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Jets as a Probe of Dense Matter at RHIC

Jets as a Probe of Dense Matter at RHIC
Jets as a Probe of Dense Matter at RHIC

a r X i v :n u c l -e x /0403060v 1 31 M a r 2004

Jets as a Probe of Dense Matter at RHIC

Kirill Filimonov

?Nuclear Science Division,Lawrence Berkeley National Laboratory,1Cyclotron Road,Berkeley CA 94720E-mail:KVFilimonov@https://www.doczj.com/doc/e89940197.html,

Abstract.Jet quenching in the matter created in high energy nucleus-nucleus collisions provides a tomographic tool to probe the medium properties.Recent experimental results on jet production at the Relativistic Heavy-Ion Collider (RHIC)are reviewed.Jet properties in p+p and d+Au collisions have been measured,establishing the baseline for studying jet modi?cation in heavy-ion collisions.Current progress on detailed studies of high transverse momentum production in Au+Au collisions is discussed,with an emphasis on dihadron correlation measurements.

Jet quenching,?rst predicted [1],and then observed at RHIC [2],is one of the most signi?cant results of the heavy-ion collider program so far.Attenuation of jets enables tomographic analysis of the created matter using the jet as an e?ectively external probe of the medium [3].To gain insight into the detailed mechanisms of the interaction of the fast propagating parton with the medium and,ultimately,to extract the medium properties,jet production and its modi?cation must be studied in a multi-parameter space as a function of p T ,particle species/?avor,centrality,and reaction plane.It is vital to perform the same measurements both in Au+Au and simpler reference systems such as p+p and d+Au,to calibrate the limited set of jet-related observables available in the complex Au+Au environment.

Three di?erent phenomena related to partonic energy loss have been observed for particle production at high p T in Au+Au collisions at RHIC:

?strong suppression of inclusive hadron spectra in central collisions [2]?large azimuthal anisotropy in non-central collisions [4]

?disappearance of back-to-back azimuthal correlations in central collisions [5]

Between the last Quark Matter conference [6]and this one,critical high p T measurements were performed with d+Au collisions [7,8,9,10].This control experiment distinguished cold and hot nuclear matter e?ects and the results con?rmed that nuclear attenuation observed in central Au+Au collisions is due to ?nal-state interactions of jets in the dense matter formed in heavy-ion collisions.Experimental results on inclusive spectra and azimuthal correlations obtained prior to this conference are reviewed by D.d’Enterria [11]and https://www.doczj.com/doc/e89940197.html,ler [12].The quantitative applications of the theory and phenomenology of medium-induced energy loss are summarized by I.Vitev [13].

At this conference,qualitatively new and important results were presented from the ?rst full reconstruction of jets at RHIC.Full jet reconstruction in p+p and d+Au collisions calibrates the dihadron observables used to infer jet properties in Au+Au

collisions.New,in-depth,analyses of the older Au+Au dataset were also reported,in particular in the area of dihadron correlations.Whereas measurements of single hadron distributions cover p T up to 12GeV/c,hadron-hadron correlation studies are currently statistics limited to rather moderate p T ~2-6GeV/c.In this region of

transverse momentum,an enhancement of baryon to meson ratios has been observed [14],indicating modi?cations to the particle production mechanism compared to p+p collisions and pQCD calculations.Nevertheless,some intriguing new results have emerged:direct evidence that back-to-back dijet quenching depends on the azimuthal orientation of the jets relative to the reaction plane;jet-like correlations are shown to exist for trigger mesons,baryons,Λand K 0;away-side azimuthal distributions associated with a high p T trigger hadron are suggestive of statistical momentum balance,perhaps indicating equilibration of the medium-induced gluon radiation.Below I will review these and other experimental results presented at this conference.1.Jet Properties in p+p and d+Au

Results on ?rst full jet reconstruction at RHIC have been presented by STAR [15].Inclusive jets have been directly measured in p+p and d+Au collisions using calorimetry and charged particle tracking.Full jet reconstruction reduces the uncertainties due to fragmentation of partons into hadrons that are present in di-hadron correlation studies.

Non-perturbative fragmentation processes result in an approximately Gaussian jet cone.The transverse shape of a jet is characterized by j T =p hadron sin θ,the hadron momentum component perpendicular to the jet thrust axis.Figure 1shows that measured j T distributions in p+p collisions agree well with Pythia which accurately describes jet features at other energies.For jets with E T ~11GeV,STAR measured j T =515±50MeV/c.PHENIX [16]performed di-hadron correlation measurements of the near-angle azimuthal (?φ)distributions and extracted j T =510±10MeV/c which agrees well with the STAR value obtained using full jet reconstruction.

