Calathus: A sample-return mission to Ceres

Ceres, as revealed by NASA's Dawn spacecraft, is an ancient, crater-saturated body dominated by low-albedo clays. Yet, localised sites display a bright, carbonate mineralogy that may be as young as 2 Myr. The largest of these bright regions (faculae) are found in the 92 km Occator Crater, and would have formed by the eruption of alkaline brines from a subsurface reservoir of fluids. The internal structure and surface chemistry suggest that Ceres is an extant host for a number of the known prerequisites for terrestrial biota, and as such, represents an accessible insight into a potentially habitable “ocean world”. In this paper, the case and the means for a return mission to Ceres are outlined, presenting the Calathus mission to return to Earth a sample of the Occator Crater faculae for high-precision laboratory analyses. Calathus consists of an orbiter and a lander with an ascent module: the orbiter is equipped with a high-resolution camera, a thermal imager, and a radar; the lander contains a sampling arm, a camera, and an on-board gas chromatograph mass spectrometer; and the ascent module contains vessels for four cerean samples, collectively amounting to a maximum 40 g. Upon return to Earth, the samples would be characterised via high-precision analyses to understand the salt and organic composition of the Occator faculae, and from there to assess both the habitability and the evolution of a relict ocean world from the dawn of the Solar System.The attached document is the authors’ final accepted version of the journal article provided here with a Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) Creative Commons Licence. You are advised to consult the publisher’s version if you wish to cite from it.

Adsorbed Natural Gas Tank feeded with Liquid Natural Gas

This paper present the idea of a natural gas reservoir, which uses technology of gas storage by adsorption on activated carbon. Such reservoir can be feeded with Liquid Natural Gas. The framework of article includes theoretical principals of gas-solid physical adsorption, and explains most important concepts associated with it. Moreover, concept of such tank and working regime is presented. Selected subject is very promising in the field of natural gas storage, although this is still a niche issue. Lack of universal models of gases physical adsorption made it very difficult to predict the runs of processes occurring in the proposed reservoir, which is why this project was based on models confirmed during in the earlier studies

Cryogenic Safety - HSE seminar

Cryogenic process pipelines are part of the basic subsystem used in installations for fundamental research in physics, as well as in industrial plants which use LNG or liquid nitrogen. The significant increase in importance of cryogenics entails the need to explore phenomena which have direct impact in the design process of cryogenic systems and their safety systems. These aspects are of high priority due to high investment costs, mainly because of safety issues and reliability. One of the issues which requires thorough investigation is the fracture mechanics of gas pipelines in cryogenic conditions. For this subject, importance is placed not only in when the cracks begin to appear, but also in how they form and how quickly they propagate. Currently, there is a lack of reliable research in the available literature in this area. This is often raised as a significant problem for designers, because knowledge in this topic should be reflected e.g., in the sizing calculations of safety valves for the vacuum systems. This presentation includes a review of the fundamentals of pipe cracking models, the impact of this phenomenon on the safety system design process, the concept of the test stand, and the method in which these studies have been conducted. The results of this research will be able to improve the selection of safety devices in cryogenic systems

Constraints on the KS0→μ+μ−K^0_S \rightarrow \mu^+ \mu^- Branching Fraction

International audienceA search for the decay KS0→μ+μ- is performed using proton-proton collision data, corresponding to an integrated luminosity of 5.6  fb-1 and collected with the LHCb experiment during 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. The observed signal yield is consistent with zero, yielding an upper limit of B(KS0→μ+μ-)<2.2×10-10 at 90% C.L.. The limit reduces to B(KS0→μ+μ-)<2.1×10-10 at 90% C.L. once combined with the result from data taken in 2011 and 2012

Measurement of the Bc−B_c^- meson production fraction and asymmetry in 7 and 13 TeV pppp collisions

International audienceThe production fraction of the Bc- meson with respect to the sum of B- and B¯0 mesons is measured in both 7 and 13 TeV center-of-mass (c.m.) energy pp collisions produced by the Large Hadron Collider (LHC), using the LHCb detector. The rate, approximately 3.7 per mille, does not change with energy, but shows a transverse momentum dependence. The Bc--Bc+ production asymmetry is also measured and is consistent with zero within the determined statistical and systematic uncertainties of a few percent

