LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Valls, P., & Sanchez Mayordomo, C. (2017). Amplitude analysis of B+ -> J/psi phi K+ decays. Phys. Rev. D, 95(1), 012002–28pp.
Abstract: The first full amplitude analysis of B+ -> J/psi phi K+ with J/psi -> mu(+)mu(-), phi -> K+K- decays is performed with a data sample of 3 fb(-1) of pp collision data collected at root s = 7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into phi K+, and four J/psi phi structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the K*(1680)+ -> phi K+ transition.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Valls, P., et al. (2017). Observation of the decay B-s(0) -> phi pi(+)pi(-) and evidence for B-0 -> phi pi(+)pi(-). Phys. Rev. D, 95(1), 012006–15pp.
Abstract: The first observation of the rare decay B-s(0) -> phi pi(+) pi(-) and evidence for B-0 -> phi pi(+) pi(-) are reported, using pp collision data recorded by the LHCb detector at center-of-mass energies root s = 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb(-1). The branching fractions in the pi(+) pi(-) invariant mass range 400 < m(pi(+) pi(-)) < 1600 MeV/c(2) are [3.48 +/- 0.23 +/- 0.17 +/- 0.35 +/- x 10(-6)] and [1.82 +/- 0.25 +/- 0.41 +/- 0.14 +/- x 10(-7) for B-s(0) -> phi pi(+) pi(-) and B-0 -> phi pi(+) pi(-) respectively, where the uncertainties are statistical, systematic and from the normalization mode B-s(0)-> phi phi. A combined analysis of the pi(+) pi(-) mass spectrum and the decay angles of the final-state particles identifies the exclusive decays B-s(0) -> phi f(0)(980), B-s(0) -> phi f(2)(1270), and B-s(0) -> phi rho(0) with branching fractions of [1.12 +/- 0.16(-0.08)(+0.09) +/- 0.11] x 10(-6), [0.61 +/- 0.13(-0.05)(+0.12) +/- 0.06] x 10-6 and [2.7 +/- 0.7 +/- 0.2 +/- 0.2] x 10(-7), respectively.
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Gimenez-Alventosa, V., Antunes, P. C. G., Vijande, J., Ballester, F., Perez-Calatayud, J., & Andreo, P. (2017). Collision-kerma conversion between dose-to-tissue and dose-to-water by photon energy-fluence corrections in low-energy brachytherapy. Phys. Med. Biol., 62(1), 146–164.
Abstract: The AAPM TG-43 brachytherapy dosimetry formalism, introduced in 1995, has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations, except in the vicinity of the source capsule. Subsequent dosimetry developments, based on Monte Carlo calculations or analytical solutions of transport equations, do not rely on the CPE assumption and determine directly the dose to different tissues. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seeds is proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences. State-of-the art Monte Carlo calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone), which in all cases include a realistic modelling of low-energy brachytherapy sources in order to benchmark the formalism proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases (e.g. bone tissue).
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Cavallaro, M., De Napoli, M., Cappuzzello, F., Orrigo, S. E. A., Agodi, C., Bondi, M., et al. (2017). Investigation of the Li-10 shell inversion by neutron continuum transfer reaction. Phys. Rev. Lett., 118(1), 012701–5pp.
Abstract: This Letter reports a study of the highly debated 10Li structure through the d(Li-9,p)Li-10 one-neutron transfer reaction at 100 MeV. The Li-10 energy spectrum is measured up to 4.6 MeV and angular distributions corresponding to different excitation energy regions are reported for the first time. The comparison between data and theoretical predictions, including pairing correlation effects, shows the existence of a p(1/2) resonance at 0.45 +/- 0.03 MeV excitation energy, while no evidence for a significant s-wave contribution close to the threshold energy is observed. Moreover, two high-lying structures are populated at 1.5 and 2.9 MeV. The corresponding angular distributions suggest a significant s(1/2) partial-wave contribution for the 1.5 MeV structure and a mixing of configurations at higher energy, with the d(5/2) partial-wave contributing the most to the cross section.
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Liang, W. H., Oset, E., & Xie, Z. S. (2017). Semileptonic Lambda(b) -> (nu)over-bar(l) l Lambda(c)(2595) and Lambda(b) -> (nu)over-bar(l)l Lambda(c)(2625) decays in the molecular picture of Lambda(c)(2595) and Lambda(c)(2625). Phys. Rev. D, 95(1), 014015–8pp.
Abstract: We evaluate the partial decay widths for the semileptonic Lambda(b) -> (nu) over bar (l) l Lambda(c)(2595) and Lambda(b) -> (nu) over bar (l)l Lambda(c)(2625) decays from the perspective that these two Lambda(c)* resonances are dynamically generated from the DN and D*N interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the D*N coupling, which becomes essential to obtain agreement with experiment. Together with the results obtained for the Lambda(b) -> pi(-)Lambda(c)* reactions, it gives strong support to the molecular picture of the two Lambda(c)* resonances arid the important role of the DN component neglected in prior studies of the Lambda(c)(2595) from the molecular perspective.
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