Excited QCD 2017

7 May 2017, 07:00 → 13 May 2017, 20:00 Europe/Lisbon

Sintra, Portugal

Jelena Jovicevic (TRIUMF (CA)), Marina Marinkovic (CERN), Nuno Cardoso (IST), Pedro Bicudo (IST Lisboa), Robert Kaminski

 

WELCOME!

The 2017 edition of Excited QCD will take place from 7 to 13 May 2017, in Sintra, 30km from the centre of Lisbon, Portugal. The location is perfect for those who love nature, history, the ocean and good food. The  Hotel Sintra Jardim, in São Pedro De Sintra, Portugal, will host the meeting. 

ABOUT THE WORKSHOP

This edition is the ninth in a series of workshops that had been previously organised in Poland (2009), Slovakia (2010 and 2015), France (2011), Portugal (2012 and 2016) and Bosnia and Herzegovina (2013 and 2014). In the year 2017 the workshop goes to  the beautiful Sintra near Lisbon, Portugal.

The workshop covers diverse aspects of QCD:

(i) QCD at low energies: excited hadrons, new resonances, glueballs, multiquarks.

(ii) QCD at high temperatures and large densities: heavy-ion collisions, jets, diffraction, hadronisation, quark-gluon plasma, holography, colour-glass condensate, compact stars, applications to astrophysics.

Emphasis is placed on new developments in theory as well as the current experimental status. Scientific atmosphere, various discussions about different topics in QCD, active participation of many young researchers and a nice environment have been the main characteristics of the previous editions and also represented the goals for the new edition. The talks are all plenary, 20' long separated by 10' for discussions and with a coffee break of 30' every three or four talks for more discussions. An extended lunch break allows for longer discussions and for inspiring open-air activities.

 

 

VENUE

 

The meeting will take place at Sintra, just 30km far from Lisbon downtown and reachable from the airport by public transports, metro and commuters train. The commuters Sintra train line starts at Rossio, Lisboa historic downtow.

Sintra is a historic town in an important natural park, a romantic mountain ~600m high over the ocean,  ideal for trekking, climbing and surfing. It is also a UNESCO world heritage site,  with many palaces, castles and gardens. It was the preferred holiday location for kings, nobles and poets. Sintra has many exquisite hotels, pubs and restaurants.

The conference hotel, where a part of the participants will stay and where the conference will run, is the Hotel Sintra Jardim, http://hotelsintrajardim.pt/pt, close to the village of São Pedro de Sintra, 10 min walking (uphill) from the Sintra train station. 

We reserved a number of rooms at the Hotel Sintra Jardim. The prices per night including breakfast, are  65 to 75 € per person if the room is used as a single room, or 25 to 40 € if the room is shared. The dinners are not included in this price and cost 12.50 €. We plan to have dinners with all participants in the same hotel. In order to make the booking at the hotel, please see details bellow. 

 

 

IMPORTANT: book your room ASAP

We advise the participants to book as soon as possible their rooms because Sintra is very touristic, moreover every year on the 13th of May many catholic pilgrims (including probably the Pope himself) visit Portugal. Participants should book their rooms directly at the hotel, sending an email or calling, and mentioning they are attending eQCD 2017.

The Hotel Sintra Jardim may organize the sharing rooms for those who wish a lower cost in the accommodation. Unfortunately this year we could not find a hotel with enough rooms for everyone (Sintra Jardim is a cosy family run hotel with only ~15 rooms). Its detailed prices (per night with breakfast) are,

• single room- 65,00 €,
• single with garden view - 75,00 €,
• double room (2 persons) - 70,00 €,
• double room with garden view - 80,00 €,
• triple room - 80,00 €,
• triple room with garden view - 95,00 €,
• quadruple room - 100,00 €,
• quadruple room with garden view- 110,00 €.

In order to make a booking at Sintra Jardim, please make your request via contact form on their website  http://hotelsintrajardim.pt/pt and mention that you are coming for the Excited QCD conference.

If you are late for the booking with Hotel Sintra Jardim, there are several other hostels, guest houses and hotels nearby the conference venue or close to the historic Sintra centre (10 to 15 min distance away in walking time units). The alternative accommodations we contacted and recommend are:

1-2 min away (guest houses with double rooms or with triple room apartments) ,

http://www.quintadasmurtas.com

http://www.casa-das-campainhas.com

10 -15 min or 1km away (hostels closer to the train station with double rooms or dorms),

http://www.moonhillhostel.com

hppt://www.saudade.pt

10 - 15 min or 1 km away (hotel in the historic centre with single and double rooms)

http://www.tivolihotels.com/pt/hoteis/sintra/tivoli-sintra/o-hotel.aspx

 

 

Organizing Committee

• Bicudo, Pedro
• Kamiski, Robert
• Krstic Marinkovic, Marina
• Jovicevic, Jelena
• Cardoso, Nuno

 

Poster_eqcd_2017.pdf

schedule_eQCD17_v2.pdf

Sunday 7 May

Arrival day: (No talks on arrival day)

Conference Dinner (Please buy the tickets at the hotel reception)

The dinner tickets must the bought in advance at the hotel reception

Monday 8 May

Opening of eQCD 17 talks

Monday Morning (20min talks + 10min discussions)

Convener: Robert Kaminski

1 Heavy and heavy-light mesons and the Lorentz structure of the quark-antiquark kernel

We use the Covariant Spectator Theory (CST) to calculate the mass spectrum and relativistic vertex functions of mesons as quark-antiquark bound states in which at least one of the quarks is either a charm or bottom quark. The quark-antiquark bound-state equation in CST is, similar to the Bethe-Salpeter equation, an integral equation in which the kernel consists of two-particle irreducible Feynman diagrams. However, in the loop integration over intermediate four-momenta, only pole terms originated by the quark propagators are kept, which represent the leading contributions. This procedure leads to equations that possess the correct one-body limit, which is necessary for a realistic description of heavy-light systems. Our interaction kernel consists of a relativistic generalization of a linear confining potential, whose Lorentz structure is taken as an adjustable mixture of scalar, pseudoscalar, and vector form, and a one-gluon exchange interaction. I will present our recent results for fits to the observed meson spectrum and discuss the conclusions we can draw about the Lorentz structure of the quark-antiquark interaction.

