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Search for the Higgs boson decay to charm quarks at the CMS experiment
Get PDFSearches for the decay of the Higgs boson in a pair of charm quarks (H → cc¯) were carried out by the CMS and ATLAS experiments with data collected during the Run-2 of the LHC in proton-proton collisions. The most stringent upper
limit on the signal strength was set by the CMS Collaboration in the VH production mode, with the Higgs boson produced in association with a leptonically decaying
vector boson (W or Z). The observed upper limit on σ(V H)B(H → cc¯) is 14 times the standard model prediction. During Run-3, tighter constraints could be established by extending the search to other production mechanisms of the Higgs boson, like the vector boson fusion. The search for H → cc¯ performed by CMS with Run-2 data is described in this work
The Electron-Ion Collider and the ePIC experiment
Get PDFThe Electron-Ion Collider (EIC) will be the only new high-energy collider worldwide in the next twenty–thirty years. Electrons and ions, from p up to U, will collide at high luminosity to explore hadronic physics, making the
ultimate understanding of QCD possible. Electron and light nucleus beams will be polarized to address fundamental questions as the origin of the nucleon spin. Other key questions addressed by the project are the origin of the hadron masses and the exploration of high-density gluonic matter. The approved project is successfully progressing at Brookhaven National Laboratory (BNL) in the USA. The project
includes the ePIC experiment designed to cover the whole physics case at EIC. The main characteristics of the EIC project and of its accelerator as well as of the design of the ePIC experiment are discussed
Search for light exotics in coupled channel PWA with PAWIAN
Get PDFThe light meson regime still is not too well understood and holds many open questions that can only be answered using sophisticated analysis strategies to describe the data. In particular, searching and investigating exotic states,
e.g., glueballs, hybrids and tetraquarks is a challenge among the many broad and overlapping resonances. Combining data of different production mechanisms in coupled channel partial wave analyses, as, e.g., gluon-poor two-photon fusion events and gluon-rich reactions, helps to disentangle the highly populated light meson spectrum. To do so, sophisticated dynamical models need to be applied respecting unitarity and analyticity. Such models are, among others, implemented in the here used par�tial wave analysis package PAWIAN. Applied methods together with new results on
coupled channel analyses are discussed
Recent results from LEPS2/BGOegg on light baryon spectroscopy
Get PDFLight baryon spectroscopy is conducted by BGOegg experiment in SPring-8 LEPS2 beamline, which uniquely provides a highly linear-polarized photon beam up to 2.4 GeV. Differential cross-sections, photon beam asymmetries, and spin density matrix elements are measured for photoproduction of the π0, η, ω, or η meson. New results contain the first precise data of differential cross-sections at extremely backward meson angles and polarization observables at Eγ > 1.9 GeV
Measurement of the photoproduction cross-section for γp→ϕπ+π−p and search for the Y(2175) at GlueX
Get PDFThe Y (2175), recently renamed to φ(2170), is one of the rare exotic candidates connected to strangeonium instead of the heavier charmonium-like and bottomoniumlike exotic states. Originally observed in initial-state radiation by the BaBar experiment in 2006, it could be a strange partner of the famous charmonium-like exotic vector state Y (4230). Various interpretations exist in the literature, such as conventional strangeonium, tetraquark or hybrid state. Meanwhile, it has been seen in different experiments and decay channels. The available experimental information obtained only from e+e− collider experiments is, however, not sufficient to confirm or disprove any of the proposed interpretations. Information about the production of this state in other processes is required. In this paper, we report on our measurement of the production cross-section of the reaction γ +p → φπ+π− +p and the search performed for Y (2175) → φπ+π− with the GlueX experiment
CMS results on the hadron production fractions ratios
Get PDFThe recent CMS measurement of the dependence of the hadron
production fraction ratios fs/fu and fd/fu on B meson kinematic variables, in proton-proton collisions at √s = 13 TeV, is reported and the significant scope of this result is discussed
Electroweak structure of the nucleon
Get PDFThe nucleon form factors (FFs) are studied in relativistic chiral perturbation theory (ChPT) in two flavors with explicit Δ(1232) degrees of freedom. For the electromagnetic isovector form factors we also employ dispersion theory to
account for ρ-dominated isovector ππ interaction and its quark-mass dependence in the t-channel nonperturbatively and beyond NLO in ChPT. With this framework we explore how LQCD data are described in both the Q2 and Mπ dimensions simultaneously. Furthermore, we have performed an NNLO calculation of the nucleon axial form factor, extracting relevant low-energy constants (LECs) from a combined
set of recent LQCD results from different collaborations
Let the instruments speak: Learning physics at the museum
Get PDFThe Physics Museum of the University of Naples is one of the most important physics museums in Italy. With an exhibition of around 900 instruments closely related to the history of the region, the museum is strongly committed to promoting scientific culture. This article describes the numerous activities that the museum offers to all citizens, with a focus on initiatives for school groups
Study of the impact of unitarity bounds on analysis of Vector Boson Scattering with same-sign W processes at LHC
Get PDFEffective Field Theories (EFT) are a powerful tool for exploring the effect of physics Beyond Standard Model (BSM) in a model independent approach. However, the introduction of EFT contributions could lead to an unphysical growth of scattering amplitudes and a violation of unitarity in the high-energy region. To validate the EFT approach, it is necessary to implement unitarity constraints. We present a preliminary study of the impact of unitarity bounds on experimental sensitivity to Vector Boson Scattering processes in proton-proton collisions at LHC, considering dimension-six EFT operators. The analysis is performed at the generator level on Monte Carlo samples at √s = 13TeV and integrated luminosity of 100 fb−1
Modelling of early-stage kilonova ejecta opacity reproducible in laboratory plasmas
Get PDFIn the framework of the multi-messenger astronomy, for a com
plete understanding of the heavy elements nucleosynthesis, investigation of the kilonova (KN) emission is crucial. The KN is a thermal transient signal following gravitational-wave events from the coalescence of compact objects. Modelling the KN light-curve is challenging: besides the difficulties in modelling the r-process synthesised elements, it requires several inputs, among which plasma ejecta opacity is still extremely uncertain. In this context, the PANDORA project aims at measuring, for the first time, opacities of a plasma resembling the plasma ejecta through which KN diffuses. In view of that, we present numerical estimates of argon plasma opacity
perturbed by an external radiation flux under non local thermodynamic equilibrium. Simulations performed serve as demonstrator for further metallic elements, and their
results underline that both thermodynamic parameters and radiation could impact on the opacity of the plasma