Revisiting Bayesian constraints on the transport coefficients of QCD
J. -F. Paquet, A. Angerami, S. A. Bass, S. Cao, Y. Chen, J. Coleman, L. Cunqueiro, T. Dai, L. Du, R. Ehlers, H. Elfner, D. Everett, W. Fan, R. Fries, C. Gale, Y… 展开作者
J. -F. Paquet, A. Angerami, S. A. Bass, S. Cao, Y. Chen, J. Coleman, L. Cunqueiro, T. Dai, L. Du, R. Ehlers, H. Elfner, D. Everett, W. Fan, R. Fries, C. Gale, Y. He, M. Heffernan, U. Heinz, B. V. Jacak, P. M. Jacobs, S. Jeon, K. Kauder, W. Ke, E. Khalaj, M. Kordell, A. Kumar, T. Luo, M. Luzum, A. Majumder, M. McNelis, J. Mulligan, C. Nattrass, D. Oliinychenko, D. Pablos, L. G. Pang, C. Park, J. H. Putschke, G. Roland, B. Schenke, L. Schwiebert, C. Shen, A. Silva, C. Sirimanna, R. A. Soltz, Y. Tachibana, G. Vujanovic, X. -N. Wang, R. L. Wolpert, Y. Xu, Z. Yang
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4 pages, 1 figure, contribution to the Quark Matter 2019 proceedings
Multistage models based on relativistic viscous hydrodynamics have proven successful in describing hadron measurements from relativistic nuclear collisions. These measurements are sensitive to the shear and the bulk viscosities of QCD and provide a unique opportunity to constrain these transport coefficients. Bayesian analyses can be used to obtain systematic constraints on the viscosities of QCD, through methodical model-to-data comparisons. In this manuscript, we discuss recent developments in Bayesian analyses of heavy ion collision data. We highlight the essential role of closure tests in validating a Bayesian analysis before comparison with measurements. We discuss the role of the emulator that is used as proxy for the multistage theoretical model. We use an ongoing Bayesian analysis of soft hadron measurements by the JETSCAPE Collaboration as context for the discussion.
We investigate the equation of state(EoS) and the effect of the hadron-quark phase transition of strong interaction matter in compact stars. The hadron matter is described with the relativistic mean field theory,and the quark matter is described with the Dyson-Schwinger equation approach of QCD. The complete EoS of the hybrid star matter is constructed with not only the Gibbs construction but also the 3-window interpolation. The mass-radius relation of hybrid stars is also investigated. We find that, although the EoSs of both the hadron matter with hyperon and $Δ$-baryon and the quark matter a…
We revisit inclusive J/psi and Upsilon photoproduction at lepton-hadron colliders, namely in the limit when the exchanged photon is quasi real. Our computation includes the next-to-leading-order (NLO) alpha_s corrections to the leading-order contributions in v. Similarly to the case of NLO charmonium-hadroproduction processes, the resulting cross sections obtained in the MS-bar factorisation scheme are sometimes found to be negative. We show that the scale-fixing criteria which we derived in a previous study of eta(c) production successfully solves this problem from the EicC all the way up to …
Revisiting identified-particle $p_{\mathrm{T}}$ spectra using the Boltzmann-Gibbs blast-wave model in a Bayesian inference framework
Shaanxi Normal University（陕西师范大学）；Central China Normal University（华中师范大学）；The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen)（香港中文大学（深圳））；China University of Geosciences（中国地质大学）；Sichuan University（四川大学）；China Institute of Atomic Energy（中国原子能科学研究院）
Revisiting QCD-induced little inflation with chiral density wave state and its implications on pulsar timing array gravitational-wave signals
Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS)（基础科学研究所宇宙理论物理中心）；Department of Physics, Sejong University（世宗大学物理系）；Department of Physics and Institute for Sciences of the Universe, Chungnam National University（忠南国立大学物理系与宇宙科学研究所）；School of Physics, Korea Institute for Advanced Study（韩国高等研究院物理学院）
