ALICE is devoted to the study of the properties of the Quark-Gluon Plasma (QGP). This new state of matter is created using ultra-relativistic heavy-ion collisions at the LHC. Heavy quarks are considered effective probes for the QGP since they, due to their large masses, are produced in hard scattering processes and experience the full evolution of the hot and dense medium while interacting...
One of the remaining puzzles in heavy-ion physics is that observables thought to be signatures of a Quark-Gluon Plasma - such as flow and strangeness enhancement - are not only observed in heavy-ion collisions, but also in high-multiplicity proton-proton and proton-nucleus collisions. Various phenomenological models are being developed to try to understand this. These include both extensions...
In future LHC runs the heavy flavour measurements in Pb–Pb collisions will enable precise studies of the Quark Gluon Plasma (QGP) transport properties. In the scope of this direction, after the major upgrade of the ALICE Inner Tracking System (ITS2) with seven layers of CMOS Monolithic Active Pixel Sensors (MAPS), a further upgrade, the ITS3, is planned for the third LHC Shutdown (LS3)....
The quark model, proposed in the 1960s, predicts exotic hadrons beyond the conventional quark-antiquark mesons and three quark baryons. However, it was less than 15 years ago that exotic candidates were observed. Since then a number of exotic states have been discovered. LHCb has reported on tetraquark candidates such as the X(3872) as well as the discovery of pentaquark resonances in 2015....
All existing experimental evidence of the bound state nature of the X(3872) relies on considering its decay products with a finite experimental spectral mass resolution which is typically Δm≥2MeV and much larger than its alleged binding energy, BX=0.00(18)MeV. On the other hand, there is a neat cancellation in the 1++ channel for the invariant DD¯∗ mass around the threshold between the...
There are many motivations to study the phase structure of quantum chromodynamics (QCD), related to investigations of relativistic heavy-ion collisions, early universe, and compact stars. Moreover, the QCD phase diagram remains poorly understood, despite all the efforts dedicated to its description over the years, due to the difficulty of first principle calculations and the lack of...
In this talk, several experimental observables used in heavy-ion collisions to probe the QCD phase diagram, such as net-baryon fluctuations and balance functions, will be reviewed, with emphasis on recent experimental results from ALICE and STAR. Important connections between the observables will be highlighted. Experimental challenges of their measurements will be discussed as well.
An overview of quarkonium physics at Belle II is presented. It includes the prospects in conventional quarkonium, double charmonium production, charmoniumlike states observed in two-photon processes, ISR, and $B$ decays, production of bottomoniumlike states in $\Upsilon(5S)$ decays, and other physics.
In this talk, we present two measurements sensitive to non-perturbative physics performed using data collected by the ATLAS experiment at the Large Hadron Collider. First, a measurement of charged-particle distributions sensitive to the properties of the underlying event is presented for an inclusive sample of events containing a Z-boson, decaying to a muon pair. Unfolded differential cross...
We analyze Sakumichi & Suganuma's, Phys.Rev.D92,034511(2015), lattice QCD results for the 3-quark potential, using hyper-spherical three-body coordinates. We show that their data supports neither the Delta, nor the Y-string interpretation, but something in-between. This lattice data is consistent with Koma & Koma's, Phys.Rev.D95, 094513 (2017) results, their different conclusions...
The center vortex model, capable of explaining confinement and chiral
symmetry breaking, has been plagued by the lattice equivalent of
Gribov copies: different maxima of the gauge functional lead to
different predictions of the string tension. By using center regions,
that is, arbitrary loops evaluating to a center element, as guide for
the gauge fixing procedure, a solution to this...
QCD string breaking results in two flavour QCD by Bali et al. 2005 combined with the Born-Oppenheimer expansion have recently been used to gain insight into I=0 quarkonium resonances (Bicudo et. al, 2019). The aim of this work is to give a more precise input of relevant lattice QCD static potentials for the aforementioned quarkonium spectrum studies and at the same time get a better...
