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At least 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Measurement of CP observables in B ± → D (*) K ± and B ± → D (*) π ± decays using two-body D final states

Measurements of CP observables in B ± → D (*) K ± and B ± → D (*) π ± decays are presented, where D (∗) indicates a neutral D or D ∗ meson that is an admixture of meson and anti-meson states. Decays of the D (∗) meson to the Dπ 0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon. Decays of the D meson are reconstructed in the K ± π ∓ , K + K - , and π + π - final states. The analysis uses a sample of charged B mesons produced in proton-proton collisions and collected with the LHCb experiment, corresponding to integrated luminosities of 2.0, 1.0, and 5.7 fb -1 taken at centre-of-mass energies of 7, 8, and 13 TeV, respectively. The measurements of partially reconstructed B ± → D (*) K ± and B ± → D (∗) π ± with D → K ∓ π ± decays are the first of their kind, and a first observation of the B ± → (Dπ 0 ) D ∗ π ± decay is made with a significance of 6.1 standard deviations. All CP observables are measured with world-best precision, and in combination with other LHCb results will provide strong constraints on the CKM angle γ.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Amplitude analysis and branching fraction measurement of the decay $D_s^{+} → K^+π^+π^-$

Using 6.32 fb -1 of e + e - collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D$^+_s$ → K + π + π - and determine the amplitudes of the various intermediate states. The absolute branching fraction of D$^+_s$ → K + π + π - is measured to be (6.11 ± 0.18 stat. ± 0.11 syst. ) x 10 -3 . The branching fractions of the dominant intermediate processes D$^+_s$ → K + ρ 0 , ρ 0 → π + π - and D$^+_s$ → K*(892) 0 π + , K*(892) 0 → K + π - are determined to be (1.96 ± 0.19 stat . ± 0.23 syst. ) x 10 -3 and (1.85 ± 0.12 stat . ± 0.13 syst .) x 10 -3 , respectively. The intermediate resonances f 0 (500), f 0 (980), and f 0 (1370) are observed for the first time in this channel.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Study of the B - → Λ c + Λ ¯ c - K - decay

The decay B - → $Λ^+_c \overline{Λ}^-_c K^-$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}$ = 13 TeV using data corresponding to an integrated luminosity of 5 fb -1 collected by the LHCb experiment. In the $Λ^+_c K^-$ system, the Ξ c (2930) 0 state observed at the BABAR and Belle experiments is resolved into two narrower states, Ξ c (2923) 0 and Ξ c (2939) 0 , whose masses and widths are measured to be m(Ξ c (2923) 0 ) = 2924.5 ± 0.4 ± 1.1 MeV, m(Ξ c (2939) 0 ) = 2938.5 ± 0.9 ± 2.3 MeV, Γ(Ξ c (2923) 0 ) = 4.8 ± 0.9 ± 1.5 MeV, Γ(Ξ c (2939) 0 ) = 11.0 ± 1.9 ± 7.5 MeV, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $Λ^+_c K^-$ sample. Evidence of a new Ξ c (2880) 0 state is found with a local significance of 3.8σ, whose mass and width are measured to be 2881.8 ± 3.1 ± 8.5 MeV and 12.4 ± 5.3 ± 5.8 MeV, respectively. In addition, evidence of a new decay mode Ξ c (2790) 0 → $Λ^+_c K^-$ is found with a significance of 3.7σ. The relative branching fraction of B - → $Λ^+_c \overline{Λ}^-_c K^-$ with respect to the B - → D + D - K - decay is measured to be 2.36 ± 0.11 0.22 ± 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Materials Data on K(In3Au2)2 by Materials Project

K(Au2In3)2 crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. K is bonded to six equivalent Au and six equivalent In atoms to form face-sharing KIn6Au6 cuboctahedra. All K–Au bond lengths are 3.70 Å. All K–In bond lengths are 3.61 Å. There are two inequivalent Au sites. In the first Au site, Au is bonded in a 6-coordinate geometry to two equivalent K and six In atoms. There are two shorter (2.88 Å) and four longer (2.93 Å) Au–In bond lengths. In the second Au site, Au is bonded in a 9-coordinate geometry to nine In atoms. There are three shorter (2.89 Å) and six longer (2.99 Å) Au–In bond lengths. There are two inequivalent In sites. In the first In site, In is bonded in a 5-coordinate geometry to five Au atoms. In the second In site, In is bonded in a 4-coordinate geometry to two equivalent K and four Au atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(SnAu)3 by Materials Project

