| 1. |
- Aad, G., et al.
(author)
-
- 2012
-
swepub:Mat__t (peer-reviewed)
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| 2. |
- Aad, G., et al.
(author)
-
- 2012
-
swepub:Mat__t (peer-reviewed)
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| 3. |
- Aad, G., et al.
(author)
-
- 2012
-
swepub:Mat__t (peer-reviewed)
|
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| 4. |
- Aad, G., et al.
(author)
-
- 2012
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Journal article (peer-reviewed)
|
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| 5. |
- Aad, G., et al.
(author)
-
- 2012
-
swepub:Mat__t (peer-reviewed)
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| 6. |
- Aad, G., et al.
(author)
-
- 2012
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Journal article (peer-reviewed)
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| 7. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
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| 8. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
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| 9. |
- Aad, G., et al.
(author)
-
- 2012
-
Journal article (peer-reviewed)
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| 10. |
- Aad, G., et al.
(author)
-
- 2012
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Journal article (peer-reviewed)
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| 11. |
- Adler, S. S., et al.
(author)
-
High transverse momentum eta meson production in p+p, d+Au, and Au+Au collisions at root s(NN)=200 GeV
- 2007
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 75:2
-
Research review (peer-reviewed)abstract
- Inclusive transverse momentum spectra of eta mesons in the range p(T)approximate to 2-12 GeV/c have been measured at midrapidity (vertical bar eta vertical bar < 0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at root s(NN)=200 GeV. The eta mesons are reconstructed through their eta ->gamma gamma channel for the three colliding systems as well as through the eta ->pi(0)pi(+)pi(-) decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R-dAu(p(T))approximate to 1.0-1.1, suggests at most only modest p(T) broadening ("Cronin enhancement"). In central Au+Au reactions, the eta yields are significantly suppressed, with R-AuAu(p(T))approximate to 0.2. The ratio of eta to pi(0) yields is approximately constant as a function of p(T) for the three colliding systems in agreement with the high-p(T) world average of R-eta/pi(0)approximate to 0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies (root sNN approximate to 3-1800 GeV) as well as, for high scaled momentum x(p), in e(+)e(-) annihilations at root s=91.2 GeV. These results are consistent with a scenario where high-p(T) eta production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons (pi(0),eta) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.
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| 12. |
- Adcox, K, et al.
(author)
-
Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration
- 2005
-
In: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 757:1-2, s. 184-283
-
Research review (peer-reviewed)abstract
- Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (PT), elliptic flow, two-particle correlations, nonstatistical fluctuations, and suppression of particle production at high PT. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.
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| 13. |
- Adler, S. S., et al.
(author)
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Evidence for a long-range component in the pion emission source in Au plus Au collisions at root s(NN)=200 GeV
- 2007
-
In: Physical Review Letters. - 1079-7114. ; 98:13
-
Journal article (peer-reviewed)abstract
- Emission source functions are extracted from correlation functions constructed from charged pions produced at midrapidity in Au+Au collisions at s(NN)=200 GeV. The source parameters extracted from these functions at low k(T) give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kinematic considerations. The possible role of a halo of secondary pions from resonance emissions is explored.
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| 14. |
- Adcox, K, et al.
(author)
-
PHENIX detector overview
- 2003
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
-
Journal article (peer-reviewed)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 15. |
- Adler, S. S., et al.
(author)
-
Dense-medium modifications to jet-induced hadron pair distributions in Au+Au collisions at root(NN)-N-S=200 GeV
- 2006
-
In: Physical Review Letters. - 1079-7114. ; 97:5
-
Journal article (peer-reviewed)abstract
- Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at root s(NN)=200 GeV. The distribution of jet-associated partner hadrons (1.0 < p(T)< 2.5 GeV/c) per trigger hadron (2.5 < p(T)< 4.0 GeV/c) is found to vary with collision centrality, in both shape and yield, indicating a significant effect of the nuclear collision medium on the jet fragmentation process.
