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Michal Praszalowicz

Publications and source records attributed to Michal Praszalowicz.

At least 19 recordsLinked to original sources
arXiv2026

Geometric Scaling and the Odderon

Based on geometric scaling of elastic $pp$ and possibly $p\bar{p}$ cross-sections, we derive simple formulae for the complex crossing-even and crossing-odd scattering amplitudes in terms of two interaction radii: $R(s)$ and $Q(s)$, respectively. Employing the COMPETE parametrization of the total cross-sections, we reproduce $ρ^{pp}$ and $ρ^{p\bar{p}}$ parameters with high accuracy, however we miss the 13~TeV TOTEM and ATLAS points. We show that a slight modification of the $p\bar{p}$ total cross-section corresponding to the Odderon, allows to accommodate $ρ^{pp}$ 13~TeV data.

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arXiv2025

Beautiful Exotica

The Chiral Quark--Soliton Model applied to baryons with one heavy quark predicts new exotic states belonging to three $\overline{\boldsymbol{15}}$ SU(3) multiplets. Here, we extend previous analysis of charm exotica to the case of beauty. All model parameters are fixed from the charm sector and from the nonexotic $b$--baryons. We present predictions for masses of beautiful exotica and discuss the decay widths, which are either very small or relatively large.

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arXiv2024

Odyssey of the elusive $Θ^+$

$Θ^+$ is a putative light pentaquark state of positive parity with minimal quark content $(uudd\bar{s})$. It naturally emerges in chiral models for baryons, but experimental evidence is uncertain. We review the theoretical foundations of chiral models and their phenomenological applications to exotic states. In particular, we discuss in detail the pentaquark widths with special emphasis on the cancellations occurring in the decay operator. We also discuss some experiments, mainly those whose positive evidence of ${\mitΘ}^+$ persists to this day. This review is dedicated to Dmitry Diakonov, Victor Petrov, and Maxim Polyakov and their contribution to the ${\mitΘ}^+$ story.

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arXiv2024

Scaling properties of elastic pp cross-section

We show that the elastic differential $pp$ cross-section has a unique universal property that the ratio of bump-to-dip position is constant from the energies of the ISR to the LHC. We explore this property to compare Geometric Scaling present at the ISR with the recently proposed scaling law at the LHC. We argue that at the LHC, within present experimental uncertainties, there is fact a family of scaling laws.

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arXiv2024

Scaling laws of elastic proton-proton scattering differential cross sections

We show that elastic scattering $pp \to pp $ differential cross sections as function of the four-momentum transfer square $|t|$ have a universal property, such that the ratio of bump-to-dip positions is constant from the energies of the ISR to the LHC, from tens of GeV and up to the TeV scale. We explore this property to compare the geometrical scaling observed at the ISR with the recently proposed scaling law at the LHC. We argue that, at the LHC, within present experimental uncertainties, there is in fact a family of scaling laws. We discuss the constraints that the scaling laws impose on the parametrization of the elastic $pp\to pp$ scattering amplitude.

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arXiv2024

Twenty years of $Θ^+$

Twenty years ago, in 2003, two experimental groups, LEPS and DIANA, announced the discovery of a light, narrow, exotic baryon with mass within the range of 1540 MeV, which was later dubbed as $Θ^+$. In this talk we recall the history of this discovery and its theoretical foundations. We also discuss possible future experiments that could determine the existence of $Θ^+$.

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arXiv2024

Heavy Quarkonia, Heavy-Light Tetraquarks and the Chiral Quark-Soliton Model

We apply the Chiral Quark-Soliton Model used previously to describe baryons with one heavy quark to the case of heavy tetraquarks. We argue, that the model is insenstive to the nature of the heavy object bound by the soliton, i.e. to its mass and spin. Therefore, a heavy quark can be replaced by an anti-diquark without modifying the soliton background. Diquark dynamics is taken into account by means of the nonrelarivistic Schrödinger equation with the Cornell potential. We fix the Cornell potential parameters from the charmonia and bottomia spectra. We first compute $B_c$ meson masses to check our fitting procedure, and then compute diquark masses by appropriately rescaling color factors in the Cornell potential. We ten compute tetraquark masses and confirm previous findings that only $bb$ tetraquarks are bound.

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arXiv2022

Doubly Heavy Tetraquarks in the Chiral Quark Soliton Model

Chiral Quark Soliton Model has been successfully applied to describe heavy baryon spectrum, both for charm and bottom, leading to the conclusion that the heavy quark has no effect on the soliton. This suggests that replacing a heavy quark by a heavy anti-diquark $\bar{Q}\bar{Q}$ in color triplet should give a viable description of heavy tetraquarks. We follow this strategy to compute tetraquark masses. To estimate heavy diquark masses we use Cornell potential with appropriately rescaled parameters. The lightest charm tetraquark is 70 MeV above the $DD^*$ threshold. On the contrary, both non-strange and strange bottom tetraquarks are bound by approximately 140 MeV and 60 MeV, respectively.

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arXiv2022

Trace anomaly as signature of conformality in neutron stars

We discuss an interpretation that a peak in the sound velocity in neutron star matter, as suggested by the observational data, signifies strongly-coupled conformal matter. The normalized trace anomaly is a dimensionless measure of conformality leading to the derivative and the non-derivative contributions to the sound velocity. We find that the peak in the sound velocity is attributed to the derivative contribution from the trace anomaly that steeply approaches the conformal limit. Smooth continuity to the behavior of high-density QCD implies that the matter part of the trace anomaly may be positive definite. We discuss a possible implication of the positivity condition of the trace anomaly on the $M$-$R$ relation of the neutron stars.

