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The NA61/SHINE experimental physics program focuses on searching for the critical point and studying the properties of the onset of deconfinement in the strongly interacting matter. A two-dimensional scan is performed by varying the beam momentum (from 13\(A\) to 150/158\(A\) GeV/\(c\)) and the system size (from \(p+p\) to Pb\(+\)Pb) of the collided nuclei. This contribution presents the most recent results from the NA61/SHINE strong interactions program and includes future data-taking and analysis plans.

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The CMS Zero Degree Calorimeters (ZDCs) are used to measure very forward and backward neutrons and photons from heavy-ion (and possibly \(pp\)) collisions at the LHC. Their purpose is to characterize the geometry of heavy-ion, photon–nucleus, and photon–photon collisions. The ZDCs are built from layers of tungsten and quartz fiber, and detect Cerenkov light produced by the showers of particles generated from incoming neutrons and photons. They will serve as a basic minimum bias trigger for 2022 PbPb run. To operate the ZDCs efficiently, it is vital to have a comprehensive monitoring system. This paper will present design considerations and results of prototype testing of the new ZDC monitoring system. This system operates within the framework of the CMS Online Monitoring System (OMS). A dedicated workspace for the ZDC allows for the organizing of monitored metrics in folders and pages. The most important metrics are energy distributions, the shower shape profile, and the single neutron peak. At a lower level charge and time distributions for individual channels are available. CMS OMS supports correlation of multiple data sources which allows for monitoring of rate per layer of ZDC average flux versus luminosity. Different pages give access to the current status of the detector as well as access to historical data.

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We discuss the confinement potential of the Cornell type arising within the framework of the generalized Soft Wall holographic model to QCD. The generalized model includes a parameter controlling the intercept of the linear Regge spectrum. Our analysis shows that the Cornell potential obtained in the scalar channel leads to a quantitative consistency with the phenomenology and lattice simulations, while the agreement in the vector channel is only qualitative.

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It is clear that the leading order perturbative QCD prediction is incompatible with the electromagnetic pion form factor at the energies which have so far been probed experimentally. As such, it is necessary to consider non-perturbative effects in its treatment. In this contribution, we consider various non-perturbative effects, in particular the Reggeization of the quark, and consider how their implementation affects the high-energy behavior of the pion form factor.

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Photoproduction is well-known as an excellent technique for studying nucleon resonances, particularly exotic meson states. Our focus centers on the \(\gamma p \rightarrow \pi ^+ \pi ^- p\) reaction with the aim of investigating the interference of meson resonance generation and meson–baryon rescattering effects. The Deck model is employed to characterize the basic aspects of diffractive \(\pi ^+\pi ^-\) photoproduction, assuming that virtual pion (denoted as \(\pi ^*\)) exchange is dominant. In an effort to describe the most recent data obtained from the CLAS12 and GlueX investigations and to validate the theoretical model, the moments of angular distributions and the projected mass distribution of \(P\)-wave are computed in the helicity frame, which is the rest frame of the \(\pi \pi \) system with its direction opposite to the \(z\)-axis.

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In this contribution, we illustrate the applicability of a new parameterization of the S-wave amplitude on the example of the \(\pi \pi \to \pi \pi \) and \(\pi K \to \pi K \) lattice data (\(m_\pi \sim 240\) MeV) from the HadSpec Collaboration. The applied parameterization follows from the dispersive representation for the inverse scattering amplitude. The left-hand cut contribution is parametrized by the series in a suitably constructed conformal variable. The crucial input in the analysis is the Adler zero, whose position we extracted from the chiral perturbation theory at next-to-leading order with the uncertainties propagated from the low-energy constants.

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We consider a simple set of equations that govern the expansion of boost-invariant plasmas of massless particles. These equations describe the transition from a collisionless regime at early time to hydrodynamics at late time. Their mathematical structure encompasses all versions of second-order hydrodynamics. We emphasize that the apparent success of the Israel–Stewart hydrodynamics at early time has little to do with “hydrodynamics” proper, but rather with a particular feature of the Israel–Stewart equations that allows them to effectively mimic the collisionless regime.