Speaker: Prof. Alfred Stadler (University of Évora, and CFTP, University of Lisbon)

Stadler eQCD Sintra 2017.pdf

2 Rho meson form factors in the point form

We present results for the electromagnetic form factors of the $\rho$ meson obtained within point-form relativistic quantum mechanics. In our formalism for the calculation of the meson current we treat elastic electron-meson scattering as a Poincaré-invariant coupled-channel problem for a Bakamjian-Thomas mass operator. From the resulting invariant one-photon-exchange amplitude we extract the meson current. The well-known violation of cluster separability in the Bakamjian-Thomas framework causes the appearance of unphysical contributions in the current, which, however, can be separated unambiguously from the physical ones such that we obtain a current with all required properties.

Speaker: Dr Elmar P. Biernat (Centro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico (IST), Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal)

Talk_Elmar_Biernat_eQCD17.pdf

3 Quark, gluon and meson correlators of unquenched QCD

We present first-principle results for the 1PI correlation functions of two-flavour Landau-gauge QCD in the vacuum. These correlation functions carry the full information about the theory. They are obtained by solving their Functional Renormalisation Group equations in a systematic vertex expansion, aiming at apparent convergence. This work represents an indispensable and pivotal prerequisite for quantitative first-principle studies of the QCD phase diagram and the hadron spectrum within this framework.

In particular, we have computed the gluon, ghost, quark and scalar-pseudoscalar meson propagators, as well as gluon, ghost-gluon, quark-gluon, quark, quark-meson, and meson interactions. Our results stress the crucial importance of the correct semi-perturbative running of the different vertices in order to quantitatively describe the phenomena and scales of confinement and spontaneous chiral symmetry breaking without further phenomenological input. Furthermore, preliminary results for the correlation functions of pure Yang-Mills at finite temperature are presented.

Speaker: Mario Mitter

Talk_Mario_Mitter_eQCD17.pdf

4 Spin 1 low lying meson spectra and the subtle link to the spin 0 mesons.

An NJL-type three-flavor quark model with a complete set of explicit
chiral symmetry breaking terms is extended to include vector and axial vector
effective interaction terms. A suitable bosonization procedure is implemented
and discussed. The bosonized Lagrangian is written up to quadratic order in the
bosonic fields and the role of the new interactions is analysed in detail. The
model's parameters are fitted to yield reasonable values to the four low-lying
spin 0 and spin 1 meson nonets' masses.

Speaker: Jorge Morais (FCTUC / CFisUC)

Talk_Jorge_Morais_eQCD17.pdf

10:30 Break

5 From the Gribov ambiguity to confining effective models

In this talk we discuss recent developments in the quantization of Yang-Mills theories in the non-perturbative regime and possible phenomenological applications. In particular, we discuss how the procedure that takes into account the presence of Gribov copies in the gauge path integral has led to the construction of a scenario of gluon confinement via an infrared effective action, the (refined) Gribov-Zwanziger theory. Motivated by the importance of implementing con􏰜finement in low-energy QCD eff􏰛ective models in a dynamical way, we shall present a confining quark model that aims at the extension of this picture to the matter sector. In this model, interactions are encoded in a nonlocal quark propagator that displays dynamical chiral symmetry breaking in the infrared, while reproducing the perturbative expectations in the deep ultraviolet limit.

Speaker: Leticia Palhares (UERJ)

Palhares-ExcitedQCD-Sintra-May2017.pdf

6 Holographic models for heavy vector mesons

Holographic AdS/QCD models provide a tool for calculating the spectra of glueballs and light mesons and baryons. In this talk we discuss some recent AdS/QCD models that extend the hadronic description to the case of heavy vector mesons.
Then we consider the finite temperature version of such a model in order to represent the thermal effects of a medium like the plasma in the states of heavy mesons. We show that it is possible to describe of the thermal behavior of the states 1S, 2S and 3S of bottomonium and charmonium.
The corresponding spectral function exhibits a consistent picture for the melting of the states where, for each flavor, the higher excitations dissociate at lower temperatures. A very clear distinction between the heavy flavors emerges, with bottomonium state $\Upsilon (1S)$ surviving deconfinemet transition at temperatures much larger than the critical deconfinement temperature of the medium.

Speaker: Nelson Braga (Universidade Federal do Rio de Janeiro)

Braga_Sintra_2017.pdf

Monday Afternoon (20min talks + 10min discussions)

Convener: Leticia Palhares (UERJ)

7 The Topological Susceptibility via the Gribov horizon?

The topological susceptibility $\chi^4$ is famous in QCD. It explains the $\eta^{\prime}$ mass, solving the $U(1)_{A}$ problem. It is also known that $\chi^4$ is related with Veneziano Ghost (VG), an unphysical mass pole in topological current $K_{\mu}$ correlator, that ensure $\chi^4 \neq 0$. Recently, Kharzeev and Levin (KL) attempted to connect the VG with confinement and so with Gribrov copies (GC) too. However, their result breaks the BRST symmetry. We analyze the topological susceptibility, in SU(3) and SU(2), using Pad{\' e} approximation and RGZ gluon propagator in MOM scheme.

Speaker: Caroline Felix

Talk_Caroline_Felix_eQCD17.pdf

8 Decays of light mesons triggered by chiral chemical potential

Light meson ($\pi,\sigma, a_0$) properties in the environment with chiral im-
balance will be analyzed with the help of meson effective lagrangian
associated with QCD. New spatial parity violating decays of scalar
meson arise as a result of mixing of $\pi$ and $a_0$ mesons. The pion electro-
magnetic formfactor obtains an unusual parity-odd contribution. Pion
effective masses vanish in flight. The possible determination of chiral
chemical potential in heavy ion collisions based on above mentioned
phenomena will be outlined.

