We discuss a model-independent estimator of the likelihood of the compositeness of a shallow S-wave bound or virtual state. The approach is based on an extension of Weinberg’s relations in Weinberg ...(Phys Rev 137:B672, 1965) and it relies only on the proximity of the energy of the state to the two-hadron threshold to which it significantly couples. The scheme only makes use of the experimental scattering length and the effective range low energy parameters, and it is shown to be fully consistent for predominantly molecular hadrons. As explicit applications, we analyse the case of the deuteron, the
1
S
0
nucleon-nucleon virtual state and the exotic
D
s
0
∗
(
2317
)
±
, and find strong support to the molecular interpretation in all cases. Results are less conclusive for the
D
s
0
∗
(
2317
)
±
, since the binding energy of this state would be significantly higher than that of the deuteron, and the approach employed here is at the limit of its applicability. We also qualitatively address the case of the recently discovered
T
cc
+
state, within the isospin limit to avoid the complexity of the very close thresholds
D
0
D
∗
+
and
D
+
D
∗
0
, which could mask the ingredients of the approach proposed in this work.
We have studied the meson-baryon S−wave interaction in the isoscalar hidden-charm strange sector with the coupled-channels, ηcΛ, J/ψΛ, D¯Ξc, D¯sΛc, D¯Ξc′, D¯⁎Ξc, D¯s⁎Λc, D¯⁎Ξc′, D¯⁎Ξc⁎ in JP=1/2−, ...J/ψΛ, D¯⁎Ξc, D¯s⁎Λc, D¯⁎Ξc′, D¯Ξc⁎, D¯⁎Ξc⁎ in 3/2− and D¯⁎Ξc⁎ in 5/2−. We impose constraints of heavy quark spin symmetry in the interaction and obtain the non vanishing matrix elements from an extension of the local hidden gauge approach to the charm sector. The ultraviolet divergences are renormalized using the same meson-baryon-loops regulator previously employed in the non-strange hidden charm sector, where a good reproduction of the properties of the newly discovered pentaquark states is obtained. We obtain five states of 1/2−, four of 3/2− and one of 5/2−, which could be compared in the near future with forthcoming LHCb experiments. The 5/2−, three of the 3/2− and another three of the 1/2− resonances are originated from isoscalar D¯(⁎)Ξc′ and D¯(⁎)Ξc⁎ interactions. They should be located just few MeV below the corresponding thresholds (4446, 4513, 4588 and 4655 MeV), and would be SU(3)-siblings of the isospin 1/2 D¯(⁎)Σc(⁎) quasi-bound states previously found, and that provided a robust theoretical description of the Pc(4440), Pc(4457) and Pc(4312) LHCb exotic states. The another two 1/2− and 3/2− states obtained in this work are result of the D¯(⁎)Ξc−Ds(⁎)Λc coupled-channels isoscalar interaction, are significantly broader than the others, with widths of the order of 15 MeV, being D¯s(⁎)Λc the dominant decay channel.
We study the structure of the Λ c ( 2595 ) and Λ c ( 2625 ) resonances in the framework of an effective field theory consistent with heavy quark spin and chiral symmetries, which incorporates the ...interplay between Σ ( * ) c π − N D ( * ) baryon-meson degrees of freedom (d.o.f.) and bare P -wave c ¯ u d quark-model states. We show that these two resonances are not heavy quark spin symmetry partners. The J P = 3 / 2 − Λ c ( 2625 ) should be viewed mostly as a dressed three-quark state, whose origin is determined by a bare state, predicted to lie very close to the mass of the resonance. The J P = 1 / 2 − Λ c ( 2595 ) seems to have, however, a predominant molecular structure. This is because it is either the result of the chiral Σ c π interaction, whose threshold is located much closer than the mass of the bare three-quark state, or because the light d.o.f. in its inner structure are coupled to the unnatural 0 − quantum numbers. We show that both situations can occur depending on the renormalization procedure used. We find some additional states, but the classification of the spectrum in terms of heavy quark spin symmetry is difficult, despite having used interactions that respect this symmetry. This is because the bare quark-model state and the Σ c π threshold are located extraordinarily close to the Λ c ( 2625 ) and Λ c ( 2595 ) , respectively, and hence they play totally different roles in each sector.
