Systematic study of the jet fragmentation function for inclusive jet-production in p+p collisions at sqrt{s}=200 GeV in STAR

Anisotropic flow of inclusive and identified particles in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV

Anisotropic flow measurements constrain the shear $(η/s)$ and bulk ($ζ/s$) viscosity of the quark-gluon plasma created in heavy-ion collisions, as well as give insight into the initial state of such collisions and hadronization mechanisms. In these proceedings, elliptic ($v_2$) and higher harmonic ($v_3, v_4$) flow coefficients of $π^{\pm}$, $K^{\pm}$, p$(\overline{\rm{p}})$ and the $ϕ$-meson,measured in Pb--Pb collisions at the highest-ever center-of-mass energy of $\sqrt{s_{\rm NN}}$ = 5.02 TeV, are presented.

Jet shapes and fragmentation functions in Au+Au collisions at sqrt(sNN) = 200 GeV in STAR

The STAR Collaboration reports measurements of differential jet shapes and semi-inclusive jet fragmentation functions in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=$ 200 GeV with the STAR detector at RHIC. Jet shapes, which represent the radial distribution of momentum carried by constituents, are measured differentially for (1) the charged particles transverse momentum and (2) the jet azimuthal angle relative to the second-order event plane. Based on the semi-inclusive population of jets recoiling from a high transverse momentum trigger hadron, jet fragmentation functions in 40-60% central h…

Measurement of jet fragmentation in p + p collision at sqrt(s) = 200 GeV with the PHENIX detector

Measurement of jet fragmentation property in p + p collisions provides a crucial baseline for the study of a possible, modified fragmentation behavior at the presence of the quark-gluon plasma. We describe the first measurement of jet fragmentation functions in sqrt(s) = 200 GeV p + p collisions at RHIC. This is facilitated by extending the linear least square unfolding technique employed by high energy and nuclear experiments to multidimensional spectra, which allows us to correct the inefficiencies in the jet energy response encountered at detectors such as PHENIX.

Measurements of inclusive photons at forward rapidities in p-Pb collisions at $\sqrt{s\rm_{NN}}$ = 5.02 TeV with ALICE

We present multiplicity and pseudorapidity distributions of inclusive photons at forward rapidity in proton-lead (p-Pb) collisions at $\sqrt{s\rm_{NN}}$ = 5.02 TeV using the data obtained from Photon Multiplicity Detector (PMD) of ALICE. The centrality dependence of pseudorapidity distributions of inclusive photons is also studied. Results are compared with the previous ALICE measurements of charged-particle production and with theoretical predictions from Monte Carlo models, DPMJET and HIJING.

重新探讨π介子核碎裂函数

Pion Nuclear Fragmentation Functions Revisited

该研究以次领头阶精度重新探讨核子-π介子碎裂函数，评估其在解释CERN-LHC质子-核碰撞及JLab CLAS轻子-核散射相关高精度数据时的可行性。

在$\sqrt{s_{\rm NN}}$ = 5.02 TeV的pp和Pb-Pb碰撞中测量包含和领头子喷注碎裂

Measurement of inclusive and leading subjet fragmentation in pp and Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV

本文利用ALICE实验测量了pp和Pb-Pb碰撞中喷注的包含和领头子喷注碎裂函数，发现Pb-Pb中$z_r$分布无显著改变，但在$z_r<0.95$区域与硬化趋势一致，且未发现QGP中碎裂函数普适性破坏。

Dijet transverse momentum imbalance, fragmentation functions and jet-track correlations in PbPb collisions at sqrt(sNN) = 2.76 TeV with CMS

Dijets in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV are studied with the CMS detector at the LHC. It is shown that the fragmentation functions of jets into charged particle tracks with transverse momenta pT > 4 GeV/c in PbPb collisions are similar to those in pp collisions, for both the leading and subleading jets. In addition, study of high statistics PbPb data acquired in 2011 shows that the quenching phenomenon exists up to highest jet pT values in excess of 300 GeV/c.

Inclusive photon production at forward rapidities using PMD in p-Pb collisions at $\sqrt{\it{s}_{\rm{NN}}} = 8.16$ TeV with ALICE

We report on the performance studies of two correction methods, namely the efficiency-purity method and the Bayesian unfolding method applied to the pseudorapidity distribution of photons. The pseudorapidity distribution of inclusive photons at forward rapidities in the range \mbox{\small $(2.3<η<3.9)$} in p\textendash Pb collisions at $\sqrt{\it{s}_{\rm{NN}}} = 8.16$ TeV is obtained with the HIJING Monte Carlo event generator. The simulated data samples were obtained from the Photon Multiplicity Detector (PMD) in ALICE.

