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All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

High-Resolution Frequency-Domain Spectroscopic and Modeling Studies of Photosystem I (PSI), PSI Mutants and PSI Supercomplexes

Photosystem I (PSI) is one of the two main pigment–protein complexes where the primary steps of oxygenic photosynthesis take place. This review describes low-temperature frequency-domain experiments (absorption, emission, circular dichroism, resonant and non-resonant hole-burned spectra) and modeling efforts reported for PSI in recent years. In particular, we focus on the spectral hole-burning studies, which are not as common in photosynthesis research as the time-domain spectroscopies. Experimental and modeling data obtained for trimeric cyanobacterial Photosystem I (PSI 3 ), PSI 3 mutants, and PSI 3 –IsiA 18 supercomplexes are analyzed to provide a more comprehensive understanding of their excitonic structure and excitation energy transfer (EET) processes. Detailed information on the excitonic structure of photosynthetic complexes is essential to determine the structure–function relationship. We will focus on the so-called “red antenna states” of cyanobacterial PSI, as these states play an important role in photochemical processes and EET pathways. The high-resolution data and modeling studies presented here provide additional information on the energetics of the lowest energy states and their chlorophyll (Chl) compositions, as well as the EET pathways and how they are altered by mutations. We present evidence that the low-energy traps observed in PSI are excitonically coupled states with significant charge-transfer (CT) character. The analysis presented for various optical spectra of PSI 3 and PSI 3 -IsiA 18 supercomplexes allowed us to make inferences about EET from the IsiA 18 ring to the PSI 3 core and demonstrate that the number of entry points varies between sample preparations studied by different groups. In our most recent samples, there most likely are three entry points for EET from the IsiA 18 ring per the PSI core monomer, with two of these entry points likely being located next to each other. Therefore, there are nine entry points from the IsiA 18 ring to the PSI 3 trimer. We anticipate that the data discussed below will stimulate further research in this area, providing even more insight into the structure-based models of these important cyanobacterial photosystems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Study of ${\mathrm{B}}_{\mathrm{c}}^{+}\to \mathrm{J}/\psi {\mathrm{D}}_{\mathrm{s}}^{+}$ and ${\mathrm{B}}_{\mathrm{c}}^{+}\to \mathrm{J}/\psi {\mathrm{D}}_{\mathrm{s}}^{\ast +}$ decays in pp collisions at $\sqrt{\mathrm{s}}$ = 13 TeV with the ATLAS detector

A study of ${B}_c^{+}\to J/\psi {D}_s^{+}$ and ${B}_c^{+}\to J/\psi {D}_s^{\ast +}$ decays using 139 fb –1 of integrated luminosity collected with the ATLAS detector from $\sqrt{s}$ = 13 TeV pp collisions at the LHC is presented. The ratios of the branching fractions of the two decays to the branching fraction of the ${B}_c^{+}$ → J/ψπ + decay are measured: $\mathcal{B}\left({B}_c^{+}\to J/\psi {D}_s^{+}\right)/\mathcal{B}\left({B}_c^{+}\to J/{\psi \pi}^{+}\right)$ = 2.76 ± 0.47 and $\mathcal{B}\left({B}_c^{+}\to J/\psi {D}_s^{\ast +}\right)/\mathcal{B}\left({B}_c^{+}\to J/{\psi \pi}^{+}\right)$ = 5.33 ± 0.96. The ratio of the branching fractions of the two decays is found to be $\mathcal{B}\left({B}_c^{+}\to J/\psi {D}_s^{\ast +}\right)/\mathcal{B}\left({B}_c^{+}\to J/\psi {D}_s^{\ast +}\right)$ = 1.93 ± 0.26. For the ${B}_c^{+}\to J/\psi {D}_s^{\ast +}$ decay, the transverse polarization fraction, Γ ±± /Γ, is measured to be 0.70 ± 0.11. The reported uncertainties include both the statistical and systematic components added in quadrature. The precision of the measurements exceeds that in all previous studies of these decays. These results supersede those obtained in the earlier ATLAS study of the same decays with $\sqrt{s}$ = 7 and 8 TeV pp collision data. A comparison with available theoretical predictions for the measured quantities is presented.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

