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Affiliation(s)
- R. Pawlowski
- Institute of Organic Chemistry Polish Academy of Sciences Warsaw Poland
| | - P. Skorka
- Medical University of Warsaw Faculty of Pharmacy Warsaw Poland
| | - M. Stodulski
- Institute of Organic Chemistry Polish Academy of Sciences Warsaw Poland
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Back BB, Baker MD, Barton DS, Betts RR, Ballintijn M, Bickley AA, Bindel R, Budzanowski A, Busza W, Carroll A, Decowski MP, García E, George N, Gulbrandsen K, Gushue S, Halliwell C, Hamblen J, Heintzelman GA, Henderson C, Hofman DJ, Hollis RS, Hołyński R, Holzman B, Iordanova A, Johnson E, Kane JL, Katzy J, Khan N, Kucewicz W, Kulinich P, Kuo CM, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey AC, Nouicer R, Olszewski A, Pak R, Park IC, Pernegger H, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Rosenberg L, Sagerer J, Sarin P, Sawicki P, Skulski W, Steadman SG, Steinberg P, Stephans GSF, Stodulski M, Sukhanov A, Tang JL, Teng R, Trzupek A, Vale C, van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FLH, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B. Significance of the fragmentation region in ultrarelativistic heavy-ion collisions. Phys Rev Lett 2003; 91:052303. [PMID: 12906591 DOI: 10.1103/physrevlett.91.052303] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2002] [Indexed: 05/24/2023]
Abstract
We present measurements of the pseudorapidity distribution of primary charged particles produced in Au+Au collisions at three energies, sqrt[s(NN)]=19.6, 130, and 200 GeV, for a range of collision centrali-ties. The distribution narrows for more central collisions and excess particles are produced at high pseudorapidity in peripheral collisions. For a given centrality, however, the distributions are found to scale with energy according to the "limiting fragmentation" hypothesis. The universal fragmentation region described by this scaling grows in pseudorapidity with increasing collision energy, extending well away from the beam rapidity and covering more than half of the pseudorapidity range over which particles are produced. This approach to a universal limiting curve appears to be a dominant feature of the pseudorapidity distribution and therefore of the total particle production in these collisions.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
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3
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Back BB, Baker MD, Barton DS, Betts RR, Bindel R, Budzanowski A, Busza W, Carroll A, Decowski MP, Garcia E, George N, Gulbrandsen K, Gushue S, Halliwell C, Hamblen J, Henderson C, Hofman D, Hollis RS, Hołyński R, Holzman B, Iordanova A, Johnson E, Kane J, Katzy J, Khan N, Kucewicz W, Kulinich P, Kuo CM, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey A, Nouicer R, Olszewski A, Pak R, Park IC, Pernegger H, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Rosenberg L, Sagerer J, Sarin P, Sawicki P, Skulski W, Steadman SG, Steinberg P, Stephans GSF, Stodulski M, Sukhanov A, Tang JL, Teng R, Trzupek A, Vale C, Van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FLH, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B. Pseudorapidity and centrality dependence of the collective flow of charged particles in Au+Au collisions at sqrt[s(NN)]=130 GeV. Phys Rev Lett 2002; 89:222301. [PMID: 12485063 DOI: 10.1103/physrevlett.89.222301] [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: 05/29/2002] [Indexed: 05/24/2023]
Abstract
This paper describes the measurement of collective flow for charged particles in Au+Au collisions at sqrt[s(NN)]=130 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). The measured azimuthal hit anisotropy is presented over a wide range of pseudorapidity (-5.0<eta<5.3) for the first time at this energy. The result, averaged over momenta and particle species, is observed to reach 7% for peripheral collisions at midrapidity, falling off with centrality and increasing |eta|. These results call into question the common assumption of longitudinal boost invariance over a large region of rapidity in RHIC collisions.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Illinois 60439-4843, USA
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Back BB, Baker MD, Barton DS, Betts RR, Bindel R, Budzanowski A, Busza W, Carroll A, Corbo J, Decowski MP, Garcia E, George N, Gulbrandsen K, Gushue S, Halliwell C, Hamblen J, Henderson C, Hicks D, Hofman D, Hollis RS, Hołyński R, Holzman B, Iordanova A, Johnson E, Kane J, Katzy J, Khan N, Kucewicz W, Kulinich P, Kuo CM, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey A, Mülmenstädt J, Nouicer R, Olszewski A, Pak R, Park IC, Pernegger H, Rafelski M, Rbeiz M, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Rosenberg L, Sagerer J, Sarin P, Sawicki P, Skulski W, Steadman SG, Steinberg P, Stephans GSF, Stodulski M, Sukhanov A, Tang JL, Teng R, Trzupek A, Vale C, van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FLH, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B. Energy dependence of particle multiplicities in central Au+Au collisions. Phys Rev Lett 2002; 88:022302. [PMID: 11801006 DOI: 10.1103/physrevlett.88.022302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2001] [Indexed: 05/23/2023]
Abstract
We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at root square[s(NN)] = 200 GeV. For the 6% most central collisions, we obtain dN(ch)/d(eta)/(/eta/<1) = 650+/-35(syst). Compared to collisions at root square[s(NN)] = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