Observation of New Ξc0\Xi_c^0 Baryons Decaying to Λc+K−\Lambda_c^+ K^-

International audienceThe Λc+K- mass spectrum is studied with a data sample of pp collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 5.6  fb-1 collected by the LHCb experiment. Three Ξc0 states are observed with a large significance and their masses and natural widths are measured to be m[Ξc(2923)0]=2923.04±0.25±0.20±0.14  MeV, Γ[Ξc(2923)0]=7.1±0.8±1.8  MeV, m[Ξc(2939)0]=2938.55±0.21±0.17±0.14  MeV, Γ[Ξc(2939)0]=10.2±0.8±1.1  MeV, m[Ξc(2965)0]=2964.88±0.26±0.14±0.14  MeV, Γ[Ξc(2965)0]=14.1±0.9±1.3  MeV, where the uncertainties are statistical, systematic, and due to the limited knowledge of the Λc+ mass. The Ξc(2923)0 and Ξc(2939)0 baryons are new states. The Ξc(2965)0 state is in the vicinity of the known Ξc(2970)0 baryon; however, their masses and natural widths differ significantly

Determination of quantum numbers for several excited charmed mesons observed in B−→D∗+π−π−B^- \to D^{*+} \pi^- \pi^- decays

International audienceA four-body amplitude analysis of the B-→D*+π-π- decay is performed, where fractions and relative phases of the various resonances contributing to the decay are measured. Several quasi-model-independent analyses are performed aimed at searching for the presence of new states and establishing the quantum numbers of previously observed charmed meson resonances. In particular the resonance parameters and quantum numbers are determined for the D1(2420), D1(2430), D0(2550), D1*(2600), D2(2740) and D3*(2750) states. The mixing between the D1(2420) and D1(2430) resonances is studied and the mixing parameters are measured. The dataset corresponds to an integrated luminosity of 4.7  fb-1, collected in proton-proton collisions at center-of-mass energies of 7, 8 and 13 TeV with the LHCb detector

Measurement of ∣Vcb∣|V_{cb}| with Bs0→Ds(∗)−μ+νμB_s^0 \to D_s^{(*)-} \mu^+ \nu_{\mu} decays

International audienceThe element |Vcb| of the Cabibbo-Kobayashi-Maskawa matrix is measured using semileptonic Bs0 decays produced in proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3  fb-1. Rates of Bs0→Ds-μ+νμ and Bs0→Ds*-μ+νμ decays are analyzed using hadronic form-factor parametrizations derived either by Caprini, Lellouch and Neubert (CLN) or by Boyd, Grinstein and Lebed (BGL). The measured values of |Vcb| are (41.4±0.6±0.9±1.2)×10-3 and (42.3±0.8±0.9±1.2)×10-3 in the CLN and BGL parametrization, respectively. The first uncertainty is statistical, the second systematic, and the third is due to the external inputs used in the measurement. These results are in agreement with those obtained from decays of B+ and B0 mesons. They are the first determinations of |Vcb| at a hadron-collider experiment and the first using Bs0 meson decays

Measurement of CPCP-Averaged Observables in the B0→K∗0μ+μ−B^{0}\rightarrow K^{*0}\mu^{+}\mu^{-} Decay

International audienceAn angular analysis of the B0→K*0(→K+π-)μ+μ- decay is presented using a dataset corresponding to an integrated luminosity of 4.7  fb-1 of pp collision data collected with the LHCb experiment. The full set of CP-averaged observables are determined in bins of the invariant mass squared of the dimuon system. Contamination from decays with the K+π- system in an S-wave configuration is taken into account. The tension seen between the previous LHCb results and the standard model predictions persists with the new data. The precise value of the significance of this tension depends on the choice of theory nuisance parameters

Measurement of CP observables in B±^{±} → DK±^{±} and B±^{±} → Dπ±^{±} with D → KS0K±π∓ {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp } decays

International audienceMeasurements of CP observables in B$^{±}$ → DK$^{±}$ and B$^{±}$ → Dπ$^{±}$ decays are presented, where D represents a superposition of D$^{0}$ and ${\overline{D}}^0$ states. The D meson is reconstructed in the three-body final states ${K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp }$ and ${K}_{\mathrm{S}}^0{K}^{\mp }{\pi}^{\pm }$. The analysis uses samples of B mesons produced in proton-proton collisions, corresponding to an integrated luminosity of 1.0, 2.0, and 6.0 fb$^{−1}$ collected with the LHCb detector at centre-of-mass energies of $\sqrt{s}$ = 7, 8, and 13 TeV, respectively. These measurements are the most precise to date, and provide important input for the determination of the CKM angle γ.[graphic not available: see fulltext