Traini, M., Rinaldi, M., Scopetta, S., & Vento, V. (2017). The effective cross section for double parton scattering within a holographic AdS/QCD approach. Phys. Lett. B, 768, 270–273.
Abstract: A first attempt to apply the AdS/QCD framework for a bottom-up approach to the evaluation of the effective cross section for double parton scattering in proton-proton collisions is presented. The main goal is the analytic evaluation of the dependence of the effective cross section on the longitudinal momenta of the involved partons, obtained within the holographic Soft-Wall model. If measured in high-energy processes at hadron colliders, this momentum dependence could open a new window on 2-parton correlations in a proton.
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Tonev, D. et al, & Gadea, A. (2021). Transition probabilities in P-31 and S-31: A test for isospin symmetry. Phys. Lett. B, 821, 136603–6pp.
Abstract: Excited states in the mirror nuclei P-31 and S-31 were populated in the 1p and 1n exit channels of the reaction Ne-20 + C-12, at a beam energy of 33 MeV. The Ne-20 beam was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident gamma-rays and Doppler-shift attenuation lifetime measurements were performed using the multi-detector array GASP in conjunction with the EUCLIDES charged particle detector. In the observed B(E1) strengths, the isoscalar component, amounting to 24% of the isovector one, provides strong evidence for breaking of the isospin symmetry in the A = 31 mass region. Self-consistent beyond mean field calculations using Equation of Motion method based on a chiral potential and including two- and three-body forces reproduce well the experimental B(E1) strengths, reinforcing our conclusion. Coherent mixing from higher-lying states involving the Giant Isovector Monopole Resonance accounts well for the effect observed. The breaking of the isospin symmetry originates from the violation of the charge symmetry of the two- and three-body parts of the potential, only related to the Coulomb interaction.
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Taprogge, J. et al, Gadea, A., & Montaner-Piza, A. (2014). Identification of a millisecond isomeric state in Cd-129(81) via the detection of internal conversion and Compton electrons. Phys. Lett. B, 738, 223–227.
Abstract: The decay of an isomeric state in the neutron-rich nucleus Cd-129 has been observed via the detection of internal conversion and Compton electrons providing first experimental information on excited states in this nucleus. The isomer was populated in the projectile fission of a U-238 beam at the Radioactive Isotope Beam Factory at RIKEN. From the measured yields of gamma-rays and internal conversion electrons, a multipolarity of E3 was tentatively assigned to the isomeric transition. A half-life of T-1/2 = 3.6(2) ms was determined for the new state which was assigned a spin of (21/2(+)), based on a comparison to shell model calculations performed using state-of-the-art realistic effective interactions.
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Srivastava, R., Ternes, C. A., Tortola, M., & Valle, J. W. F. (2018). Testing a lepton quarticity flavor theory of neutrino oscillations with the DUNE experiment. Phys. Lett. B, 778, 459–463.
Abstract: Oscillation studies play a central role in elucidating at least some aspects of the flavor problem. Here we examine the status of the predictions of a lepton quarticity flavor theory of neutrino oscillations against the existing global sample of oscillation data. By performing quantitative simulations we also determine the potential of the upcoming DUNE experiment in narrowing down the currently ill-measured oscillation parameters theta(23) and delta(CP). We present the expected improved sensitivity on these parameters for different assumptions.
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Song, J., Yang, Z. Y., & Oset, E. (2025). Searching for signals of an exotic I=1,JP=2+ state of D*K* nature and the structure of the Pc(4312) in the Λb→Σc plus plus D-K- reaction. Phys. Lett. B, 861, 139294–7pp.
Abstract: This paper investigates the decay process Lambda-Sigma++-- with the objective of finding a predicted molecular state with isospin = 1, = 2+ of nature, plus finding support for the (4312) state as made out of Sigma. The mass distribution of the -- system shows distinct features as a consequence of the existence of this 2+ state, while the Sigma distribution exhibits a significant peak near the threshold, much bigger than phase space expectations, which is linked to our assumed Sigma nature of the (4312) state below the Sigma threshold. The reaction has been measured at LHCb Collaboration, but only the branching ratio is measured. The present study shows that much valuable information can be obtained about the predicted 2+ (2834) of nature and the (4312) states from the measurements of the mass distributions in this reaction, which will be accessible in the planned updates of LHCb.
