共查询到20条相似文献,搜索用时 687 毫秒
1.
Chung P Ajitanand NN Alexander JM Anderson M Best D Brady FP Case T Caskey W Cebra D Chance JL Cole B Crowe K Das AC Draper JE Gilkes ML Gushue S Heffner M Hirsch AS Hjort EL Holzmann W Huo L Issah M Justice M Kaplan M Keane D Kintner JC Klay J Krofcheck D Lacey RA Lauret J Lisa MA Liu H Liu YM McGrath R Milosevich Z Odyniec G Olson DL Panitkin S Porile NT Rai G Ritter HG Romero JL Scharenberg R Srivastava B Stone NT Symons TJ Taranenko A Whitfield J Witt R Wood L Zhang WN Brown D Pratt S 《Physical review letters》2003,91(16):162301
Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs p Lambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p. These observations suggest important differences in the space-time emission histories for protons, pions, and neutral strange baryons produced in the same events. 相似文献
2.
M. Zawisza 《Indian Journal of Physics》2011,85(7):1051-1056
Correlations between non-identical particles at small relative velocity probe asymmetries in the average space-time emission
points at freezeout [1]. Such asymmetries may arise from long-lived resonances, bulk collective effects, or differences in
the freezeout scenario for the different particle species. STAR has extracted pion-proton correlation functions from a high-statistics
dataset of Au+Au collisions at ?{sNN }\sqrt {s_{NN} } = 200 GeV. We present a femtoscopic analysis of this data for all combinations of charged pions and (anti-) protons, for
collisions of different centrality. The measurements are compared with calculations of a simple Blast-wave model, in which
asymmetries are driven only by collective flow, as well as with Therminator [2], which also accounts fully for resonance effects. 相似文献
3.
Panitkin SY Ajitanand NN Alexander J Anderson M Best D Brady FP Case T Caskey W Cebra D Chance J Chung P Cole B Crowe K Das A Draper J Gilkes M Gushue S Heffner M Hirsch A Hjort E Huo L Justice M Kaplan M Keane D Kintner J Klay J Krofcheck D Lacey R Lauret J Lisa MA Liu H Liu YM McGrath R Milosevich Z Odyniec G Olson D Pinkenburg C Porile N Rai G Ritter HG Romero J Scharenberg R Schroeder LS Srivastava B Stone NT Symons TJ Wang S Wells R Whitfield J Wienold T Witt R Wood L Yang X Zhang WN 《Physical review letters》2001,87(11):112304
We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au+Au collisions at beam energies between 2A and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional Hanburg-Brown-Twiss analysis. 相似文献
4.
R. Bock K. G. R. Doss H. H. Gutbrod K. H. Kampert B. Kolb I. Lund H. G. Ritter H. R. Schmidt T. Siemiarczuk W. Wislicki 《Zeitschrift für Physik A Hadrons and Nuclei》1989,333(2):193-202
The analysis of Bose-Einstein correlations for systems of two and three low-momentum pions in interactions of Au+Au and Nb+Nb at 650 A MeV kinetic energy are presented. The data were taken with the Plastic Ball spectrometer. The pion-emitting source sizes obtained from specific three-pion correlations are significantly smaller than those extracted from two-pion correlations. The dependence of the source parameters on the multiplicity of produced pions was examined. The low-p t pions are emitted from a larger region than the high-p t ones. 相似文献
5.
The source imaging technique of Brown and Danielewicz has been used to extract two-pion emission source functions over a broad range of k T and centralities in Au+Au collisions at $\sqrt s = 200$ GeV. The source functions reflect the combined contributions of a short-range Gaussian-like component and a long-range exponential-like component. A parametrization of the source function gives a RMS radius for the long-range source which is approximately three times that for the short-range source. The centrality dependence of the extracted source parameters for the short- and long-range sources indicate similar patterns. 相似文献
6.
《Physical review letters》2004,92(11):112301
Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies. 相似文献
7.
Adler C Ahammed Z Allgower C Amonett J Anderson BD Anderson M Averichev GS Balewski J Barannikova O Barnby LS Baudot J Bekele S Belaga VV Bellwied R Berger J Bichsel H Bland LC Blyth CO Bonner BE Bossingham R Boucham A Brandin A Cadman RV Caines H Calderón De La Barca Sánchez M Cardenas A Carroll J Castillo J Castro M Cebra D Chattopadhyay S Chen ML Chen Y Chernenko SP Cherney M Chikanian A Choi B Christie W Coffin JP Conin L Cormier TM Cramer JG Crawford HJ DeMello M Deng WS Derevschikov AA 《Physical review letters》2001,87(8):082301
Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)]. 相似文献
8.