Speaker: Prof. Aleksandr Andrianov (Saint-Petersburg State University)

18:00 Break

9 Hadron properties from nPI: towards first principles results

The Green's functions of QCD encode the properties of hadrons, with the appearance of (colour singlet) poles in n-point functions corresponding to bound-states and resonances. There are several techniques by which such information may be extracted, including lattice QCD and functional methods. We discuss recent progress in applying nPI effective action techniques to the systematic truncation of Dyson-Schwinger and Bethe-Salpeter equations, with particular emphasis on the spectrum of mesons and baryons.

Speaker: Dr Richard Williams (University of Giessen)

10 The structure of light baryons and tetraquarks

I will review results for the light baryon spectrum, obtained from solving the genuine three-body equation as well as its quark-diquark simplification. The basic ingredients are QCD's n-point functions which are solved self-consistently. This allows for a combined description of baryons, light and heavy mesons, tetraquarks and other observables from the same underlying building blocks. The three-body and quark-diquark calculations yield similar results, which underlines the role of diquark correlations within baryons. The resulting baryons carry a rich structure with relativistically induced orbital angular momentum that would be forbidden in the non-relativistic quark model. In the second part I will give a status report on the light scalar mesons as tetraquarks. We have solved the four-body equation as well as its two-body (meson-meson / diquark-antidiquark) simplification. Also in this case we obtain similar results in both approaches, which suggest a meson-molecule nature of the light scalar mesons. I will conclude with a survey of current efforts towards treating tetraquarks as genuine resonances.

Speaker: Dr Gernot Eichmann (IST Lisboa)

11 The analytic properties of the Landau gauge quark propagator Dyson-Schwinger equation at rainbow level

In this talk I review the status of an ongoing study that is aimed at solving the quark propagator Dyson-Schwinger equation (qDSE) in the complex domain. Knowledge of the propagator's analytic properties is required for bound state equations, but can also potentially provide insights into fundamental phenomena such as confinement through its spectral characteristics. Using only the infrared part of the so-called Maris-Tandy interaction model renders the integrand of the quark-self energy loop analytic, and it is then straightforward to solve the equation in the complex domain. This (over)simplified model serves as a starting point in this work. A Graphics Processing Unit (GPU) based code has been developed, that allows for fast, robust and reliable computation of the complex solution for a wide range of bare mass values. The resulting poles and residues are extracted automatically, and can be used to approximate and model the solution of the propagator. The next step in this project is to not only consider the infrared term of the interaction model, but also the (logarithmic) ultraviolet (UV) term, which induces non-analyticities in the self-energy integrand in form of branch cuts. These branch cuts must be taken into account when evaluating the self-energy integral. I will discuss the techniques I employ to address these complications.

Speaker: Andreas Windisch (Washington University in St Louis)

sintra_17_aw.pdf

talk_sintra_aw.zip

movies 3d_cuts.mp4 contour.mp4

Conference Dinner (Please buy the tickets at the hotel reception)

The dinner tickets must the bought in advance at the hotel reception

Tuesday 9 May

Tuesday Morning (20min talks + 10min discussions)

Convener: Marina Marinkovic (CERN)

12 Monte Carlo calculations using the holomorphic gradient flow

Questions about quantum field theories at non-zero chemical potential and/or real-time correlators are often impossible to investigate numerically due to the notorious sign problem. A possible solution to this problem is to deform the integration domain for the path integral in the complex plane. We describe a family of such deformations, built using the holomorphic gradient flow, that interpolate between the original integration domain (where the sign problem is severe) and the union of relevant thimbles (where the sign problem is mild but a multimodal probability distribution complicates the Monte Carlo sampling). We show how this works in a fermionic model and for computing real time correlators for a simple thermal quantum field theory.

Speaker: Andrei Alexandru (The George Washington University)

alexandru.pdf

13 A new theoretical method for lattice QCD calculations at finite density beyond the sign problem

We propose a new theoretical method for the practical lattice QCD calculation at finite density as a possible solution of the sign problem in finite-density QCD. In this method, the fermionic determinant becomes real and non-negative, and therefore no sign problem appears and the practical numerical calculation can be performed in lattice QCD.

Speaker: Hideo Suganuma (Kyoto University)

eQCD2017.pptx

eQCD2017Revised.pptx

14 Lattice Landau gauge gluon propagator at finite temperature: non-zero Matsubara frequencies and spectral densities

The lattice Landau gauge gluon propagator at finite temperature is computed including the non-zero Matsubara frequencies. Furthermore, the Källén-Lehmann representation is inverted and the corresponding spectral density evaluated using a Tikhonov regularisation together with Morozov discrepancy principle. Implications for gluon confinement are also discussed.

Speaker: Paulo Silva (Center for Physics, University of Coimbra)

silva_eqcd17.pdf

15 Center Vortices and Topological Charge

I review important aspects of the interplay between center vortices and topological charge.

Speaker: Roman Höllwieser

eQCD_hoellwieser.pdf

10:30 Break

16 Chern-Simons 5-form and Holographic Baryons

In the top-down holographic model of QCD based on D4/D8-branes in type IIA string theory and some of the bottom up models, the low energy effective theory of mesons is described by a 5 dimensional Yang-Mills-Chern-Simons theory in a certain curved background with two boundaries. The 5 dimensional Chern-Simons term plays a crucial role to reproduce the correct chiral anomaly in 4 dimensional massless QCD. However, there are some subtle ambiguities in the definition of the Chern-Simons term for the cases with topologically non-trivial gauge bundles, which include the configurations with baryons. In particular, for the cases with three flavors, it was pointed out by Hata and Murata that the naive Chern-Simons term does not lead to an important constraint on the baryon spectrum, which is needed to pick out the correct baryon spectrum observed in nature. In this talk, we propose a formulation of well-defined Chern-Simons term which can be used for the cases with baryons, and show that it recovers the correct baryon constraint as well as the chiral anomaly in QCD.
This talk is based on our recent paper arXiv:1612.09503 written with P.H.C. Lau.

