The Spectacle of Crime, Digitized

International audienceOne of the most significant features of the television series CSI: Crime Scene Investigationis its central preoccupation – forensic evidence – and the profession practised by its major characters – forensic science. Scientific inscriptions consistently allow the crime scene investigators (CSIs) to determine 'evidence' and 'truths' that otherwise elude them. At the same time, the dazzling digital effects used to punctuate key moments in each episode inevitably reference scientific technologies and the knowledge about reality that these promise. The success of the CSIs in every episode is premised upon knowledge guaranteed by scientific inscriptions and is itself an inscription of ways of seeing human bodies and the social body, represented by police scientists working to ensure public safety – a healthy social body. And it is also about how bodies, individual and social, are constituted as information, made knowable and validated by scientific instruments and procedures used to produce evidence

Geological history of the Winchcombe meteorite - A new cm Chrondrite fall

Introduction: The Mighei-like (CM) carbonaceous chondrites are the largest class of hydrated meteorites, representing collisionally derived fragments of water-rich asteroids [1,2]. Most (>95%) are breccias, whose clasts sample a range of aqueous alteration extents [3]. They can therefore act as “snapshots” recording the progression of fluidrock interaction on the CM parent body. Conversely, analysis of the material between clasts (termed cataclastic matrix) provides an opportunity to study the post-hydration history of the CM parent body, specifically its fragmentation and re-accretion. Here, we investigate both aspects of the CM chondrites’ geological history through study of the newly recovered fall: Winchcombe [4, 5]. Methods: Sixteen polished sections with a total area of 190 mm2 were generated for this work. They were studied under scanning electron microscopy (SEM) using backscattered electron (BSE) imaging, energy dispersive X-ray spectroscopy (EDX) and electron microprobe analysis (EMPA). These sections sample the two largest masses (the main mass [320 g] and the agricultural field stone [152 g]) recovered from the Winchcombe strewn field [4]. Results: Winchcombe is a breccia, composed of lithological clasts held within a cataclastic matrix. We identified eight distinct lithologies. Their aqueous alteration extents vary between intensely altered CM2.0 and moderately altered CM2.6 [6]. Although no lithology dominates, three rock types represent >70% of the studied area. Several lithologies contain abundant tochilinite-cronstedtite intergrowths (TCIs). Type-II forms with zoned textures are most common, typically they have Fe-rich rims (“FeO”/SiO2 wt.%: 1-5) and Mg-rich cores (“FeO”/SiO2 wt.%: < 1), however, forms with hollow cores or cores containing a mix of phyllosilicate and calcite or phyllosilciates and anhydrous silicate are also found. The cataclastic matrix represents ~15% of the studied area. It has a coarse, heterogenous texture and includes abundant subangular fragments. Fragments include the full range of CM chondrite components (e.g. Fe-sulphides, whole chondrules with or without fine-grained rims, olivine and pyroxene grains, serpentine, carbonate grains, TCI clusters, as well as coherent blocks of fine-grained matrix). The cataclastic matrix is, therefore, a complex mix of components, with both heavily altered and mildly altered phases found in close association. Another striking feature is the apparent low abundance (< 3 area%) of identifiable whole chondrules. Discussion and conclusions: Our data suggest that both anhydrous silicates and carbonates (T1a calcites) act as precursor phases for type-II TCI formation. Cross-cutting relationships allow the sequence of mineralization to be reconstructed. Initially, inward dissolution by Fe-rich and S-rich fluids forms rims composed of intermixed tochilinite and cronstedtite. In the intermediate stages of type-II TCI formation, further dissolution continues without concurrent precipitation, resulting in the formation of hollow structures. These voids were later infilled, most often by Mg-rich phyllosilicates. As alteration advanced, early-formed secondary phases became unstable and were either dissolved (e.g. T1a calcites) or chemically altered (e.g. TCI rims). The presence of numerous lithological clasts with variable aqueous alteration extents and abrupt boundaries found in close juxtaposition indicates that the cataclastic matrix formed by the deposition of fines, alongside larger fragments (the clasts), on or near the surface of the parent asteroid. Furthermore, the composition of the cataclastic matrix is consistent with formation by fragmentation and mixing of debris derived from the entire clast population. The cataclastic matrix is, therefore, interpreted as an impact-derived fallback breccia. Analysis of grain size and texture suggests that disruption of the original parent asteroid responded by intergranular fracture at grain sizes <100 μm, while larger phases, such as whole chondrules, splintered apart. Re-accretion formed a poorly lithified rubble-pile body. During atmospheric entry, the meteoroid broke apart with new fractures preferentially cutting through the weaker cataclastic matrix and thereby separating the Winchcombe meteoroid into its component- lithological clasts. Thus, the strength of the cataclastic matrix imparts a significant control on the survival of CM chondrite meteoroids. References: [1] McSween, 1979. GCA, 43:1761-1770. [2] Suttle et al. 2021. GCA, 299:219-256. [3] Bischoff, et al. 2017, 80th MetSoc. (Abstr.#6089), [4] Meteoritical Bulletin Database, Winchcombe entry (available at: https://www.lpi.usra.edu/meteor/metbull.php?code=74388). [5] Daly et al., (this meeting). [6] Rubin et al. 2007,GCA, 71:2361-2382