K(AuSn)3 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. K is bonded in a 10-coordinate geometry to six equivalent Au and four equivalent Sn atoms. There are two shorter (3.47 Å) and four longer (3.62 Å) K–Au bond lengths. All K–Sn bond lengths are 3.59 Å. There are two inequivalent Au sites. In the first Au site, Au is bonded in a 1-coordinate geometry to three equivalent K, three equivalent Au, and four Sn atoms. There are two shorter (2.92 Å) and one longer (3.30 Å) Au–Au bond lengths. There are a spread of Au–Sn bond distances ranging from 2.81–2.93 Å. In the second Au site, Au is bonded in a 7-coordinate geometry to seven Sn atoms. There are a spread of Au–Sn bond distances ranging from 2.91–2.98 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 4-coordinate geometry to two equivalent K and four Au atoms. In the second Sn site, Sn is bonded to seven Au atoms to form distorted edge-sharing SnAu7 hexagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(WO3)3 by Materials Project

K(WO3)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.10–3.15 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.12–3.21 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.11–3.19 Å. In the fourth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.11–3.17 Å. In the fifth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.13–3.20 Å. There are fifteen inequivalent W+5.67+ sites. In the first W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–31°. There are a spread of W–O bond distances ranging from 1.92–1.96 Å. In the second W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.93–1.98 Å. In the third W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.91–1.98 Å. In the fourth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.99 Å. In the fifth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is five shorter (1.94 Å) and one longer (1.95 Å) W–O bond length. In the sixth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is three shorter (1.93 Å) and three longer (1.95 Å) W–O bond length. In the seventh W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–31°. There are a spread of W–O bond distances ranging from 1.91–1.98 Å. In the eighth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–32°. There are a spread of W–O bond distances ranging from 1.92–1.98 Å. In the ninth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–32°. There are a spread of W–O bond distances ranging from 1.93–1.98 Å. In the tenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.92–1.96 Å. In the eleventh W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–31°. There are a spread of W–O bond distances ranging from 1.92–1.96 Å. In the twelfth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.94–1.98 Å. In the thirteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the fourteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the fifteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.98 Å. There are forty-five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the eleventh O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twelfth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the sixteenth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the nineteenth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twentieth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-fourth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-eighth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirtieth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-third O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-sixth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fortieth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the forty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-third O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the forty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-fifth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(WO3)3 by Materials Project

K(WO3)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.10–3.15 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.12–3.21 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.11–3.19 Å. In the fourth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.10–3.17 Å. In the fifth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 3.13–3.20 Å. There are fifteen inequivalent W+5.67+ sites. In the first W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–31°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. In the second W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the third W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the fourth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.94–1.97 Å. In the fifth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is two shorter (1.94 Å) and four longer (1.95 Å) W–O bond length. In the sixth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.95 Å. In the seventh W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–32°. There are a spread of W–O bond distances ranging from 1.94–1.97 Å. In the eighth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–32°. There are a spread of W–O bond distances ranging from 1.92–1.97 Å. In the ninth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.94–1.97 Å. In the tenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 2–32°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. In the eleventh W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–31°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. In the twelfth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is four shorter (1.94 Å) and two longer (1.96 Å) W–O bond length. In the thirteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the fourteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 1–32°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. In the fifteenth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is four shorter (1.94 Å) and two longer (1.96 Å) W–O bond length. There are forty-five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the eleventh O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twelfth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the sixteenth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the nineteenth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twentieth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-fourth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the twenty-eighth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the twenty-ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirtieth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-third O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-sixth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the thirty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the thirty-ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the fortieth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the forty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-third O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms. In the forty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W+5.67+ atoms. In the forty-fifth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(InGa)2 by Materials Project

K(InGa)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K is bonded in a 8-coordinate geometry to eight equivalent In and eight equivalent Ga atoms. All K–In bond lengths are 3.80 Å. All K–Ga bond lengths are 3.63 Å. In is bonded to four equivalent K, four equivalent In, and four equivalent Ga atoms to form a mixture of distorted face, edge, and corner-sharing InK4In4Ga4 cuboctahedra. All In–In bond lengths are 3.39 Å. All In–Ga bond lengths are 2.91 Å. Ga is bonded in a 9-coordinate geometry to four equivalent K, four equivalent In, and one Ga atom. The Ga–Ga bond length is 2.58 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(SiPd)4 by Materials Project

K(PdSi)4 crystallizes in the tetragonal I4 space group. The structure is three-dimensional. K is bonded in a 4-coordinate geometry to eight equivalent Pd and four equivalent Si atoms. There are four shorter (3.24 Å) and four longer (3.47 Å) K–Pd bond lengths. All K–Si bond lengths are 3.51 Å. Pd is bonded in a 9-coordinate geometry to two equivalent K and five equivalent Si atoms. There are a spread of Pd–Si bond distances ranging from 2.44–2.54 Å. Si is bonded in a 5-coordinate geometry to one K and five equivalent Pd atoms.