Speaker: Shigeki Sugimoto (Kyoto University)

Sugimoto-exQCD2017.pdf

Sugimoto-exQCD2017.pptx

17 The Quark propagator in QCD and QCD-like theories

QCD-like theories provide testing grounds for truncations of functional equations at non-zero density, since comparisons with lattice results are possible due to the absence of the sign problem. As a first step towards such a comparison, we determine for various theories the chiral and confinement/deconfinement transitions from the quark propagator Dyson-Schwinger equation by calculating the chiral and dual chiral condensates, respectively.

Speaker: Romain Contant (University of Graz)

eQCD2017_CONTANT_Romain.pdf

Tuesday Afternoon (20min talks + 10min discussions)

Convener: Andrei Alexandru (The George Washington University)

18 Decays of excited vector mesons

We study two types of excited vector mesons, radially excited vector mesons characterised by quantum numbers $n \hspace{0.15cm} ^{2s+1}L_J = 2 ^{3}S_{1}$ and angular-momentum excited vector mesons with quantum numbers $n \hspace{0.15cm}^{2s+1}L_J = 1 ^{3}D_{1}$. We evaluate the decays of these mesons into pseudoscalar and ground-state vector mesons. By using an effective relativistic QFT model based on flavour symmetry, we calculate the decay widths and we compare the results with experimental data taken from PDG. We also make predictions for the $s\bar{s}$ state in the $1 ^{3}D_1$ nonet which has not yet been experimentally seen. We calculate also the decay rates of excited vector mesons into a photon and a pseudoscalar meson by making use of „Vector Meson Dominance”.

Speaker: Milena Piotrowska (Jan Kochanowski University)

eQCD_Piotrowska.pdf

19 Heavy glueballs

Glueballs, i.e. bound state of gluons, were predicted to exist in the very early days of QCD. This expectation has been confirmed by numerous lattice calculations. However, glueballs could not yet be experimentally identified. While in the low-energy sector (below 2.6 GeV) some candidates exist, in the high-mass sector (between 2.6-5 GeV) the situation is not satisfactory. In this talk, after a brief review of the status of glueballs in general, we concentrate on novel aspects of glubeall's search. A general discussion of the width of an heavy glueball is presented . Then, predictions for the decays of the vector glueball (whose mass is about 3.6 GeV according to lattice calculations) and for the decays of a pseudotensor glueball (whose mass is about 3 GeV) are shown. In the end, an outlook concerning other heavy glueballs is presented.

Speaker: Prof. Francesco Giacosa (Kielce University)

GiacosaeQCD2017.pdf

18:00 Break

20 Excited Scalar and Pseudoscalar Mesons in the Extended Linear Sigma Model

Masses and decays of excited scalar and pseudoscalar $\bar{q}q$ states are studied in depth within the Extended Linear Sigma Model (eLSM). The model also contains ground-state scalar, pseudoscalar, vector and axial-vector mesons. The main objective is to investigate the hypothesis that the $f_0(1790)$ resonance, observed a decade ago by the BES Collaboration and recently by LHCb, represents an excited scalar quarkonium. In addition the possibility is analysed that the new $a_0(1950)$ resonance, observed recently by BABAR, may also be an excited scalar state. Both hypotheses receive justification in this approach although there appears to be some tension between the simultaneous interpretation of $f_0(1790)$/$a_0(1950)$ and pseudoscalar mesons $\eta(1295)$, $\eta(1300)$, $\eta(1440)$ and $K(1460)$ as excited $\bar{q}q$ states.
Work presented in arXiv:1612.09218.

Speaker: Denis Parganlija (TU Wien)

Parganlija.pdf

21 Analytic approach to pion-kaon scattering and strange resonances

Here we will discuss a recent dispersive determination of pion-kaon scattering and the use of analytic methods to extract the parameters of the poles associated to light strange resonances, without assuming a specific model.

Speaker: Arkaitz Rodas Bilbao (Universidad Complutense de Madrid)

Excited 2017.pdf

22 Photoproduction of exotic states

The experimental investigation of hadrons is an unique way to understand how QCD behaves at the low-energy non-perturbative scale, where the bulk of the Universe visible mass exists. The search for "exotic" states, in particular, could permit to access further degrees of freedom of the theory that are characteristics of these particles, behind those of the Constituent Quark Model that well describes "conventional" hadrons.

In the past, these studies have been performed with different experimental techniques, such as peripheral production with high-energy pion or kaon beams. Today, the availability of high-energy, high-intensity photon beams permitted to start a new experimental program based on this probe, made of different efforts.

In the talk, after briefly presenting the physical motivations of hadron spectroscopy and discussing the main properties of photo-production, I'll first present few results from past experiments, such as LEPS and CLAS. Then, I'll discuss plans for exotic hadron searches in two "modern" photo-production experiments at Jefferson Lab: “Meson-Ex” in Hall B and “GlueX” in Hall D.

Speaker: Andrea Celentano (INFN - National Institute for Nuclear Physics)

Celentano.pdf

Conference Dinner (Please buy the tickets at the hotel reception)

The dinner tickets must the bought in advance at the hotel reception

Wednesday 10 May

Wednesday Morning (20min talks + 10min discussions)

Convener: Prof. Emílio Ribeiro (CeFEMA, Instituto Superior Técnico (IST), Universidade de Lisboa, 1049-001 Lisboa, Portugal)

23 Formation and deformation of the $\psi(3770)$

Unexpected line-shapes disclose information about the non-perturbative mechanisms involved in the formation of a mesonic resonance. We study the non-Breit-Wigner amplitude of the $\psi(3770)$ using an unitarized effective Lagrangian approach, including the effect of the nearby threshold $D\bar{D}$. Possible contributions are analyzed and discussed.

Speaker: Susana Coito

susanacoito.pdf

24 General unquenching properties of two-meson scattering and production amplitudes

Besides the unitarity and symmetry requirements for a multi-resonance scattering amplitude, several other natural conditions can easily exclude unrealistic proposals. In particular, the behaviour of singularities under the variation of model parameters yield important information. We discuss how resonance poles should move in the complex-energy plane when coupling constants and masses are varied, how resonances above threshold can turn into bound states below threshold and how the light-quark spectrum can be turned into the spectrum of heavy quarks, with one and the same analytic expression for the scattering amplitude. Moreover, it is shown that perturbative approximations usually do not satisfy the natural conditions.