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The existence of genuine complex conjugated poles in the gluon propagator is discussed and related to confinement, string tension, and condensates. The existence of the anomalous poles leads to an untrivial analytic continuation from Euclidean to Minkowski space, where the pole part of the propagator is related to the spectrum of excited quasi-gluons.

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We review applications of the Chiral Quark-Soliton Model to heavy baryons and to doubly-heavy tetraquarks.

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The excellent performance of the LHCb experiment has opened the road to precise hadron spectroscopy studies. A rich variety of new resonances has already been discovered for the last years. The very recent LHCb results on pentaquarks and tetraquarks are presented here.

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The LHCb Collaboration pursues a full physics program studying dense QCD with both beam–beam and fixed-target collisions. In this contribution, we present the recent LHCb results including quarkonia production in peripheral and ultra-peripheral heavy-ion (HI) collisions, antiproton, and charm production in fixed-target collisions.

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In these proceedings, we briefly show an alternative formalism to perform a stability analysis of inhomogeneous phases in QCD. We discuss how it is more general than the “classic” framework and some peculiarities with respect to its application to QCD-like theories.

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The Higgs decay \(H \rightarrow gg(g)\) using an effective Higgs–Yang–Mills interaction as well as usual QCD interactions is revisited in the context of Implicit Regularization (IReg) and compared with conventional dimensional regularization (CDR), four dimensional helicity (FDH), and dimensional reduction (DRED) schemes, showing that no evanescent fields such as \(\epsilon \)‑scalars need to be introduced. Unambiguous identification and separation of UV from IR divergences is achieved and UV singularities are removed as usual by renormalization. The IR divergences are cancelled due to the method’s compliance with the Kinoshita–Lee–Nauenberg (KLN) theorem.

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The NA48/2 and NA62 experiments at CERN were designed to measure kaon decays from a high-intensity fixed-target setup that took data between 2003–04 and 2016–18, respectively. The first observation of the \(K^\pm \to \pi ^0\pi ^0\mu ^\pm \nu \) decay based on the 2003–04 data sample is reported. Several preliminary results using the 2016–18 data set are presented. The result from the \(K^+\to \pi ^+\nu \bar {\nu }\) analysis of the 2018 data sample is presented, as well as the combination with the previous 2016 and 2017 results. An analysis of the \(K^+\to \pi ^0e^+\nu \gamma \) decay is presented, improving the previous measurement of the relative branching ratio with respect to the \(K^+\to \pi ^0e^+\nu \) decay and the T-asymmetry in three kinematic regions. An updated measurement of the \(K^+\to \pi ^+\mu ^+\mu ^-\) form-factor is presented. The Chiral Perturbation Theory parameter \(\hat {c}\) is measured using the \(K^+\to \pi ^+\gamma \gamma \) decay.

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We present new results on charge-parity (CP) violation in charm decay. We show that final-state interactions (FSI) within a CPT-invariant two-channel framework can explain the current experimental value for the CP violation difference between \(D^0\to \pi ^-\pi ^+\) and \(D^0\to K^-K^+\) decays. Our result relies upon: (i) the dominant tree-level diagram, (ii) the well-known experimental values for the \(D^ 0\to \pi ^-\pi ^+\) and \(D^ 0\to K^-K^+\) branching ratios, and (iii) the \(\pi \pi \to \pi \pi \) and \(\pi \pi \to K K \) scattering data to extract the strong phase difference and inelasticity. Based on well-grounded theoretical properties, we find the sign and bulk value of the \(\Delta A_\mathrm {CP}\) and \(A_\mathrm {CP}(D^0 \to \pi ^-\pi ^+)\) recently observed by the LHCb Collaboration.

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In recent years, there has been a concerted effort to formalize the many similarities between jet evolution, which models high-energy particle production experiments, and CGC evolution, which models high-energy scattering experiments. In this paper, the spatial correspondence of kernels and measures in both evolution equations and the spacetime correspondence of Wilson line geometries have been discussed in terms of conformal transformations.

