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Zhu LY, Peng JC, Reimer PE, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Mueller BA, Nord PM, Papavassiliou V, Park BK, Petitt G, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Wise DK, Young GR. Measurement of angular distributions of Drell-Yan dimuons in p+p interactions at 800 GeV/c. Phys Rev Lett 2009; 102:182001. [PMID: 19518860 DOI: 10.1103/physrevlett.102.182001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Indexed: 05/27/2023]
Abstract
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5<m micromicro<15 GeV/c2 (excluding the Upsilon resonance region), 0<p T <4 GeV/c, and 0<x F<0.8. The p+p angular distributions are similar to those of p+d, and both data sets are compared with models which attribute the cos2varphi distribution either to the presence of the transverse-momentum-dependent Boer-Mulders structure function h1 perpendicular to 1 or to QCD effects. The data indicate the need to include QCD effects before reliable information on the Boer-Mulders function can be extracted. The validity of the Lam-Tung relation in p+p Drell-Yan data is also tested.
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Affiliation(s)
- L Y Zhu
- Hampton University, Hampton, Virginia 23187, USA
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Zhu LY, Reimer PE, Mueller BA, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Howell DE, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Nord PM, Papavassiliou V, Park BK, Petitt G, Peng JC, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Winter P, Wise DK, Yin Y, Young GR. Measurement of Upsilon production for p + p and p + d interactions at 800 GeV/c. Phys Rev Lett 2008; 100:062301. [PMID: 18352463 DOI: 10.1103/physrevlett.100.062301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Indexed: 05/26/2023]
Abstract
We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0<x(F)<0.6, this ratio is found to be consistent with unity, in striking contrast to the behavior of the Drell-Yan cross section ratio sigma(p+d)(DY)/2sigma(p+p)(DY). This result shows that the gluon distributions in the proton and neutron are very similar. The Upsilon production cross sections are also compared with the p+d and p+Cu cross sections from earlier measurements.
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Affiliation(s)
- L Y Zhu
- University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Zhu LY, Peng JC, Reimer PE, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Mueller BA, Nord PM, Papavassiliou V, Park BK, Petitt G, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Wise DK, Young GR. Measurement of angular distributions of Drell-Yan dimuons in p+d interactions at 800 GeV/c. Phys Rev Lett 2007; 99:082301. [PMID: 17930942 DOI: 10.1103/physrevlett.99.082301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Indexed: 05/25/2023]
Abstract
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range 4.5<m{mu mu}<15 GeV/c{2}, 0<p{T}<4 GeV/c, and 0<x{F}<0.8. No significant cos2phi dependence is found in these proton-induced Drell-Yan data, in contrast with the situation for pion-induced Drell-Yan data. The data are compared with expectations from models which attribute the cos2phi distribution to a QCD vacuum effect or to the presence of the transverse-momentum-dependent Boer-Mulders structure function h{1}{perpendicular}. Constraints on the magnitude of the sea-quark h{1}{perpendicular} structure functions are obtained.
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Affiliation(s)
- L Y Zhu
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Brown CN, Awes TC, Beddo ME, Brooks ML, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Kirk PN, Koetke DD, Kyle G, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Mueller BA, Nord PM, Papavassiliou V, Park BK, Peng JC, Petitt G, Reimer PE, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Wise DK, Young GR. Observation of polarization in bottomonium production at square root of s = 38.8 GeV. Phys Rev Lett 2001; 86:2529-2532. [PMID: 11289972 DOI: 10.1103/physrevlett.86.2529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2000] [Indexed: 05/23/2023]
Abstract
We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at square root of s = 38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state shows no polarization at small values of the fractional longitudinal momentum x(F) and transverse momentum p(T) but significant positive transverse production polarization for either p(T)>1.8 GeV/c or for x(F)>0.35. The Upsilon(2S+3S) (unresolved) states show a large transverse production polarization at all values of x(F) and p(T) measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.
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Affiliation(s)
- C N Brown
- Fermi National Laboratory, Argonne, IL 60439, USA
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Leitch MJ, Lee WM, Beddo ME, Brown CN, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Koetke DD, McGaughey PL, Moss JM, Mueller BA, Papavassiliou V, Peng JC, Petitt G, Reimer PE, Sadler ME, Sondheim WE, Stankus PW. Measurement of differences between J/psi and psi(') suppression in p-A collisions. Phys Rev Lett 2000; 84:3256-3260. [PMID: 11019064 DOI: 10.1103/physrevlett.84.3256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/1999] [Revised: 12/17/1999] [Indexed: 05/23/2023]
Abstract
Measurements of the suppression of the yield per nucleon of J/psi and psi(') production for 800 GeV/ c protons incident on heavy nuclear targets, relative to light nuclear targets, have been made with very broad coverage in x(F) and p(T). The observed suppression is smallest at x(F) values of 0.25 and below, and increases at larger values of x(F). It is also strongest at small p(T). Substantial differences between psi(') and J/psi production are observed for the first time in p-A collisions. The suppression for psi(') production is stronger than that for J/psi for x(F) near zero, but becomes comparable to that for J/psi for x(F)>0.6.
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Affiliation(s)
- MJ Leitch
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Hilscher D, Rossner H, Gamp A, Jahnke U, Cheynis B, Chambon B, Drain D, Pastor C, Giorni A, Morand C, Dauchy A, Stassi P, Petitt G. Energy and linear-momentum dissipation in the fusion reaction of 165Ho + 20Ne at 30 MeV/nucleon. Phys Rev C Nucl Phys 1987; 36:208-219. [PMID: 9954065 DOI: 10.1103/physrevc.36.208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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