### Conveners

#### Correlations and fluctuations: 1

- Ulrich Heinz (The Ohio State University)

#### Correlations and fluctuations: 2

- George Fai (U)

#### Correlations and fluctuations: 3

- Jurgen Schukraft (CERN)

#### Correlations and fluctuations: 4

- Alberica Toia (Johann-Wolfgang-Goethe Univ. (DE))

Ron Belmont
(Wayne State University (US))

5/20/14, 11:10โฏAM

Collective Dynamics

Contributed Talk

While no P- or CP-violation has ever been observed in the strong
sector of the Standard Model, there is no first principles reason
for it not to be present. Theoretical calculations have shown the
possibility of P-violating bubbles in the QCD vacuum, which in
combination with the strong magnetic field created in off-central
heavy-ion collisions leads to the Chiral Magnetic Effect...

Umut Gursoy
(University of Utrecht (NL))

5/20/14, 11:30โฏAM

Correlations and Fluctuations

Contributed Talk

The hot QCD matter produced in any heavy ion collision with a nonzero impact
parameter is produced within a strong magnetic field.
We study the imprint that these fields leave on the azimuthal distributions and
correlations of the produced charged hadrons.
The magnetic field is time-dependent and the medium is expanding, which leads to the induction of
charged currents due to the...

Prof.
Sergei Voloshin
(Wayne State University)

5/20/14, 11:50โฏAM

Correlations and Fluctuations

Contributed Talk

Recently, the STAR Collaboration has reported a strong dependence of
the elliptic flow of positive and negative pions on the net charge
density [1]. This measurement attracted a lot of community attention,
as the signal appeared to be of the magnitude and the sign of that
predicted by the theory of the Chiral Magnetic Wave [2]. At the same
time the interpretation of the results and...

Quan Wang
(University of Kansas (US))

5/20/14, 12:10โฏPM

Correlations and Fluctuations

Contributed Talk

Motivated by two- and four-particle azimuthal correlation measurements that suggest possible collective flow for charged particles emitted in pPb collisions at $\sqrt{s_{NN}}$ =5.02 TeV, we extend the correlation results for these collisions using the six- and eight-particle cumulant methods, and the Lee-Yang Zeros method. CMS has an extensive program studying azimuthal harmonic coefficients...

Dominik Karol Derendarz
(Polish Academy of Sciences (PL))

5/20/14, 12:30โฏPM

Correlations and Fluctuations

Contributed Talk

We report on measurements of the anisotropy of charged particles in lead-lead collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV, using multi-particle cumulants calculated with the generating function method. The results on the transverse momentum, pseudorapidity and centrality dependence of the elliptic flow (v2) obtained from two-, four-, six- and eight-particle cumulants are presented....

Li Yan

5/20/14, 12:50โฏPM

Correlations and Fluctuations

Contributed Talk

We propose a new, universal parametrization of the probability distribution of initial anisotropies in proton-proton, proton-nucleus and nucleus-nucleus collisions. The distribution of fluctuation-driven anisotropies, such as the initial triangularity $\varepsilon_3$, is described by a one-parameter power distribution. When a mean anisotropy in the reaction plane is also present, as in the...

Lingshan Xu
(Purdue University (US))

5/20/14, 2:20โฏPM

Collective Dynamics

Contributed Talk

Two-particle long-range pseudorapidity ($\Delta$$\eta$) correlations are observed in pPb collisions at the LHC. Previous correlation measurements have been averaged over both the trigger and associated particle $\eta$. In order to explore the possible pseudorapidity dependence of the long-range correlations in asymmetric pPb collisions, a new analysis of two-particle correlations with trigger...

Leonardo Milano
(CERN)

5/20/14, 2:40โฏPM

Correlations and Fluctuations

Contributed Talk

The observation of long-range correlations on the near- and away-side (also known as the double-ridge) in high-multiplicity p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV and its similarity to Pb-Pb collisions remains one of the open questions from the p-Pb run at the Large Hadron Collider. It has been attributed to mechanisms that involve initial-state effects, such as gluon saturation and...

Sooraj Krishnan Radhakrishnan
(State University of New York (US))

5/20/14, 3:00โฏPM

Correlations and Fluctuations

Contributed Talk

Detailed measurement of the Fourier harmonics ($v_n$) associated with the
azimuthal modulation of two-particle correlation structures over
$-5 < \delta\eta < 5$ in 31 nb$^{-1}$ p + Pb collisions are presented. The $v_n$
results are presented as a function of $p_T$, \eta, and event activity
characterized by the number of reconstructed tracks in $-2.5 < \eta < 2.5$,
and the total transverse...

Dr
shengli huang
(PHENIX Collaboration)

5/20/14, 3:20โฏPM

Correlations and Fluctuations

Contributed Talk

Traditionally $p(d)$$+$A collisions at RHIC and the LHC were considered as
a tool to study cold nuclear matter effects. Production of the hot and
dense medium in such collisions was not expected. However recent
measurements has challenged this assumption with the observation of
long-range correlations in angular distributions of hadron pairs
with low transverse momentum. The observed...

Monika Sharma
(Vanderbilt University (US))

5/20/14, 3:40โฏPM

Collective Dynamics

Contributed Talk

Observation of a long-range near-side two-particle correlation (known as the "Ridge") in high-multiplicity pp and pPb collisions opened up new opportunities of exploring novel QCD dynamics in small collision systems. To further investigate the origin of this phenomenon, new measurements of two-particle correlations with identified $\pi^0$, $K^0_s$ and Lambda trigger particles in 5.02 TeV pPb...