M. Csanád 《Physics of Particles and Nuclei Letters》2011,8(9):934-937
Ultra-relativistic gold-gold and proton-proton collisions are investigated in the experiments of the Relativistic Heavy Ion
Collider (RHIC). In the last several years large amount of results were revealed about the matter created in these collisions.
The latest PHENIX results for femtoscopy and correlations are reviewed in this paper. Bose-Einstein correlations of charged
kaons in 200 GeV Au + Au collisions and of charged pions in 200 GeV p + p collisions are shown. They are both compatible with
previous measurements of charged pions in gold-gold collisions, with respect to transverse mass or number of participants
scaling. 相似文献
9.
The transverse momentum spectra for identified hadrons at different rapidities in central Au+Au collisions at = 200 GeV are studied in a quark combination model. The results for PT spectra of π±,K±, p(p-) and for the p/π ratios in a broader PT range at midrapidity agree well with the data. The transverse momentum spectra of pions, protons and antiprotons at various rapidities y 1, η= 2.2 and y≈3.2 are calculated and compared with the data. 相似文献
10.
M. Zawisza 《Physics of Particles and Nuclei Letters》2011,8(9):924-927
Correlations between non-identical particles at small relative velocity probe asymmetries in the average space-time emission
points at freeze-out. The origin of such asymmetries may be from long-lived resonances, bulk collective effects, or differences
in the freeze-out scenario for the different particle species. STAR has extracted pion-proton correlation functions from a
dataset of Au+Au collisions at √s
NN
= 200 GeV. We present correlation functions in the spherical harmonic decomposition representation, for different centralities
and for different combinations of pions and (anti-)protons. 相似文献
11.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Alexander J Amirikas R Aphecetche L Aronson SH Averbeck R Awes TC Azmoun R Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bazilevsky A Belikov S Berdnikov Y Bhagavatula S Boissevain JG Borel H Borenstein S Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chai JS Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choi J Choudhury RK Chujo T 《Physical review letters》2003,91(17):172301
We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at sqrt[s(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
相似文献
12.
Bearden IG Beavis D Besliu C Blyakhman Y Budick B Bøggild H Chasman C Christensen CH Christiansen P Cibor J Debbe R Enger E Gaardhøje JJ Germinario M Hagel K Hansen O Holm A Holme AK Ito H Jakobsen E Jipa A Jundt F Jørdre JI Jørgensen CE Karabowicz R Keutgen T Kim EJ Kozik T Larsen TM Lee JH Lee YK Løvhøiden G Majka Z Makeev A McBreen B Mikelsen M Murray M Natowitz J Nielsen BS Norris J Olchanski K Olness J Ouerdane D Płaneta R Rami F Ristea C Röhrich D Samset BH Sandberg D Sanders SJ 《Physical review letters》2003,90(10):102301
We present ratios of the numbers of charged antihadrons to hadrons (pions, kaons, and protons) in Au+Au collisions at sqrt[s(NN)]=200 GeV as a function of rapidity in the range y=0-3. While the ratios at midrapidity are approaching unity, the K(-)/K(+) and p;/p ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from mu(B) approximately 130 MeV at y=3 to mu(B) approximately 25 MeV at y=0. 相似文献
13.
A. Ster M. Csanád T. Csörgő B. Lörstad B. Tomášik 《The European Physical Journal A - Hadrons and Nuclei》2011,47(4):58
We present calculations of elliptic flow and azimuthal dependence of correlation radii in the ellipsoidally symmetric generalization
of the Buda-Lund hydrodynamic model of hadron production in high-energy nuclear collisions. We compare them to data from RHIC
by simultaneous fits to azimuthally integrated invariant spectra of pions, kaons and protons-antiprotons measured by PHENIX
in Au + Au reactions at center-of-mass energy of 200 AGeV. STAR data were used for azimuthally sensitive two-particle correlation
function radii and for the transverse momentum dependence of the elliptic flow parameter v
2. We have found that the transverse flow is faster in the reaction plane than out of plane, which results in a reaction zone
that gets slightly more elongated in-plane than out of plane. The model parameters extracted from the fits are shown and discussed. 相似文献
14.
《Nuclear Physics A》1997,624(4):755-772
Using the FOPI detector at GSI Darmstadt, excitation functions of collective flow components were measured for the Au+Au system, in the reaction plane and out of this plane, at seven incident energies ranging from 100A MeV to 800A MeV. The threshold energies, corresponding to the onset of sideward-flow (balance energy) and squeeze-out effect (transition energy), are extracted from extrapolations of these excitation functions toward lower beam energies for charged products with Z ⩾ 2. The transition energy is found to be larger than the balance energy. The impact parameter dependence of both balance and transition energies, when extrapolated to central collisions, suggests comparable although slightly higher values than the threshold energy for the radial flow. The relevant parameter seems to be the energy deposited into the system in order to overcome the attractive nuclear forces. 相似文献
15.
