SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "LAR1:lu ;lar1:(lu);pers:(Stenlund Evert);pers:(Drees A.);pers:(He X.);pers:(Cianciolo V.);pers:(Reygers K.)"

Sökning: LAR1:lu > Lunds universitet > Stenlund Evert > Drees A. > He X. > Cianciolo V. > Reygers K.

  • Resultat 1-10 av 77
  • [1]234567...8Nästa
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Adare, A, et al. (författare)
  • Azimuthal-Angle Dependence of Charged-Pion-Interferometry Measurements with Respect to Second- and Third-Order Event Planes in Au+Au Collisions at sqrts_{NN}=200 GeV.
  • 2014
  • Ingår i: Physical review letters. - American Physical Society. - 0031-9007 .- 1079-7114. ; 112:22, s. 222301
  • Tidskriftsartikel (refereegranskat)abstract
    • Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrts_{NN}=200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.
  •  
2.
  • Adare, A., et al. (författare)
  • Azimuthal anisotropy of pi(0) and eta mesons in Au plus Au collisions at root s(NN)=200 GeV
  • 2013
  • Ingår i: Physical Review C. - Amer. Physical Soc.. - 0556-2813. ; 88:6, s. 064910
  • Tidskriftsartikel (refereegranskat)abstract
    • The azimuthal anisotropy coefficients v2 and v4 of p 0 and. mesons are measured in Au + Au collisions at root s(NN) = 200 GeV as a function of transverse momentum p(T) (1-14 GeV/c) and centrality. The extracted v(2) coefficients are found to be consistent between the two meson species over the measured p(T) range. The ratio of v(4)/v(2)(2) for pi(0) mesons is found to be independent of p(T) for 1- 9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with p(T). Furthermore, the ratio of v(4)/v(2)(2) is systematically larger in central collisions, which may reflect the combined effects of fluctuations in the initial collision geometry and finite viscosity in the evolving medium.
  •  
3.
  • Adare, A., et al. (författare)
  • Azimuthal Anisotropy of pi(0) Production in Au plus Au Collisions at root s(NN)=200 GeV: Path-Length Dependence of Jet Quenching and the Role of Initial Geometry
  • 2010
  • Ingår i: Physical Review Letters. - Amer Physical Soc. - 0031-9007. ; 105:14
  • Tidskriftsartikel (refereegranskat)abstract
    • We have measured the azimuthal anisotropy of pi(0) production for 1 < p(T) < 18 GeV/c for Au + Au collisions at root s(NN) = 200 GeV. The observed anisotropy shows a gradual decrease for 3 less than or similar to p(T) less than or similar to 7-10 GeV/c, but remains positive beyond 10 GeV/c. The magnitude of this anisotropy is underpredicted, up to at least similar to 10 GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.
  •  
4.
  • Adare, A., et al. (författare)
  • Centrality categorization Rp(d)+A in high-energy collisions
  • 2014
  • Ingår i: Physical Review C. - Amer Physical Soc. - 0556-2813. ; 90:3, s. 034902
  • Tidskriftsartikel (refereegranskat)abstract
    • High-energy proton- and deuteron-nucleus collisions provide an excellent tool for studying a wide array of physics effects, including modifications of parton distribution functions in nuclei, gluon saturation, and color neutralization and hadronization in a nuclear environment, among others. All of these effects are expected to have a significant dependence on the size of the nuclear target and the impact parameter of the collision, also known as the collision centrality. In this article, we detail a method for determining centrality classes in p(d) + A collisions via cuts on the multiplicity at backward rapidity (i.e., the nucleus-going direction) and for determining systematic uncertainties in this procedure. For d + Au collisions at root s(NN) = 200 GeV we find that the connection to geometry is confirmed by measuring the fraction of events in which a neutron from the deuteron does not interact with the nucleus. As an application, we consider the nuclear modification factors Rp(d)+A, for which there is a bias in the measured centrality-dependent yields owing to auto correlations between the process of interest and the backward-rapidity multiplicity. We determine the bias-correction factors within this framework. This method is further tested using the HIJING Monte Carlo generator. We find that for d + Au collisions at root s(NN) = 200 GeV, these bias corrections are small and vary by less than 5% (10%) up to p(T) = 10 (20) GeV/c. In contrast, for p + Pb collisions at v root s(NN) = 5.02 TeV we find that these bias factors are an order of magnitude larger and strongly pT dependent, likely attributable to the larger effect of multiparton interactions.
