| 1. |
- Adare, A., et al.
(författare)
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Measurement of K-S(0) and K*(0) in p plus p, d plus Au, and Cu plus Cu collisions at root s(NN)=200 GeV
- 2014
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 90:5
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of K-S(0) and K*(0) meson production at midrapidity in p + p, d + Au, and Cu + Cu collisions at root s(NN) = 200 GeV. The K-S(0) and K*(0) mesons are reconstructed via their K-S(0) -> pi(0)(-> gamma gamma) pi(0)(-> gamma gamma) and K*(0) -> K-+/-pi(-/+) decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of K-S(0) and K*(0) mesons in d + Au and Cu + Cu collisions at different centralities. In the d + Au collisions, the nuclear modification factor of K-S(0) and K*(0) mesons is almost constant as a function of transverse momentum and is consistent with unity, showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu + Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the p + p yield scaled by the number of binary nucleon-nucleon collisions in the Cu + Cu system. In the p(T) range 2-5 GeV/c, the strange mesons (K-S(0), K*(0)) similarly to the phi meson with hidden strangeness, showan intermediate suppression between the more suppressed light quark mesons (pi(0)) and the nonsuppressed baryons (p, (p) over bar). At higher transverse momentum, p(T) > 5 GeV/c, production of all particles is similarly suppressed by a factor of approximate to 2.
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| 2. |
- Adare, A., et al.
(författare)
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Cross section and transverse single-spin asymmetry of eta mesons in p up arrow plus p collisions at root s=200 GeV at forward rapidity
- 2014
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 90:7
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the cross section and transverse single-spin asymmetry (AN) for. mesons at large pseudorapidity from root s = 200 GeV p up arrow + p collisions. The measured cross section for 0.5 < p(T) < 5.0 GeV/c and 3.0 < vertical bar eta vertical bar < 3.8 is well described by a next-to-leading-order perturbative-quantum-chromodynamics calculation. The asymmetries A(N) have been measured as a function of Feynman-x (x(F)) from 0.2 < vertical bar x(F)vertical bar < 0.7, as well as transverse momentum (p(T)) from 1.0 < p(T) < 4.5 GeV/c. The asymmetry averaged over positive x(F) is < A(N)> = 0.061 +/- 0.014. The results are consistent with prior transverse single-spin measurements of forward eta and pi(0) mesons at various energies in overlapping x(F) ranges. Comparison of different particle species can help to determine the origin of the large observed asymmetries in p up arrow + p collisions.
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| 3. |
- Adare, A., et al.
(författare)
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Low-mass vector-meson production at forward rapidity in p plus p collisions at root s=200 GeV
- 2014
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 90:5
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low-mass vector-meson ,omega, rho, and phi, production through the dimuon decay channel at forward rapidity (1.2 < vertical bar y vertical bar < 2.2) in p + p collisions at root s = 200 GeV. The differential cross sections for these mesons are measured as a function of both p(T) and rapidity. We also report the integrated differential cross sections over 1 < p(T) < 7 GeV/c and 1.2 < vertical bar y vertical bar < 2.2: d sigma/dy(omega + rho rho -> mu mu) = 80 +/- 6(stat) +/- 12(syst)nb and d sigma/dy(phi -> mu mu) = 27 +/- 3(stat) +/- 4(syst)nb. These results are compared with midrapidity measurements and calculations.
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| 4. |
- Adare, A., et al.
(författare)
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Nuclear matter effects on J/psi production in asymmetric Cu plus Au collisions at root S-NN=200 GeV
- 2014
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 90:6
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Tidskriftsartikel (refereegranskat)abstract
- We report on J/psi production from asymmetric Cu + Au heavy-ion collisions at root S-NN = 200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/psi yields in Cu + Au collisions in the Au-going direction is found to be comparable to that inAu + Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/psi production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in the larger Au nucleus.
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| 5. |
- Garg, K. B., et al.