The Earth: Plasma Sources, Losses, and Transport Processes

This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Study of the lineshape of the chi(c1) (3872) state

A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations

Measurement of the CKM angle γγ in B±→DK±B^\pm\to D K^\pm and B±→Dπ±B^\pm \to D π^\pm decays with D→KS0h+h−D \to K_\mathrm S^0 h^+ h^-

A measurement of $CP$-violating observables is performed using the decays $B^\pm\to D K^\pm$ and $B^\pm\to D \pi^\pm$, where the $D$ meson is reconstructed in one of the self-conjugate three-body final states $K_{\mathrm S}\pi^+\pi^-$ and $K_{\mathrm S}K^+K^-$ (commonly denoted $K_{\mathrm S} h^+h^-$). The decays are analysed in bins of the $D$-decay phase space, leading to a measurement that is independent of the modelling of the $D$-decay amplitude. The observables are interpreted in terms of the CKM angle $\gamma$. Using a data sample corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$ collected in proton-proton collisions at centre-of-mass energies of $7$, $8$, and $13\,\text{TeV}$ with the LHCb experiment, $\gamma$ is measured to be $\left(68.7^{+5.2}_{-5.1}\right)^\circ$. The hadronic parameters $r_B^{DK}$, $r_B^{D\pi}$, $\delta_B^{DK}$, and $\delta_B^{D\pi}$, which are the ratios and strong-phase differences of the suppressed and favoured $B^\pm$ decays, are also reported

Helium identification with LHCb

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Curvature-bias corrections using a pseudomass method

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

Flow harmonic coefficients, v n , which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV . The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features

Study of CP violation in B0 → DK⋆(892)0 decays with D → Kπ(ππ), ππ(ππ), and KK final states

A measurement of CP-violating observables associated with the interference of B0 → D0K⋆ (892)0 and B0 → D¯ 0K⋆ (892)0 decay amplitudes is performed in the D0 → K∓π ±(π +π −), D0 → π +π −(π +π −), and D0 → K+K− fnal states using data collected by the LHCb experiment corresponding to an integrated luminosity of 9 fb−1 . CP-violating observables related to the interference of B0 s → D0K¯ ⋆ (892)0 and B0 s → D¯ 0K¯ ⋆ (892)0 are also measured, but no evidence for interference is found. The B0 observables are used to constrain the parameter space of the CKM angle γ and the hadronic parameters r DK⋆ B0 and δ DK⋆ B0 with inputs from other measurements. In a combined analysis, these measurements allow for four solutions in the parameter space, only one of which is consistent with the world average