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| 16. |
- Adler, S. S., et al.
(author)
-
Detailed study of high-p(T) neutral pion suppression and azimuthal anisotropy in Au plus Au collisions at root s(NN) =200 GeV
- 2007
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 76:3
-
Journal article (peer-reviewed)abstract
- Measurements of neutral pion (pi(0)) production at midrapidity in root s(NN)=200 GeV Au+Au collisions as a function of transverse momentum, p(T), collision centrality, and angle with respect to reaction plane are presented. The data represent the final pi(0) results from the PHENIX experiment for the first RHIC Au+Au run at design center-of-mass energy. They include additional data obtained using the PHENIX Level-2 trigger with more than a factor of 3 increase in statistics over previously published results for p(T)>6 GeV/c. We evaluate the suppression in the yield of high-p(T) pi(0)'s relative to pointlike scaling expectations using the nuclear modification factor R-AA. We present the p(T) dependence of R-AA for nine bins in collision centrality. We separately integrate R-AA over larger p(T) bins to show more precisely the centrality dependence of the high-p(T) suppression. We then evaluate the dependence of the high-p(T) suppression on the emission angle Delta phi of the pions with respect to event reaction plane for seven bins in collision centrality. We show that the yields of high-p(T) pi(0)'s vary strongly with Delta phi, consistent with prior measurements 1,2. We show that this variation persists in the most peripheral bin accessible in this analysis. For the peripheral bins we observe no suppression for neutral pions produced aligned with the reaction plane, whereas the yield of pi(0)'s produced perpendicular to the reaction plane is suppressed by a factor of similar to 2. We analyze the combined centrality and Delta phi dependence of the pi(0) suppression in different p(T) bins using different possible descriptions of parton energy loss dependence on jet path-length averages to determine whether a single geometric picture can explain the observed suppression pattern.
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| 17. |
- Adler, S. S., et al.
(author)
-
Measurement of single muons at forward rapidity in p+p collisions at root s=200 GeV and implications for charm production
- 2007
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-2368. ; 76:9
-
Journal article (peer-reviewed)abstract
- Muon production at forward rapidity (1.5 <=|eta|<= 1.8) has been measured by the PHENIX experiment over the transverse momentum range 1 <= p(T)<= 3 GeV/c in root s=200 GeV p+p collisions at the Relativistic Heavy Ion Collider. After statistically subtracting contributions from light hadron decays an excess remains which is attributed to the semileptonic decays of hadrons carrying heavy flavor, i.e. charm quarks or, at high p(T), bottom quarks. The resulting muon spectrum from heavy flavor decays is compared to PYTHIA and a next-to-leading-order perturbative QCD calculation. PYTHIA is used to determine the charm quark spectrum that would produce the observed muon excess. The corresponding differential cross section for charm quark production at forward rapidity is determined to be d sigma(c (c) over bar)/dy|(y=1.6)=0.243 +/- 0.013(stat.)+/- 0.105(data syst.)(-0.087)(+0.049)(PYTHIA syst.) mb.
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| 18. |
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| 19. |
|
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| 20. |
|
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| 21. |
- Adler, SS, et al.
(author)
-
Elliptic flow of identified hadrons in Au+Au collisions at root s(NN)=200 GeV
- 2003
-
In: Physical Review Letters. - 1079-7114. ; 91:18: 182301
-
Journal article (peer-reviewed)abstract
- The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at roots(NN)=200 GeV for identified and inclusive charged particle production at central rapidities (eta<0.35) with respect to the reaction plane defined at high rapidities (eta=3-4 ). We observe that the v(2) of mesons falls below that of (anti)baryons for p(T)>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.
|
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| 22. |
- Adler, SS, et al.
