Soft Physics in Pb-Pb at the LHC

The LHC results on particle and transverse energy production and Bose-Einstein correlations show that the system produced in Pb-Pb collisions at psNN = 2:76TeV is significantly larger, lives longer and is hotter and denser than at RHIC energies. The particle spectra and soft particle correlations allow a more detailed study of the properties of the produced system and its initial conditions. This contribution highlights some of the first soft physics results from the LHC.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 5 figur

Commissioning and Prospects for Early Physics with ALICE

The ALICE detector has been commissioned and is ready for taking data at the Large Hadron Collider. The first proton-proton collisions are expected in 2009. This contribution describes the current status of the detector, the results of the commissioning phase and its capabilities to contribute to the understanding of both pp and PbPb collisionsComment: 8 pages, 7 figures, To appear in the proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Radiation Tolerance of Single-Sided Microstrip Detector with Si3N4Si_{3}N_{4} Insulator

The ALICE Collaboration is investigating the radiation tolerance and operation of silicon microstrip detectors for the inner tracking system. Detectors with and without an additional layer of Si3N4 insulator were made in one set, using the same thickness of SiO2 insulator. Measurements were made on both types of detectors after irradiation with 20 MeV electrons, using doses up to 2Mrad. The additional Si3N4 layer allows a coupling capacitor breakdown voltage larger than 100 V and capacitor yield larger than 99 percent. However, the leakage current for detectors with double layer insulator is about 20 nA per strip while the leakage current for the single layer SiO2 insulated detectors is only 0.5 nA. The 20 nA leakage current leads to 450 electrons noise when the ALICE 128C electronics with a peaking time of 1.4 microseconds is used. At a 1 nA leakage current the noise is 100 electrons. The ENC for an input capacitance of 5 pF is 300 electrons. Since all detectors show an increased leakage current after irradiation, the difference between the single and duoble layer insulation detectors becomes negligible when doses of the order of several hundreds of krad are applied

Very low mass microcables for the ALICE silicon strip detector

Proposal of abstract for LEB99, Snowmass, Colorado, 20-24 September 1999The ALICE Inner Tracker (ITS) silicon strip layers will use kapton/aluminium microcables (12/14 um thickness) exclusively for all interconnections to and from the front-end chips and hybrids, completely eliminating traditional wirebonding. Benefits are increased robustness and an extra degree of dimensional freedom. Utilising a low-power, low temperature and low-force (10-15 grams) single-point TAB bonding process, aluminium traces are directly bonded through bonding windows in the kapton foil to bond pads on the chips and the hybrid. The same technique is also used to interconnect these microcables to create multi-layer bus structures with "bonded via's". A double-sided strip detector using prototype cables has been installed in the NA57 experiment in 1998

Conductive Cooling of SDD and SSD Front-End Chips for ALICE

We present analysis, technology developments and test results of the heat drain system of the SDD and SSD front-end electronics for the ALICE Inner Tracker System (ITS). Application of super thermoconductive carbon fibre thin plates provides a practical solution for the development of miniature motherboards for the FEE chips situated inside the sensitive ITS volume. Unidirectional carbon fibre motherboards of 160 -300 micron thickness ensure the mounting of the FEE chips and an efficient heat sink to the cooling arteries. Thermal conductivity up to 1.3 times better than copper is achieved while preserving a negligible multiple scattering contribution by the material (less than 0.15 percent of X/Xo)

Dynamic IMF production in 24Mg+27Al^{24}Mg + ^{27}Al at intermediate energies

The azimuthal correlations and polar-angle distributions of intermediate-mass fragments (IMFs) produced in Mg+Al at 45 an 95 AMeV were studied. Measurements of $\alpha$-particles and IMFs with $3\le Z\le8$ emmitted in the mid-rapidity region for mid-central events were compared to IQMD results and results from a static-source model. A maximum in the azimuthal-correlation function at 180\degree\/ can not be described by independently emmitted particles. Momentum conservation of a small source as well as target-projectile correlations from IQMD show the same azimuthal correlations as the experimental data. The polar-angle distributions in the experimental data show a target-projectile seperation, thus giving evidence of dynamic IMF production.\\ {\it Keywords:} dynamic multifragmentation, IMF, IQMD, azimuthal correlations

High Rates of Return to Sports Activities and Work After Osteotomies Around the Knee: A Systematic Review and Meta-Analysis

