Wang, E., Li, H. S., Liang, W. H., & Oset, E. (2021). Analysis of the gamma gamma -> D(D)over-bar reaction and the D(D)over-bar bound state. Phys. Rev. D, 103(5), 054008–10pp.
Abstract: In this work, we investigate the reaction of gamma gamma -> D (D) over bar, taking into account the S-wave D (D) over bar final state interaction. By fitting to the D (D) over bar, invariant mass distributions measured by the Belle and BABAR Collaborations, we obtain a good reproduction of the data by means of a D (D) over bar, amplitude that produces a bound D (D) over bar, statewith isospin I = 0 close to threshold. The error bands of the fits indicate, however, that more precise data on this reaction are needed to be more assertive about the position and width of such a state.
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Bodeker, D., Kuhnel, F., Oldengott, I. M., & Schwarz, D. J. (2021). Lepton flavor asymmetries and the mass spectrum of primordial black holes. Phys. Rev. D, 103(6), 063506–6pp.
Abstract: We study the influence of lepton flavor asymmetries on the formation and the mass spectrum of primordial black holes. We estimate the detectability of their mergers with LIGO/Virgo and show that the currently published gravitational wave events may actually be described by a primordial black hole spectrum from nonzero asymmetries. We suggest to use gravitational-wave astronomy as a novel tool to probe how lepton flavor asymmetric the Universe has been before the onset of neutrino oscillations.
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Baglio, J., Campanario, F., Glaus, S., Muhlleitner, M., Ronca, J., & Spira, M. (2021). gg -> HH: Combined uncertainties. Phys. Rev. D, 103(5), 056002–5pp.
Abstract: In this paper we discuss the combination of the usual renormalization and factorization scale uncertainties of Higgs-pair production via gluon fusion with the novel uncertainties originating from the scheme and scale choice of the virtual top mass. Moreover, we address the uncertainties related to the top-mass definition for different values of the trilinear Higgs coupling and their combination with the other uncertainties.
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Gombas, J., DeYoung, P. A., Spyrou, A., Dombos, A. C., Algora, A., Baumann, T., et al. (2021). beta-decay feeding intensity distributions for Nb-103,Nb-104m. Phys. Rev. C, 103(3), 035803–8pp.
Abstract: The beta decays of Nb-103,Nb-104m were studied with the Summing NaI(Tl) (SuN) detector at the National Superconducting Cyclotron Laboratory. The beta-decay feeding intensity distribution I-beta(E) for each isotope was extracted by measuring gamma rays in coincidence with an emitted electron. The I-beta(E) was extracted via the total absorption spectroscopy technique. The I-beta(E) for each nucleus was compared to predictions made by the quasiparticle random-phase approximation (QRPA) model which is commonly used to calculate beta-decay properties for astrophysical applications. The main goal was to provide experimental data for neutron-rich nuclei, relevant to the astrophysical r process. In addition, the extracted beta-decay feeding intensity distributions can lead to a better understanding of nuclear structure in a region of rapid structure changes around A = 100. Finally, experimental data for Nb-104m are also of interest to antineutrino studies of nuclear reactors.
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ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., Castillo, F. L., et al. (2021). Search for Dark Matter Produced in Association with a Dark Higgs Boson Decaying into (WW -/+)-W-+/- or ZZ in Fully Hadronic Final States from root s=13 TeV pp Collisions Recorded with the ATLAS Detector. Phys. Rev. Lett., 126(12), 121802–21pp.
Abstract: Several extensions of the Standard Model predict the production of dark matter particles at the LHC. An uncharted signature of dark matter particles produced in association with VV = (WW -/+)-W-+/- or ZZ pairs from a decay of a dark Higgs boson s is searched for using 139 fb(-1) of pp collisions recorded by the ATLAS detector at a center-of-mass energy of 13 TeV. The s -> V(q (q) over bar )V(q (q) over bar) decays are reconstructed with a novel technique aimed at resolving the dense topology from boosted VV pairs using jets in the calorimeter and tracking information. Dark Higgs scenarios with m(s) > 160 GeV are excluded.
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LHCb Collaboration(Aaij, R. et al), Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2021). Observation of a New Excited D-s(+) Meson in B-0 -> D- D+ K+ pi(-) Decays. Phys. Rev. Lett., 126(12), 122002–11pp.