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Back BB, Baker MD, Barton DS, Betts RR, Bindel R, Budzanowski A, Busza W, Carroll A, Decowski MP, Garcia E, George N, Gulbrandsen K, Gushue S, Halliwell C, Heintzelman GA, Henderson C, Hołyński R, Hofman D, Holzman B, Johnson E, Kane J, Katzy J, Khan N, Kucewicz W, Kulinich P, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey A, Mülmenstädt J, Nouicer R, Olszewski A, Pak R, Park IC, Pernegger H, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Rosenberg L, Sarin P, Sawicki P, Skulski W, Steadman SG, Stephans GS, Steinberg P, Stodulski M, Sukhanov A, Tang JL, Teng R, Trzupek A, Vale C, van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FL, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B. Ratios of charged antiparticles-to-particles near mid-rapidity in Au + Au collisions at sqrt[s(NN)]=130 GeV. Phys Rev Lett 2001; 87:102301. [PMID: 11531474 DOI: 10.1103/physrevlett.87.102301] [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: 04/17/2001] [Indexed: 05/23/2023]
Abstract
We have measured the ratios of antiparticles to particles for charged pions, kaons, and protons near mid-rapidity in central Au+Au collisions at sqrt[s(NN)] = 130 GeV. We observe <pi(-)>/<pi(+)> = 1.00+/-0.01(stat)+/-0.02(syst), <K->/<K+> = 0.91+/-0.07(stat)+/-0.06(syst), and <p>/<p> = 0.60+/-0.04(stat)+/-0.06(syst). The <K->/<K+> and <p>/<p> ratios give a consistent estimate of the baryo-chemical potential mu(B) of 45 MeV, a factor of 5-6 smaller than in central Pb+Pb collisions at sqrt[s(NN)] = 17.2 GeV.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
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6
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Back BB, Baker MD, Barton DS, Betts RR, Bindel R, Budzanowski A, Busza W, Carroll A, Decowski MP, Garcia E, George N, Gulbrandsen K, Gushue S, Halliwell C, Heintzelman GA, Henderson C, Hofman DJ, Hołyński R, Holzman B, Johnson E, Kane JL, Katzy J, Khan N, Kucewicz W, Kulinich P, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey AC, Mülmenstädt J, Nouicer R, Olszewski A, Pak R, Park IC, Pernegger H, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Rosenberg L, Sarin P, Sawicki P, Skulski W, Steadman SG, Steinberg P, Stephans GS, Stodulski M, Sukhanov A, Tang JL, Teng R, Trzupek A, Vale C, van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FL, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B. Charged-particle pseudorapidity density distributions from Au+Au collisions at sqrt[s(NN)]=130 GeV. Phys Rev Lett 2001; 87:102303. [PMID: 11531476 DOI: 10.1103/physrevlett.87.102303] [Citation(s) in RCA: 4] [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: 06/06/2001] [Indexed: 05/23/2023]
Abstract
The charged-particle pseudorapidity density dN(ch)/d eta has been measured for Au+Au collisions at sqrt[s(NN)] = 130 GeV at RHIC, using the PHOBOS apparatus. The total number of charged particles produced for the 3% most-central Au+Au collisions for /eta/<or=5.4 is found to be 4200+/-470. The evolution of dN(ch)/d eta with centrality is discussed, and compared to model calculations and to data from proton-induced collisions. The data show an enhancement in charged-particle production at midrapidity, while in the fragmentation regions, the results are consistent with expectations from pp and pA scattering.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
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7
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Back BB, Baker MD, Barton DS, Basilev S, Bates BD, Baum R, Betts RR, Białas A, Bindel R, Bogucki W, Budzanowski A, Busza W, Carroll A, Ceglia M, Chang YH, Chen AE, Coghen T, Conner C, Czyz W, Dabrowski B, Decowski MP, Despet M, Fita P, Fitch J, Friedl M, Gałuszka K, Ganz R, Garcia E, George N, Godlewski J, Gomes C, Griesmayer E, Gulbrandsen K, Gushue S, Halik J, Halliwell C, Haridas P, Hayes A, Heintzelman GA, Henderson C, Hollis R, Hołyński R, Holzman B, Johnson E, Kane J, Katzy J, Kita W, Kotuła J, Kraner H, Kucewicz W, Kulinich P, LawV C, Lemler M, Ligocki J, Lin WT, Manly S, McLeod D, Michałowski J, Mignerey A, Mülmenstädt J, Neal M, Nouicer R, Olszewski A, Pak R, Park IC, Patel M, Pernegger H, Plesko M, Reed C, Remsberg LP, Reuter M, Roland C, Roland G, Ross D, Rosenberg L, Ryan J, Sanzgiri A, Sarin P, Sawicki P, Scaduto J, Shea J, Sinacore J, Skulski W, Steadman SG, Stephans GS, Steinberg P, Straczek A, Stodulski M, Strek M, Stopa Z, Sukhanov A, Surowiecka K, Tang JL, Teng R, Trzupek A, Vale C, van Nieuwenhuizen GJ, Verdier R, Wadsworth B, Wolfs FL, Wosiek B, Woźniak K, Wuosmaa AH, Wysłouch B, Zalewski K, Zychowski P. Charged-particle multiplicity near midrapidity in central Au+Au collisions at sqrt[SNN]=56 and 130 GeV. Phys Rev Lett 2000; 85:3100-3104. [PMID: 11019276 DOI: 10.1103/physrevlett.85.3100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2000] [Indexed: 05/23/2023]
Abstract
We present the first measurement of pseudorapidity densities of primary charged particles near midrapidity in Au+Au collisions at sqrt[s(NN)] = 56 and 130 GeV. For the most central collisions, we find the charged-particle pseudorapidity density to be dN/deta|(|eta|<1) = 408+/-12(stat)+/-30(syst) at 56 GeV and 555+/-12(stat)+/-35(syst) at 130 GeV, values that are higher than any previously observed in nuclear collisions. Compared to proton-antiproton collisions, our data show an increase in the pseudorapidity density per participant by more than 40% at the higher energy.
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Affiliation(s)
- B B Back
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
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