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Aristizabal Sierra, D., De Romeri, V., Flores, L. J., & Papoulias, D. K. (2020). Light vector mediators facing XENON1T data. Phys. Lett. B, 809, 135681–5pp.
Abstract: Recently the XENON1T collaboration has released new results on searches for new physics in low-energy electronic recoils. The data shows an excess over background in the low-energy tail, particularly pronounced at about 2-3 keV. With an exposure of 0.65 tonne-year, large detection efficiency and energy resolution, the detector is sensitive as well to solar neutrino backgrounds, with the most prominent contribution given by pp neutrinos. We investigate whether such signal can be explained in terms of new neutrino interactions with leptons mediated by a light vector particle. We find that the excess is consistent with this interpretation for vector masses below less than or similar to 0.1 MeV. The region of parameter space probed by the XENON1T data is competitive with constraints from laboratory experiments, in particular GEMMA, Borexino and TEXONO. However we point out a severe tension with astrophysical bounds and cosmological observations.
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AGATA Collaboration(Siciliano, M. et al), Gadea, A., Perez-Vidal, R. M., & Domingo-Pardo, C. (2020). Pairing-quadrupole interplay in the neutron-deficient tin nuclei: First lifetime measurements of low-lying states in Sn-106,Sn-108. Phys. Lett. B, 806, 135474–7pp.
Abstract: The lifetimes of the low-lying excited states 2(+) and 4(+) have been directly measured in the neutron-deficient Sn-106,Sn-108 isotopes. The nuclei were populated via a deep-inelastic reaction and the lifetime measurement was performed employing a differential plunger device. The emitted gamma rays were detected by the AGATA array, while the reaction products were uniquely identified by the VAMOS++ magnetic spectrometer. Large-Scale Shell-Model calculations with realistic forces indicate that, independently of the pairing content of the interaction, the quadrupole force is dominant in the B(E2; 2(1)(+) -> 0(g.s)(+)) values and it describes well the experimental pattern for Sn104-114 ; the B(E2;(+)(4) -> 2(1)(+)) values, measured here for the first time, depend critically on a delicate pairing-quadrupole balance, disclosed by the very precise results in Sn-108.
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Celis, A., Fuentes-Martin, J., & Serodio, H. (2014). Effective aligned 2HDM with a DFSZ-like invisible axion. Phys. Lett. B, 737, 185–190.
Abstract: We discuss the possibility of having a non-minimal scalar sector at the weak scale within the framework of invisible axion models. To frame our discussion we consider an extension of the Dine-Fischler-Srednicki-Zhitnitsky invisible axion model with two additional Higgs doublets blind under the Peccei-Quinn symmetry. Due to mixing effects among the scalar fields, it is possible to obtain a rich scalar sector at the weak scale in certain decoupling limits of the theory. In particular, this framework provides an ultraviolet completion of the so-called aligned two-Higgs-doublet model and solves the strong CP problem. The axion properties and the smallness of active neutrino masses are also discussed.
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Scandale, W. et al, & Lari, L. (2013). Optimization of the crystal assisted collimation of the SPS beam. Phys. Lett. B, 726(1-3), 182–186.
Abstract: The possibility for optimization of crystal assisted collimation has been studied at the CERN SPS for stored beams of protons and Pb ions with 270 GeV/c per unit charge. A bent silicon crystal used as a primary collimator deflects halo particles in the channeling regime, directing them into a tungsten absorber. In channeling conditions a strong reduction of off-momentum particle numbers produced in the crystal and absorber, which form collimation leakage, has been observed in the first high dispersion (HD) area downstream. The present study shows that the collimation leakage is minimal for some values of the absorber offset relative to the crystal. The optimal offset value is larger for Pb ions because of their considerably larger ionization losses in the crystal, which cause large increases of particle betatron oscillation amplitudes. The optimal absorber offset allows obtaining maximal efficiency of crystal-assisted collimation.
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Scandale, W. et al, & Lari, L. (2015). Observation of nuclear dechanneling length reduction for high energy protons in a short bent crystal. Phys. Lett. B, 743, 440–443.
Abstract: Deflection of 400 GeV/c protons by a short bent silicon crystal was studied at the CERN SPS. It was shown that the dechanneling probability increases while the dechanneling length decreases with an increase of incident angles of particles relative to the crystal planes. The observation of the dechanneling length reduction provides evidence of the particle population increase at the top levels of transverse energies in the potential well of the planar channels. (C) 2015 The Authors. Published by Elsevier B.V.
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