\(J/\psi \) and \(\psi (2S)\) Production in Small Systems with PHENIX

The suppression of the ψ(2S) nuclear modification factor has been seen as a trademark signature of final-state effects in large collision systems for decades. In small systems, deviations of the nuclear modification from unity had been attributed to cold nuclear matter effects until the observation of strong differential suppression of the ψ(2S) state in p/d+A collisions, which suggests the presence of final-state effects. Here in this paper, we present results of J/ψ and ψ(2S) measurements in the dimuon decay channel for p + p, p+Al, and p+Au collision systems at $\sqrt{s_{NN}}$ = 200 GeV. Key results include the nuclear modification factors R pA as a function of centrality and rapidity. The measurements are compared with shadowing and transport model predictions, as well as complementary measurements at LHC energies.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Observation of B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}\pi^+\pi^-$ and B$^0_\mathrm{S}$$\to$$\psi$(2S)K$^0_\mathrm{S}$ decays

Using a data sample of $\sqrt{s} =$ 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb$^{-1}$, the B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$ and B$^0_\mathrm{S}$$\to$$\psi$(2S)K$^0_\mathrm{S}\pi^+\pi^-$ decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to $\mathcal{B}$(B$^0_\mathrm{S}$$\to$$\psi$(2S)K$^0_\mathrm{S}$) / $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$) = (3.33 $\pm$ 0.69 (stat) $\pm$ 0.11 (syst) $\pm$ 0.34 ($f_\mathrm{s} / f_\mathrm{d}$)) $\times$ 10$^{-2}$ and $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}\pi^+\pi^-$) / $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$) = 0.480 $\pm$ 0.013 (stat) $\pm$ 0.032 (syst), where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B$^0_\mathrm{s}$ and B$^0$ mesons, $f_\mathrm{s} / f_\mathrm{d}$.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Evidence of a $J/$$\psi$$K_S^0$ Structure in $B^0$ → $J/$$\psi$$\phi$$K_S^0$

An amplitude analysis of $B^0$ → $J/$$\psi$$\phi$$K_S^0$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9 fb –1 , collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. Evidence with a significance of 4.0 standard deviations of a structure in the $J/$$\psi$$K_S^0$ system, named $T_{ψs1}^{θ}$⁢⁢(4000) 0 , is seen, with its mass and width measured to be 3991$_{–10 –17}^{+12 +9}$ MeV/⁢c 2 and 105$_{–25 –23}^{+29 +17}$ MeV, respectively, where the first uncertainty is statistical and the second systematic. The $T_{ψs1}^{θ}$⁢⁢(4000) 0 state is likely to be the isospin partner of the $T_{ψs1}^{θ}$⁢⁢(4000) + state, previously observed in the $J/ψK^+$ system of the $B^+$→$J/ψ$$\phi$$K^+$ decay. When isospin symmetry for the charged and neutral $T_{ψs1}^{θ}$⁢⁢(4000) states is assumed, the signal significance increases to 5.4 standard deviations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Measurement of branching fractions of $J/\psi$ and $\psi$(3686) decays to $\Sigma^+$< and $\overline\Sigma^-$

Using 1310.6 x 10 6 J/ψ and 448.1 x 10 6 ψ(3686) events collected with the BESIII detector, the branching fractions of J/ψ decays to $Σ^+\overline{Σ}^-$ is measured to be (10.61 ± 0.04 ± 0.36) x 10 -4 , which is significantly more precise than the current world average. The branching fractions of ψ(3686) decays to $Σ^+\overline{Σ}^-$ is measured to be (2.52 ± 0.04 ± 0.09) x 10 -4 , which is consistent with the previous measurements. In addition, the ratio of $\mathcal{B}$(ψ(3686) → $Σ^+\overline{Σ}^-$)/$\mathcal{B}$(J/ψ → $Σ^+\overline{Σ}^-$) is determined to be (23.8 ± 1.1)% which violates the “12% rule”.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

Measurement of the production cross-section of $J/\psi$ and $\psi (2{\textrm{S}})$ mesons in pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

