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Recent charmed baryon results from BESIII
Get PDFBESIII has collected 4.5 fb−1 of e+e− collision data between 4.6 and 4.7 GeV. This unique data offers ideal opportunities to study Λ+c decays. In this article, we report the partial wave analysis of Λ+c → Λπ+π0 and the first observation of the singly Cabibbo-suppressed decay Λ+c → nπ+. In addition, we report the measurement in Λ+c → Λe+νe, the observation of Λ+
c → pK−e+νe, and improved measurement of Λ+c → Xe+νe
PANDA perspectives in exotics ---Performances in line shape measurements
Get PDFThe new Facility for Antiproton and Ion Research (FAIR) is under construction at GSI in Darmstadt (Germany). Antiprotons are planned to be provided by the High Energy Storage Ring, where the PANDA experiment will directly be located. It represents the central part of the hadron physics programme. The field of hadron spectroscopy has gained new momentum by the discovery of the so-called charmonium-like and bottomonium-like exotic states over the past two decades. The nature of many of the so-called exotic XY Z states in the charmonium region are, however, not yet understood. Precise measurements of hadron masses and widths are mandatory to sort out different theoretical models and clarify the nature of these unexpected states. One example is the χc1(3872), formerly known as X(3872) —although being the first of the new charmonium-like states discovered
since 2003, the nature of this state is still not clarified. In pp¯ annihilation, such XY Z states can be produced in direct formation, allowing for a precise resonance energy
scan. Using the example of the X(3872), we quantified the expected sensitivity of energy scans of narrow resonances and how well we can distinguish between models that turn out to be indistinguishable from the LHCb data
Sill distribution: Genesis and salient features
Get PDFWe present the so-called Sill distribution, both in the nonrelativistic and relativistic cases, as a natural and simple way to include the effect of threshold(s) on the energy line shapes of resonances. The Sill is correctly normalized (even for broad states), is continuous at threshold(s), does not require any modification to the
“mass part”, is easily extendable to the multichannel case, and can be applied to both mesons and baryons. Here, as a novel example, we employ the Sill to describe the resonance ψ(3770)
Modeling spin effects in electron-positron annihilation to hadrons
Get PDFThe string+3P0 model of spin-dependent hadronization is applied to the fragmentation of a string stretched between a quark and an antiquark with entangled spin states, assumed to be produced in the e+e− annihilation process. The model accounts systematically for the spin correlations in the hadronization chain and is formulated as a recursive recipe suitable for the implementation in a Monte Carlo event generator. The recipe is applied to the production of two back-to-back pseudoscalar mesons produced in e+e− annihilation, and it is shown to reproduce the form of the azimuthal distribution of the hadrons as expected from QCD
Thermal hadron resonances and Ward Identities: Results for the QCD phase diagram
Get PDFWe review recent work regarding the role of light scalar resonances at finite temperature for chiral symmetry and U(1)A restoration. The results obtained are based on unitarized Chiral Perturbation Theory and Ward Identities and are directly connected with presently open problems within the QCD phase diagram
Ξ -hypernuclear spectroscopy with the S-2S spectrometer
Get PDFPower supplies for the J-PARC Main Ring (MR) synchrotron were renewed in 2022. The repetition rate for the fast extraction beam (FX; pulsed extraction mode) of a neutrino beam line will be shortened in order to achieve higher beam power better than 740 kW. In the J-PARC hadron experimental hall, we have a slow extraction mode (SX), and hope to reach more than 80 kW (51 kW at this moment). At the same time, better time structure of the slow extraction (SX; high duty mode) are expected owing to the power supply improvements. A highintensity K− beam at 1.8 GeV/c to conduct the strangeness −2 physics programs will be soon available for spectroscopy of Ξ-hypernuclei with the (K−, K+) reaction,
and X-ray spectroscopy measurements from Ξ− atoms, etc. will be performed
The muon collider: A challenge for the future
Get PDFThe future of high-energy physics relies on the capability of exploring a broader energy range than current accelerators, with higher accuracy. A muon collider combines the great precision of electron-positron machines, with a
low level of beamstrahlung and synchrotron radiation, and the high center-of-mass energy and luminosity of hadron colliders. For these reasons, current studies aim at
designing a muon collider able to reach more than 10 TeV center-of-mass energies with luminosity higher than 1034 cm−2 s −1. These operational conditions open an
unprecedented physics program, which ranges from precision studies of the Higgs boson to Beyond Standard Model (BSM) searches. Among the technological challenges, the ability to produce collimated beams of unstable particles, the muons, for a period sufficiently long to allow high-luminosity collisions, together with the treatment of the Beam-Induced Background (BIB) are the most critical issues for the detector design. This contribution will present the status of the detector design and will discuss the expected reach of the most representative physics processes
Previsione, prevenzione e contrasto delle crisi idriche: il valore aggiunto della conoscenza tecnico-scientifica nelle attività di protezione civile
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Siccità ed ecosistemi
Get PDFStefani, F., Quadroni, S., Boggero, A., Di Lorenzo, T., Balestrini, R., Morganti, M., Vergine, P.,
Mammola, S., Ciampittiello, M., Buffagni, A., Barra Caracciolo, A., Fontaneto, D. 2024. “Sic
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cità ed ecosistemi”, in Siccità, scarsità e crisi idriche, Emanuele Romano, Ivan Portoghese
(a cura di), Habitat signa 1, 475-510. Roma: Cnr Edizioni. https://doi.org/10.69115/habitatsigna-2024-1/1