Abstract: Using pp collision data corresponding to an integrated luminosity of 5.4 fb(-1) collected with the LHCb detector at a center-of-mass energy of 13 TeV, the B-0 -> D- D+ K+ pi(-) decay is studied. A new excited D-s(+) meson is observed decaying into the D+K+pi(-) final state with large statistical significance. The pole mass and width, and the spin parity of the new state are measured with an amplitude analysis to be m(R) = 2591 +/- 6 +/- 7 MeV, Gamma(R) = 89 +/- 16 +/- 12 MeV, and J(P) = 0(-), where the first uncertainty is statistical and the second systematic. Fit fractions for all components in the amplitude analysis are also reported. The new resonance, denoted as D-s0(2590)(+), is a strong candidate to be the D-s(2(1)S(0))(+) state, the radial excitation of the pseudoscalar ground-state D-s(+) meson.
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n_TOF Collaboration(Dietz, M. et al), Domingo-Pardo, C., & Tain, J. L. (2021). Measurement of the Ge-72(n, y) cross section over a wide neutron energy range at the CERN n_TOF facility. Phys. Rev. C, 103(4), 045809–8pp.
Abstract: The Ge-72(n, gamma) cross section was measured for neutron energies up to 300 keV at the neutron time-of-flight facility n_TOF (CERN), Geneva, for the first time covering energies relevant to heavy-element synthesis in stars. The measurement was performed at the high-resolution beamline EAR-1, using an isotopically enriched (GeO2)-Ge-72 sample. The prompt capture gamma rays were detected with four liquid scintillation detectors, optimized for low neutron sensitivity. We determined resonance capture kernels up to a neutron energy of 43 keV, and averaged cross sections from 43 to 300 keV. Maxwellian-averaged cross section values were calculated from kT = 5 to 100 keV, with uncertainties between 3.2% and 7.1%. The new results significantly reduce uncertainties of abundances produced in the slow neutron capture process in massive stars.
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Moon, B. et al, & Montaner-Piza, A. (2021). Nuclear structure of Te isotopes beyond neutron magic number N=82. Phys. Rev. C, 103(3), 034320–15pp.
Abstract: Newly observed decay schemes of the nuclei Sb-137 and Sb-138 are reported. The neutron-rich Sb isotopes were produced by the in-flight fragmentation of a U-238 primary beam with an energy of 345 MeV/nucleon. Several new excited states of Te-137 with tentatively assigned spin-parities of (5/2(-)), (9/2(-)), and (7/2) have been established which play an important role in the evolution of neutron levels beyond N = 82. The study of the beta decay of Sb-138 led to a considerable extension of the level scheme of Te-138 including the identification of several nonyrast states. The structure of Te-137 and Te-138 is discussed on the basis of large-scale shell-model calculations performed using two different effective interactions.
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Bruschini, R., & Gonzalez, P. (2021). Diabatic description of charmoniumlike mesons. II. Mass corrections and strong decay widths. Phys. Rev. D, 103(7), 074009–13pp.
Abstract: From a diabatic bound state approach to J(PC) = 1(--) and (0,1,2)(++) charmoniumlike resonances below 4.1 GeV, formulated in terms of c (c) over bar and closed meson-meson channels, we calculate mass shifts and widths due to open meson-meson channels. This calculation does not involve any new free parameter, so comparison of our predictions with existing data provides a direct test of our approach. Further mass corrections are also estimated and good agreement with the measured masses comes out. As for the calculated widths, overall reasonable, they point out to the need of some refinement of our current bound state approximation for an accurate description of data. These results give additional support to the diabatic approach in QCD as an adequate framework for a complete unified description of conventional and unconventional charmoniumlike resonances. In this respect, the experimental discovery of a predicted 2(++) resonance with a mass around 4 GeV would be of special relevance.
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ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Castillo, F. L., Castillo Gimenez, V., et al. (2021). Longitudinal Flow Decorrelations in Xe plus Xe Collisions at root s(NN )=5.44 TeV with the ATLAS Detector. Phys. Rev. Lett., 126(12), 122301–20pp.
Abstract: The first measurement of longitudinal decorrelations of harmonic flow amplitudes v(n) for n = 2-4 in Xe + Xe collisions at root s(NN) = 5.44 TeV is obtained using 3 μb(-1) of data with the ATLAS detector at the LHC. The decorrelation signal for v(3) and v(4) is found to be nearly independent of collision centrality and transverse momentum (p(T)) requirements on fmal-state particles, but for v(2) a strong centrality and p(T) dependence is seen. When compared with the results from Pb + Pb collisions at. root s(NN) = 5.02 TcV, the longitudinal decorrelation signal in midcentral Xe + Xe collisions is found to be larger for v(2), but smaller for v(3). Current hydrodynamic models reproduce the ratios of the v(n) measured in Xe + Xe collisions to those in Pb + Pb collisions but fail to describe the magnitudes and trends of the ratios of longitudinal flow decorrelations between Xe + Xe and Pb + Pb. The results on the system-size dependence provide new insights and an important lever arm to separate effects of the longitudinal structure of the initial state from other early and late time effects in heavy-ion collisions.
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