Measurements of the differential production cross-sections of prompt and non-prompt J/ψ and ψ(2S) mesons with transverse momenta between 8 and 360 GeV and rapidity in the range |y| < 2 are reported. Furthermore, measurements of the non-prompt fractions of J/ψ and ψ(2S), and the prompt and non-prompt ψ(2S)-to-J/ψ pro duction ratios, are presented. The analysis is performed using 140 fb -1 of $\sqrt{s}$ = 13 TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015–2018.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2014

Calculation of State Specific Rate Coefficients for Non-Equilibrium Hypersonics Applications: from H(Psi) = E(Psi) to k(T) = A *exp(-E(sub a)/RT)

Development of High-Fidelity Physics-Based Models to describe hypersonic flight through the atmospheres of Earth and Mars is underway at NASA Ames Research Center. The goal is to construct chemistry models of the collisional and radiative processes that occur in the bow shock and boundary layers of spacecraft during atmospheric entry that are free of empiricism. In this talk I will discuss our philosophy and describe some of our progress. Topics to be covered include thermochemistry, internal energy relaxation, collisional dissociation and radiative emission and absorption. For this work we start by solving the Schrodinger equation to obtain accurate interaction potentials and radiative properties. Then we invoke classical mechanics to compute state-specific heavy particle collision cross sections and reaction rate coefficients. Finally, phenomenological rate coefficients and relaxation times are determined from master equation solutions.

aerothermodynamics↗
DOE OSTI2022

Small angle neutron scattering and lipidomic analysis of a native, trimeric PSI-SMALP from a thermophilic cyanobacteria

The use of styrene-maleic acid copolymers (SMAs) to produce membrane protein-containing nanodiscs without the initial detergent isolation has gained significant interest over the last decade. We have previously shown that a Photosystem I SMALP from the thermophilic cyanobacterium, Thermosynechococcus elongatus (PSI-SMALP), has much more rapid energy transfer and charge separation in vitro than detergent isolated PSI complexes. In this study, we have utilized small-angle neutron scattering (SANS) to better understand the geometry of these SMALPs. These techniques allow us to investigate the size and shape of these particles in their fully solvated state. Further, the particle's proteolipid core and detergent shell or copolymer belt can be interrogated separately using contrast variation, a capability unique to SANS. Here we report the dimensions of the Thermosynechococcus elongatus PSI-SMALP containing a PSI trimer. At ~1.5 MDa, PSI-SMALP is the largest SMALP to be isolated; our lipidomic analysis indicates it contains ~1300 lipids/per trimeric particle, >40-fold more than the PSI-DDM particle and > 100 fold more than identified in the 1JB0 crystal structure. Interestingly, the lipid composition to the PSI trimer in the PSI-SMALP differs significantly from bulk thylakoid composition, being enriched ~50 % in the anionic sulfolipid, SQDG. Finally, utilizing the contrast match point for the SMA 1440 copolymer, we also can observe the ~1 nm SMA copolymer belt surrounding this SMALP for the first time, consistent with most models of SMA organization.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Fragmentation of jets containing a prompt J$/\psi$ meson in PbPb and pp collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV

Jets containing a prompt J$/\psi$ meson are studied in lead-lead collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using the CMS detector at the LHC. Jets are selected to be in the transverse momentum range of 30 $\lt p_\mathrm{T} \lt$ 40 GeV. The J$/\psi$ yield in these jets is evaluated as a function of the jet fragmentation variable $z$, the ratio of the J$/\psi$$p_\mathrm{T} $ to the jet $p_\mathrm{T}$. The nuclear modification factor, $R_\mathrm{AA}$, is then derived by comparing the yield in lead-lead collisions to the corresponding expectation based on proton-proton data, at the same nucleon-nucleon center-of-mass energy. The suppression of the J$/\psi$ yield shows a dependence on $z$, indicating that the interaction of the J$/\psi$ with the quark-gluon plasma formed in heavy ion collisions depends on the fragmentation that gives rise to the J$/\psi$ meson.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

High salt-induced PSI-supercomplex is associated with high CEF and attenuation of state transitions