Dr
Bjoern Schenke
(Brookhaven National Lab)

5/21/14, 9:00โฏAM

Correlations and Fluctuations

Contributed Talk

The IP-Glasma initial state model [1,2] coupled to relativistic viscous fluid dynamics successfully describes particle spectra, anisotropic flow, and its fluctuations in central to mid-central heavy-ion collisions [3]. Here we extend the study to more peripheral events and determine if the description remains robust. We then perform a direct comparison of peripheral A+A events with p+A and p+p...

Igor Kozlov
(McGill University)

5/21/14, 9:20โฏAM

Correlations and Fluctuations

Contributed Talk

We perform 3+1D viscous hydrodynamic calculations of proton-nucleus
and nucleus-nucleus collisions. The goal is to ascertain the nature
of the striking correlations seen in recent proton-nucleus collisions.
In particular, one would like to know: is the observed ridge a
signature of collective behavior? Can the highest multiplicity
collision systems be accurately described as a...

Prof.
Joseph Kapusta
(University of Minnesota)

5/21/14, 9:40โฏAM

Correlations and Fluctuations

Contributed Talk

We construct a model of baryon diffusion which has the desired properties of causality and analyticity. The model also has the desired property of colored noise, meaning that the noise correlation function is not a Dirac delta function in space and time; rather, it depends on multiple time and length constants. The model can readily be incorporated in 3+1 dimensional 2nd order viscous...

Dr
Jussi Auvinen
(Frankfurt Institute for Advanced Studies)

5/21/14, 10:00โฏAM

Collective Dynamics

Contributed Talk

The midrapidity slope d$v_1$/d$y$ of the directed flow $v_1$ has been predicted to be sensitive to the possible first-order phase transition between the hadron gas and the quark-gluon
plasma. The recent STAR data from the RHIC beam energy scan (BES) show that the net-proton d$v_1$/d$y$ changes sign twice within the collision energy range 7.7 - 39 GeV. To further investigate this phenomenon,...

Laszlo Csernai
(Department of Physics and Technology)

5/21/14, 10:20โฏAM

Correlations and Fluctuations

Contributed Talk

With increasing beam energies the angular momentum of the fireball in peripheral heavy ion collisions is increasing. The earlier predicted rotation effect and Kelvin Helmholtz Instability, leads to space-time momentum correlations among the emitted particles. For these reactions two particle correlations are studied. A specific combination of two particle correlation measurements is proposed,...

Sunil Manohar Dogra
(UNESP - Universidade Estadual Paulista (BR))

5/21/14, 11:10โฏAM

Correlations and Fluctuations

Contributed Talk

Multidimensional and one-dimensional quantum-statistical (Bose-Einstein) correlations are measured in proton-proton collisions at 0.9, 2.76 and 7 TeV, and in proton-lead collisions at 5.02 TeV/nucleon pair center-of-mass energy with the CMS detector at the LHC. The correlation functions are extracted in terms of different components of the relative momentum of the pair, in order to investigate...

Dhevan Raja Gangadharan
(Lawrence Berkeley National Lab. (US))

5/21/14, 11:30โฏAM

Correlations and Fluctuations

Contributed Talk

Two-pion Bose-Einstein correlations are often used to extract the radius of the particle emitting source at freeze-out. The extraction of the radii in low multiplicity systems is complicated by the presence of background correlations such as mini-jets. Such backgrounds can be suppressed through the use of three-pion cumulant correlations. We present two- and three-pion Bose-Einstein...

Prof.
Yuri Sinyukov
(Bogolyubov Institute for Theoretical Physics)

5/21/14, 11:50โฏAM

Correlations and Fluctuations

Contributed Talk

The femtoscopic scales for identical pions and kaons are presented at different centralities for the top energy RHIC and LHC A+A collisions in comparison with ones for p+p collisions. The later results are obtained in hydrokinetic model (HKM) in view of the quantum uncertainty principle. The three-dimensional pion and kaon emission source functions are extracted from the HKM model...

Shinichi Esumi
(University of Tsukuba (JP))

5/21/14, 12:10โฏPM

Correlations and Fluctuations

Contributed Talk

The initial density distribution in a heavy ion collision fluctuates
due to the finite number of participating nucleons, which leads to
higher harmonic flow as recently measured at RHIC and the LHC. Such
spatial fluctuations may be preserved until kinetic freeze-out,
depending on the strength of the initial fluctuations, the flow
profile, the expansion time, and viscosity of the created...

Nuggehalli AJITANAND
(Stony Brook University)

5/21/14, 12:30โฏPM

Collective Dynamics

Contributed Talk

Recent results obtained at RHIC and the LHC have revealed the presence
of unexpected collective effects in central $p(d)$$+$A collisions.
Different techniques and physical observables have been utilized to
understand whether these collective effects have a similar origin to
heavy ion collisions or can be explained solely by cold nuclear matter
effects. Two-pion Bose-Einstein correlation...

Chiho Nonaka
(Nagoya University)

5/21/14, 12:50โฏPM

Collective Dynamics

Contributed Talk

Recently the results of azimuthal HBT measurements with respect to
the second and third order event plane are presented by PHENIX [1].
They extract $\epsilon_2$ and $\epsilon_3$ from the HBT radii
which contain information about not only the source shape at freezeout
but also the space-time evolution of QGP matter.
They show the relation between initial $\epsilon_{2, 3}$ which are...

Vera Loggins
(Wayne State University (US))

5/21/14, 1:10โฏPM

Correlations and Fluctuations

Contributed Talk

Femtoscopy of non-central heavy-ion collisions provides access to information on the geometry of the effective pion-emitting source. In particular, its shape can be studied by measuring femtoscopic radii as a function of the emission angle relative to the collision plane of symmetry.
We present the first measurements of azimuthally differential femtoscopy in Pb-Pb collisions $\sqrt{s_{\rm...