期刊：
Reports on Progress in Physics,2021年84(2):024301 ISSN：0034-4885
通讯作者：
Wang, Xin-Nian
作者机构：
[Cao, Shanshan] Shandong Univ, Inst Frontier & Interdisciplinary Sci, Qingdao 266237, Shandong, Peoples R China.;[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA.
通讯机构：
[Wang, Xin-Nian] C;[Wang, Xin-Nian] L;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA.
关键词：
Heavy-ion collisions;Jet quenching;Medium response;Parton energy loss;Quark-gluon plasma;Transport theory
关键词：
Heavy-ion physics;QCD equation of state;Hybrid model;Deep learning
摘要：
In this proceeding, we review our recent work using deep convolutional neural network (CNN) to identify the nature of the QCD transition in a hybrid modeling of heavy-ion collisions. Within this hybrid model, a viscous hydrodynamic model is coupled with a hadronic cascade “after-burner”. As a binary classification setup, we employ two different types of equations of state (EoS) of the hot medium in the hydrodynamic evolution. The resulting final-state pion spectra in the transverse momentum and azimuthal angle plane are fed to the neural network as the input data in order to distinguish different EoS. To probe the effects of the fluctuations in the event-by-event spectra, we explore different scenarios for the input data and make a comparison in a systematic way. We observe a clear hierarchy in the predictive power when the network is fed with the event-by-event, cascade-coarse-grained and event-fine-averaged spectra. The carefully-trained neural network can extract high-level features from pion spectra to identify the nature of the QCD transition in a realistic simulation scenario.
作者机构：
[Prado, Caio A. G.; Qin, Guang-You; Wang, Xin-Nian; Xing, Wen-Jing] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Prado, Caio A. G.; Qin, Guang-You; Wang, Xin-Nian; Xing, Wen-Jing] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.;[Qin, Guang-You; Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Prado, Caio A. G.] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
会议名称：
28th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[Prado, Caio A. G.;Xing, Wen-Jing;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.^[Prado, Caio A. G.;Xing, Wen-Jing;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.^[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.^[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.^[Qin, Guang-You;Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
关键词：
heavy ion collisions;quark-gluon plasma;open heavy flavor;parton suppression
摘要：
It is widely acknowledged that heavy flavor probes are sensitive to the properties of the quark-gluon plasma and are often considered an important tool for the plasma tomography studies. Forward rapidity observables can provide further insight on the dynamics of the medium due to the interplay between the medium size and the differences in the production spectra of heavy quark probes. In this proceedings we present the nuclear modification factor R-AA's for B and D mesons, as well as heavy flavor leptons, in the rapidity range -4.0 < y < 4.0 obtained from relativistic Langevin equation with gluon radiation coupled with a (3+1)-dimensional viscous hydrodynamics medium background. We present comparison with experimental data at mid-rapidity as well as predictions for different rapidity ranges.
作者机构：
[Chen, Wei] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.;[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.;[Cao, Shanshan] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 USA.;[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Luo, Tan] Univ Santiago de Compostela, Inst Galego Fis Altas Enerxias IGFAE, E-15782 Galicia, Spain.
通讯机构：
[Chen, Wei] U;Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.
会议名称：
28th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[Chen, Wei] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.^[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.^[Cao, Shanshan] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 USA.^[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.^[Luo, Tan] Univ Santiago de Compostela, Inst Galego Fis Altas Enerxias IGFAE, E-15782 Galicia, Spain.^[Pang, Long-Gang;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.^[Pang, Long-Gang;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.^[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div MS 70R0319, Berkeley, CA 94720 USA.^[Wang, Xin-Nian] Univ Calif Berkeley, Phys Dept, Berkeley, CA 94720 USA.
关键词：
jet-induced medium excitation;baryon-to-meson ratio;CoLBT-hydro model
摘要：
We use CoLBT-hydro model for simultaneous event-by-event simulations of jet propagation and hydrodynamics evolution of the bulk medium including jet-induced medium excitation. The final reconstructed jet in heavy-ion collision include not only hadrons from medium response for the deposited energy and momentum of hard partons, but also hadrons from the fragmentation and recombination process of in-medium hard partons. We carry out the study with CoLBT-hydro of medium modification of the Lambda/k(s)(0) in jet in Pb-Pb collisions at root s(NN) = 2.76 TeV. We qualitatively describe the enhancement of the Lambda/k(s)(0) ratio in jet in the intermediate pT region due to the contribution from jet-induced medium flow.
