Using the flexibility ERLs provides, a short bunch operation mode will also be investigated. A modified optics is presented and different non-linear issues are addressed.

title: Flux trapping in niobium cavities during breakdown events ∗
abstract: We report on the discovery of increased residual losses in niobium cavities following rapid quenches, in particular after thermal breakdown and multipacting. Increases of the residual resistance in the breakdown affected region by more than a factor of 10 have been recorded in some instances. It is believed that magnetic flux, generated by thermocurrents during breakdown, is trapped as the cavity reverts to the superconducting state, resulting in the enhanced losses. A thermal cycle to above the critical temperature of niobium is required to restore the initial low-loss state.

title: Cryogenic Considerations for CW Operation of TESLA-type Superconducting Cavity Modules for the BESSY FEL ∗
abstract: The proposed BESSY FEL uses a CW superconducting driver linac to provide acceleration up to 2.3 GeV. Its design is based on TESLA cavity modules, originally intended for pulsed operation and heat loads of order 1 W/m at 2 K. CW operation increases this load to about 21 W/m for a total heat load of 3 kW. Presented here is an analysis of the cryogenic layout, including two-phase-flow simulations of the superfluid helium which help identify the changes needed for reliable CW operation. A modified “CW” module and helium distribution scheme is proposed.

title: Dark current measurements on a superconducting cavity using a cryogenic current comparator.
abstract: This paper presents nondestructive dark current measurements of tera electron volt energy superconducting linear accelerator cavities. The measurements were carried out in an extremely noisy accelerator environment using a low temperature dc superconducting quantum interference device based cryogenic current comparator. The overall current sensitivity under these rough conditions was measured to be 0.2 nA/Hz(1/2), which enables the detection of dark currents of 5 nA.