### Conveners

#### Parallel Session T07: Correlations and fluctuations: I

- Tomasz Bold (AGH Univ. of Science and Technology, Krakow (PL))

#### Parallel Session T07: Correlations and fluctuations: II

- Jiangyong Jia (Stony Brook University (US))

#### Parallel Session T07: Correlations and fluctuations: III

- Adam Trzupek (Institute of Nuclear Physics Polish Academy of Sciences (PL))

Event geometry and initial state correlations have been invoked as possible explanations of long-range rapidity correlations observed in high multiplicity pp and pPb collisions. We study initial state momentum correlations and event-by-event geometry in p+Pb collisions at \sqrt{s}=5.02 TeV by following the approach of extending the impact parameter dependent Glasma model (IP-Glasma) to 3D...

The production mechanism of deuterons, which have a binding energy of 2.2 MeV, is a topic of current interest in high energy heavy-ion collisions, where the system undergoes kinetic freeze-out at temperatures around 100 MeV. Two possible scenarios include (a) statistical thermal process and (b) coalescence of nucleons. Cumulants of deuteron number distributions and proton-deuteron correlations...

A valuable tool used in the search for QCD's critical point is the computation of cumulants of conserved charge. Near this point, it is expected a sharp increase of this quantity due to divergence of correlation lengths. This calculation requires high statistics, which poses a challenge to hydrodynamics simulations, which tends to be computationally expensive. The issue can be ameliorated by...

Fluctuations of conserved charges are important probes to explore hot and dense medium in relativistic heavy-ion collisions. In this talk we focus on the experimentally-observed second-order cumulants of baryon number and electric charge at the top RHIC energy. We compare the ratio of these cumulants with the corresponding susceptibility ratio observed in lattice QCD numerical simulations. We...

We present a dynamical description of (anti)proton number cumulants and correlation functions in heavy-ion collisions by utilizing hydrodynamics simulations [1]. The cumulants are calculated via an appropriately extended Cooper-Frye procedure describing particlization of an interacting hadron resonance gas [2] while the effects of global baryon number conservation are taken into account using...

The elliptic flow harmonic $v_{2}\{2k\}$ is determined using Q-cumulants of different orders, with $k=1,...,5$, for 5.02 TeV PbPb collisions. The results were obtained using data from the CMS experiment at the LHC. The $v_{2}\{2k\}$ values show an ordering, with $v_{2}\{2\} > v_{2}\{4\} > \approx v_{2}\{6\} > \approx v_{2}\{8\} > \approx v_{2}\{10\}$. The hydrodynamics behavior of the medium...

We present a novel approach to quantify correlations between baryon-antibaryon, baryon-baryon, and antibaryon-antibaryon pairs. For special case of Gaussian correlations, we used the Cholesky factorization [1] of the covariance matrix, while arbitrary correlations were introduced using the well-known Metropolis and Simulated Annealing [2] methods. Our approach is general enough to be used for...

Particle flow measurements, which provide evidence of the QGP medium, are a powerful tool to study the QGP evolution in heavy-ion collisions. Using the two-particle correlation technique, LHCb has observed the ridge structure due to particle flow, in the forward pseudorapidity range $2<\eta<5$ alongside the leading jet peak in long-range correlations ($|\eta|>2$). This talk will detail the...

This talk presents a new measurement of longitudinal decorrelation in $pp$ collisions with ATLAS. It is expected that the deposited energy in the transverse ($x,y$) plane varies, depending on the longitudinal ($z$) slice examined, which is correlated with the rapidity of the produced particles. Thus, particles from different rapidity slices will have flow vectors that differ in magnitude...

The collective flow of particles, generated in the expansion of the dense matter that is created in heavy-ion collisions, fluctuates from event to event. In particular, the flow vectors at two different transverse momenta fluctuate with respect to each other. One way to probe this flow fluctuation is to study the decorrelation between the flow at two different momentum bins. However, the...

Charmed hadron interactions are very important in current exotic hadron physics. For example, charmed pentaquark state ($P_c$) appears around the $\Sigma_c \bar{D}^{(*)}$ thresholds, and then $P_c$'s are suggested to be hadron molecules caused by the attraction between $\Sigma_c$ and $\bar{D}^{(*)}$. While it is difficult to perform charmed hadron scattering, recent femtoscopic studies allows...

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven is a facility to create and study the strongly interacting Quark-Gluon Plasma (sQGP). Higher-order cumulants of the conserved quantities and their ratios are powerful tools to study the properties of sQGP and explore the QCD phase structure, such as critical point and/or the first-order phase transition boundary. It has been reported by...

A challenging goal in relativistic heavy-ion physics is the

investigation of the phase diagram of strongly interacting matter and

the determination of its phase structure, governed by the approximate

chiral symmetry of the light-quark sector of QCD. In this study [1] we

investigate a linear quark-meson $\sigma$ model in and out of

equilibrium employing Schwinger-Keldysh real-time...

In this presentation, I'll introduce the effective viscosity that can be computed from the viscous damping of anisotropic flow in heavy-ion collisions for arbitrary temperature-dependent shear and bulk viscosities, running ideal and viscous hydrodynamic simulations. I'll show that the damping is solely determined by effective shear and bulk viscosities, which are weighted averages over the...

One important challenge in our field is to understand the initial condition of the QGP and constrain it using sensitive experimental observables. Recent studies show that the Pearson Correlation Coefficient (PCC) between $v_n$ and event-wise mean transverse momentum $[p_\mathrm{T}]$, $\rho_n(v_n, [p_\mathrm{T}])$, and its centrality dependence can probe several ingredients of the initial...

Femtoscopic correlations of identified and unidentified hadrons are measured with data re-corded by the CMS experiment at the LHC over a broad multiplicity range and pair transverse momentum. The first femtoscopy measurements carried in CMS for all pair combinations of $\mathrm{K}^{0}_{\mathrm{S}}$, $\Lambda$ and $\overline{\Lambda}$ are reported. These identified particles are employed to...

Two-particle correlations at small relative momenta contain information about the space-time characteristics of the particle emitting source and final-state interaction effects. Light nuclei, such as deuteron ($d$), triton ($t$), and helium ($^{3}\mathrm{He}$, $^{4}\mathrm{He}$), are loosely bound objects that are expected to be formed at the late stage of relativistic heavy-ion collisions....

The main goal of ultrarelativistic heavy-ion collisions is to create a new state of matter called quark-gluon plasma (QGP) and study its properties. One of the dominant uncertainties present in such a study originates from poorly constrained initial conditions. In this talk, we present the final results of anisotropic flow measurements with high-order cumulants for inclusive and identified...