Experiments also reported the measurements of k T ,or the transverse momentum of an individual parton within a nucleon (k T pp )or nucleus (k T nucl ),inferred from the acoplanarity in the dijet production (away-side ?φdistribution).Non-zero values of k T in hadronic collisions are usually attributed to the intrinsic transverse momentum of the initial state partons due to the ?nite size of the incoming hadron and to

Figure 1.Jet j T distributions in p+p collisions from STAR [15]for two hadron p T thresholds.Histograms are Pythia Monte Carlo events.

multiple soft-gluon emission by the partons prior to the hard scattering.Measurements of dimuon,diphoton and dijet production in hadronic collisions have indicated the presence of signi?cant e?ective k T[17].

Figure2(left)shows the dijet?φdistribution in p+p and d+Au collisions

measured by STAR at

k2T =√

s,within current statistical and systematic uncertainties it is too early to conclude about possible discrepancies in the measurements of k T nucl.

Figure2.Left:Di-jet?φdistribution in p+p and d+Au collisions at√

measurements in d+Au collisions extend up to p T =11GeV/c and are reviewed by R.Averbeck [18].

One of the important new results regarding spectra was shown by PHENIX [19].New data on the nuclear modi?cation factor,the ratio of central and peripheral d+Au spectra normalized by the number of binary collisions,are shown in Fig.3.It was previously observed that in d+Au collisions,nuclear e?ects are signi?cant (nuclear modi?cation factor exceeds unity,manifestation of “Cronin”enhancement)in the region of p T =2-7GeV/c [8,9].The new PHENIX data extend up to p T =12-15GeV/c and for p T >6-8GeV/c the yields scale with the number of binary collisions,consistent with no signi?cant initial state nuclear e?ects for high transverse momentum hadrons produced at midrapidity.

(GeV/c)

T p

C P

R Figure 3.PHENIX data [19]on nuclear modi?cation factor in d+Au collisions at

composition and multiplicities in a jet due to coalescence/recombination in the medium.Several aspects of particle production in central Au+Au collisions at RHIC in the p T-range of2-6GeV/c are incompatible with jet fragmentation in simpler systems:large p/πratio[20],antibaryon to baryon ratio constant with p T[22], di?erent suppression of proton/pion[20]and lambda/kaon yields[22],and deviation from hydrodynamic mass-ordering in strength of elliptic?ow of pions/protons[23]and kaons/lambdas[24].Models based on coalescence of thermal partons are successful in qualitatively describing the features observed in the data[25].

On the other hand,new data on the relative azimuthal distributions of identi?ed baryons and mesons(PHENIX[26]),Λand K0(STAR[27])with p T>2.5GeV/c and charged particles show?nite jet-like correlations.STAR?nds thatΛandˉΛcorrelations with charged hadrons in central Au+Au collisions have di?erent trigger p T dependences.PHENIX results on the centrality dependence of associated particle yields per identi?ed trigger are shown in Fig.4.No signi?cant change in yield on the

Figure 4.PHENIX data[26]on near(left)and away-side(right)associated

particle yields per baryon/meson trigger.

near-side,or decrease expected in a naive coalescence picture,is observed as a function of the number of participants.On the away-side,an overall decrease in the yields is observed similar to back-to-back suppression of charged particles[5].The data perhaps indicate slightly larger yields on the away side for the baryon triggers.The tendencies shown in the data are quite indecisive at this point;signi?cantly higher p T probes are required to clarify the observations.It will be interesting to apply asymmetric p T thresholds for baryons and mesons(with the ratio corresponding to the number of constituent quarks)to test coalescence models.Theoretical progress is also needed to understand whether coalescence/recombination may result in sizable correlations in the azimuthal distributions[25].

4.Jet Production versus Reaction Plane

Direct evidence of the variation of the strength of back-to-back suppression with azimuthal orientation of the jets relative to the reaction plane was presented by STAR[28].Di-hadron correlations were measured in non-central Au+Au collisions at √

subtracted

[29])compared with p+p reference data.The near-side jet-like correlations measured in Au+Au are similar to those measured in p+p collisions.The back-to-back correlations measured in Au+Au collisions for in-plane trigger particles are suppressed compared to p+p,and even more suppressed for the out-of-plane trigger particles.Such behavior is naturally predicted by jet quenching models,where the energy loss of a parton depends on the distance traveled through the dense medium [30].Due to energy loss in these models,the high p T trigger biases the initial production point to be near the surface so the near-side correlations should be similar to those seen in p+p collisions.The away-side correlations are more suppressed when the trigger hadron is emitted perpendicular to the reaction plane.Measurements of the e?ect as a function of centrality will allow to precisely determine the energy loss dependence on the path length.