We produced a set of gauge configurations generated with a new $N_f=3+1$ massive renormalization scheme for three degenerate light quarks with a mass that equals the average light quark mass in nature and a physical charm quark mass, and a non-perturbatively determined clover coefficient for dynamical Wilson quarks on the lattice. We present the details of the algorithmic setup and tuning...
We present a recent application of the Glazek-Wilson similarity renormalization group for Hamiltonians (SRG).
We consider the $\pi\pi$-scattering problem in the context of the Kadyshevsky equation, a 3D reduction of the Bethe-Salpeter equation that allows for a Hamiltonian formulation. In this scheme, we introduce a momentum grid and provide an isospectral definition of the phase-shift...
Within the framework of AdS/QCD models, the spectra of radially excited hadrons
are identified with towers of Kaluza-Klein (KK) states in a putative dual theory.
It is known, however, that the KK modes of dual theory must be qualitatively different
from the QCD excited states. We propose a possible solution for this discrepancy.
The idea is to describe excited hadrons as "would be" ground...
NA61/SHINE is a fixed target experiment at the CERN Super Proton Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a...
The NA62 experiment at CERN was designed to measure the branching ratio of the ultra-rare decay $K^+\rightarrow\pi^+\nu\bar\nu$ with a decay-in-flight technique. The Standard Model prediction for this branching ratio is very precise and $K^+\rightarrow\pi^+\nu\bar\nu$ is an ideal candidate to search for indirect new physics at high-mass scales. NA62 took its first physics run in 2016, reaching...
The existence and the location of the critical end point (CEP) between the crossover and the first order chiral phase transition in the phase diagram of the strongly interacting matter is a heavily studied area of recent particle physics. The baryon number fluctuations and related quantities such as kurtosis and other susceptibility ratios, that supposed be a good signature of CEP, has been...
We have constructed O(6) permutationally symmetric three-particle hyper-spherical harmonics. These hyper-spherical harmonics were applied to the non-relativistic three-quark problem, yielding eigen-energies corresponding to various confining potentials. We display these energy level splittings up to the K=5 shell as a function of confinement potential and briefly discuss the effects of relativity.
Inner structure of compact stars is a heavily studied field of research currently. The compact star is divided into two major parts, to the outer part called crust and the inner part called core. There are several possible scenarios of the composition of these parts. One possibility is the hybrid star, in which the crust is some nuclear matter, while the core part is quark matter. Since at...
We present a precise and model-independent dispersive determination from data of the existence and parameters of the lightest strange resonance. We use both subtracted and unsubtracted partial-wave hyperbolic and fixed-t dispersion relations as constraints on combined piK and pipi to KKbar data. We then use the hyperbolic equations for the analytic continuation of the isospinI=1/2 scalar...
The elaborated Unitary and Analytic models of pseudoscalar meson
nonet structure, and to some extent also of nucleons, give more
precise theoretical prediction for the hadronic contribution
$\Delta\alpha_had^{(5)}(t)$ to the running fine structure constant
QED $\alpha(t)$ in space like region, which by the novel approach
leads to the following complete SM muon anomalous magnetic...
Utilizing the SU(3) invariant vector-meson-baryon interaction
Lagrangian, the knowledge of the invariant vector-meson coupling
constants $f_v$ and the numerical values of nucleon coupling
constant ratios, specified in a comparison of the nucleon EM
structure Unitary and Analytic model with all existing data on
nucleon EM form factors, the coupling constant ratio values in all
hyperon EM...
The experimental low-energy kaon-nucleon/nuclei interaction studies are playing a key-role for the understanging of the low-energy QCD, impacting in particle and nuclear physics as well as in astrophysics.
The excellent quality of the kaon beam delivered by the DAFNE collider in Frascati (Italy), combined with a new dedicated technology of Silicon Drift Detectors as well as the high...