36 MATERIALS SCIENCE↗
NASA NTRS2016

Discordant K-Ar and Young Exposure Dates for the Windjana Sandstone, Kimberley, Gale Crater, Mars

K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K2O concentration of 3.09 +/- 0.20 wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to approximately 915 C yielded a K-Ar age of 627 +/- 50 Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710 +/- 110 Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710 Ma. Incomplete extraction at approximately 900 C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from He-3 and Ne-21 in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the He-3 (57 +/- 49 and 18 +/- 32 Ma, mean 30 Ma) and Ne-21 (2 +/- 32 and 83 +/- 24 Ma, mean 54 Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop.

K-Ar↗
DOE OSTI2023

New determination of the branching ratio of the structure dependent radiative K + → e + ν e γ

The branching ratio of the structure dependent (SD) radiative K + → e + ν e γ decay relative to that of the K + → e + ν e (γ) decay including the internal bremsstrahlung (IB) process (K e2 (γ) ) has been measured in the J-PARC E36 experiment using plastic scintillator/lead sandwich detectors, in contrast to the previous E36 measurement, which used a CsI(Tl) calorimeter. In the analysis, the effect of IB was also taken into account in the SD radiative decay as $K$$^{SD}_{e2γ(γ)}$. By combining the new data with the previous E36 result after revision for the IB correction for $K$$^{SD}_{e2γ(γ)}$, a new value Br($K$$^{SD}_{e2γ(γ)}$)/Br(Ke 2(γ) ) = 1.20 ± 0.07 has e2γ(γ) e2γ(γ) been determined. This is consistent with a recent lattice QCD calculation, but larger than the expectation of Chiral Perturbation Theory (ChPT) at order O(p 4 ) and the previous KLOE value. Using the method to relate form factor and branching ratio described in the KLOE paper, the present result is also consistent with the form factor prediction based on a gauged nonlocal chiral quark model, but larger than that from ChPT at order O(p 6 ).

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

High Yield of B-Side Electron Transfer at 77 K in the Photosynthetic Reaction Center Protein from Rhodobacter sphaeroides

In this work, the primary electron transfer (ET) processes at 295 K and 77 K are compared for the Rhodobacter sphaeroides reaction center (RC) pigment-protein complex from thirteen mutants including a wild-type control. The engineered RCs bear mutations in the L and M polypeptides that largely inhibit ET from the excited state P* of the primary electron donor (P, a bacteriochlorophyll dimer) to the normally photoactive A-side cofactors and enhance ET to the C 2 -symmetry related, and normally photoinactive, B-side cofactors. P* decay is multi-exponential at both temperatures and modeled as arising from subpopulations that differ in contributions of two-step ET (e.g., P* → P + B B – → P + H B – ), one-step superexchange ET (e.g., P* → P + H B – ) and P* → ground state. [H B and B B are monomeric bacteriopheophytin and bacteriochlorophyll, respectively.] The relative abundances of the subpopulations and the inherent rate constants of the P* decay routes vary with temperature. Regardless, ET to produce P + H B – is generally faster at 77 K than at 295 K by about a factor of two. A key finding is that the yield of P + H B – , which ranges from ~5% to ~90% among the mutant RCs, is essentially the same at 77 K as at 295 K in each case. Overall, the results show that ET from P* to the B-side cofactors in these mutants does not require thermal activation and involves combinations of ET mechanisms analogous to those operative on the A side in the native RC.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Cryo-EM structures of the small-conductance Ca 2+ -activated K Ca 2.2 channel

Small-conductance Ca 2+ -activated K + (K Ca 2.1-K Ca 2.3) channels modulate neuronal and cardiac excitability. We report cryo-electron microscopy structures of the K Ca 2.2 channel in complex with calmodulin and Ca 2+ , alone or bound to two small molecule inhibitors, at 3.18, 3.50, 2.99 and 2.97 angstrom resolution, respectively. Extracellular S3-S4 loops in β-hairpin configuration form an outer canopy over the pore with an aromatic box at the canopy’s center. Each S3-S4 β-hairpin is tethered to the selectivity filter in the neighboring subunit by inter-subunit hydrogen bonds. This hydrogen bond network flips the aromatic residue (Tyr362) in the filter’s GYG signature by 180°, causing the outer selectivity filter to widen and water to enter the filter. Disruption of the tether by a mutation narrows the outer selectivity filter, realigns Tyr362 to the position seen in other K + channels, and significantly increases unitary conductance. UCL1684, a mimetic of the bee venom peptide apamin, sits atop the canopy and occludes the opening in the aromatic box. AP14145, an analogue of a therapeutic for atrial fibrillation, binds in the central cavity below the selectivity filter and induces closure of the inner gate. These structures provide a basis for understanding the small unitary conductance and pharmacology of K Ca 2.x channels.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Probing Exotic Cross-Shell Interactions at N = 28 with Single-Neutron Transfer on 47 K