Figure 5.STAR data [28]on azimuthal distributions of associated particles for trigger particles in-plane (squares)and out-of-plane (circles)for Au+Au collisions at centrality 20%-60%,compared with p+p reference data (histogram).

Results on single particle high p T charged hadron (STAR [28])and π0production (PHENIX [31])with respect to the reaction plane were also presented.Azimuthal anisotropy,quanti?ed by the second harmonic Fourier coe?cient v 2,is found to reach its maximum at p T ~3GeV,decreasing very slowly if at all up to p T ~7-10GeV/c.STAR performed higher order cumulant analysis for v 2and compared azimuthal correlations measured in p+p collisions to those in Au+Au.The results con?rm strong elliptic ?ow in mid-central Au+Au collisions at least up to p T ~7GeV/c,qualitatively consistent with jet quenching.The strength of the v 2signal remains too large to be explained by quenching alone [32].Measurements of v 2that are free of non-?ow e?ects in the p T -region which is clearly dominated by jets (most likely,p T >7GeV/c)are highly desirable.

5.Reconstruction of the Lost Energy

Measurements of the redistribution of the energy radiated o?high energy partons in the medium would provide a very important cross-check of jet quenching and,perhaps,

a means to probe

the degree of thermalization.First attempt of such studies was presented by STAR[27,33].The analysis involves statistical reconstruction of charged

hadrons associated with a high p T trigger particle(p trig

T

=4-6GeV/c)in azimuth and pseudorapidity.The azimuthal distribution of the associated particles with p T=0.15-4.0GeV/c with respect to the trigger hadron,after subtraction of the combinatorial background,exhibits jet-like near-angle correlations in p+p and Au+Au collisions (Fig.6,left).On the away side,the distribution is broad and consistent with a cos?φshape,as expected for statistical momentum balance[34]with no additional dynamical

correlations.The dependence of the correlation magnitude on p trig

T

for central Au+Au collisions seems to be in agreement with the estimates from momentum conservation,

even for p trig

T

>6.5GeV/c[27].This may signal equilibration of the medium-induced gluon radiation with momentum distributed over many particles.

Figure6.Left:?φdistribution for5%central Au+Au collisions measured by

STAR[33].The solid line shows an estimate from the statistical momentum

conservation for the away side.Right:STAR data[33]on near-side(a)and away-

side(b)p T distributions of associated charged hadrons for p+p,peripheral and

central Au+Au collisions.Lower panels:Ratios of Au+Au to p+p distributions.

The correlation signals were integrated,and charged hadron multiplicities and p T distributions of associated particles within|?φ|<1.0and|?η|<1.4(near-side cone)and|?φ|>1.0(away-side cone)of the trigger hadron were studied as a function of centrality in Au+Au collisions and compared to p+p collisions.Figure6shows the p T distributions of associated particles.The away side is observed to be depleted at large p T and enhanced at low p T compared to p+p collisions.The broad angular distribution and softening of the spectrum may be consistent with predictions of the softening of the hadron-triggered fragmentation function due to parton energy loss and enhancement of soft hadrons from emitted gluons[35].

6.Conclusions

To summarize,in the last year experiments have gained solid ground on elucidating jet properties at RHIC.Preliminary results on measurements of jet fragmentation in p+p and d+Au collisions provide a baseline for comparison to Au+Au collisions. First direct evidence that back-to-back dijet quenching depends on the azimuthal orientation of the jets relative to the reaction plane has been presented.Future high-

statistics measurements of?avor-tagged di-hadron correlations will probe energy loss e?ects of quark versus gluon jets and test string fragmentation versus recombination. Finding the lost remnants of jets may provide a cross-check of the picture of medium induced?nal-state energy loss.Statistical reconstruction of jets in Au+Au collisions has shown potential to get an experimental handle on the degree of thermalization at the partonic level.In general,presented data broadly support pQCD-based models of ?nal-state parton energy loss in a dense QCD medium produced in Au+Au collisions at RHIC and put strong experimental constraints on its properties.

This work was supported by the Director,O?ce of Science,Nuclear Physics,U.S. Department of Energy under Contract DE-AC03-76SF00098.