(author)
-
Bose-Einstein correlations of charged pion pairs in Au+Au collisions at root(NN)-N-s = 200 GeV
- 2004
-
In: Physical Review Letters. - 1079-7114. ; 93:15
-
Journal article (peer-reviewed)abstract
- Bose-Einstein correlations of identically charged pion pairs were measured by the PHENIX experiment at midrapidity in Au+Au collisions at roots(NN)=200 GeV. The Bertsch-Pratt radius parameters were determined as a function of the transverse momentum of the pair and as a function of the centrality of the collision. Using the standard core-halo partial Coulomb fits, and a new parametrization which constrains the Coulomb fraction as determined from the unlike-sign pion correlation, the ratio R-out/R-side is within 0.8-1.1 for 0.25<<1.2 GeV/c. The centrality dependence of all radii is well described by a linear scaling in N-part(1/3), and R-out/R-side for similar to0.45 GeV/c is approximately constant at unity as a function of centrality.
|
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| 23. |
- Adler, SS, et al.
(author)
-
Common suppression pattern of eta and pi(0) mesons at high transverse momentum in Au plus Au collisions at root SNN=200 GeV
- 2006
-
In: Physical Review Letters. - 1079-7114. ; 96:20
-
Journal article (peer-reviewed)abstract
- Inclusive transverse momentum spectra of eta mesons have been measured within p(T)=2-10 GeV/c at midrapidity by the PHENIX experiment in Au+Au collisions at root s(NN) = 200 GeV. In central Au+Au the eta yields are significantly suppressed compared to peripheral Au+Au, d+Au, and p+p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p(T) dependence of the suppression is common, within errors, for eta and pi(0). The ratio of eta to pi(0) spectra at high p(T) amounts to 0.40 < R-eta/pi(0)< 0.48 for the three systems, in agreement with the world average measured in hadronic and nuclear reactions and, at large scaled momentum, in e(+)e(-) collisions.
|
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| 24. |
- Adler, SS, et al.
(author)
-
Deuteron and antideuteron production in Au+Au collisions at root s(NN)=200 GeV
- 2005
-
In: Physical Review Letters. - 1079-7114. ; 94:12
-
Journal article (peer-reviewed)abstract
- The production of deuterons and antideuterons in the transverse momentum range 1.1 < p(T)< 4.3 GeV/c at midrapidity in Au+Au collisions at root s(NN) = 200 GeV has been studied by the PHENIX experiment at RHIC. A coalescence analysis, comparing the deuteron and antideuteron spectra with that of proton and antiproton, has been performed. The coalescence probability is equal for both deuterons and antideuterons and it increases as a function of p(T), which is consistent with an expanding collision zone. Comparing (anti)proton yields, (p) over bar /p = 0.73 +/- 0.01, with (anti)deuteron yields, (d) over bar /d = 0.47 +/- 0.03, we estimate that (n) over bar /n = 0.64 +/- 0.04. The nucleon phase space density is estimated from the coalescence measurement.
|
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| 25. |
- Adler, SS, et al.
(author)
-
J/psi production from proton-proton collisions at root s=200 GeV
- 2004
-
In: Physical Review Letters. - 1079-7114. ; 92:5
-
Journal article (peer-reviewed)abstract
- J/psi production has been measured in proton-proton collisions at roots=200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at the Relativistic Heavy Ion Collider. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 4.0+/-0.6(stat)+/-0.6(syst)+/-0.4(abs) mub. The mean transverse momentum is 1.80+/-0.23(stat)+/-0.16(syst) GeV/c.
|
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| 26. |
- Adler, SS, et al.
(author)
-
J/psi production in Au-Au collisions at root s(NN)=200 GeV
- 2004
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 69:1
-
Journal article (peer-reviewed)abstract
- First results on charm quarkonia production in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The yield of J/psi's measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au-Au reactions at roots(NN) = 200 GeV is analyzed as a function of collision centrality. For this analysis we have studied 49.3x10(6) minimum bias Au-Au reactions. We present the J/psi invariant yield dN/dy for peripheral and midcentral reactions. For the most central collisions where we observe no signal above background, we quote 90% confidence level upper limits. We compare these results with our J/psi measurement from proton-proton reactions at the same energy. We find that our measurements are not consistent with models that predict strong enhancement relative to binary collision scaling.
|
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| 27. |
- Adler, SS, et al.