© 2017, The Author(s). Background: Knee osteotomies are proven treatment options, especially in younger patients with unicompartmental knee osteoarthritis, for certain cases of chronic knee instability, or as concomitant treatment for meniscal repair or transplantation surgery. Presumably, these patients wish to stay active. Data on whether these patients return to sport (RTS) activities and return to work (RTW) are scarce. Objectives: Our aim was to systematically review (1) the extent to which patients can RTS and RTW after knee osteotomy and (2) the time to RTS and RTW. Methods: We systematically searched the MEDLINE and Embase databases. Two authors screened and extracted data, including patient demographics, surgical technique, pre- and postoperative sports and work activities, and confounding factors. Two authors assessed methodological quality. Data on pre- and postoperative participation in sports and work were pooled. Results: We included 26 studies, involving 1321 patients (69% male). Mean age varied between 27 and 62 years, and mean follow-up was 4.8 years. The overall risk of bias was low in seven studies, moderate in ten studies, and high in nine studies. RTS was reported in 18 studies and mean RTS was 85%. Reported RTS in studies with a low risk of bias was 82%. No studies reported time to RTS. RTW was reported in 14 studies; mean RTW was 85%. Reported RTW in studies with a low risk of bias was 80%. Time to RTW varied from 10 to 22 weeks. Lastly, only 15 studies adjusted for confounders. Conclusion: Eight out of ten patients returned to sport and work after knee osteotomy. No data were available on time to RTS. A trend toward performing lower-impact sports was observed. Time to RTW varied from 10 to 22 weeks, and almost all patients returned to the same or a higher workload

First measurement of Ξc0\Xi_{\rm c}^0 production in pp collisions at s\mathbf{\sqrt{s}} = 7 TeV

The production of the charm-strange baryon $\Xi_{\rm c}^0$ is measured for the first time at the LHC via its semileptonic decay into e$^+\Xi^-\nu_{\rm e}$ in pp collisions at $\sqrt{s}=7$ TeV with the ALICE detector. The transverse momentum ($p_{\rm T}$) differential cross section multiplied by the branching ratio is presented in the interval 1 $<$ $p_{\rm T}$ $<$ 8 GeV/$c$ at mid-rapidity, $|y|$ $<$ 0.5. The transverse momentum dependence of the $\Xi_{\rm c}^0$ baryon production relative to the D$^0$ meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.Comment: 22 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/412

Measurement of the production of charm jets tagged with D0^{0} mesons in pp collisions at s\sqrt{s}= 7 TeV

The production of charm jets in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=7$ TeV was measured with the ALICE detector at the CERN Large Hadron Collider. The measurement is based on a data sample corresponding to a total integrated luminosity of $6.23$ ${\rm nb}^{-1}$, collected using a minimum-bias trigger. Charm jets are identified by the presence of a D$^0$ meson among their constituents. The D$^0$ mesons are reconstructed from their hadronic decay D$^0\rightarrow$K$^{-}\pi^{+}$. The D$^0$-meson tagged jets are reconstructed using tracks of charged particles (track-based jets) with the anti-$k_{\mathrm{T}}$ algorithm in the jet transverse momentum range $5<p_{\rm{T,jet}}^{\mathrm{ch}}<30$ ${\rm GeV/}c$ and pseudorapidity $|\eta_{\rm jet}|<0.5$. The fraction of charged jets containing a D$^0$-meson increases with $p_{\rm{T,jet}}^{\rm{ch}}$ from $0.042 \pm 0.004\, \mathrm{(stat)} \pm 0.006\, \mathrm{(syst)}$ to $0.080 \pm 0.009\, \rm{(stat)} \pm 0.008\, \rm{(syst)}$. The distribution of D$^0$-meson tagged jets as a function of the jet momentum fraction carried by the D$^0$ meson in the direction of the jet axis ($z_{||}^{\mathrm{ch}}$) is reported for two ranges of jet transverse momenta, $5<p_{\rm{T,jet}}^{\rm{ch}}<15$ ${\rm GeV/}c$ and $15<p_{\rm{T,jet}}^{\rm{ch}}<30$ ${\rm GeV/}c$ in the intervals $0.2<z_{||}^{\rm{ch}}<1.0$ and $0.4<z_{||}^{\rm{ch}}<1.0$, respectively. The data are compared with results from Monte Carlo event generators (PYTHIA 6, PYTHIA 8 and Herwig 7) and with a Next-to-Leading-Order perturbative Quantum Chromodynamics calculation, obtained with the POWHEG method and interfaced with PYTHIA 6 for the generation of the parton shower, fragmentation, hadronisation and underlying event.Comment: 29 pages, 8 captioned figures, 3 tables, authors from page 24, published version, figures at http://alice-publications.web.cern.ch/node/525