Speaker: Dr Eef van Beveren (Coimbra University)

25 Unquenching and unitarising mesons in quark models and on the lattice

Modern approaches to mesons and baryons go beyond the traditional description in terms of pure valence quark-antiquark or three-quark systems confined by some infinitely rising interquark potential inspired by QCD. As most hadrons are broad to very broad resonances, with decay widths often of the same order of magnitude as the average level splittings, pretending that they are stable systems is a gross approximation. This was recognised and dealt with long ago in a couple of unitarised quark models, and more recently also in lattice calculations.

In this context, I shall discuss the concepts of unquenching and unitarisation for mesons in quark models and on the lattice in a historical perspective, presenting old and recent results that appear to converge towards a better common understanding of the meson spectrum.

Speaker: Dr George Rupp (CeFEMA, IST, Lisbon)

Rupp.pdf

26 Predictions for $\eta_c \to \eta \pi^+ \pi^-$ producing $f_0(500)$, $f_0(980)$ and $a_0(980)$

We perform calculations for the $\eta_c \to \eta \pi^+ \pi^-$ decay using elements of SU(3) symmetry to see the weight of different trios of pseudoscalars produced in this decay, prior to the final state interaction of the mesons. After that, the interaction of pairs of mesons, leading finally to $\eta \pi^+ \pi^-$, is done using the chiral unitary approach. We evaluate the $\pi^+ \pi^-$ and $\pi \eta$ mass distributions and find large and clear signals for $f_0(500)$, $f_0(980)$ and $a_0(980)$ excitation. The reaction is similar to the $\chi_{c1} \to \eta \pi^+ \pi^-$, which has been recently measured at BESIII and its implementation and comparison with these predictions will be very valuable to shed light on the nature of the low mass scalar mesons.

Speaker: Mr Vinicius Rodrigues Debastiani (IFIC, University of Valencia)

DebastianiVRetacdecay.pdf

10:30 Break

27 Resent results from the KLOE-2 experiment

We will report on recent results of the KLOE-2 experiment on
the measurement of the running of the fine structure constant below 1 GeV, and the search for the light gauge boson in the mass range below 1 GeV.

Speaker: Prof. Pawel Moskal (Jagiellonian University)

2017_Moskal_Ecited_QCD_Sintra.pdf

28 Thermodynamically consistent formulation of quasiparticle viscous hydrodynamics

We present the derivation of second-order relativistic viscous hydrodynamics from an effective Boltzmann equation for a system consisting of quasiparticles of a single species. We consider temperature-dependent masses of the quasiparticles and devise a thermodynamically-consistent framework to formulate second-order evolution equations for shear and bulk viscous pressure corrections. The main advantage of this formulation is that one can consistently implement realistic equation of state of the medium within the framework of kinetic theory. Specializing to the case of one-dimensional purely-longitudinal boost-invariant expansion, we study the effect of this new formulation on viscous hydrodynamic evolution of strongly-interacting matter formed in relativistic heavy-ion collisions.

Speaker: Dr Radoslaw Ryblewski (Institute of Nuclear Physics PAN)

ryblewski.pdf

Wednesday Afternoon (20min talks + 10min discussions)

Convener: Susana Coito

29 Excited Baryons and Quark-Hadron Duality

We analyse the role of the excited Baryonic spectrum in Quark Hadron Duality.

Speaker: Prof. Enrique Ruiz Arriola (Universidad de Granada)

Ruiz-Arriola_Excited-QCD-2017.pdf

30 Features of the QCD phase diagram from small, noisy, fluctuating systems

Statistical moments of particle multiplicities in heavy-ion collision experiments are an important probe in the exploration of the phase diagram of strongly-interacting matter and, particularly, in the search for the QCD critical endpoint. In order to appropriately interpret experimental measures of these moments, however, it is necessary to understand the role of experimental limitations, as well as background contributions, providing expectations on how critical behavior should be affected by them. We present a framework for calculating moments of particle multiplicities in the presence of correlations of both critical and spurious origins. We also include effects from resonance decay and a limited acceptance window, as well as detector efficiency. Although we focus on second-order moments, for simplicity, an extension to higher-order moments is straightforward.

Speaker: Eduardo Fraga (Universidade Federal do Rio de Janeiro)

eQCD-fraga.pdf

18:00 Break

31 Transverse momentum fluctuations and correlations

We study the fluctuations and correlations of the average transverse momentum of particles emitted in heavy-ion collisions. The momentum fluctuations are related to event-by-event fluctuations of the size and entropy of the initial source. Hydrodynamic calculations using a Glauber model with quark degrees of freedom reproduce the data. We study correlation of the average transverse momentum in different rapidity bins. We propose a definition of the observable that can be directly related to correlations of the collective flow variables. The correlation as function of rapidity separation can serve to pin down possible sources of momentum fluctuations in the initial state and the dynamics.

Speaker: Piotr Bozek (AGH University of Science and Technology)

Bozek-Sintra.pdf

32 Scale invariant resummed perturbation at finite temperature

We will illustrate how our recently developed
nonperturbative variational technique combined with renormalization group (RG) properties efficiently resums perturbative expansions in thermal field theories. The resulting convergence and scale dependence of optimized thermodynamical quantities are drastically improved as compared to standard perturbative expansions, as well as to other related methods such as the screened perturbation or (resummed) hard-thermal-loop perturbation. Our general method will be illustrated for the nonlinear sigma model, as a toy model for thermal QCD, and we will also discuss some preliminary results in the framework of hard thermal loop resummation for QCD thermodynamical quantities.