Event activity dependence of inclusive J/ψ production in p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV with ALICE at the LHC

Studying p-Pb collisions at LHC energies allows a quantitative evaluation of the cold nuclear matter (CNM) effects. Event activity dependence of the J/ψ production is under intense studies both theoretically and experimentally and is expected to provide important insights on the influence of CNM. This paper presents the first results on event activity dependence of the inclusive J/ψ production at backward (-4.46 < $y_{cms}$ < -2.96) and forward (2.03 < $y_{cms}$ < 3.53) rapidity in ALICE for p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV.

Measurement of inclusive jet charged-particle fragmentation functions in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV with the ATLAS detector

Measurements of charged-particle fragmentation functions of jets produced in ultra-relativistic nuclear collisions can provide insight into the modification of parton showers in the hot, dense medium created in the collisions. ATLAS has measured jets in $\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC using a data set recorded in 2011 with an integrated luminosity of 0.14 nb$^{-1}$. Jets were reconstructed using the anti-$k_{t}$ algorithm with distance parameter values $R$ = 0.2, 0.3, and 0.4. Distributions of charged-particle transverse momentum and longitudinal momentum fraction are re…

Measurement of jet fragmentation in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV

The jet fragmentation function of inclusive jets with transverse momentum pt above 100 GeV in PbPb collisions has been measured using reconstructed charged particles with pt above 1 GeV in a cone of radius 0.3 around the jet axis. A data sample of PbPb collisions collected in 2011 at a nucleon-nucleon center-of-mass energy of sqrt(s[NN]) = 2.76 TeV corresponding to an integrated luminosity of 150 inverse microbarns is used. The results for PbPb collisions as a function of collision centrality and jet transverse momentum are compared to reference distributions based on pp data collected at the …

Measurement of the inclusive differential jet cross section in pp collisions at $\sqrt{s}$ = 2.76 TeV

The ALICE collaboration at the CERN Large Hadron Collider reports the first measurement of the inclusive differential jet cross section at mid-rapidity in pp collisions at $\sqrt{s} = 2.76$ TeV, with integrated luminosity of 13.6 nb$^{-1}$. Jets are measured over the transverse momentum range 20 to 125 GeV/c and are corrected to the particle level. Calculations based on Next-to-Leading Order perturbative QCD are in good agreement with the measurements. The ratio of inclusive jet cross sections for jet radii $R = 0.2$ and $R = 0.4$ is reported, and is also well reproduced by a Next-to-Leading O…

Single inclusive pion pT-spectra in proton-proton collisions at sqrt(s) = 22.4GeV: data versus perturbative QCD calculations

We compare the inclusive transverse momentum spectra of single pions above pT = 3 GeV/c measured in proton-proton (p-p) collisions at sqrt(s) = 21.7 - 23.8 GeV, with next-to-leading order (NLO) perturbative QCD (pQCD) predictions using recent parametrizations of the parton densities and parton-to-pion fragmentation functions. Although the dependence on the theoretical scales is large, the calculations can reproduce the experimental results both in magnitude and shape. Based on the existing data and on a pQCD $\sqrt{s}$-rescaling of the measured spectra, we provide a practical parametrization o…

Diphoton production in high-energy p+A collisions

We consider semi-inclusive diphoton+jet and inclusive diphoton production in high-energy proton-nucleus collisions, treating the target nucleus as a Color-Glass-Condensate and the projectile proton in the parton model. We obtain the prompt diphoton production cross-section in terms of fragmentation and direct contributions. The fragmentation part is given in terms of single-photon and double-photon fragmentation functions. We study prompt, direct and fragmentation diphoton correlations in p+p and p+A collisions at the LHC, and show that at low values of transverse momenta of the produced photo…

Jet substructure using semi-inclusive jet functions within SCET

We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron $h$ is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function ${\mathcal G}^h_i(z= ω_J/ω,z_h=ω_h/ω_J,ω_J, R,μ)$, which depends on the jet radius $R$ and the large light-cone momenta of the parton `$i$' initiating the jet ($ω$), the jet ($ω_J$), and the hadron $h$ ($ω_h$). The…