Here, we present the first measurement of the 47 K ⁡(𝑑, 𝑝⁢𝛾)⁢ 48 K transfer reaction, performed in inverse kinematics using a reaccelerated beam of 47 K. The level scheme of 48 K has been greatly extended, with nine new bound excited states identified and spectroscopic factors deduced. Uniquely, the 47 K ⁡(𝑑, 𝑝) reaction gives access to nuclear states that are sensitive to the interaction of protons and neutrons in the widely spaced 1⁢𝑠 and 𝑓⁡𝑝 orbitals, respectively. Detailed comparisons with SDPF-U and SDPF-MU shell-model calculations reveal a number of discrepancies between theory and experiment. Intriguingly, a systematic overestimation of spectroscopic factors and a poor reproduction of the energies for 1 − states suggests that the mixing between the 𝜋⁢𝑠$^1_{1/2}$⁢𝑑$^4_{3/2}$ and 𝜋⁢𝑠$^2_{1/2}$⁢𝑑$^3_{3/2}$ proton configurations in 48 K is not correctly described using current interactions, challenging our description of light nuclei around the 𝑁 = 28 island of inversion.

Paxman, Charlie J. [Univ. of Surrey, Guildford (Un↗
DOE OSTI2020

Materials Data on K by Materials Project

K crystallizes in the tetragonal P4/mmm space group. The structure is one-dimensional and consists of one K ribbon oriented in the (0, 0, 1) direction. K is bonded in a linear geometry to two equivalent K atoms. Both K–K bond lengths are 4.22 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Determination of the Diffusion Coefficients of Binary CH4 and C2H6 in a Supercritical CO2 Environment (500–2000 K and 100–1000 atm) by Molecular Dynamics Simulations

The self-diffusion coefficients of carbonaceous fuels in a supercritical CO2 environment provide transport information that can help us understand the Allam Cycle mechanism at a high pressure of 300 atm. The diffusion coefficients of pure CO2 and binary CO2/CH4 and CO2/C2H6 at high temperatures (500 K~2000 K) and high pressures (100 atm~1000 atm) are determined by molecular dynamics simulations in this study. Increasing the temperature leads to an increase in the diffusion coefficient, and increasing the pressure leads to a decrease in the diffusion coefficients for both methane and ethane. The diffusion coefficient of methane at 300 atm is approximately 0.012 cm2/s at 1000 K and 0.032 cm2/s at 1500 K. The diffusion coefficient of ethane at 300 atm is approximately 0.016 cm2/s at 1000 K and 0.045 cm2/s at 1500 K. The understanding of diffusion coefficients potentially leads to the reduction in fuel consumption and minimization of greenhouse gas emissions in the Allam Cycle.

Energy & Fuels↗
NASA NTRS1973

K alpha line emission during solar X-ray bursts

The expected flux of K alpha line emission from sulfur, argon, calcium, and iron is calculated during both thermal and nonthermal solar X-ray events. Such emission is shown to be weak during the course of most of the nonthermal hard X-ray bursts that Kane and Anderson (1970) have observed. If Compton backscattering is significant at high energies, the flux is reduced still further for disk flares, but it is noted that the strong, near-limb burst of June 26 would have produced about 100 photons /sq cm/sec of sulfur and iron K alpha emission. The impulsive hard X-ray bursts may in general be too short-lived for much K alpha emission. It may be noted that sulfur K alpha emission in particular depends sensitively on the lower-energy limit of the nonthermal electron spectrum, assuming such a sharply defined boundary exists. During soft X-ray bursts, when temperatures of a few 10 to the 7th power K are obtained, K alpha emission from certain iron ions, specifically Fe XVIII-XXIII, may be important.

Phillips, K. J. H.↗
NASA NTRS1986

The excitation of the iron K-alpha feature in solar flares

The relationship between the hard X-ray photon spectrum and the flux of iron K-alpha emission in a thick-target electron bombardment model is evaluated. Results are presented for various power-law hard X-ray spectra. These results are applied to two events observed with the Hard X-Ray Burst Spectrometer and the K-alpha channel of the X-Ray Polychromator Bent Crystal Spectrometer on the Solar Maximum Mission satellite. For one of the events, on March 29, 1980, at 09:18 UT, the K-alpha flux predicted for a thick-target nonthermal process is significant compared to the background fluorescent component, and the data are indeed consistent with an enhancement of the predicted amount. For the other event, on October 14, 1980 at 0.6:09 UT, the hard X-ray spectrum is so steep that no significant K-alpha flux is predicted for this process, and no enhancement is seen. It is concluded that the agreement between the predicted K-alpha flux and the observed magnitude of the K-alpha enhancement above the fluorescent background at the time of the large hard X-ray bursts lends support to a thick-target nonthermal interpretation of impulsive hard X-ray emission in solar flares.

Emslie, A. G.↗