  •  
5.
  • Adare, A., et al. (författare)
  • Cold-Nuclear-Matter Effects on Heavy-Quark Production in d+Au Collisions at root S-NN=200 GeV
  • 2012
  • Ingår i: Physical Review Letters. - American Physical Society. - 0031-9007. ; 109:24, s. 242301
  • Tidskriftsartikel (refereegranskat)abstract
    • The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d + Au and p + p collisions at root S-NN = 200 GeV in the transverse-momentum range 0.85 <= p(T)(e) <= 8.5 GeV/c. In central d + Au collisions, the nuclear modification factor R-dA at 1.5 < p(T) < 5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p + p collisions, and shows that the mass-dependent Cronin enhancement observed at the Relativistic Heavy Ion Collider extends to the heavy D meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the pi(0) and heavy-flavor-electron nuclear modification factors R-AA. DOI: 10.1103/PhysRevLett.109.242301
  •  
6.
  • Adare, A., et al. (författare)
  • Cross Section and Parity-Violating Spin Asymmetries of W-+/- Boson Production in Polarized p plus p Collisions at root s=500 Gev
  • 2011
  • Ingår i: Physical Review Letters. - Amer Physical Soc. - 0031-9007. ; 106:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = 0.86(-0.14)(+0.30) and Ae(L)(e-) = 0.88(-0.71)(+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p + p collisions at a center-of-mass energy of root s = 500 GeV with the PHENIX detector at RHIC. These e(+/-) come mainly from the decay of W-+/- and Z(0) bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W-+/- to the light quarks. The observed electron and positron yields were used to estimate W-+/- boson production cross sections for the e(+/-) channels of sigma(pp -> W+X) X BR(W+ -> e(+) nu(e)) = 144.1 +/- 21.2(stat)(-10.3)(+3.4)(syst) +/- 21.6(norm) pb, and sigma(pp -> W-X) X BR(W- -> e(-) (nu) over bar (e)) = 3.17 +/- 12.1(stat)(-8.2)(+10.1)(syst) +/- 4.8(norm) pb.
  •  
7.
  • Adare, A., et al. (författare)
  • Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p plus p collisions at root s = 62.4 GeV
  • 2012
  • Ingår i: Physical Review D. - American Physical Society. - 1550-7998. ; 86:9, s. 092006
  • Tidskriftsartikel (refereegranskat)abstract
    • Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p + p collisions at root s = 62.4 GeV are presented. The PHENIX measurement of the cross sections for 1.0 < p(T) < 4.5 GeV/c are consistent with perturbative QCD calculations at next-to-leading order in the strong-coupling constant, alpha(s). Resummed pQCD calculations including terms with next-to-leading-log accuracy, yielding reduced theoretical uncertainties, also agree with the data. The double-helicity asymmetry, sensitive at leading order to the gluon polarization in a momentum-fraction range of 0.05 less than or similar to x(gluon) less than or similar to 0.2, is consistent with recent global parametrizations disfavoring large gluon polarization.
  •  
8.
  • Adare, A., et al. (författare)
  • Deviation from quark number scaling of the anisotropy parameter v(2) of pions, kaons, and protons in Au+Au collisions at root s(NN)=200 GeV
  • 2012
  • Ingår i: Physical Review C. - American Physical Society. - 0556-2813. ; 85:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Measurements of the anisotropy parameter v(2) of identified hadrons (pions, kaons, and protons) as a function of centrality, transverse momentum p(T), and transverse kinetic energy KET at midrapidity (vertical bar eta vertical bar < 0.35) in Au + Au collisions at root s(N N) = 200 GeV are presented. Pions and protons are identified up to p(T) = 6 GeV/c, and kaons up to p(T) = 4 GeV/c, by combining information from time-of-flight and aerogel Cerenkov detectors in the PHENIX Experiment. The scaling of v(2) with the number of valence quarks (n(q)) has been studied in different centrality bins as a function of transverse momentum and transverse kinetic energy. A deviation from previously observed quark-number scaling is observed at large values of KET/n(q) in noncentral Au + Au collisions (20-60%), but this scaling remains valid in central collisions (0-10%).