Speaker: Jean-Loic Kneur (Univ Montpellier)

kneur_exqcd17.pdf

33 Phase diagram and isentropic curves from the vector meson extended Polyakov quark meson model

In the framework of the $N_f = 2 + 1$ flavor (axial)vector meson extended Polyakov quark meson model we investigate the QCD phase diagram at finite temperature and density. We use a $\chi^2$ minimization procedure to parametrize the model based on tree-level decay widths and vacuum scalar and pseudoscalar curvature masses which incorporate also the contribution of the constituent quarks. Using a hybrid approximation (mesons at tree level, fermions at one-loop level) for the grand potential we determine the pressure and other thermodynamical observables derived from it together with the phase boundary. We also determine the location of the critical end point of the phase diagram on the $\mu_B − T$ and $\rho - T$ planes. Moreover we determine a set of isentropic curves in the crossover and in the first order region. We show that the curves behave very similarly as their counterparts obtained from the lattice in the crossover regime.

Speaker: Peter Kovacs (Wigner RCP)

pkovacs_eQCD_Sintra_2017_05_10.pdf

Conference Social Dinner at Taverna dos Trovadores

Thursday 11 May

Thursday Morning (20min talks + 10min discussions)

Convener: Jelena Jovicevic (TRIUMF (CA))

34 Lambda_b and Xi_b decays into Lambda_c* and Xi_c* states and dynamics of Lambda_c* and Xi_c*

I shall report on two unitary coupled channels works where the Λc(2595) (1/2- ) and Λc(2625) (3/2-) states are generated on one side and the Xi_c^0 (2790), Xi_c^0 (2815) are generated in another case. After that I shall show the formalism by means of which these resonances are produced in the decays of Lambda_b and Xi_b, with results and comparison with experiment.

Speaker: Prof. Eulogio Oset (University of Valencia)

LbpiLc.pdf

35 Polarized Drell-Yan measurements at COMPASS

COMPASS is a fixed-target experiment that was put in operation in 2002 at CERN (SPS, M2 beamline). An important part of its physics programme is the exploration of the transverse spin structure of the nucleon via measurements of spin (in)dependent azimuthal asymmetries in semi-inclusive DIS and, recently, also in Drell-Yan processes. Drell-Yan measurements with a $\pi^-$ beam interacting with a transversely polarized NH$_3$ target started with the 2015 run and will be continued in 2018. The measurement of the Sivers and other azimuthal asymmetries in polarized SIDIS and Drell-Yan performed by COMPASS provides a unique possibility to test (pseudo-)universal features of transverse momentum dependent parton distribution functions, predicted in QCD. Results of the first ever measurements of the polarised Drell-Yan reaction
performed by COMPASS will be presented.

Speaker: Riccardo Longo (Universita e INFN Torino (IT))

Longo_eQCD17_FINAL.pdf

36 Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS

The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN, which is fundamental to solve longstanding questions in the non-perturbative strangeness QCD sector. AMADEUS step 0 consisted in the reanalysis of 2004/2005 KLOE data, exploiting $K^−$ absorptions in H, ${}^4$He, ${}^9$Be and ${}^{12}$C, leading to the first invariant mass spectroscopy study with very low momentum (100MeV) in-flight $K^−$ captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest $K^−$ nuclear interaction.
The results obtained in the analyses of the hyperon-pion correlated events, searching for the resonant shapes of Y$^*$ states, and the analyses of hyperon-proton, deuteron, and triton correlations, searching for possible $K^-$-multi nucleon bound states, will be presented.

Speaker: Kristian Piscicchia

piscicchia-excitedQCD-2017.pdf

37 ATLAS results on exotics searches

The significant increase of the centre-of-mass energy of the Large Hadron Collider (LHC) from 8 to 13 TeV has allowed the LHC experiments to explore previously inaccessible kinematic regimes in their search for phenomena beyond the Standard Model (BSM).
Many BSM theories predict new phenomena accessible by the LHC. Searches for new physics models are performed using the ATLAS experiment at the LHC. The results reported here use the pp collision data sample collected in 2015 and 2016 by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.

Speaker: Nectarios Benekos (National Technical Univ. of Athens (GR))

Nektarios_eQCD2017_ATLASTalk.pdf

10:30 Break

38 Photoproduction of Light Exotic and Strange Mesons

Studies of meson spectra via strong decays provide insight regarding QCD at the
confinement scale. These studies have led to phenomenological models for QCD
such as the constituent quark model. However, QCD allows for a much richer
spectrum of meson states which include extra states such as hybrids, exotics,
multi-quarks, and glueballs. Within the past two decades a number of
experiments have put forth tantalizing evidence for the existence of light
quark exotic hybrid mesons in the mass range below $2 ~GeV$. Recent Lattice QCD
calculations of the light-quark meson spectrum indicate a constituent
gluon-like excitation contributing an additional $J^{PC} = 1^{+-}$ and mass
$1-1.5 ~GeV$ resulting in the lightest hybrid nonets with masses near $2.0 ~GeV$. High statistical yields from recent experiments along with new advances
in analysis techniques have shed a new light towards the understanding the
latest experimental exotic candidates. Recent results from
photo-production will be presented.

Speaker: Prof. Paul Eugenio (Florida State University)

Eugenio-ExcitedQCD-2017.pdf

39 Combined Gravitational and Electromagnetic observations of Gamma-ray Bursts

Gamma-Ray Bursts (GRBs) are the brightest events in the universe since the big bang. Detailed studies of the electromagnetic emission from these transient events have show that the short GBRs are likely associated with the merger of two compact objects such as neutron stars. With the start of gravitational wave detection a new window is opened to study these events and their progenitors. The gravitational counter part of a neutron star merger event is expected to be observable by LIGO in the coming years. Furthermore the combined electromagnetic and gravitational detection potential of GRBs allows for a search for more exotic astrophysical objects such as boson and quark stars.

