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  1. Connected and disconnected sea partons from the CT18 parametrization of PDFs

    Hou, Tie-Jiun ; Yan, Mengshi ; Liang, Jian ; ... - Physical Review D

  2. Proton momentum and angular momentum decompositions with overlap fermions

    Wang, Gen ; Yang, Yi-Bo ; Liang, Jian ; ... - Physical Review D

  3. Production of b b ¯ at forward rapidity in p + p collisions at s = 510     GeV

    Acharya, U. ; Adare, A. ; Aidala, C. ; ... - Physical Review. D.
    The cross section of bottom quark-antiquark ( b b ¯ ) production in p+p collisions at s =510 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider. The results are based on the yield of high mass, like-sign muon pairs measured within the PHENIX muon arm acceptance ( 1.2<|y|<2.2 ). The b b ¯ signal is extracted from like-sign dimuons by utilizing the unique properties of neutral B meson oscillation. We report a differential cross section of d more » σ b b ¯ → μ ± μ ± / d y = 0.16 ± 0.01 ( stat ) ± 0.02 ( syst ) ± 0.02 ( global ) nb for like-sign muons in the rapidity and p T ranges 1.2<|y|<2.2 and p T > 1 GeV / c , and dimuon mass of 5 – 10 GeV / c 2 . The extrapolated total cross section at this energy for b b ¯ production is 13.1 ± 0.6 ( stat ) ± 1.5 ( syst ) ± 2.7 ( global ) μ b . The total cross section is compared to a perturbative quantum chromodynamics calculation and is consistent within uncertainties. The azimuthal opening angle between muon pairs from b b ¯ decays and their p T distributions are compared to distributions generated using ps pythia6, which includes next-to-leading order processes. The azimuthal correlations and pair p T distribution are not very well described by pythia calculations, but are still consistent within uncertainties. Flavor creation and flavor excitation subprocesses are favored over gluon splitting.« less

  4. Towards the spatial resolution of metalloprotein charge states by detailed modeling of XFEL crystallographic diffraction

    Sauter, Nicholas K. ; Kern, Jan ; Yano, Junko ; ... - Acta Crystallographica. Section D. Structural Biology
    Oxidation states of individual metal atoms within a metalloprotein can be assigned by examining X-ray absorption edges, which shift to higher energy for progressively more positive valence numbers. Indeed, X-ray crystallography is well suited for such a measurement, owing to its ability to spatially resolve the scattering contributions of individual metal atoms that have distinct electronic environments contributing to protein function. However, as the magnitude of the shift is quite small, about +2 eV per valence state for iron, it has only been possible to measure the effect when performed with monochromated X-ray sources at synchrotron facilities with energy resolutions inmore » the range 2–3 × 10 −4 (Δ E / E ). This paper tests whether X-ray free-electron laser (XFEL) pulses, which have a broader bandpass (Δ E / E = 3 × 10 −3 ) when used without a monochromator, might also be useful for such studies. The program nanoBragg is used to simulate serial femtosecond crystallography (SFX) diffraction images with sufficient granularity to model the XFEL spectrum, the crystal mosaicity and the wavelength-dependent anomalous scattering factors contributed by two differently charged iron centers in the 110-amino-acid protein, ferredoxin. Bayesian methods are then used to deduce, from the simulated data, the most likely X-ray absorption curves for each metal atom in the protein, which agree well with the curves chosen for the simulation. The data analysis relies critically on the ability to measure the incident spectrum for each pulse, and also on the nanoBragg simulator to predict the size, shape and intensity profile of Bragg spots based on an underlying physical model that includes the absorption curves, which are then modified to produce the best agreement with the simulated data. This inference methodology potentially enables the use of SFX diffraction for the study of metalloenzyme mechanisms and, in general, offers a more detailed approach to Bragg spot data reduction.« less

  5. LIGO/Virgo Black Holes from a First Order Quark Confinement Phase Transition

    Davoudiasl, Hooman - Physical Review Letters

  6. Valence parton distribution function of pion from fine lattice

    Izubuchi, Taku ; Jin, Luchang ; Kallidonis, Christos ; ... - Physical Review. D.

  7. Model-independent determination of B c + → η c ℓ + ν form factors

    Murphy, Christopher W. ; Soni, Amarjit - Physical Review D

  8. Flavor diagonal tensor charges of the nucleon from ( 2 + 1 + 1 )-flavor lattice QCD

    Gupta, Rajan ; Yoon, Boram ; Bhattacharya, Tanmoy ; ... - Physical Review. D.

  9. Factorization theorem relating Euclidean and light-cone parton distributions

    Izubuchi, Taku ; Ji, Xiangdong ; Jin, Luchang ; ... - Physical Review. D.

  10. Finite-volume correction on the hadronic vacuum polarization contribution to the muon g − 2 in lattice QCD

    Izubuchi, Taku ; Kuramashi, Yoshinobu ; Lehner, Christoph ; ... - Physical Review. D.
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