作者机构：
[Wang, X-N; Luo, T.; He, Y.; Chen, W.] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Wang, X-N; Luo, T.; He, Y.; Chen, W.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Cao, S.] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Wang, X-N; Pang, L-G] Univ Calif Berkeley, Phys Dept, Berkeley, CA 94720 USA.;[Wang, X-N; Pang, L-G] Lawrence Berkeley Natl Lab, Nucl Sci Div, Mailstop 70R0319, Berkeley, CA 94740 USA.
通讯机构：
[He, Y.] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
会议名称：
28th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[He, Y.;Chen, W.;Luo, T.;Wang, X-N] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.^[He, Y.;Chen, W.;Luo, T.;Wang, X-N] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.^[Cao, S.] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.^[Pang, L-G;Wang, X-N] Univ Calif Berkeley, Phys Dept, Berkeley, CA 94720 USA.^[Pang, L-G;Wang, X-N] Lawrence Berkeley Natl Lab, Nucl Sci Div, Mailstop 70R0319, Berkeley, CA 94740 USA.
关键词：
quark-gluon plasma;jet quenching;jet R-AA;jet energy loss distributions;Bayesian analysis
摘要：
The observed inclusive jet suppression in heavy-ion collisions at LHC has a very weak PT dependence over a large range of P-T = 50-1000 GeV and is almost independent of the colliding energy, though the initial energy density of the bulk medium has increased from root s = 2.76 to 5.02 TeV by about 20%. This interesting phenomenon is investigated in the linear Boltzmann transport (LBT) model for jet propagation in an event-by-event 3+1D hydro background. We show that the PT dependence of jet RAA is determined by the initial spectrum in p + p collisions and P-T dependence of jet energy loss. Furthermore, jet energy loss distributions for inclusive jet and y-jet at both LHC energies are extracted directly from experimental data through the state-of-art Bayesian analysis. The averaged jet energy loss has a weak PT dependence and the scaled jet energy loss distributions have a large width, both of which are consistent with the LBT simulations and indicate that jet quenching is caused by only a few out-of-cone jet medium scatterings.
作者机构：
[Gyulassy, M.; Jacobs, P. M.; Wang, X. N.; Yuan, F.] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.;[Gyulassy, M.; Wang, X. N.] Cent China Normal Univ, Inst Particle Phys, Wuhan, Peoples R China.;[Liao, J.] Indiana Univ, Phys Dept, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.;[Liao, J.] Indiana Univ, Ctr Explorat Energy & Matter, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.;[Shi, S.] McGill Univ, Dept Phys, 3600 Rue Univ, Montreal, PQ H3A 2T8, Canada.
通讯机构：
[Gyulassy, M.] L;[Gyulassy, M.] C;Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.;Cent China Normal Univ, Inst Particle Phys, Wuhan, Peoples R China.
会议名称：
28th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[Gyulassy, M.;Jacobs, P. M.;Wang, X. N.;Yuan, F.] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.^[Gyulassy, M.;Wang, X. N.] Cent China Normal Univ, Inst Particle Phys, Wuhan, Peoples R China.^[Liao, J.] Indiana Univ, Phys Dept, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.^[Liao, J.] Indiana Univ, Ctr Explorat Energy & Matter, 2401 N Milo B Sampson Lane, Bloomington, IN 47408 USA.^[Shi, S.] McGill Univ, Dept Phys, 3600 Rue Univ, Montreal, PQ H3A 2T8, Canada.
关键词：
Quark Gluon Plasmas;Heavy Ion Collision;Jet Quenching;Dijet Acoplanarity
摘要：
Using the CUJET3=DGLV+VISHNU jet-medium interaction framework, we show that dijet azimuthal acoplanarity in high energy A + A collisions is sensitive to possible non-perturbative enhancement of the jet transport coefficient, (q) over cap (T, E), in the QCD crossover temperature T similar to 150 - 300 MeV range. With jet-medium couplings constrained by global RHIC& LHC chi(2) fits to nuclear modification data on R-AA(p(T) > 20) GeV, we compare predictions of the medium induced dijet transverse momentum squared, Q(s)(2) similar to ((q) over capL) similar to Delta phi E-2(2), in two models of the temperature, T, and jet energy E dependence of the jet medium transport coefficient, (q) over cap (T, E). In one model, wQGP, the chromo degrees of freedom (dof) are approximated by a perturbative dielectric gas of quark and gluons dof. In the second model, sQGMP, we consider a nonperturbative partially confined semi-Quark-Gluon-Monopole-Plasma with emergent color magnetic dof constrained by lattice QCD data. Unlike the slow variation of the scaled jet transport coefficient, (q) over cap (wQGP)/T-3, the sQGMP model (q) over cap (sQGMP)/T-3 features a sharp maximum in the QCD confinement crossover T range. We show that the dijet path averaged medium induced azimuthal acoplanarity, Delta phi(2), in sQGMP is robustly similar to 2 times larger than in perturbative wQGP. even though the radiative energy loss in both models is very similar as needed to fit the same R-AA data. Future A+A dijet acoplanarity measurements constrained together with single jet R-AA and v(n) measurements therefore appears to be a promising strategy to search for possible signatures of critical opalescence like phenomena in the QCD confinement temperature range.