9.
  • Adare, A., et al. (författare)
  • Direct photon production in p plus p collisions at root s=200 GeV at midrapidity
  • 2012
  • Ingår i: Physical Review D. - American Physical Society. - 1550-7998. ; 86:7, s. 072008
  • Tidskriftsartikel (refereegranskat)abstract
    • The differential cross section for the production of direct photons in p + p collisions at root s = 200 GeV at midrapidity was measured in the PHENIX detector at the Relativistic Heavy Ion Collider. Inclusive direct photons were measured in the transverse momentum range from 5: 5-25 GeV/c, extending the range beyond previous measurements. Event structure was studied with an isolation criterion. Next-to-leading-order perturbative-quantum-chromodynamics calculations give a good description of the spectrum. When the cross section is expressed versus x(T), the PHENIX data are seen to be in agreement with measurements from other experiments at different center-of-mass energies.
  •  
10.
  • Adare, A., et al. (författare)
  • Double-spin asymmetry of electrons from heavy-flavor decays in p plus p collisions at root s=200 GeV
  • 2013
  • Ingår i: Physical Review D. - American Physical Society. - 1550-7998. ; 87:1, s. 012011
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the first measurement of the double-spin asymmetry, A(LL), of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized p + p collisions at root s = 200 GeV for p(T) = 0.5 to 3.0 GeV/c. The asymmetry was measured at midrapidity (vertical bar eta vertical bar < 0.35) with the PHENIX detector at the Relativistic Heavy Ion Collider. The measured asymmetries are consistent with zero within the statistical errors. We obtained a constraint for the polarized gluon distribution in the proton of vertical bar Delta g/g(log(10)(x) = -1.6(-0.4)(+0.5), mu = m(T)(c)vertical bar(2) < 0.030 (1 sigma) based on a leading-order perturbative quantum chromodynamics model, using the measured asymmetry. DOI: 10.1103/PhysRevD.87.012011
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 77
  • [1]234567...8Nästa
Åtkomst
fritt online (4)
Typ av publikation
tidskriftsartikel (76)
forskningsöversikt (1)
Typ av innehåll
refereegranskat (77)
Författare/redaktör
Gustafsson, Hans-Åke (77)
Bathe, S. (77)
Buesching, H. (77)
Chujo, T. (77)
Glenn, A. (77)
visa fler...
Esumi, S. (77)
Hamagaki, H. (77)
Lebedev, A. (77)
Tanaka, Y. (77)
Hong, B (77)
Akiba, Y (77)
Alexander, J (77)
Bassalleck, B (77)
Baublis, V (77)
Bazilevsky, A (77)
Bumazhnov, V (77)
Bunce, G (77)
Butsyk, S (77)
Chiu, M (77)
David, G (77)
Denisov, A (77)
Deshpande, A (77)
Durum, A (77)
En'yo, H (77)
Franz, A (77)
Goto, Y (77)
Hayano, R (77)
Homma, K (77)
Ichihara, T (77)
Imai, K (77)
Ishihara, M (77)
Jia, J (77)
Kurita, K (77)
Kwon, Y (77)
Lacey, R (77)
Miake, Y (77)
Milov, A (77)
Newby, J (77)
O'Brien, E (77)
Pinkenburg, C (77)
Ravinovich, I (77)
Riabov, V (77)
Riabov, Y (77)
Rosati, M (77)
Saito, N (77)
visa färre...
Lärosäte
Språk
Engelska (77)

År

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy