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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 523 records · Page 29

The Foreign Clast Populations of Anomalous Polymict Urelite Almahata Sitta (Asteroid 2008 TC(sub3) and Typical Polymict Ureilites: Implications for Asteroid-Meteorite Connections

Almahata Sitta (AhS) is the first meteorite to originate from an asteroid (2008 TC3) that had been studied in space before it hit Earth [1,2]. It is also unique because the fallen fragments comprise a variety of types: approximately 69% ureilites (achondrites) and 31% chondrites [3]. Two models have been proposed for the origin 2008 TC3: 1) an accretionary model [3,4]; or 2) a regolith model [5,6]. Typical polymict ureilites are interpreted to represent regolith, and contain a few % foreign clasts [7,8]. The most common are dark (CC matrix-like) clasts similar to those in many meteoritic breccias [9]. A variety of other chondrites, as well as achondrites (angrites), have also been reported [7,9,10]. We have been working to determine the full diversity of these clasts [10-13] for comparison with AhS. We discuss implications for mixing of materials in the early solar system and the origin of 2008 TC3.

Goodrich, C. A.↗

Progress of chemical characterization of asteroid Ryugu samples

It is believed that meteorites come from asteroids. Samples of asteroid (25143) Itokawa returned by the JAXA Hayabusa mission revealed that S-type asteroids are composed of materials consistent with the ordinary chondrite class[1,2]. The JAXA Hayabusa 2 [3]spacecraft launched on December 3rd, 2014 towards an asteroid (162173) Ryuguto clarify relationships between C-type asteroids and the carbonaceous chondrite class. Remote sensing observations from Hayabusa 2 show that (1) the albedo of Ryugu is darker than those of every known meteorite class[4, 5], (2) an absorption band at 2.72 μm indicates that phyllosilicates are ubiquitous on Ryugu [5],(3) the strength and shape of the absorption band feature suggests that Ryugu materials experienced heating above 300 °C[6], and (4) thermal inertia suggests that Ryugu materials are more porous than every known carbonaceous chondrite[7]. These results suggest that carbonaceous chondrite class materials are plausible for Ryugu materials, but no known carbonaceous chondrite completely matches the results obtained from Ryugu. *Complete abstract available in attached document

Lan Anh Ngoc Nguyen↗

Meteoritical Society Service Award Citation for Richard C. Greenwood

We are honored to recognize the many years of service our colleague Dr. Richard C. Greenwood has provided the community with the Meteoritical Society’s Service Award. Richard’s myriad efforts include his extensive work in education and public outreach, his service to the Meteoritical Society and the broader scientific community, his extensive classification and curation of extraterrestrial samples for research, his committed student mentorship, and his exceptional support of other’s research.

Devin L. Schrader↗

Ion energization in upwelling ion events

A source of H(+), He(+), O(+), and N(+) outflow from the ionosphere has been identified near the polar cusp/cleft using the Dynamics Explorer/retarding ion mass spectrometer data set. This ion outflow termed 'upwelling ions' is characterized by large outfluxes of H(+) and O(+) ions and high transverse ion temperatures. This paper reports on the associated particle and field characteristics of one such upwelling ion event on March 12, 1982. Field-aligned currents and strong E x B convection channels are associated with the event as well as strong broadband plasma wave emission. One or all of these sources may play an important role in the ion energization in this region.

Waite, J. H., Jr.↗

Study of ${\mathrm{B}}_{\mathrm{s}}^0$ → J/ψπ + π – K + K – decays

The decays ${\mathrm{B}}_{\mathrm{s}}^0$ → J/ψπ + π – K + K – are studied using a data set corresponding to an integrated luminosity of 9 fb –1 , collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The decays ${\mathrm{B}}_{\mathrm{s}}^0$ → $\mathrm{J}/{ψ \mathrm{K}}^{\ast 0}{\overline{\mathrm{K}}}^{\ast 0}$ and ${\mathrm{B}}_{\mathrm{s}}^0$ → χ c1 (3872)K + K – , where the K + K – pair does not originate from a Φ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate χ c1 (3872)Φ, $\mathrm{J}/{ψ \mathrm{K}}^{\ast 0}{\overline{\mathrm{K}}}^{\ast 0}$, ψ(2S)Φ and χ c1 (3872)K + K – states are reported. A structure, denoted as X(4740), is observed in the J/ψΦ mass spectrum and, assuming a Breit-Wigner parameterisation, its mass and width are determined to be ${\displaystyle \begin{array}{c}{m}_{\mathrm{X}(4740)}=4741\pm 6\pm 6\kern0.5em \mathrm{MeV}/{c}^2,\\ {}{\Gamma}_{\mathrm{X}(4740)}=53\pm 15\pm 11\kern0.5em \mathrm{MeV},\end{array}}$ where the first uncertainty is statistical and the second is systematic. In addition, the most precise single measurement of the mass of the ${\mathrm{B}}_{\mathrm{s}}^0$ meson is performed and gives a value of ${m}_{{\mathrm{B}}_{\mathrm{s}}^0}=5366.98\pm 0.07\pm 0.13\kern0.5em \mathrm{MeV}/{c}^2.$

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Observation of the ${B}_s^0 $ → D*±D∓ decay

A search for the B 0 → D *± D ∓ decay is performed using proton-proton collision data at centre-of-mass energies of 7, 8 and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb -1 . The decay is observed with a high significance and its branching fraction relative to the B 0 → D *± D ∓ decay is measured to be $\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {D}^{\ast \pm }{D}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {D}^{\ast \pm }{D}^{\mp}\right)}=0.137\pm 0.017\pm 0.002\pm 0.006$, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the $B_{s}^{0}$ and $B^{0}$ hadronisation fractions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Search for the rare decay $ B^0\to J/ \psi\phi$*

A search for the rare decay $ B^0\to J/ \psi\phi$ is performed using $ pp$ collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb -1 . No significant signal of the decay is observed and an upper limit of $ 1.1 \times 10^{-7}$ at 90% confidence level is set on the branching fraction.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Amplitude analysis of the B + → D + D - K + decay

Results are reported from an amplitude analysis of the B + → D + D - K + decay. The analysis is carried out using LHCb proton-proton collision data taken at $\sqrt{s}$ = 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb -1 . In order to obtain a good description of the data, it is found to be necessary to include new spin-0 and spin-1 resonances in the D - K + channel with masses around 2.9 GeV/c 2 , and a new spin-0 charmonium resonance in proximity to the spin-2 χ c2 (3930) state.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Model-Independent Study of Structure in B + → D + D - K + Decays

The only anticipated resonant contributions to B + → D + D - K + decays are charmonium states in the D + D - channel. A model-independent analysis, using LHCb proton-proton collision data taken at center of-mass energies of $\sqrt{s}$ = 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb -1 , is carried out to test this hypothesis. The description of the data assuming that resonances only manifest in decays to the D + D - pair is shown to be incomplete. This constitutes evidence for a new contribution to the decay, potentially one or more new charm-strange resonances in the D + K - channel with masses around 2.9 GeV/c 2

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

First measurement of the CP-violating phase in $B_{s}^{0}$→J/ψ(→ e + e - )Φ decays

A flavour-tagged time-dependent angular analysis of $B_{s}^{0}$→J/ψΦ decays is presented where the J/ψ meson is reconstructed through its decay to an e + e - pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8\,Te V, corresponding to an integrated luminosity of 3\,fb -1 . The CP-violating phase and lifetime parameters of the $B_{s}^{0}$ system are measured to be Φ s =0.00±0.28±0.07\,rad , ΔΓ s =0.115±0.045±0.011\,ps -1 and Γ s =0.608±0.018±0.012\,ps -1 where the first uncertainty is statistical and the second systematic. This is the first time that CP-violating parameters are measured in the $B_{s}^{0}$→J/ψΦ decay with an e + e - pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Search for long-lived particles decaying to e± μ∓ ν

Long-lived particles decaying to e±μ∓ν, with masses between 7 and 50GeV/c 2 and lifetimes between 2 and 50 ps, are searched for by looking at displaced vertices containing electrons and muons of opposite charges. The search is performed using 5.4 fb -1 of p p collisions collected with the LHCb detector at a centre-of-mass energy of $\sqrt{s}$=13TeV. Three mechanisms of production of long-lived particles are considered: the direct pair production from quark interactions, the pair production from the decay of a Standard-Model-like Higgs boson with a mass of 125GeV/c 2 , and the charged current production from an on-shell W boson with an additional lepton. No evidence of these long-lived states is obtained and upper limits on the production cross-section times branching fraction are set on the different production modes.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Observation of new excited ${B} ^0_{s}$ states

A structure is observed in the ${B} ^{\pm }{K} ^{\mp }$ mass spectrum in a sample of proton–proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9$\,\text {fb} ^{-1}$. The structure is interpreted as the result of overlapping excited ${B} ^0_{s}$ states. With high significance, a two-peak hypothesis provides a better description of the data than a single resonance. Under this hypothesis the masses and widths of the two states, assuming they decay directly to ${B} ^{\pm }{K} ^{\mp }$, are determined to be $\begin{aligned} m_1&= 6063.5 \pm 1.2 \text { (stat)} \pm 0.8\text { (syst)}\,\text {Me}\text {V}, \\ \Gamma _1&= 26 \pm 4 \text { (stat)} \pm 4\text { (syst)}\,\text {Me}\text {V}, \\ m_2&= 6114 \pm 3 \text { (stat)} \pm 5\text { (syst)}\,\text {Me}\text {V}, \\ \Gamma _2&= 66 \pm 18 \text { (stat)} \pm 21\text { (syst)}\,\text {Me}\text {V}. \end{aligned}$ Alternative values assuming a decay through ${B} ^{*\pm }{K} ^{\mp }$, with a missing photon from the $B^{*\pm } \rightarrow B^{\pm }\gamma $ decay, which are shifted by approximately 45 $\,\text {Me}$V, are also determined. The possibility of a single state decaying in both channels is also considered. The ratio of the total production cross-section times branching fraction of the new states relative to the previously observed $B_{s2}^{*0}$ state is determined to be $0.87 \pm 0.15 \text { (stat)} \pm 0.19 \text { (syst)}$.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