References

[1]Gyulassy M and Pl¨u mer M1990Phys.Lett.B243432

Wang X N and Gyulassy M1992Phys.Rev.Lett.681480

Baier R,Schi?D and Zakharov B G2000Ann.Rev.Nucl.Part.Sci.5037

[2]Adcox K et al(PHENIX Collaboration)2002Phys.Rev.Lett.88022301

Adler C et al(STAR Collaboration)2002Phys.Rev.Lett.89202301

Adler S S et al(PHENIX Collaboration)2003Phys.Rev.Lett.91072301

Adams J et al(STAR Collaboration)2003Phys.Rev.Lett.91172302

[3]Gyulassy M,Levai P and Vitev I2002Phys.Lett.B538282

Wang E and Wang X N2002Phys.Rev.Lett.89162301

Salgado C A and Wiedermann U A2002Phys.Rev.Lett.89092303

Vitev I and Gyulassy M2002Phys.Rev.Lett.89252301

[4]Adler C et al(STAR Collaboration)2003Phys.Rev.Lett.90032301

[5]Adler C et al(STAR Collaboration)2003Phys.Rev.Lett.90082302

[6]Proc.of the16th Int.Conf.on Ultra-Relativistic Nucleus-Nucleus Collisions(Quark Matter02)

[7]Back B B et al(PHOBOS Collaboration)2003Phys.Rev.Lett.91072302

[8]Adler S S et al(PHENIX Collaboration)2003Phys.Rev.Lett.91072303

[9]Adams J et al(STAR Collaboration)2003Phys.Rev.Lett.91072304

[10]Arsene I et al(BRAHMS Collaboration)2003Phys.Rev.Lett.91072305

[11]d’Enterria D2004these proceedings

[12]Miller M2004these proceedings

[13]Vitev I2004these proceedings

[14]Adler S S et al(PHENIX Collaboration)2003Phys.Rev.Lett.91172301

[15]Henry T(STAR Collaboration)2004these proceedings

[16]Rak J(PHENIX Collaboration)2004these proceedings

[17]Apanasevich L et al1999Phys.Rev.D5*******

[18]Averbeck R2004these proceedings

[19]Klein-B¨o sing C(PHENIX Collaboration)2004these proceedings

[20]Matathias F(PHENIX Collaboration)2004these proceedings

[21]Adams J et al(STAR Collaboration)2003nucl-ex/0309012.

[22]Lamont M(STAR Collaboration)2004these proceedings

[23]Adler S S et al(PHENIX Collaboration)2003Phys.Rev.Lett.91182301

[24]Adams J et al(STAR Collaboration)2004Phys.Rev.Lett.92052302

[25]Fries R J2004these proceedings

[26]Sickles A(PHENIX Collaboration)2004these proceedings

[27]Guo Y(STAR Collaboration)2004poster presentation,hep-ex/0403018

[28]Tang A(STAR Collaboration)2004these proceedings

[29]Bielcikova J et al2004Phys.Rev.C69021901(R)

[30]Wang X N2001Phys.Rev.C63054902

Gyulassy M,Vitev I and Wang X N2001Phys.Rev.Lett.862537

[31]Kaneta M(PHENIX Collaboration)2004these proceedings

[32]Shuryak E V2002Phys.Rev.C66027902

[33]Wang F(STAR Collaboration)2004these proceedings

[34]Borghini N,Dihn P M and Ollitrault J Y2000Phys.Rev.C62034902

[35]Wang X N2004Phys.Lett.B579299

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感官动词

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感官动词用法

我们学过了五个与人的感觉有关的动词,它们是look,sound,smel l,taste,feel,我们可称之为“感官”动词。它们的用法有着许多相同点,但也有不同之处,现就此作一小结。 一、这五个动词均可作连系动词,后面接形容词作表语,说明主语所处的状态。其意思分别为“看/听/闻/尝/摸起来……”。除loo k之外,其它几个动词的主语往往是物,而不是人。例如:These flowers smell very sweet. 这些花闻起来很香。 The tomatoes feel very soft. 这些西红柿摸起来很软。 The music sounds beautiful. 二、这些动词后面也可接介词like短语,like后面常用名词。例如: Her idea sounds like fun. 她的主意听起来很有趣。 He looks like his father. 三、这五个感官动词也可作实义动词,除look(当“看起来……”讲时)只能作不及物动词外,其余四个既可作及物动词也可作不及物动词,其主语通常是人。例如: She smelt the meat. 她闻了闻那块肉。

I felt in my pocket for cigarettes. 我用手在口袋里摸香烟。 He tasted the soup and added some salt. Miss Wang asked us to look at the blackboard. 四、taste,smell作不及物动词时,可用于“taste / smell + of + 名词”结构,意为“有……味道 / 气味”。例如: The air in the room smells of earth. 房间里的空气有股泥土味。 The bread taste of sugar. 五、它们(sound除外)可以直接作名词,与have或take构成短语。例如: May I have a taste of the mooncakes?我可以尝一口这月饼吗? May I have a look at your photo? 六、其中look,sound,feel还能构成“look / sound / feel + as if +从句”结构,意为“看起来/听起来/ 感觉好像……”。例如:

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