(author)
-
Measurement of single electron event anisotropy in Au plus Au collisions at root s(NN)=200 GeV
- 2005
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:2
-
Journal article (peer-reviewed)abstract
- The transverse momentum dependence of the azimuthal anisotropy parameter v(2), the second harmonic of the azimuthal distribution, for electrons at midrapidity (vertical bar eta vertical bar < 0.35) has been measured with the PHENIX detector in Au+Au collisions at root s(NN) = 200 GeV. The measurement was made with respect to the reaction plane defined at high rapidities (vertical bar eta vertical bar = 3.1-3.9). From the result we have measured the v(2) of electrons from heavy flavor decay after subtraction of the v(2) of electrons from other sources such as photon conversions and Dalitz decay from light neutral mesons. We observe a nonzero single electron v(2) with a 90% confidence level in the intermediate-p(T) region. The precision of the present data set does not permit us to conclude definitively that heavy quarks exhibit thermalization with the transverse flow of the bulk matter.
|
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| 28. |
- Adler, SS, et al.
(author)
-
Measurement of transverse single-spin asymmetries for midrapidity production of neutral pions and charged hadrons in polarized p+p collisions at root s=200 GeV
- 2005
-
In: Physical Review Letters. - 1079-7114. ; 95
-
Journal article (peer-reviewed)abstract
- Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions at midrapidity and root s = 200 GeV. The data cover a transverse momentum (pT) range 1.0-5.0 GeV/c for neutral pions and 0.5-5.0 GeV/c for charged hadrons, at a Feynman-x value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from 0.5 < P-T < 7.0 GeV/c is presented and compared to next-to-leading order perturbative QCD ( pQCD) calculations. Successful description of the unpolarized cross section above similar to 2 GeV/c suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.
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| 29. |
- Adler, SS, et al.
(author)
-
Midrapidity direct-photon production in p+p collisions at root s=200 GeV
- 2005
-
In: Physical Review D (Particles and Fields). - 0556-2821. ; 71:7
-
Journal article (peer-reviewed)abstract
- A measurement of direct photons in p+p collisions at root s=200 GeV is presented. A photon excess above background from pi(0)->gamma+gamma, eta ->gamma+gamma and other decays is observed in the transverse momentum range 5.5 < p(T)< 7 GeV/c. The result is compared to a next-to-leading-order perturbative QCD calculation. Within errors, good agreement is found between the QCD calculation and the measured result.
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| 30. |
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| 31. |
- Adler, SS, et al.
(author)
-
Production of phi mesons at midrapidity in root S-NN=200 GeVAu+Au collisions at relativistic energies
- 2005
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:1
-
Journal article (peer-reviewed)abstract
- We present the results of phi meson production in the K+K- decay channel from Au+Au collisions at root s(NN) =200 GeV as measured at midrapidity by the PHENIX detector at Brookhaven National Laboratory's Relativistic Heavy Ion Collider. Precision resonance centroid and width values are extracted as a function of collision centrality. No significant variation from the Particle Data Group accepted values is observed, contrary to some model predictions. The phi transverse mass spectra are fitted with a linear exponential function for which the derived inverse slope parameter is seen to be constant as a function of centrality. However, when these data are fitted by a hydrodynamic model the result is that the centrality-dependent freeze-out temperature and the expansion velocity values are consistent with the values previously derived from fitting identified charged hadron data. As a function of transverse momentum the collisions scaled peripheral-to-central yield ratio R-CP for the phi is comparable to that of pions rather than that of protons. This result lends support to theoretical models that distinguish between baryons and mesons instead of particle mass for explaining the anomalous (anti) proton yield.
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| 32. |
- Adler, SS, et al.
