Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}}$ = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in $|\eta|<0.8$ and $0.3 < p_T < 20$ GeV/$c$ are compared to the expectation in pp collisions at the same $\sqrt{s_{\rm NN}}$, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor $R_{\rm AA}$. The result indicates only weak medium effects ($R_{\rm AA} \approx$ 0.7) in peripheral collisions. In central collisions, $R_{\rm AA}$ reaches a minimum of about 0.14 at $p_{\rm T}=6$-7GeV/$c$ and increases significantly at larger $p_{\rm T}$. The measured suppression of high-$p_{\rm T}$ particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter

Context. The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. Aims. In this paper, we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. Methods. We use a set of precise radial velocity observations from HARPS, PFS, and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. Results. We find that TOI-969 b is a transiting close-in (Pb ∼ 1.82 days) mini-Neptune planet (Formula Presented), placing it on the lower boundary of the hot-Neptune desert (Teq,b = 941 \ub1 31 K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of (Formula Presented) days, a minimum mass of (Formula Presented), and a highly eccentric orbit of (Formula Presented). Conclusions. The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93 and orbits a moderately bright (G = 11.3 mag) star, making it an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Centrality dependence of \u3c0, K, and p production in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV

In this paper measurements are presented of \u3c0\ub1, K\ub1, p, and p(bar) production at midrapidity (|y| < 0.5), in Pb-Pb collisions at 1asNN= 2.76 TeV as a function of centrality. The measurement covers the transverse-momentum (pT ) range from 100, 200, and 300 MeV/c up to 3, 3, and 4.6 GeV/c for \u3c0, K, and p, respectively. The measured pT distributions and yields are compared to expectations based on hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In peripheral collisions, the pT distributions are not well reproduced by hydrodynamic models. Ratios of integrated particle yields are found to be nearly independent of centrality. The yield of protons normalized to pions is a factor 3c1.5 lower than the expectation from thermal models

J/\u3c8 Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=2.76\u2009\u2009TeV

We report on the first measurement of inclusive J/\u3c8 elliptic flow v2 in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at 1asNN=2.76 TeV in the rapidity range 2,5<y<4,0. The dependence of the J=c v2 on the collision centrality and on the J/\u3c8 transverse momentum is studied in the range 0 64pT 64 10 GeV/c. For semicentral Pb-Pb collisions at 1asNN=2.76 TeV, an indication of nonzero v2 is observed with a largest measured value of v2=0.116 \ub1 0.046 (stat) \ub1 0:029 (syst) for J/\u3c8 in the transverse momentum range 2 64 pT 64 4 GeV/c. The elliptic flow measurement complements the previously reported ALICE results on the inclusive J/\u3c8 nuclear modification factor and favors the scenario of a significant fraction of J/\u3c8 production from charm quarks in a deconfined partonic phase

Transverse Momentum Distribution and Nuclear Modification Factor of Charged Particles in p+Pb Collisions at sqrt[s_{NN}]=5.02\u2009\u2009TeV

The transverse momentum (pT) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p+Pb collisions at 1asNN=5.02 TeV with the ALICE detector at the LHC. The p T spectra measured near central rapidity in the range 0.5<p T<20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor RpPb is consistent with unity for pT above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high pT observed in Pb+Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations

Long-range angular correlationsof \u3c0, K and p in p\u2013Pb collisions at 1asNN =5.02TeV

Angular correlations between unidentified charged trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the transverse-momentum range 0.3<pT<4 GeV/c. The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range |\u3b7lab|<0.8. Fourier coefficients are extracted from the long-range correlations projected onto the azimuthal angle difference and studied as a function of pT and in intervals of event multiplicity. In high-multiplicity events, the second-order coefficient for protons, v2p, is observed to be smaller than that for pions, v2\u3c0, up to about pT=2 GeV/c. To reduce correlations due to jets, the per-trigger yield measured in low-multiplicity events is subtracted from that in high-multiplicity events. A two-ridge structure is obtained for all particle species. The Fourier decomposition of this structure shows that the second-order coefficients for pions and kaons are similar. The v2p is found to be smaller at low pT and larger at higher pT than v2\u3c0, with a crossing occurring at about 2 GeV/c. This is qualitatively similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass ordering effect at low transverse momenta is consistent with expectations from hydrodynamic model calculations assuming a collectively expanding system

Relationship between the mineralogical composition of the clay fraction of some andalusian caracteristic soils and theri behaviour in relation to potassium

12 páginas, 7 figuras, 3 tablas, 7 referencias.[ES]: Se estudia la fracción arcilla de los suelos más característicos de nuestra región y su comportamiento frente al potasio, relacionándolo con la composición mineralógica de dicha fracción. Exceptuando el suelo fersialítico, los diferentes horizontes de cada suelo no presentan variaciones importantes en su comportamiento frente al potasio. Los suelos vérticos litomorfos y vérticos topomorfos presentan los valores más altos de Kx, lo que está de acuerdo con una mayor edafización y con altas concentraciones de montmorillonita e ilita. El suelo calcimorfo, a pesar de poseer composición mineralógica simlar, está muy poco evolucionado y presenta valores más bajos de Kx, similares a los del suelo aluvial, que está asimismo poco evolucionado, con alta proporción de ilita, a la que acompañan pequeñas proporciones de montmorillonita y caolinita. En el suelo fersialítico lavado disminuye el valor de Kx, al descender en el perfil, en el mismo sentido en que disminuye la ilita y aumenta la montmorillonita. Los horizontes C de los suelos de gran desarrollo edafogenético presentan en relación con los horizontes superiores, a pesar de poseer composición mineralógica similar, valores muy pequeños de Kx. El grado de desarrollo del suelo es el que tiene mayor influencia en los valores de Kx. Los tratamientos de eliminación de materia orgánica y/o geles producen un aumento muy apreciable de los valores de Kx.[EN]: The clay fractions of soils caracteristic of western Anclalucía and their behaviour in relation to potassium are studied, and the latter in related to the mineralogical composition of the former. Except the "fersialitico soil" (Rhocloxeralfs), the various horizons of each soil do not present distinct variations in their behaviour in relation to potassium. The "vertisol litomorfo" (chromoxererts) and «topomorfo» (Pelloxererts) soils present the highest values of Kx which agrees with the strong weathering of these soils and their nigh proportions of montmoillonite and illite. The "calcimorfo soil" (Calciorthids) is little weathered and present lower values of Kx, despite its mineralogical composition, which is analogous to the preceding soils. Similarly low values of Kx are obtained for the «aluvial soil» (Xerofluvents), also little weathered, which contains high proportion of illite, with small amounts of montmorillonite and kaolinite. The value of Kx and the proportion of illite for the leached fersialitico soil decrease and the proportion of montmorillonite increases as getting down across the profile. C horizons of soils with high podogenic development present much lower values of Kx than upper horizona, despite the analogy of their mineralogical compositions. The degree of development of soils has the highest influence on Kx, values. Treatments for removing organic matter and/or gels originate important increases in Kx values.Peer reviewe