There is a need to understand the role of nutrition, beyond calcium and vitamin D, in the treatment and prevention of osteoporosis in adults. Results regarding soy compounds on bone density and bone ...turnover are inconclusive perhaps due to differences in dose and composition or in study population characteristics. The skeletal benefit of black cohosh and red clover are unknown. Dehydroepiandrosterone (DHEA) use may benefit elderly individuals with low serum dehydroepiandrosterone-sulfate levels, but even in this group, there are inconsistent benefits to bone density (BMD). Higher fruit and vegetable intakes may relate to higher BMD. The skeletal benefit of flavonoids, carotenoids, omega-3-fatty acids, and vitamins A, C, E and K are limited to observational data or a few clinical trials, in some cases investigating pharmacologic doses. Given limited data, it would be better to get these nutrients from fruits and vegetables. Potassium bicarbonate may improve calcium homeostasis but with little impact on bone loss. High homocysteine may relate to fracture risk, but the skeletal benefit of each B vitamin is unclear. Magnesium supplementation is likely only required in persons with low magnesium levels. Data are very limited for the role of nutritional levels of boron, strontium, silicon and phosphorus in bone health. A nutrient rich diet with adequate fruits and vegetables will generally meet skeletal needs in healthy individuals. For most healthy adults, supplementation with nutrients other than calcium and vitamin D may not be required, except in those with chronic disease and the frail elderly.
New and more precise measurements of neutrino cross sections have renewed interest in a better understanding of electroweak interactions on nucleons and nuclei. This effort is crucial to achieving ...the precision goals of the neutrino oscillation program, making new discoveries, like the CP violation in the leptonic sector, possible. We review the recent progress in the physics of neutrino cross sections, putting emphasis on the open questions that arise in the comparison with new experimental data. Following an overview of recent neutrino experiments and future plans, we present some details about the theoretical development in the description of (anti)neutrino-induced quasielastic (QE) scattering and the role of multi-nucleon QE-like mechanisms. We cover not only pion production in nucleons and nuclei but also other inelastic channels including strangeness production and photon emission. Coherent reaction channels on nuclear targets are also discussed. Finally, we briefly describe some of the Monte Carlo event generators, which are at the core of all neutrino oscillation and cross-section measurements.
A
bstract
We present a full kinematic analysis of neutrino-nucleus charged current quasielastic interactions based on the Local Fermi Gas model and the Random Phase Approximation. The model was ...implemented in the NEUT Monte Carlo framework, which allows us to investigate potentially measurable observables, including hadron distributions. We compare the predictions simultaneously to the most recent T2K and MINERvA charged current (CC) inclusive, CC0
π
and transverse kinematic-imbalance variable results. We pursuit a microscopic interpretation of the relevant reaction mechanisms, with the aim to achieving in neutrino oscillation experiments a correct reconstruction of the incoming neutrino kinematics, free of conceptual biasses. Such study is of the utmost importance for the ambitious experimental program which is underway to precisely determine neutrino properties, test the three-generation paradigm, establish the order of mass eigenstates and investigate leptonic CP violation.
The charged-current double differential neutrino cross section, measured by the MiniBooNE Collaboration, has been analyzed using a microscopical model that accounts for, among other nuclear effects, ...long range nuclear (RPA) correlations and multinucleon scattering. We find that MiniBooNE data are fully compatible with the world average of the nucleon axial mass in contrast with several previous analyses which have suggested an anomalously large value. We also discuss the reliability of the algorithm used to estimate the neutrino energy.
Understanding single pion production reactions on free nucleons is the first step towards a correct description of these processes in nuclei, which are important for signal and background ...contributions in current and near future accelerator neutrino oscillation experiments. In this work, we reanalyze our previous studies of neutrino-induced one-pion production on nucleons for outgoing πN invariant masses below 1.4 GeV. Our motivation is to get a better description of the νμn→μ−nπ+ cross section, for which current theoretical models give values significantly below data. This channel is very sensitive to the crossed Δ(1232) contribution and thus, to spin 1/2 components in the Rarita-Schwinger Δ propagator. We show how these spin 1/2 components are nonpropagating and give rise to contact interactions. In this context, we point out that the discrepancy with experiment might be corrected by the addition of appropriate extra contact terms and argue that this procedure will provide a natural solution to the νμn→μ−nπ+ puzzle. To keep our model simple, in this work, we propose to change the strength of the spin 1/2 components in the Δ propagator and use the νμn→μ−nπ+ data to constraint its value. With this modification, we now find a good reproduction of the νμn→μ−nπ+ cross section without affecting the good results previously obtained for the other channels. We also explore how this change in the Δ propagator affects our predictions for pion photoproduction and find also a better agreement with experiment than with the previous model.
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