The VIP experiment aims to perform high sensitivity tests of the Pauli Exclusion Principle (PEP) for electrons, and look for a possible small violation.
In Local Quantum Field Theories approach any PEP violating transition is strongly constrained by the Messiah Greenberg Superselection (MGS) rule, which forbids superpositions of states with different symmetry. Such models can then be only...
We extend a chiral model of QCD, the so-called extended Linear Sigma Model (eLSM), in order to include ground-state hybrids (with exotic quantum numbers 1^-+) and their axial-vector chiral partners. We then evaluate both masses and decays of these hybrid mesons into conventional quark-antiquark states, such as pseudoscalar and (pseudo)vector mesons. In particular, we also show that the decays...
The main aim of our study is to understand some conventional and non-conventional mesons by using an effective QFT models. Starting from a single $q\bar{q}$ seed state in the Lagrangian some states appear as a dynamically generated companion poles. We show that $K_0^* (700)$ is a companion pole of the heavier $K_0^* (1430)$ resonance, $X(3872)$ emerges as a virtual companion pole of...
This talk takes a new look at the thermodynamics of QCD in the large Nc limit. In many contexts QCD in the large Nc limit gives a reasonable, if somewhat cartoonish, description of the theory at Nc=3. It is well-known, However, that the description of QCD near its cross-over from a hadronic regime to QGP is a place where the large Nc limit is quite different from Nc=3. Instead of having a...
In this talk, we present theoretical findings on fluid dynamics with conformal symmetry broken. We discuss the physics of bulk viscosity and its limits. We focus on results concerning bulk relaxation time obtained from both a quantum-field-theoretical approach and kinetic theory.
We present predictions for the double parton distribution of valence quarks in the pion in the framework of chiral quark models. The distribution has a very simple form with factorized transverse and longitudinal degrees of freedom. The dependence on the longitudinal momenta of the valence quarks is of the form $\delta(1-x_1-x_2)$, which complies to the formal requirements of the...
I review recent results on exotic hadrons such as glueballs,
hybrids and tetraquarks obtained in the framework of functional
Dyson-Schwinger and Bethe-Salpeter equations. First results for
quenched glueballs in this framework have been published in 2012;
I present an update of these results. For tetraquarks, based on our
earlier results on the light scalar mesons we have generalized...
With the reported observation of the Higgs boson at the LHC, the Standard Model of particle physics seems to be complete now as for its particle content. However, several experimental data at low and intermediate energies indicate that there may be two surprises.
The strongest evidence concerns $E(38)$, a very light spinless boson, probably a scalar, with a mass of 38 MeV and decaying into...
We show how to fulfill the low energy theorem of current algebra relating the form factors associated with the neutral pion decay in two photons and the anomalous virtual photon decay in three pions. This has been a long standing puzzle in a class of chiral models involving the mixing of pion and axial-vector mesons. The key to the solution is a gauge covariant formulation of the mixing and...
The excess in the diphoton spectrum near the invariant mass Mγγ = 750 GeV at LHC late in 2016 generated considerable interest in the scientific community. One of the models that tried to explain this anomaly was a new scalar that can be produced at LHC via gluon fusion, and decays into two photons much like the Standard Model(SM) Higgs boson.
Hereby, my research work consisted of analyzing...
We compare thermodynamic and kinetic approaches, that have been recently
used to study relations between the spin polarization and fluid
vorticity in systems consisting of spin-one-half particles. The
thermodynamic approach refers to general properties of global thermal
equilibrium with a rigid-like rotation and demonstrates that the
spin-polarization and thermal-vorticity tensors...
We show how to fulfill the low energy theorem of current algebra relating the form factors associated with the neutral pion decay in two photons and the anomalous virtual photon decay in three pions. This has been a long standing puzzle in a class of chiral models involving the mixing of pion and axial-vector mesons. The key to the solution is a gauge covariant formulation of the mixing and...