Abstract While PSI-driven cyclic electron flow (CEF) and assembly of thylakoid supercomplexes have been described in model organisms like Chlamydomonas reinhardtii , open questions remain regarding their contributions to survival under long-term stress. The Antarctic halophyte, C. priscuii UWO241 (UWO241), possesses constitutive high CEF rates and a stable PSI-supercomplex as a consequence of adaptation to permanent low temperatures and high salinity. To understand whether CEF represents a broader acclimation strategy to short- and long-term stress, we compared high salt acclimation between the halotolerant UWO241, the salt-sensitive model, C. reinhardtii , and a moderately halotolerant Antarctic green alga, C. sp. ICE-MDV (ICE-MDV). CEF was activated under high salt and associated with increased non-photochemical quenching in all three Chlamydomonas species. Furthermore, high salt-acclimated cells of either strain formed a PSI-supercomplex, while state transition capacity was attenuated. How the CEF-associated PSI-supercomplex interferes with state transition response is not yet known. We present a model for interaction between PSI-supercomplex formation, state transitions, and the important role of CEF for survival during long-term exposure to high salt.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Deciphering the mechanism of near-threshold $$J/\psi $$ photoproduction

Abstract The photoproduction of the $$J/\psi $$ J / ψ off the proton is believed to deepen our understanding of various physics issues. On the one hand, it is proposed to provide access to the origin of the proton mass, based on the QCD multipole expansion. On the other hand, it can be employed in a study of pentaquark states. The process is usually assumed to proceed through vector-meson dominance, that is the photon couples to a $$J/\psi $$ J / ψ which rescatters with the proton to give the $$J/\psi p$$ J / ψ p final state. In this paper, we provide a compelling hint for and propose measurements necessary to confirm a novel production mechanism via the $$\varLambda _c \bar{D}^{(*)}$$ Λ c D ¯ ( ∗ ) intermediate states. In particular, there must be cusp structures at the $$\varLambda _c \bar{D}^{(*)}$$ Λ c D ¯ ( ∗ ) thresholds in the energy dependence of the $$J/\psi $$ J / ψ photoproduction cross section. The same mechanism also implies the $$J/\psi $$ J / ψ -nucleon scattering lengths of order 1 mfm. Given this, one expects only a minor contribution of charm quarks to the nucleon mass.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1977

Inclusive gamma-ray spectra from psi/3095/ and psi-prime/3684/ decays

Inclusive gamma-ray experiments were carried out in a e(+)e(-) colliding-beam apparatus with NaI(Tl) arrays as detectors. The inclusive gamma-ray spectra, after cosmic-ray background subtraction, are shown as histograms for the decays of the psi(3095) and psi-prime(3684). The psi spectrum has no significant narrow structure, while the psi-prime spectrum shows at least four peaks. Three major radiative decays of the psi-prime(3684) are found, and their respective branching fractions are computed.

Biddick, C. J.↗
DOE OSTI2023

${{J}/\psi }$ and ${{D}} ^0$ production in $\sqrt{s_{\scriptscriptstyle \text {NN}}} =68.5\,\text {GeV} $ PbNe collisions

The first measurement of ${{J}/\psi }$ and ${{D}} ^0$ production in PbNe collisions by the LHCb experiment in its fixed-target configuration is reported. The production of ${{J}/\psi }$ and ${{D}} ^0$ mesons is studied with a beam of lead ions with an energy of 2.5 TeV per nucleon colliding on gaseous neon targets at rest, corresponding to a nucleon-nucleon centre-of-mass energy of $\sqrt{s_{\scriptscriptstyle \text {NN}}} =68.5\,\text {GeV}$. The ${{J}/\psi }$/${{D}} ^0$ production cross-section ratio is studied as a function of rapidity, transverse momentum and collision centrality. These data are compared with measurements from $p\text {Ne}$ collisions at the same energy and show no difference in the observed ${{J}/\psi }$ suppression trend when comparing $p\text {Ne}$ and PbNe peripheral collisions with PbNe central collisions. Similar content being vie

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRSDate not supplied

What's New in the PSI? (Physical Sciences Informatics)