Speaker: Merlin Reynaard Kole (Universite de Geneve (CH))

talk.pdf

Thursday Afternoon (20min talks + 10min discussions)

Convener: Prof. Eulogio Oset (University of Valencia)

40 Fragmentation and Monte Carloe generators at Belle II

The Belle II experiment at the SuperKEKB collider is a major upgrade of the KEK “B factory” facility in Tsukuba, Japan aiming at an increase of the peak luminosity by a factor of 40. Commissioning of the SuperKEKB main ring took place in the first half of 2016. Phase 2 of the commissioning will start beginning of 2018 after the installation of the final focus system in the IR but still without the vertex detector system. Once machine operation in the nano-beam scheme is established, the goal is to accumulate data for early physics analyses at different center-of-mass energies. In this talk we describe the Belle II physics program in the QCD sector focusing on the tuning of the fragmentation process of quarks in PYTHIA8 Monte Carlo generator.

Speaker: Ami Rostomyan (DESY)

eQCD2017.pdf

41 Azimuthal correlations and mixed higher order flow harmonics from CMS at the LHC

Two-particle correlations measurements of $v_{n}$ (n=2-4) in 8.16 TeV pPb collisions, and event-by-event correlations of different $v_{n}$ measured using symmetric cumulants in 13 TeV pp, 5.02 and 8.16TeV pPb and 5.02 TeV PbPb collisions at the LHC. These new results give important insights to the origin of collectivity observed in small collision systems. Additionally, using the scalar product method and the method of two-particle correlations, the mixed higher order flow harmonics and extracted nonlinear response coefficients of charged particles are measured for the first time as a function of $p_{T}$ and centrality in 2.76 and 5.02 teV PbPb collisions. The obtained results are compared with different theoretical predictions.

Speaker: Milan Stojanovic (University of Belgrade (RS))

exQCD2017_Milan.pdf

18:00 Break

42 Relativistic perfect fluid hydrodynamics of particles with spin 1/2

Starting from local equilibrium distribution functions for particles and antiparticles with spin 1/2, which are generalised to two by two hermitian matrices to include spin degrees of freedom, and using the conservation laws for energy, momentum and angular momentum, we derive hydrodynamic equations for the local temperature, chemical potential and hydrodynamic flow, as well as for the spin tensor. The resulting framework results in a set of differential equations which, in the minimal way, extend the standard picture of perfect-fluid hydrodynamics with the entropy current conserved. They can be used in space-time analyses of spin and polarisation evolution for various physical systems including high-energy nuclear collisions. As a special solution of the obtained approach, we find a stationary vortex-like solution which exhibits the vorticity-spin alignment and has been found in earlier studies of fluids at global equilibrium.

Speaker: Wojciech Florkowski (Institute of nuclear Physics, Krakow)

florkowski-EQCD-2017.pdf

43 One-loop exclusive diffractive impact factors in the CGC framework

The Color Glass Condensate picture, or shockwave formalism, provides the non-planar extensions of the non-linear extension of the BFKL formalism for low-x physics. In such a framework, we will detail how to obtain IR- and UV-finite impact factors for two exclusive diffractive processes at one-loop accuracy.

Speaker: Renaud Boussarie (IFJ Krakow)

BoussarieEQCD.pdf

44 Thermal entropic destruction and entanglement entropy of the quark-antiquark pair from dynmical holographic QCD

To be announced.

Speaker: Dr Subhash Mahapatra (KU Leuven)

Subhash_eCQD2017.pdf

Conference Dinner (Please buy the tickets at the hotel reception)

The dinner tickets must the bought in advance at the hotel reception

Friday 12 May

Friday Morning (20min talks + 10min discussions)

Convener: Ami Rostomyan (DESY)

45 Overview on QCD studies at BESIII

The BESIII detector has been taking data for QCD study in the energy region of 2.0-4.6 GeV at the Beijing Electron and Positron Collider (BEPCII). There are totally 130 scan energy points with an integrated luminosity of 1.4 pb-1. Various QCD-related topics are performed, such as measurements of baryon form factors, hadron spectroscopy, precision tests of the standard model and Jpsi lineshape scan. In this report, the experimental situation for the QCD study at BESIII is reviewed together with a prospect at BESIII.

Speaker: Xiaorong Zhou (USTC)

BESIII-overview-v3.pdf

BESIII-overview-v3.pdf

BESIII-overview-v3.pptx

46 Recent QCD-related results from Kaon physics at CERN (NA48 and NA62)

The NA48/2 experiment presents a final result of the charged kaon semileptonic decays form factors measurement based on 4.28 million $K^\pm_{e3}$ and 2.91 million $K^\pm_{\mu 3}$ selected decays collected in 2004. The result is competetive with other measurements in $K^\pm_{\mu 3}$ mode and has a smallest uncertainty for $K^\pm_{e3}$, that leads to the most precise combined $K^\pm_{l3}$ result and allows to reduce the form factor uncertainty of $|V_{US}|$. The NA62 experiment at the CERN SPS collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A preliminary result of a new measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like momentum region from 1.05 million fully reconstructed π 0 Dalitz decays is presented in the second part of this report.

Speaker: Mr Sergey Shkarovskiy (Joint Institute for Nuclear Research (RU))

eQCD2017_Shkarovskiy.pdf

47 Interference effect in vacuum polarization from BABAR, KLOE,CMD2 and SND data.

The cross section of the process $e^+e^- ->\mu^+\mu^-$ is calculated within hadronic polarization taken into account. The interference effects in vicinity of $\phi$ and $\omega$ mesons are calculated (not only) from $\sigma(e^+e^- -> hadrons)$ and compared with available experiments.

Speaker: Vladimir Sauli (Nuclear Institute Rez near Prague)

sauli2017.pdf

48 A novel multiquark approach to hadron resonances

A new scheme for the hadron spectroscopy is put forward. By
assumption, the form of spectrum is dictated by the trace of
energy momentum tensor in QCD. This provides the relativistic and
renormalization invariance of hadron masses. The schema is applied
to the light mesons. Two complementary interpretations of hadron
states emerge. The first one represents an "atomic" structure of
resonances, in which the quanta of non-perturbative gluon
contributions are quantified via an effective formation of
quasiparticles representing gluon analogues of positronium. This
picture allows to build a "periodic table of hadronic elements",
i.e. to classify the hadron states, in some sense, in analogy with
Mendeleev table in Chemistry. The Regge spin and radial
trajectories appear in a natural way and without use of
non-relativistic notion of orbital momentum or any semiclassical
quantization conditions. The second interpretation is based on a
"collisional" nature of some (or many) hadrons. This picture suits
better for explaining the decay modes and isospin. In particular,
it leads to a simple explanation of the scalar sector below 1~GeV
with correct masses and decay modes.

