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Mass spectra of Ξ and Ω baryons using hypercentral constituent quark model
Get PDFHadron spectroscopy is an important tool towards the study of
internal quark dynamics in a composite system. The present article focuses on the study of resonance spectra of strange baryons with S = −2, −3. The non-relativistic approach utilizes screened potential as hypercentral one to obtain masses. The spindependent part for all possible hyperfine states has been incorporate
Threshold-cusp explanation for X and Zcs in B+→J/ψϕK+
Get PDFSeveral X and Zcs exotic hadrons were claimed in the LHCb’s amplitude analysis on B+ → J/ψφK+. The data shows that all the peaks and also dips in the spectra are located at thresholds of seemingly relevant meson-meson channels. While the LHCb analysis fitted the peaks with Breit-Wigner resonances, threshold kinematical cusps might be the cause of such structures. We thus analyze the LHCb data considering the threshold cusps. Our model is simultaneously fitted to J/ψφ, J/ψK+, and K+φ invariant mass distributions. The threshold cusps fit well all the X, Zcs, and dip structures. Our analysis indicates that spin-parity of
the X(4274) and X(4500) structures are 0− and 1−, respectively. This is different from the LHCb’s spin-parity assignments (1+ and 0+). The number of fitting parameters can be significantly reduced by considering the relevant threshold cusps. Our analysis shows that D(∗) s D¯ ∗ scattering lengths are consistent with zero. This
disfavors an explanation of Zcs(4000) and Zcs(4220) as D(∗) s D¯ ∗ molecules, which is consistent with lattice QCD via the SU (3) relation
Renormalization in various schemes of nucleon-nucleon chiral EFT
Get PDFRenormalizability of an effective field theory allows one to perform a systematic expansion of the calculated observable quantities in terms of some small parameter in accordance with a certain power counting. We consider chiral effective
field theory in application to the nucleon-nucleon interaction at next-to-leading order in the chiral expansion as an example of the renormalizability of a theory with a nonperturbative leading-order interaction. The requirement of the renormalizability imposes nontrivial constraints on a choice of such interaction. Two different approaches are discussed: the finite- and the infinite-cutoff schemes. Another considered example is the quantum mechanical problem of the inverse-square potential, which is often regarded as a toy model for various physical systems
Spectral reconstruction of Euclidean correlator moments in lattice QCD
Get PDFA novel application of lattice QCD spectral reconstruction is presented, in which Euclidean correlation function data in a fixed time range are used to infer values outside the range, enabling a model-independent investigation of the
asymptotic large-time behavior. Moments of the correlator are also determined, and reconstructed correlation matrices between different moments are included in a variational optimization similar to the standard Generalized Eigenvalue Problem (GEVP). These ideas are illustrated using a single-nucleon correlation function determined on an Nf = 2 + 1 ensemble of gauge configurations at mπ = 200 MeV
Quarkonium spectral functions in a bulk viscous quark-gluon plasma
Get PDFWe study the interplay of non-equilibrium properties of a quarkgluon plasma (QGP) and heavy quarkonia. For this purpose, we compute the quarkonium spectral functions in a bulk viscous QGP. We take into account the bulk viscous nature of the medium by modifying the distribution functions of thermal quarks and gluons. This modification affects the dielectric permittivity,which is used to calculate the in-medium heavy quark potential. With this modified complex
potential, we calculate the quarkonium spectral functions and extract their physical properties. We discuss the impact of bulk viscosity on quarkonia properties such as decay widths and binding energies. We also estimate the relative production yield of ψ to J/ψ and discuss the bulk viscous effects on it
Recent measurements and prospects from analysis of fixed-target collisions at LHCb
Get PDFThe LHCb spectrometer has the unique capability to function as a fixed-target experiment by injecting gas into the LHC beampipe while proton or ion beams are circulating. The resulting beam-gas collisions cover an unexplored energy
range that is above previous fixed-target experiments, but below the RHIC or LHC collider energies. Here we present recent results on J/ψ and D0 production from pNe and PbNe fixed-target collisions at LHCb. Some preliminary results obtained during the commissioning of the upgraded system SMOG2 are also reported
Hyperon physics at BESIII
Get PDFWith the large datasets on e+e− annihilation at the J/ψ and ψ(3686) resonances collected at the BESIII experiment, multi-dimensional analyses making use of polarization and entanglement can shed new light on the production and decay
properties of hyperon–anti-hyperon pairs. In a series of recent studies performed at BESIII, significant transverse polarization of the (anti-)hyperons has been observed
in J/ψ or ψ(3686) to ΛΛ, Σ ¯ Σ and Ξ ¯ Ξ. The decay parameters for the most common ¯ hadronic weak decay modes were measured, and due to the non-zero polarization, the
parameters of hyperon and anti-hyperon decays could be determined independently of each other for the first time. Comparing the hyperon and anti-hyperon decay parameters yields precise tests of direct, ΔS = 1 CP violation that complement studies performed in the kaon sector
Experimental input to the hadronic corrections of the muon g−2
Get PDFThe hadronic contributions to the anomalous magnetic moment of the muon completely limit its Standard Model prediction. The recent advances in lattice QCD have shown tensions with the long established data-driven methods. A thorough assessment of the experimental inputs is necessary to identify potential improvements, which will allow to settle the situation in the future
Tecniche di modellazione 3D per una documentazione accurata delle incisioni rupestri: confronto tra Structure from Motion e stereofotometria
Get PDF3D modelling represents a fundamental survey technique to represent archaeological evidence. It is particularly important to draw and analyse engravings because it is more descriptive and, somehow, objective than traditional drawings, which result interpretative and not replicable, becoming a debatable and often controversial matter. A technique able to verify the overlaying of signs is essential to establish the relative sequence, thus the chronology of engravings. However, there are several techniques and they provide different results. The paper tries to empirically compare SfM and PS methods to understand how they work on surface representation and which are their specificities in a difficult context such as the Pianaura engravings. The aim of the paper is to verify the accuracy of the techniques. Three paths are pursued: the first analyses pure quantitative data, such as counting the number of points or faces built and so on; the second aims to verify quantitatively distortions by geometric measurements analysis; the third is a visual quality test, which focuses on users perception of 3D models. It can be concluded that the distinct fields of application and the diverse purposes of the research enhance the different specificities of the two techniques
L’Acqua e gli Etruschi Città, infrastrutture e approdi, tra acque interne e marittime. Atti del convegno 22-24 marzo 2024, Grotte di Castro
Get PDFIl volume raccoglie gli atti del secondo convegno tenutosi a Grotte di Castro (VT) nel marzo 2024, organizzato nell’ambito del progetto “Scenari nuovi per borgo e territori antichi. Una comunità̀ immagina il suo futuro” (2023-2025), finanziato con fondi del PNRR/MiC/Attrattività dei borghi storici, di cui il CNR-ISPC è partner.
Il volume raccoglie i contributi di specialisti del settore, i quali, attraverso la presentazione di casi studio dall’Etruria e dall’Italia preromana, pongono la loro attenzione sull'uso dell’acqua come elemento legato e funzionale al trasporto. Sono presentati alcuni tra i più noti esempi di sistemi di approdo etruschi marittimi, fluviali e lacustri e particolare attenzione è riservata alla relazione di tali sistemi con il territorio circostante e con la città cui facevano capo. Una sezione è dedicata alle attività laboratoriali “fuori Convegno”, di stampo maggiormente divulgativo e ludico, rivolte al pubblico