作者机构：
[Qin, Guang-You; Wang, Xin-Nian; Zhang, Yuan-Yuan] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Qin, Guang-You; Wang, Xin-Nian; Zhang, Yuan-Yuan] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Zhang, Yuan-Yuan] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
会议名称：
28th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[Zhang, Yuan-Yuan;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.^[Zhang, Yuan-Yuan;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.^[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
关键词：
QCD;DIS;Cold Nuclear Matter Effect;Radiative Energy Loss
摘要：
We calculate the radiative parton energy loss in the deeply inelastic scattering (DIS) off a large nucleus within a generalized high-twist approach. The final gluon radiation spectrum is a convolution of the hard partonic part and the transverse momentum dependent (TMD) quark-gluon correlation function, without the twist expansion in the transverse momentum of the initial gluons used in original high twist approach. The TMD quark-gluon correlation function can be factorized approximately as the product of initial quark distribution and TMD gluon distribution which can be used to define the generalized or TMD jet transport coefficient. The radiation spectrum will recover the Gylassy-Levai-Vitev (GLV) result in the first order of the opacity expansion, under the static scattering center and soft gluon radiation approximation. We also investigate numerically the difference as a result of the soft gluon radiation approximation, under the static scattering center approximation.
作者机构：
[Qin, Guang-You; Wu, Xiang-Yu; Wang, Xin-Nian; Pang, Long-Gang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Qin, Guang-You; Wu, Xiang-Yu; Wang, Xin-Nian; Pang, Long-Gang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Qin, Guang-You; Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Wu, Xiang-Yu] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
会议名称：
28th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter)
会议时间：
NOV 04-09, 2019
会议地点：
Wuhan, PEOPLES R CHINA
会议主办单位：
[Wu, Xiang-Yu;Pang, Long-Gang;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.^[Wu, Xiang-Yu;Pang, Long-Gang;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.^[Qin, Guang-You;Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
关键词：
quark-gluon plasma;anisotropic flow;beam energy scan;baryon diffusion;relativistic hydrodynamics
摘要：
The CLVisc (3+1)D viscous hydrodynamic model is extended to include the equation of net baryon conservation and the Israel-Stewart-like equations for dissipative baryon current. Using the NEOSB equation of state, we simulate the dynamical evolution and collectivity of the quark-gluon plasma with finite chemical potential, assuming smooth energy density and net baryon density distributions at the initial proper time. Numerical results are shown for the impact of net-baryon dissipation on particle yields and p(T) spectra in heavy-ion collisions at beam energy scan energies.
作者机构：
[Prado, Caio A. G.; Qin, Guang-You; Wang, Xin-Nian; Xing, Wen-Jing] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Prado, Caio A. G.; Qin, Guang-You; Wang, Xin-Nian; Xing, Wen-Jing] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.;[Cao, Shanshan] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 USA.;[Qin, Guang-You; Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Prado, Caio A. G.] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
作者：
Kumar, A.*;Tachibana, Y.;Pablos, D.;Sirimanna, C.;Fries, R. J.;...
期刊：
PHYSICAL REVIEW C,2020年102(5) ISSN：2469-9985
通讯作者：
Kumar, A.
作者机构：
[Putschke, J. H.; Kumar, A.; Vujanovic, G.; Majumder, A.; Park, C.; Pablos, D.; Kauder, K.; Cao, S.; Shen, C.; Tachibana, Y.; Sirimanna, C.; Soltz, R. A.] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Jeon, S.; Park, C.; Pablos, D.; Gale, C.] McGill Univ, Dept Phys & Astron, Montreal, PQ H3A 2T8, Canada.;[Yang, Z.; Fries, R. J.; Kordell, M., II] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.;[Yang, Z.; Fries, R. J.] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 USA.;[Soltz, R. A.; Angerami, A.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA.