The NASA Physical Sciences Informatics (PSI) database is NASA’s archival for physical sciences research in microgravity – on ISS and also other reduced gravity platforms. The database has been making data from microgravity physical science investigations publicly available since its launch late 2014. The database was an early investment in Open Science for NASA’s Biophysics and Physical Sciences (BPS) Division of the Science Mission Directorate (SMD), who conducts fundamental and applied physical sciences yielding research data in 6 disciplines: biophysics, combustion science, complex fluids, fluid physics, fundamental physics, and materials science. PSI started initially with data from 14 microgravity investigations. Receipt of data through the years and an annual NRA to fund ground investigations extending flight datasets has increased the total to 72 investigations available with 8 new datasets in the 2020 NRA (NNH20ZDA014N). These new datasets are open for public access at the PSI website at https://www.nasa.gov/PSI.

Physical Sciences Informatics PSI database↗
DOE OSTI2023

Measurement of the ratio of branching fractions $\mathcal{B}\left({B}_c^{+}\to {B}_s^0{\pi}^{+}\right)/\mathcal{B}\left({B}_c^{+}\to J/\psi {\pi}^{+}\right)$

The ratio of branching fractions of ${B}_c^{+}\to {B}_s^0{\pi}^{+}$ and ${B}_c^{+}\to J/\psi {\pi}^{+}$ decays is measured with proton-proton collision data of a centre-of-mass energy of 13 TeV. The data were collected with the LHCb experiment during 2016–2018, corresponding to an integrated luminosity of 5.4 fb –1 . The ${B}_s^0$ mesons are reconstructed via the decays ${B}_s^0\to J/\psi \phi$ and ${B}_s^0\to {D}_s^{-}{\pi}^{+}$. The ratio of branching fractions is measured to be $\mathcal{B}\left({B}_c^{+}\to {B}_s^0{\pi}^{+}\right)/\mathcal{B}\left({B}_c^{+}\to J/\psi {\pi}^{+}\right)=91\pm 10\pm 8\pm 3$ where the first uncertainty is statistical, the second is systematic and the third is due to the knowledge of the branching fractions of the intermediate state decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Enhanced grindability of bastnaesite ore by ex-situ CO 2 treatment under the partial pressure of 0-100 psi

High grinding energy consumption has long constrained the sustainable development of mineral processing. This study introduces an innovative technology that employs ex-situ CO 2 treatment to enhance the grindability of bastnaesite ore. The grinding aid effect was evaluated under CO 2 partial pressures ranging from 0 psi to 100 psi using particle size distribution and the Bond work index (BWI), while the underlying mechanism was elucidated with various characterization techniques including inductively coupled plasma (ICP), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET). The optimal grinding aid effect was achieved at 100 psi partial pressure, 50% slurry concentration, and 3 h reaction duration. Correspondingly, the P80 of the grinding product decreased from 81.76 μm to 72.73 μm and the BWI of bastnaesite ore decreased from 6.96 kW·h/t to 6.30 kW·h/t, a reduction of 9.48%. The grinding aid effect primarily resulted from the transformation of sparingly soluble carbonates like calcite and dolomite into more soluble bicarbonates, which created substantial cracks and pores, thereby reducing the ore's hardness and improving its grindability. By significantly saving grinding energy consumption while delivering environmental benefits, this technology exhibits great promise for further optimization and widespread adoption.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Exclusive J/$\psi$ detection and physics with ECCE

The EIC Comprehensive Chromodynamics Experiment (ECCE) detector has been recommended as a reference design for the proposed Electron-Ion Collider (EIC) program. Here, this paper presents simulation studies of exclusive J/$\psi$ detection and selected physics impact results in EIC using the projected ECCE detector concept. Exclusive quarkonium photoproduction is one of the most popular processes in EIC, which has a large cross section and a simple final state. Due to the gluonic nature of the exchange Pomeron, this process can be related to the gluon distributions in the nucleus. Preliminary results estimate the excellent statistics benefited from the large cross section of J/$\psi$ photoproduction and superior performance of ECCE detector concept. The precise measurement of exclusive J/$\psi$ photoproduction at EIC will help us to more deeply understand nuclear gluon distributions, near threshold production mechanism and nucleon mass structure.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