Adams J Aggarwal MM Ahammed Z Amonett J Anderson BD Arkhipkin D Averichev GS Badyal SK Bai Y Balewski J Barannikova O Barnby LS Baudot J Bekele S Belaga VV Bellingeri-Laurikainen A Bellwied R Berger J Bezverkhny BI Bhardwaj S Bhasin A Bhati AK Bichsel H Bielcik J Bielcikova J Billmeier A Bland LC Blyth CO Blyth S Bonner BE Botje M Boucham A Bouchet J Brandin AV Bravar A Bystersky M Cadman RV Cai XZ Caines H de la Barca Sánchez MC Castillo J Catu O Cebra D Chajecki Z Chaloupka P Chattopadhyay S 《Physical review letters》2005,95(6):062301
We present the first measurement of pseudorapidity distribution of photons in the region 2.3 < or = eta < or = 3.7 for different centralities in Au+Au collisions at square root of (S(NN)) = 62.4 GeV. We find that the photon yield scales with the number of participating nucleons at all collision centralities studied. The pseudorapidity distribution of photons, dominated by pi0 decays, has been compared to those of charged pions, photons, and inclusive charged particles from heavy-ion and nucleon-nucleon collisions at various energies. The photon production has been shown to be consistent with the energy and centrality independent limiting fragmentation scenario. 相似文献
16.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Alexander J Amirikas R Aphecetche L Aronson SH Averbeck R Awes TC Azmoun R Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bazilevsky A Belikov S Berdnikov Y Bhagavatula S Boissevain JG Borel H Borenstein S Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chai JS Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choi J Choudhury RK Chujo T 《Physical review letters》2003,91(7):072301
Transverse momentum spectra of neutral pions in the range 1
相似文献
17.
Tadaaki Isobe 《Acta Physica Hungarica A》2006,27(2-3):227-230
Neutral pions (π0) in √NN=200 GeV and 62.4 GeV Au+Au collisions were measured at RHIC-PHENIX Year-4 Run. In √NN=200 GeV, π0 spectra are measured up to p T=20 GeV/c. A strong suppression by a factor of ~5 is observed and stays almost constant up to 20 GeV/c. 相似文献
18.
19.
Afanasiev S Aidala C Ajitanand NN Akiba Y Alexander J Al-Jamel A Aoki K Aphecetche L Armendariz R Aronson SH Averbeck R Awes TC Azmoun B Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bauer F Bazilevsky A Belikov S Bennett R Berdnikov Y Bjorndal MT Boissevain JG Borel H Boyle K Brooks ML Brown DS Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Campbell S Chai JS Chernichenko S Chiba J Chi CY Chiu M Choi IJ Chujo T Chung P Cianciolo V 《Physical review letters》2008,100(23):232301
A three-dimensional correlation function obtained from midrapidity, low p(T), pion pairs in central Au+Au collisions at sqrt[s(NN)]=200 GeV is studied. The extracted model-independent source function indicates a long range tail in the directions of the pion pair transverse momentum (out) and the beam (long). A proper breakup time tau(0) ~ 9 fm/c and a mean proper emission duration Delta tau ~ 2 fm/c, leading to sizable emission time differences ({|Delta t(LCM)|} approximately 12 fm/c), are required to allow models to be successfully matched to these tails. The model comparisons also suggest an outside-in "burning" of the emission source reminiscent of many hydrodynamical models. 相似文献
20.
Sturm C Böttcher I D&ecedil;bowski M Förster A Grosse E Koczoń P Kohlmeyer B Laue F Mang M Naumann L Oeschler H Pühlhofer F Schwab E Senger P Shin Y Speer J Ströbele H Surówka G Uhlig F Wagner A Waluś W 《Physical review letters》2001,86(1):39-42
The production of pions and kaons has been measured in 197Au+197Au collisions at beam energies from 0.6 to 1.5A GeV with the kaon spectrometer at SIS/GSI. The K+ meson multiplicity per nucleon is enhanced in Au+Au collisions by factors up to 6 relative to C+C reactions, whereas the corresponding pion ratio is reduced. The ratio of the K+ meson excitation functions for Au+Au and C+C collisions increases with decreasing beam energy. This behavior is expected for a soft nuclear equation-of-state. 相似文献