Realizing the full potential of interconnecting the large amounts of data created in physics experiments, phenomenological models and theory simulations requires robust tools for statistical inference. Here I review a particularly promising branch, Bayesian statistics, which over the past decade has found manifold use in high-energy physics. After a brief introduction to Bayesian statistics I will present two concrete examples, where Bayesian thinking has led to progress in understanding strongly interacting matter: unfolding problems in the form of lattice QCD spectral functions (in spirit si…
Revisiting the role of saturation in diffractive vector meson production
University of Jyväskylä（于韦斯屈莱大学）；Helsinki Institute of Physics（赫尔辛基物理研究所）；Brookhaven National Laboratory（布鲁克海文国家实验室）；Wayne State University（韦恩州立大学）；Central China Normal University（华中师范大学）
QCD sum rules are analyzed with the help of the Maximum Entropy Method. We develop a new technique based on the Bayesion inference theory, which allows us to directly obtain the spectral function of a given correlator from the results of the operator product expansion given in the deep euclidean 4-momentum region. The most important advantage of this approach is that one does not have to make any a priori assumptions about the functional form of the spectral function, such as the "pole + continuum" ansatz that has been widely used in QCD sum rule studies, but only needs to specify the asymptot…
We propose an analysis method for the leading-twist operator product expansion based lattice QCD determinations of the valence parton distribution function (PDF). In the first step, we determine the confidence-intervals of the leading-twist $\overline{\mathrm{MS}}$ Wilson coefficients, $C_n(μ^2 z^2)$, of the equal-time bilocal quark bilinear, given the lattice QCD matrix element of Ioffe-time distribution for a particular hadron $H$ as well as the prior knowledge of the valence PDF, $f(x,μ)$ of the hadron $H$ determined via global fit from the experimental data. In the next step, we apply the …
We present the first combined study of correlators and spectral properties of charmonium and open-charm-mesons at finite temperature using a fully relativistic lattice QCD approach. The QCD medium is captured by second generation anisotropic 24^3xN_t lattices from the FASTSUM collaboration, including 2+1 flavors of clover discretized quarks with m_pi~380 MeV. Two Bayesian methods are deployed to reconstruct the spectral functions, the recent BR method as well as the Maximum Entropy Method with Fourier basis. We take particular care to disentangle genuine in-medium effects from method artifacts…
Revisiting the soft-hard separation in the transverse momentum spectra of $pp$ collisions
HUN-REN Wigner Research Center for Physics（匈牙利科学院维格纳物理研究中心）；ELTE Eötvös Loránd University, Institute of Physics（布达佩斯罗兰大学物理研究所）；Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México（墨西哥国立自治大学核科学研究所）；Facultad de Ciencias, Universidad Nacional Autónoma de México（墨西哥国立自治大学理学院）
We perform a global QCD analysis of unpolarized parton distributions within a Bayesian Monte Carlo framework, including the new $W$-lepton production data from the STAR Collaboration at RHIC and Drell-Yan di-muon data from the SeaQuest experiment at Fermilab. We assess the impact of these two new measurements on the light antiquark sea in the proton, and the $\bar{d}-\bar{u}$ asymmetry in particular. The SeaQuest data are found to significantly reduce the uncertainty on the $\bar{d}/\bar{u}$ ratio at large parton momentum fractions $x$, strongly favoring an enhanced $\bar{d}$ sea up to $x \app…
Background: The "proton radius puzzle" refers to an eight-year old problem that highlights major inconsistencies in the extraction of the charge radius of the proton from muonic Lamb-shift experiments as compared against experiments using elastic electron scattering. For the latter, the determination of the charge radius involves an extrapolation of the experimental form factor to zero momentum transfer. Purpose: To estimate the proton radius by introducing a novel non-parametric approach to model the electric form factor of the proton. Methods: Within a Bayesian paradigm, we develop a model f…