(författare)
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Mechanism of quenching of superconductivity in the YBa2Cu3O7-delta system on substitution of Zn for Cu
- 2010
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Ingår i: International Journal of Modern Physics B. - 0217-9792. ; 24:14, s. 2135-2148
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Tidskriftsartikel (refereegranskat)abstract
- Substituting Zn for Cu is known to rapidly quench superconductivity in the doped perovskites but the mechanism behind it is still not clearly understood. Single phase YBa2(Cu1-xZnx)(3)O7-delta (x=0.0 to 0.06) samples were synthesized and characterized using XRD, wet titration, resistivity, and ac susceptibility. Angle-integrated Valence Band Photo emission and Zn K-edge XAFS results clearly show that their oxygen stoichiometry (delta) changes on Zn substitution, there by adversely affecting the density of free charge carriers and hence the normal state resistivity and the T-c. However, the observed changes in the two happen to be too large to be accounted for solely on the basis of changes in the oxygen stoichiometry delta. We find that the Zn cation acts as a strong "impurity" scattering centre in the YBCO lattice and causes local lattice distortion (LLD). It consequently induces local magnetic moment, seen in our dc susceptibility measurements. It is thus a composite of (Delta delta), LLD and possibly also magnetic pair-breaking that is responsible for the rapid quenching of the super conductivity observed with Zn doping in this system.
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| 6. |
- Krasznahorkay, A., et al.
(författare)
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Neutron-skin thickness from the study of the anti-analog giant dipole resonance
- 2012
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735411036 ; 1491, s. 190-197
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Konferensbidrag (refereegranskat)abstract
- The γ-decay of the anti-analog of the giant dipole resonance (AGDR) to the isobaric analog state has been measured following the p( 124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent relativistic random-phase approximation (RPA) and turned out to be very sensitive to the neutronskin thickness (ΔRpn). By comparing the theoretical results with the measured one, the ΔRpn value for 124Sn was deduced to be 0.21 ± 0.07 fm, which agrees well with the previous results. The present method offers new possibilities for measuring the neutron-skin thicknesses of very exotic isotopes.
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| 7. |
- Wijns, W, et al.
(författare)
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Myocardial revascularization
- 2011
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Ingår i: REVISTA PORTUGUESA DE CARDIOLOGIA. - : Elsevier BV. - 0870-2551 .- 2174-2049. ; 30:12, s. 951-1005
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Garg, K B, et al.
(författare)
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A comparative study of oxygen loss on in situ heating in PrMnO3 and BaMnO3
- 2011
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Ingår i: International Journal of Modern Physics B. - 0217-9792. ; 25:9, s. 1235-1250
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Tidskriftsartikel (refereegranskat)abstract
- We have thoroughly investigated the Oxygen loss in PrMnO3 and BaMnO3 the end members of the AMnO(3) system, on in situ heating in a reducing at This was done to drive some oxygen out from them and thus possibly alter the valence of the Mn cation. Sample characterization was done through X-ray diffraction and SEM measurements. The core-level photoemission point to oxygen loss from only BaMnO3 changing some of Mn4+ to Mn3+ in it, transfer of some spectral weight to the highly localized Fehrenbacher-Rice states and an increased Mn 3d-O 2p hybridization. Magnetization measurements show that at low temperatures, the samples depict a canted antiferromagnetic ordering.
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| 9. |
- Garg, K. K., et al.
(författare)
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Jatropha production on wastelands in India: opportunities and trade-offs for soil and water management at the watershed scale
- 2011
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Ingår i: Biofuels, Bioproducts and Biorefining. - : Wiley. - 1932-1031 .- 1932-104X. ; 5:4, s. 410-430
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Tidskriftsartikel (refereegranskat)abstract
- Biofuel production from feedstocks grown on wastelands is considered a means of addressing concerns about climate change and improving energy security while at the same time providing an additional source of income for the land users. The establishment of biomass plantations on wastelands is likely to affect local livelihoods and can affect surrounding ecosystems by influencing hydrologic flows and processes such as erosion. We present an assessment of Jatropha plantation establishment on wastelands, using the ArcSWAT modeling tool. The assessment was made for a wasteland located in the Velchal watershed, Andhra Pradesh, India, which recently was converted to a biofuel plantation with Jatropha. The previous land use, in this case grazing, could continue in the Jatropha plantations. Several desirable effects occurred as a result of the land-use conversion: non-productive soil evaporation was reduced as a larger share of the rainfall was channeled to productive plant transpiration and groundwater recharge, and at the same time a more stable (less erosive) runoff resulted in reduced soil erosion and improved downstream water conditions. A win-win situation between improved land productivity and soil carbon content was observed for the Jatropha plantations. On the other hand, the results indicate that at the sub-basin scale, reductions in runoff generation as a result of large-scale conversion of wastelands to Jatropha cropping may pose problems to downstream water users and ecosystems. From a livelihoods perspective, Jatropha production was generally positive, creating a complementary source of income to the farmers, thus strengthening the resilience of the local community. In the future, the potential gain from Jatropha cropping is expected to increase as cropping systems improve and growing biofuel markets result in better conditions for biofuel producers.
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| 10. |
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