通讯机构：
[Kumar, A.] W;Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.
摘要：
The JETSCAPE framework is a modular and versatile Monte Carlo software package for the simulation of high energy nuclear collisions. In this work we present a new tune of JETSCAPE, called PP19, and validate it by comparison to jet-based measurements in p p collisions, including inclusive single jet cross sections, jet shape observables, fragmentation functions, charged hadron cross sections, and dijet mass cross sections. These observables in p + p collisions provide the baseline for their counterparts in nuclear collisions. Quantifying the level of agreement of JETSCAPE results with p + p data is thus necessary for meaningful applications of JETSCAPE to A +A collisions. The calculations use the JETSCAPE PP19 tune, defined in this paper, based on version 1.0 of the JETSCAPE framework. For the observables discussed in this work calculations using JETSCAPE PP19 agree with data over a wide range of collision energies at a level comparable to standard Monte Carlo codes. These results demonstrate the physics capabilities of the JETSCAPE framework and provide benchmarks for JETSCAPE users.
作者机构：
[Wang, Xin-Nian; Pang, Long-Gang; He, Yayun] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Wang, Xin-Nian; Pang, Long-Gang; He, Yayun] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Wang, Xin-Nian] C;[Wang, Xin-Nian] L;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.
摘要：
Transverse momentum broadening and energy loss of a propagating parton are dictated by the space-time profile of the jet transport coefficient q^ in a dense QCD medium. The spatial gradient of q^ perpendicular to the propagation direction can lead to a drift and asymmetry in parton transverse momentum distribution. Such an asymmetry depends on both the spatial position along the transverse gradient and path length of a propagating parton as shown by numerical solutions of the Boltzmann transport in the simplified form of a drift-diffusion equation. In high-energy heavy-ion collisions, this asymmetry with respect to a plane defined by the beam and trigger particle (photon, hadron, or jet) with a given orientation relative to the event plane is shown to be closely related to the transverse position of the initial jet production in full event-by-event simulations within the linear Boltzmann transport model. Such a gradient tomography can be used to localize the initial jet production position for more detailed study of jet quenching and properties of the quark-gluon plasma along a given propagation path in heavy-ion collisions.
作者机构：
[Sheng, Xin-Li; Wang, Qun] Univ Sci & Technol China, Peng Huanwu Ctr Fundamental Theory, Hefei 230026, Anhui, Peoples R China.;[Sheng, Xin-Li; Wang, Qun] Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China.;[Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, MS 70R0319, Berkeley, CA 94720 USA.
通讯机构：
[Sheng, Xin-Li] U;Univ Sci & Technol China, Peng Huanwu Ctr Fundamental Theory, Hefei 230026, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China.
摘要：
We propose an improved quark coalescence model for spin alignment of vector mesons and polarization of baryons by spin density matrix with phase space dependence. The spin density matrix is defined through Wigner functions. Within the model we propose an understanding of spin alignments of vector mesons phi and K*(0) (including (K) over bar*(0)) in the static limit: a large positive deviation of rho(00) for phi mesons from 1/3 may come from the electric part of the vector phi field, while a negative deviation of rho(00) for K*(0) may come from the electric part of vorticity tensor fields. Such a negative contribution to rho(00) for K*(0) mesons, in comparison with the same contribution to rho(00 )for phi mesons which is less important, is amplified by a factor of the mass ratio of strange to light quark times the ratio of < p(b)(2)> on the wave function of K*(0) to phi (P-b is the relative momentum of two constituent quarks of K*(0) and phi). These results should be tested by a detailed and comprehensive simulation of vorticity tensor fields and vector meson fields in heavy ion collisions.
作者机构：
[Chen, Wei] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.;[Chen, Wei; Wang, Xin-Nian; Pang, Long-Gang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Chen, Wei; Wang, Xin-Nian; Pang, Long-Gang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Cao, Shanshan] Texas A&M Univ, Cyclotron Inst, College Stn, TX 77843 USA.
通讯机构：
[Wang, Xin-Nian] C;[Wang, Xin-Nian] L;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;Lawrence Berkeley Natl Lab, Nucl Sci Div, MS 70R0319, Berkeley, CA 94720 USA.
