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Dai, L. R., & Oset, E. (2020). Helicity amplitudes in the (B)over-bar -> D*(nu)over-bar(tau)tau decay with V-A breaking in the quark sector. Eur. Phys. J. A, 56(5), 154–8pp.
Abstract: In view of the recent measurement of the F-D*(L) magnitude in the (B) over bar -> D*(nu) over bar (tau)tau reaction we evaluate this magnitude within the standard model and for a family of models with the gamma(mu) – alpha gamma(mu)gamma(5) current structure for the quarks for different values of a. At the same time we evaluate also the transverse contributions, M = -1, M = +1, and find that the difference between the M = -1 and M = +1 contributions is far more sensitive to changes in a than the longitudinal component. These findings should be looked as an incentive to measure the transverse helicities which are bound to be a far more sensitive magnitude to possible new physics than F-D*(L).
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Barucca, G. et al, & Diaz, J. (2021). The potential of Lambda and Xi(-) studies with PANDA at FAIR. Eur. Phys. J. A, 57(4), 154–26pp.
Abstract: The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss groundstate hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: (p) over barp -> (Lambda) over bar Lambda and (p) over barp -> (Xi) over bar+Xi(-). The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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Thisse, D. et al, Algora, A., & Guadilla, V. (2023). Study of N=50 gap evolution around Z=32: new structure information for Ge-82. Eur. Phys. J. A, 59(7), 153–13pp.
Abstract: Medium spin states of light N = 50 isotones have been populated using fast neutron-induced fission of Th-232. Online prompt gamma spectroscopy has been performed using the hybrid gamma spectrometer nu-Ball coupled to the LICORNE directional neutron source at the ALTO facility of IJCLab. Medium spin states of the neutron-rich nucleus Ge-82 have been investigated using gamma-gamma and gamma-gamma-gamma coincidence data to exploit the resolving power of nu-Ball. Two new transitions were assigned to this nucleus and a new level was placed in the level scheme. We tentatively assigned to this new state a (7(+)) spin-parity, which is interpreted as a new N = 50 core breaking state. This provides further insight into the energy evolution of the N = 50 shell gap toward Ni-78.
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Clement, E., Bracco, A., Gadea, A., & Simpson, J. (2023). Organisation of the AGATA collaboration and physics campaigns. Eur. Phys. J. A, 59(7), 152–5pp.
Abstract: The AGATA spectrometer has a well-established organisational and management structure for its construction and operation. The roles and responsibilities of each of the management committees and their interaction, as well as the scientific organisation is described in this contribution. The organisation of the present campaign, which aims to realise the 4p spectrometer, is presented. General comments on the previous physics campaigns at LNL (2010-2011), GSI (2012-2014) and GANIL (2015-2021) are made.
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Rinaldi, M., & Vento, V. (2018). Scalar and tensor glueballs as gravitons. Eur. Phys. J. A, 54(9), 151–7pp.
Abstract: The bottom-up approach of the AdS/CFT correspondence leads to the study of field equations in an AdS(5) background and from their solutions to the determination of the hadronic mass spectrum. We extend the study to the equations of AdS(5) gravitons and determine from them the glueball spectrum. We propose an original presentation of the results which facilitates the comparison of the various models with the spectrum obtained by lattice QCD. This comparison allows to draw some phenomenological conclusions.
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