(author)
-
Scaling properties of proton and antiproton production in root s(NN)=200 GeV Au+Au collisions
- 2003
-
In: Physical Review Letters. - 1079-7114. ; 91:17: 172301
-
Journal article (peer-reviewed)abstract
- We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at rootS(NN)=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5
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| 33. |
- Adler, SS, et al.
(author)
-
Single electrons from heavy-flavor decays in p + p collisions at root s=200 GeV
- 2006
-
In: Physical Review Letters. - 1079-7114. ; 96:3
-
Journal article (peer-reviewed)abstract
- The invariant differential cross section for inclusive electron production in p+p collisions at root s=200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.4 <= p(T) <= 5.0 GeV/c in the central rapidity region (vertical bar eta vertical bar <= 0.35). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e., charm quarks or, at high p(T), bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy-flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined to be sigma(c (c) over bar) = 0.92 +/- 0.15(stat) +/- 0.54(syst) mb.
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| 34. |
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| 35. |
- Polme, S., et al.
(author)
-
FungalTraits: a user-friendly traits database of fungi and fungus-like stramenopiles
- 2020
-
In: Fungal Diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 105:1, s. 1-16
-
Journal article (peer-reviewed)abstract
- The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies. Over the past decades, rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging. In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels. Combining the information from previous efforts such as FUNGuild and Fun(Fun) together with involvement of expert knowledge, we reannotated 10,210 and 151 fungal and Stramenopila genera, respectively. This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera, designed for rapid functional assignments of environmental studies. In order to assign the trait states to fungal species hypotheses, the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences. On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1% dissimilarity threshold.
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| 36. |
- Boso, A., et al.
(author)
-
Isospin dependence of electromagnetic transition strengths among an isobaric triplet
- 2019
-
In: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 797
-
Journal article (peer-reviewed)abstract
- Electric quadrupole matrix elements, M-p, for the J(pi) = 2(+) -> 0(+), Delta T = 0, T = 1 transitions across the A = 46 isobaric multiplet Cr-46-V-46-Ti-46 have been measured at GSI with the FRS-LYCCA-AGATA setup. This allows direct insight into the isospin purity of the states of interest by testing the linearity of M-p with respect to T-z. Pairs of nuclei in the T = 1 triplet were studied using identical reaction mechanisms in order to control systematic errors. The M-p values were obtained with two different methodologies: (i) a relativistic Coulomb excitation experiment was performed for Cr-46 and Ti-46; (ii) a "stretched target" technique was adopted here, for the first time, for lifetime measurements in V-46 and Ti-46. A constant value of M-p across the triplet has been observed. Shell-model calculations performed within the fp shell fail to reproduce this unexpected trend, pointing towards the need of a wider valence space. This result is confirmed by the good agreement with experimental data achieved with an interaction which allows excitations from the underlying sd shell. A test of the linearity rule for all published data on complete T = 1 isospin triplets is presented. (C) 2019 The Author(s). Published by Elsevier B.V.
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| 37. |
- Chishti, M.M.R., et al.
(author)
-
Response of the FAst TIMing Array (FATIMA) for DESPEC at FAIR Phase-0
- 2023
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier B.V.. - 0168-9002 .- 1872-9576. ; 1056
-
Journal article (peer-reviewed)abstract
- The Monte-Carlo simulated response for γ-ray detection of the FAst TIMing Array (FATIMA) for exploitation within the DEcay SPECtroscopy (DESPEC) experimental system at the FAIR Phase-0 facility at Darmstadt, Germany is presented. In this configuration, FATIMA consisted of 36 LaBr3(Ce) detectors surrounding the AIDA, position-sensitive charged-particle active stopper. The decay of the Iπ=8+ isomer-fed decay cascade in 96Pd, measured in the first DESPEC experiment at the FAIR-0 facility was used to validate the simulations. The experimental data yielded in-situ full-energy peak efficiency values for FATIMA of 11.2(11)%, 6.8(7)%, 3.8(4)% and 2.1(4)% at 106, 325, 684 and 1415 keV respectively, consistent with the values derived from the simulated response.