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Results on small collision systems are still under study to characterize whether a strongly interacting perfect fluid is formed or not. In this work, we present an estimate of the initial-state energy density on small collision systems. Results consider effects of initial state fluctuations on geometry and finite volume in the clustering of color sources framework. The results are compared with Lattice QCD calculations. This work presents a perspective of how high-energy densities can be reached in such small collision systems at the LHC energies. The results give a collective description of the system.

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The main predictions of the so-called Graviton Soft-Wall Model (GSW) are presented. The calculations of hadronic (scalar, vector, pseudoscalar, and axial mesons) and glueball spectra will be discussed together with the mixing conditions. Moreover, a detailed analysis of quantities related to the pion has been also shown. The main outcome of these investigations is that the GSW model is capable to describe very different features of different hadrons and glueballs with only few parameters, thus unveiling his impressive predicting power.

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The Belle experiment has given a substantial contribution into the field of heavy quarkonia. Several new states were announced by Belle for the first time, in both the charmonium and bottomonium spectrum, or the confirmation from Belle corroborated former observations. Belle II is a next-generation experiment, which aims further at continuing expanding the Belle physics program. In this document, we report on the current status of the experiment and early physics results. Particular attention is devoted to the results of the analyses of the data sets collected during the energy scan (Nov. 2021).

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The bottomonium spectrum is the perfect testing ground for the confining potential and unitarisation effects. The bottom quark is about three times heavier than the charm quark, so that \(b\bar {b}\) systems probe primarily the short-range part of that potential. Also, the much smaller colour-hyperfine interaction in the \(B\) mesons makes the \(B\bar {B}\) threshold lie significantly higher than the \(D\bar {D}\) threshold in charmonium, on a relative scale of course. A further complicating circumstance is that none of the experimentally observed vector \(b\bar {b}\) mesons has been positively identified as a \(^{3\!}D_1\) state, contrary to the situation in charmonium. This makes definite conclusions about level splittings very problematic. Finally, there are compelling indications that the \({\mit \Upsilon }(10580)\) is not the \({\mit \Upsilon }(4S)\) state, as is generally assumed. Here, we review an analysis of experimental bottomonium data which show indications of the two lowest and so far unlisted \(^{3\!}D_1\) states below the \(B\bar {B}\) threshold. Next, an empirical modelling of vector \(b\bar {b}\) resonances above the open-bottom threshold is revisited, based on the Resonance-Spectrum-Expansion production formalism applied to other experimental data. A recent effective-Lagrangian study supporting our non-resonant assignment of the \({\mit \Upsilon }(10580)\) is briefly discussed as well.

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In this proceedings contribution I review recent work which computes the suppression of bottomonium production in heavy-ion collisions using open quantum systems methods applied within the potential non-relativ-istic quantum chromodynamics (pNRQCD) effective field theory. I discuss how the computation of bottomonium suppression can be reduced to solving a Gorini–Kossakowski–Sudarshan–Lindblad (GKSL) quantum master equation for the evolution of the \(b\bar {b}\) reduced density matrix. The used open quantum systems approach allows one to take into account the non-equilibrium dynamics and decoherence of bottomonium in the quark–gluon plasma. Finally, I present comparisons of phenomenological predictions obtained using a recently obtained next-to-leading-order GKSL equation with ALICE, ATLAS, and CMS experimental data for bottomonium suppression and elliptic flow.

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In the Coulomb-gauge QCD, there exists an instantaneous chromo-electric interaction between static quark–antiquark pairs. The confining nature of this ‘Coulomb potential’ was hypothesized as the main contributor to the large-distance behavior of the Wilson loop in the non-gauge fixed QCD. We examine the existing definitions of this interaction in the SU\((2)\) and SU\((3)\) Yang–Mills theory on anisotropic lattices by performing the Hamiltonian limit. We find an artificial enhancement of the corresponding string tension and suggest a corrected definition of the potential.

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We investigate a representation of static quark operators based on trial states formed by eigenvector components of the covariant lattice Laplace operator. We present an improved method for computing the static quark–anti-quark potential, we visualize optimal quark–anti-quark creation operators, and show first results of the method applied to hybrid mesons as well as static-light systems.