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arXiv2022

Landscape of heavy baryons from the perspective of the chiral quark-soliton model

We employ the chiral quark-soliton model and the heavy quark symmetry to describe spectra of charm and beauty baryons. Heavy baryons can be classified according to the SU(3) representations of the light sector. We argue that recently discovered $Ξ_b$ states can be interpreted as negative parity excited anti-triplets or sextets, and the $Σ_b$ states as negative parity sextets. Consequences of such assignments for the decay patterns are discussed and also predictions of masses of the yet unmeasured sextet members are given.

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arXiv2022

Geometrical Scaling of Direct Photons in Relativistic Heavy Ion and d+Au Collisions

In this paper, we show that multiplicity spectra of direct photons in A+A and d+Au collisions at different centrality classes and different energies exhibit geometrical scaling, {\em i.e.}, they depend on a specific combination of number of participants $N_{\rm part}$, collisions energy $W$, and transverse momentum $p_{T}$ -- called saturation scale -- rather than on all these three variables separately. In particular, the dependence on the geometry of collisions encoded in the dependence on $N_{\rm part}$ is in agreement with the expectations based on the Color Glass Condensate theory.

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arXiv2020

Scaling properties of direct photon yields in heavy ion collisions

A recent analysis from the PHENIX collaboration of available direct photon measurement results in collisions of various systems such as Au+Au, Cu+Cu, and Pb+Pb, at different beam energies ranging from 39 to 2760 GeV, has shown a universal, within experimental uncertainties, $multiplicity$ scaling, in which direct photon $p_{T}$-spectra for transverse momenta up to 2 GeV/$c$ are scaled with charged hadron pseudorapidity density at midrapidity raised to power $α=1.25$. On the other hand, those direct photon $p_{T}$-spectra also exhibit $geometrical$ scaling in the similar $p_{T}$ range. Assuming power-law dependence of the scaled photon spectra for both scaling laws, we formulate two independent conditions for the power $α$, which overshoot experimental data by $\sim 10\%$ on average. We discuss possible sources that might improve this estimate.

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arXiv2019

Doubly heavy $QQ$ tetraquarks

With the discovery of a doubly charmed $Ξ_{cc}$ baryon a somewhat forgotten issue of tetraquarks containing two heavy and two light (anti) quarks, ${\cal T}_{QQ}$, triggered theorist's interest. We discuss quark model estimates of ${\cal T}_{QQ}$ masses and such objects including a model where the light sector is treated as a soliton. We show that this model has different large $N_c$ limit than other approaches.

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arXiv2018

Geometrical scaling of prompt photons in heavy ion collisions

We discuss geometrical scaling (GS) for the prompt (direct) photons produced in heavy ion collisions. To this end we first introduce the concept of GS and illustrate its emergence on the example of charged particles. Next, we analyse direct photon data from RHIC and from the LHC. We show that the data support the hypothesis of GS in terms of participant number related to different centrality classes. We also study GS at different energies, however a more detailed study will be possible only when data for at least three different energies from one experiment will be available and also when we use the data obtained from the collisions of large systems (Cu+Cu, Au+Au, Pb+Pb) and small systems (p+p, d+Au, p+Au).

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arXiv2018

Heavy baryons in the chiral quark-soliton model: a possibility for exotica?

We discuss possible interpretation of five excited $Ω^0_c$ states within the Chrial Quark Soliton Model. We show that it is not possible to interpret all five $Ω^0_c$'s as parity minus excitations and argue that two narrowest states are pentaquarks belonging to the SU(3) representation $\overline{15}$.

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arXiv2018

Heavy baryon decay widths in the large $N_c$ limit in chiral theory

We propose large $N_c$ generalizations for the "diquark" representations of SU(3)$_{\rm flav}$ relevant for positive parity heavy baryons, including putative exotic states. Next, within the framework of the Chiral Quark Soliton Model, we calculate heavy baryon masses and decay widths. We show that in the limit of $N_c \rightarrow \infty$ {\em all} decay widths vanish, including the widths of exotica. This result is in fact more general than the model itself, as it relies only on the underlying symmetries: i.e. SU(3)$_{\rm flav}$ and hedgehog symmetry. Furthermore, using explicit model formulae for the decay constants in the non-realtivistic limit, we show that there is a hierarchy of the decay couplings, which may explain observed pattern of experimental widths.

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arXiv2018

On a possibility of exotic heavy baryons

Triggered by a recent announcement by the LHCb Collaboration of five excited $Ω^0_c$ resonances of small widths we propose an interpretation based on the Chiral Quark Soliton Model. We argue that three of the LHCb resonances are parity ($-$) excitations of the ground state SU(3) sextets, while the other two with the smallest widths are exotic pentaquarks that belong to the SU(3) $\overline{\mathbf{15}}$. We first briefly review the model and discuss the status of the putative $Θ^+(1540)$. Next we show how to generalize the model to the case of heavy baryons. We test this approach against the ground state $\overline{\mathbf{3}}$ and ${\mathbf{6}}$ heavy baryons, and discuss different excitations that are possible in the Chiral Quark Soliton Model. We show that the model accommodates two excited $\overline{\mathbf{3}}$ in the charm sector that are experimentally observed. Finally we discuss possible assignments of the LHCb $Ω^0_c$ states.

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