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| 38. |
- Ertoprak, Aysegul, et al.
(author)
-
Evidence for octupole collectivity in 172Pt
- 2020
-
In: European Physical Journal A. - : Springer. - 1434-6001 .- 1434-601X. ; 56:2
-
Journal article (peer-reviewed)abstract
- Excited states in the extremely neutron-deficient nucleus 172Pt were populated via 96Ru(78Kr,2p) and 92Mo(83Kr,3n) reactions. The level scheme has been extended up to an excitation energy of ~ 5 MeV and tentative spin-parity assignments up to Iπ = 18+. Linear polarization and angular distribution measurements were used to determine the electromagnetic E1 character of the dipole transitions connecting the positive-parity ground-state band with an excited side-band, firmly establishing it as a negative-parity band. The lowest member of this negative-parity structure was firmly assigned spin-parity 3-. In addition, we observed an E3 transition from this 3- state to the ground state, providing direct evidence for octupole collectivity in 172Pt. Large-scale shell model (LSSM) and total Routhian surface (TRS) calculations have been performed, supporting the interpretation of the 3- state as a collective octupole-vibrational state.
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| 39. |
- Goldkuhle, A., et al.
(author)
-
Lifetime measurements in Ti-52,Ti-54 to study shell evolution toward N=32
- 2019
-
In: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 100:5
-
Journal article (peer-reviewed)abstract
- Lifetimes of the excited states in the neutron-rich Ti-52,Ti-54 nuclei, produced in a multinucleon-transfer reaction, were measured by employing the Cologne plunger device and the recoil-distance Doppler-shift method. The experiment was performed at the Grand Accelerateur National d'Ions Lourds facility by using the Advanced Gamma Tracking Array for the gamma-ray detection, coupled to the large-acceptance variable mode spectrometer for an event-by-event particle identification. A comparison between the transition probabilities obtained from the measured lifetimes of the 2(1)(+) to 8(1)(+) yrast states in Ti-52,Ti-54 and that from the shell-model calculations based on the well-established GXPF1A, GXPF1B, and KB3G fp shell interactions support the N = 32 subshell closure. The B(E2) values for Ti-52 determined in this work are in disagreement with the known data, but are consistent with the predictions of the shell-model calculations and reduce the previously observed pronounced staggering across the even-even titanium isotopes.
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| 40. |
- Martel, I., et al.
(author)
-
An innovative Superconducting Recoil Separator for HIE-ISOLDE
- 2023
-
In: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : ELSEVIER. - 0168-583X .- 1872-9584. ; 541, s. 176-179
-
Journal article (peer-reviewed)abstract
- The ISOLDE Scientific Infrastructure at CERN offers a unique range of post-accelerated radioactive beams. The scientific program can be improved with the “Isolde Superconducting Recoil Separator” (ISRS), an innovative spectrometer able to deliver unprecedented (A, Z) resolution. In this paper we present an overview of the physics and ongoing technical developments.
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| 41. |
- Parr, E., et al.
(author)
-
Single-particle states and parity doublets in odd- Z Ac 221 and Pa 225 from α -decay spectroscopy
- 2022
-
In: Physical Review C. - 2469-9985. ; 105:3
-
Journal article (peer-reviewed)abstract
- Low-lying states in the odd-Z isotopes Ac13289221 and Pa13491225 have been studied using α-particle and αγ-coincidence spectroscopy in the Pa225→Ac221→Fr217 decay chain. Ground-state spin and parity assignments of Iπ = 5/2- are proposed for both Ac221 and Pa225, with the odd proton occupying the ω = 5/2 orbital of the quadrupole-octupole deformed shell model in both nuclei. In Ac221, excited states in the bands based on the ω = 5/2 and ω = 3/2 orbitals have been identified, including proposed parity-doublet states. The results suggest that reflection-asymmetric deformation of the ground state persists in the odd-A members of the isotope chains down to N = 132 for Ac and N = 134 for Pa, before reaching the transitional region at N = 130.