摘要：
Coupled linear Boltzmann transport and hydrodynamic (CoLBT-hydro) model has been developed for simultaneous simulations of jet propagation and jet-induced medium excitation in heavy-ion collisions. Within this coupled approach, the final reconstructed jets in heavy-ion collisions include not only hadrons from the hadronization of medium modified jet shower partons from the linear Boltzmann transport (LBT) but also hadrons from the freeze-out of the jet-induced medium excitation in the hydrodynamic evolution of the bulk medium. Using the CoLBT-hydro model, we study medium modification of the fragmentation functions of gamma-triggered jets in high-energy heavy-ion collisions at the Large Hadron Collider. The CoLBT-hydro model is shown to describe the experimental data not only on the suppression of leading hadrons within the jet cone at large momentum fraction z(gamma) = p(T)(h)/p(T)(gamma) relative to the transverse momentum of the trigger photon due to parton energy loss but also the enhancement of soft hadrons at small z(gamma) and z(jet) = pie/pie r due to jet-induced medium excitation. There is no suppression of the fragmentation function, however, at large momentum fraction z(jet) relative to the transverse momentum of the reconstructed jet due to trigger bias and medium modification of quark to gluon jet fraction. For jets whose final transverse momenta are comparable to or larger than that of the trigger photon, the trigger bias can lead to enhancement of the jet fragmentation function at large z(jet). (C) 2020 The Authors. Published by Elsevier B.V.
作者机构：
[Wang, Xin-Nian; He, Yayun] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Wang, Xin-Nian; He, Yayun] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Pang, Long-Gang; Wang, Xin-Nian; He, Yayun] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.;[Pang, Long-Gang; Wang, Xin-Nian] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.
通讯机构：
[Wang, Xin-Nian] C;[Pang, LG; Wang, XN] L;[Pang, LG; Wang, XN] U;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
摘要：
Based on the factorization in perturbative QCD, a jet cross section in heavy-ion collisions can be expressed as a convolution of the jet cross section in p+p collisions and a jet energy loss distribution. Using this simple expression and the Markov Chain Monte Carlo method, we carry out Bayesian analyses of experimental data on jet spectra to extract energy loss distributions for both single inclusive and γ-triggered jets in Pb+Pb collisions with different centralities at two colliding energies at the Large Hadron Collider. The average jet energy loss has a dependence on the initial jet energy that is slightly stronger than a logarithmic form and decreases from central to peripheral collisions. The extracted jet energy loss distributions with a scaling behavior in x=ΔpT/⟨ΔpT⟩ have a large width. These are consistent with the linear Boltzmann transport model simulations, in which the observed jet quenching is caused on the average by only a few out-of-cone scatterings.
作者机构：
[Chen, Wei; Wang, Xin-Nian; He, Yayun; Luo, Tan] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Chen, Wei; Wang, Xin-Nian; He, Yayun; Luo, Tan] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Wang, Xin-Nian; Pang, Long-Gang; He, Yayun] Lawrence Berkeley Natl Lab, Nucl Sci Div, Mailstop 70R0319, Berkeley, CA 94720 USA.;[Cao, Shanshan] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA.;[Wang, Xin-Nian; Pang, Long-Gang] Univ Calif Berkeley, Phys Dept, Berkeley, CA 94720 USA.
通讯机构：
[Wang, Xin-Nian] C;[Wang, Xin-Nian] L;[Wang, Xin-Nian] U;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.
摘要：
The suppression factor for single inclusive jets in Pb+Pb collisions at the Large Hadron Collider (LHC) has a weak dependence on the transverse momentum pT and remains almost the same at two colliding energies, s=2.76 and 5.02 TeV, though the central rapidity density of bulk hadrons increases by about 20%. This phenomenon is investigated within the linear Boltzmann transport (LBT) model, which includes elastic and inelastic processes based on perturbative QCD for both jet shower and recoil medium partons as they propagate through a quark-gluon plasma (QGP). With the dynamic evolution of the QGP given by the 3+1D CLVisc hydrodynamic model with event-by-event fully fluctuating initial conditions, single inclusive jet suppression in Pb+Pb collisions from LBT agrees well with experimental data. The weak s and pT dependence of the jet suppression factor at LHC are found to result directly from the s dependence of the initial jet pT spectra and slow pT dependence of the jet energy loss. Contributions from jet-induced medium response, influence of radial expansion, both of which depend on jet-cone size, and jet flavor composition all conjoin to give a slow pT dependence of jet energy loss and the single jet suppression factor RAA, their dependence on s, and jet-cone size. Single inclusive jet suppression at s=200GeV is also predicted that actually decreases slightly with pT in the pT<50GeV/c range because of the steeper initial jet spectra though the pT dependence of the jet energy loss is weaker than that at LHC.