Speaker: Prof. Sergey Afonin

Excited QCD 2017afonin.pdf

10:30 Break

49 Mixture of quark and gluon fluids described in terms of anisotropic hydrodynamics

Relativistic hydrodynamics has been a fundamental tool to understand the evolution of matter in heavy-ion experiments at RICH and LHC. Despite the success of second order viscous hydrodynamics in reproducing collective behavior and particle spectra, there are still theoretical shortcomings that may question the validity of the approach in heavy-ion experiments conditions. Large gradients and fast longitudinal expansion produce very large pressure corrections, in contrast to the founding hypothesis of small deviation from local equilibrium and the perturbative treatment viscous corrections. One way to address this problem is anisotropic hydrodynamics. Most of the theoretical investigations about hydrodynamics started from a kinetic underlying substrate of a single species of particles. Unfortunately the striking agreement of anisotropic hydrodynamics with the exact solution of the Boltzmann equation was not preserved in the case of a mixtures of quarks and gluons.

We recently extended the anisotropic hydrodynamics prescription for massless particles in 1+1-dimensions to the case of mixtures of fluids, largely improving the agreement with the exact solutions compared to previous works [1-3]. We allow quarks and gluons to have different momentum scales during the evolution and a non vanishing baryon chemical potential. We take the dynamical equations from the zeroth, the first and the second moment of the Boltzmann equation [4]. We performed a test of the new formulation, comparing the results of anisotropic hydorodynamics with the exact solution of the Boltzmann equation for a mixture of fluid in the Bjorken flow limit, finding a very good agreement [5].

[1] W.Florkowski, R.Maj, R.Ryblewski, M.Strickland, Phys.Rev.C87 (2013) 3, 034914.

[2] W.Florkowski, R.Maj, Acta Phys.Polon.B44 (2013) 10, 2003-2017.

[3] W.Florkowski, O.Madetko, Acta Phys.Polon.B45 (2014) 1103.

[4] L.Tinti, W.Florkowski, Phys.Rev.C89 (2014) 3, 034907.

[5] W.Florkowski, E.Maksymiuk, R.Ryblewski, L.Tinti, Phys.Rev. C92 (2015) no.5, 054912

Speaker: Ewa Maksymiuk (Jan Kochanowski University)

Maksymiuk_eQCD2017.pdf

50 Dilepton production in Relativistic heavy ion collisions

Dilepton production plays a very important role to study hot and dense matter in relativistic heavy ion production.
At HADES or JPARC energies in pion induced dilepton production the interference between the dileptons stemming from intermediate rho and omega helps to study the propagation of the omega meson in dense matter, furthermore, we can study how the coherence is lost in strongly interacting enviroment.
In heavy ion collisions the low mass dileptons provide us information about the in-medium properties of vector mesons.

Speaker: Gyorgy Wolf (Wigner FK)

Wolf-EQCD-2017.pdf

Friday Afternoon (20min talks + 10min discussions)

51 Recent results from NA61/SHINE

NA61/SHINE at the CERN SPS is a fixed-target experiment pursuing a rich physics program including measurements for heavy ion, neutrino and cosmic ray physics. The main goal of the ion program is to study the properties of the onset of deconfinement and to search for the signatures of the critical point.

In this contribution the latest NA61/SHINE results on particle spectra as well as on fluctuations and correlations from p+p, Be+Be, and Ar+Sc energy scans will be presented. The NA61 measurements
will be compared with world data and with model predictions.

Speaker: Maja Katarzyna Mackowiak-Pawlowska (Warsaw University of Technology (PL))

Recent results from NA61/SHINE

52 Jets and charged hadrons in heavy ion collisions with the ATLAS detector

Ultrarelativistic heavy ion collisions at the LHC produce the Quark Gluon Plasma. Jets are a useful probe to study this state of matter as they are produced at the early stages of the collisions and are expected to be modified as propagating through the medium. One observable is the energy loss lowering the jet yields at a given transverse momentum. Other observables are the modification of the dijet momentum balance and the modification of fragmentation functions. A phenomenon strictly correlated to the jet energy loss is the modification of the charged-hadron momentum spectrum. The large new Pb+Pb data sample collected by ATLAS in Run 2 allows precision measurements of these observables in a wide transverse momentum range and in different centrality and rapidity intervals.

Speaker: Helena Santos (LIP - Lisbon)

eQCD_HSantos_2.pdf

18:00 Break

53 QCD phase diagram and magnetic fields

We examine possible effects of an external magnetic field on the phase diagram structure of QCD. The study is performed using NJL-type models. We focus on the influence of a magnetic field on the chiral and deconfinement phase transitions. Possible consequences of the Inverse Magnetic Catalysis effect on the QCD phase diagram at both finite chemical potential and temperature is analyzed. We devote special emphasis on how the location of the Critical-End-Point (CEP) changes in a magnetized medium.

Speaker: Márcio Ferreira (CFisUC)

Marcio.pdf

54 Hollowness in pp at the LHC

Parameterizations of the pp scattering data at the LHC collision
energies indicate a hollow in the inelasticity profile of the pp
interaction, with, curiously, less absorption for the
head-on collisions than for collisions at a non-zero
impact parameter. We argue that the hollowness in the impact
parameter is a quantum effect; it precludes models of inelastic
collisions where inelasticity is obtained by naive folding of
partonic densities.

Speaker: Wojciech Broniowski (IFJ PAN)

eQCD_17.pdf

Closing of eQCD 17 talks

Conference Dinner (Please buy the tickets at the hotel reception)

The dinner tickets must the bought in advance at the hotel reception

Saturday 13 May

Departure day: no talks on departure day