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| 42. |
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| 43. |
- Butler, P. A., et al.
(author)
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Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive ^{222}Ra and ^{228}Ra Beams
- 2020
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In: Physical Review Letters. - 1079-7114. ; 124:4
-
Journal article (peer-reviewed)abstract
- There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.
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| 44. |
- Butler, P. A., et al.
(author)
-
The observation of vibrating pear-shapes in radon nuclei
- 2019
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
-
Journal article (peer-reviewed)abstract
- There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.
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| 45. |
- Spagnoletti, P., et al.
(author)
-
Coulomb excitation of Rn 222
- 2022
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In: Physical Review C. - 2469-9985. ; 105:2
-
Journal article (peer-reviewed)abstract
- The nature of quadrupole and octupole collectivity in Rn222 was investigated by determining the electric-quadrupole (E2) and octupole (E3) matrix elements using subbarrier, multistep Coulomb excitation. The radioactive Rn222 beam, accelerated to 4.23 MeV/u, was provided by the HIE-ISOLDE facility at CERN. Data were collected in the Miniball γ-ray spectrometer following the bombardment of two targets, Sn120 and Ni60. Transition E2 matrix elements within the ground-state and octupole bands were measured up to 10ℏ and the results were consistent with a constant intrinsic electric-quadrupole moment, 518(11)efm2. The values of the intrinsic electric-octupole moment for the 0+→3- and 2+→5- transitions were found to be respectively 2360-210+300efm3 and 2300-500+300efm3 while a smaller value, 1200-900+500efm3, was found for the 2+→1- transition. In addition, four excited non-yrast states were identified in this work via γ-γ coincidences.
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| 46. |
- Zhang, W., et al.
(author)
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Decay spectroscopy of 171,172Os and 171,172,174Ir
- 2023
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In: Physical Review C. - : American Physical Society (APS). - 2469-9985 .- 2469-9993. ; 107:1
-
Journal article (peer-reviewed)abstract
- We report on a study of the α-decay fine structure and the associated Eα−Eγ correlations in the decays of 171,172Os and 171,172,174Ir. In total, 13 new α-decay energy lines have been resolved, and three new γ-ray transitions have been observed following the new decay branches to 168Re and 167W. The weak α-decay branch from the bandhead of the νi13/2 band in 171Os observed in this work highlights an unusual competition between α, β, and electromagnetic decays from this isomeric state. The nucleus 171Os is therefore one of few nuclei observed to exhibit three different decay modes from the same excited state. The nuclei of interest were produced in 92Mo(83Kr,xpyn) fusion-evaporation reactions at the Accelerator Laboratory of the University of Jyväskylä, Finland. The fusion products were selected using the gas-filled ion separator RITU and their decays were characterized using an array of detectors for charged particles and electromagnetic radiation known as GREAT. Prompt γ-ray transitions were detected and correlated with the decays using the JUROGAM II germanium detector array surrounding the target position. Results obtained from total Routhian surface (TRS) calculations suggest that α-decay fine structure and the associated hindrance factors may be a sensitive probe of even relatively small shape changes between the final states in the daughter nucleus.
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| 47. |
- Zhang, Wei, et al.
(author)
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Lifetime measurements of excited states in 169,171,173Os : Persistence of anomalous B(E2) ratios in transitional rare earth nuclei in the presence of a decoupled i13/2 valence neutron
- 2021
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 820
-
Journal article (peer-reviewed)abstract
- Lifetimes of low-lying excited states in the νi13/2+ bands of the neutron-deficient osmium isotopes 169,171,173Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) in 169Os, similar to the “anomalously” low values of the ratio B(E2;41+→21+)/B(E2;21+→0gs+) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring 168,170Os. Furthermore, the evolution of B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) with increasing neutron number in the odd-mass isotopic chain 169,171,173Os is observed to follow the same trend as observed previously in the even-even Os isotopes. These findings indicate that the possible quantum phase transition from a seniority conserving structure to a collective regime as a function of neutron number suggested for the even-even systems is maintained in these odd-mass osmium nuclei, with the odd valence neutron merely acting as a “spectator”. As for the even-even nuclei, the phenomenon is highly unexpected for nuclei that are not situated near closed shells.
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| 48. |
- Moschner, K., et al.
(author)
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Relativistic Coulomb excitation of 88Kr
- 2016
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 94:5
-
Journal article (peer-reviewed)abstract
- To investigate the systematics of mixed-symmetry states in N=52 isotones, a relativistic Coulomb excitation experiment was performed during the PreSPEC campaign at the GSI Helmholtzzentrum für Schwerionenforschung to determine E2 transition strengths to 2+ states of the radioactive nucleus 88Kr. Absolute transition rates could be measured towards the first and third 2+ states. For the latter a mixed-symmetry character is suggested on the basis of the indication for a strong M1 transition to the fully symmetric 2+1 state, extending the knowledge of the N=52 isotones below Z=40. A comparison with the proton-neutron interacting boson model and shell-model predictions is made and supports the assignment.
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| 49. |
- Roberts, Jason D., et al.
(author)
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Ankyrin-B dysfunction predisposes to arrhythmogenic cardiomyopathy and is amenable to therapy
- 2019
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In: Journal of Clinical Investigation. - : AMER SOC CLINICAL INVESTIGATION INC. - 0021-9738 .- 1558-8238. ; 129:8, s. 3171-3184
-
Journal article (peer-reviewed)abstract
- Arrhythmogenic cardiomyopathy (ACM) is an inherited arrhythmia syndrome characterized by severe structural and electrical cardiac phenotypes, including myocardial fibrofatty replacement and sudden cardiac death. Clinical management of ACM is largely palliative, owing to an absence of therapies that target its underlying pathophysiology, which stems partially from our limited insight into the condition. Following identification of deceased ACM probands possessing ANK2 rare variants and evidence of ankyrin-B loss of function on cardiac tissue analysis, an ANK2 mouse model was found to develop dramatic structural abnormalities reflective of human ACM, including biventricular dilation, reduced ejection fraction, cardiac fibrosis, and premature death. Desmosomal structure and function appeared preserved in diseased human and murine specimens in the presence of markedly abnormal beta-catenin expression and patterning, leading to identification of a previously unknown interaction between ankyrin-B and beta-catenin. A pharmacological activator of the WNT/beta-catenin pathway, SB-216763, successfully prevented and partially reversed the murine ACM phenotypes. Our findings introduce what we believe to be a new pathway for ACM, a role of ankyrin-B in cardiac structure and signaling, a molecular link between ankyrin-B and beta-catenin, and evidence for targeted activation of the WNT/beta-catenin pathway as a potential treatment for this disease.
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| 50. |
- Wadsworth, R., et al.
(author)
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THE NORTHWEST FRONTIER : SPECTROSCOPY OF N similar to Z NUCLEI BELOW MASS 100
- 2009
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In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 40:3, s. 611-620
-
Journal article (peer-reviewed)abstract
- The spectroscopy and structure of excited states of N similar to Z nuclei in the mass 70-100 region has been investigated using two techniques. In the A similar to 70-80 region fusion evaporation reactions coupled with the recoil-beta-tagging method have been employed at Jyvaskyla to study low-lying states in odd-odd N = Z nuclei. Results from these and other data for known odd-odd nuclei above mass 60 will be discussed. In the heavier mass 90 region a fragmentation experiment has been performed using the RIS-ING/FRS setup at GSI. This experiment was primarily aimed at searching for spin gap isomers in nuclei around A similar to 96. The objectives of the latter experiment will be discussed.
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