arXiv subjects

H. Kamano

Publications and source records attributed to H. Kamano.

At least 19 recordsLinked to original sources

arXiv2026

Low-lying $\Lambda$ and $\Sigma$ resonances studied with the forward $K^*$ productions off the proton induced by a high-momentum $\pi$ beam

We develop a novel model utilizing the forward $K^*$ production reaction off the nucleon, $\pi N \to K^* MB$, induced by a high-momentum $\pi$ beam, as a tool to study low-lying $Y^*$ resonances below and just above the $\bar{K}N$ threshold. Because conventional $K^- p$ scattering experiments face difficulties in directly accessing this kinematic region, the proposed reaction offers a valuable complementary approach for $Y^*$ spectroscopy. The constructed model is based on the one-meson exchange mechanism, which is known to dominate forward-angle production at high energies, and the half-off-shell scattering amplitudes from the ANL-Osaka dynamical coupled-channels models (Model A and Model B). We predict various observables, including differential cross sections and angular distributions. Our results demonstrate significant enhancements in the subthreshold region of the invariant mass spectra. Notably, we show that overlapping resonances, such as a potential new $3/2^+$ $\Sigma$ state and the well-established $\Sigma(1385)3/2^+$, can constitute a single peak in the $\pi\Lambda$ mass spectrum, indicating that the existence of previously unconfirmed subthreshold states cannot be ruled out by analyzing only the existing mass spectrum data. Furthermore, we find that angular distributions provide strong discriminatory power to disentangle such overlapping states through partial-wave interference effects, while the $t'$ and $\phi_M^*$ dependencies provide crucial constraints on the high-energy production mechanisms. Our predictions for these highly sensitive observables can facilitate high-statistics measurements, which are accessible at modern hadron facilities such as J-PARC, to unravel the $S=-1$ $Y^*$ mass spectrum.

hep-ph↗

arXiv2026

Dynamical study of $\pi N\to \pi\pi N$ reactions revisited

Using the Argonne National Laboratory-The University of Osaka (ANL-Osaka) DCC model of meson-nucleon reactions, we extend the study of Phys. Rev. C 79, 025206 (2009) and Phys. Rev. C 88, 045203 (2013) to predict the cross sections of the $\pi N \to \pi \pi N$ reactions. The model was constructed by fitting only the two-body reactions: $\pi N,\gamma N \to \pi N, \eta N, K\Lambda, K\Sigma$. Thus, the results for $\pi N \to \pi \pi N$ presented here are predictions of the ANL-Osaka DCC model, which serve to examine the extent to which the forthcoming data from J-PARC can be described. This study provides information for improving the extraction of nucleon resonances that have large decay widths to $\pi\pi N$ states. We present results for the total cross sections, invariant mass distributions, and angular distributions. We also identify the observables and energy regions where the higher mass nucleon resonances in the $S_{31}$, $P_{33}$, $D_{33}$, $F_{37}$, $D_{13}$, $D_{15}$, and $F_{15}$ partial waves can be most effectively investigated.

hep-ph↗

arXiv2019

The ANL-Osaka Partial-Wave Amplitudes of $πN$ and $γN$ Reactions

The determination of the Argonne National Laboratory-Osaka University (ANL-Osaka) Partial-Wave Amplitudes (PWA) of $πN$ and $γN$ Reactions is reviewed. The predicted PWA are presented on a web page (https://www.phy.anl.gov/theory/research/anl-osaka-pwa). The formulas are given for using the predicted PWA to calculate the cross sections of (1) meson-baryon ($MB$) scattering $MB \rightarrow M'B'$ with $MB, M'B'= πN, ηN, KΛ, KΣ$, (2) two-pion production $πN \rightarrow πΔ, ρN, σN \rightarrow ππN$, (3) Meson photoproduction $γN \rightarrow πN, ηN, KΛ, KΣ$, (4) Pion electroproduction $N(e,e'π)N$, (5) inclusive $N(e,e')X$. We also present sample results from our fits to the data.

nucl-th↗

arXiv2019

Impact of final state interactions on neutrino-nucleon pion production cross sections extracted from neutrino-deuteron reaction data

The current and near-future neutrino oscillation experiments require significantly improved neutrino-nucleus reaction models. Neutrino-nucleon pion production data play a crucial role to validate corresponding elementary amplitudes that go into such neutrino-nucleus models. Thus the currently available data extracted from charged-current neutrino-deuteron reaction data ($ν_μd\to μ^-πNN$) must be corrected for nuclear effects such as the Fermi motion and final state interactions (FSI). We study $ν_μd\to μ^-πNN$ with a theoretical model including the impulse mechanism supplemented by FSI from $NN$ and $πN$ rescatterings. An analysis of the spectator momentum distributions reveals that the FSI effects significantly reduce the spectra over the quasi-free peak region, and leads to a useful recipe to extract information of elementary $ν_μN\to μ^-πN$ processes using $ν_μd\to μ^-πNN$ data, with the important FSI corrections taken into account. We provide $ν_μN\to μ^-πN$ total cross sections by correcting the deuterium bubble chamber data for the FSI and Fermi motion. The results will bring a significant improvement on neutrino-nucleus reaction models for the near-future neutrino-oscillation experiments.

hep-ph↗

arXiv2018

$η$ photoproduction off the deuteron and low-energy $η$-nucleon interaction

We study $η$ photoproduction off the deuteron ($γd\toηpn$) at a special kinematics: $\sim 0.94$ GeV of the photon beam energy and $\sim 0^\circ$ of the scattering angle of the proton. This kinematics is ideal to extract the low-energy $η$-nucleon scattering parameters such as $a_{ηN}$ (scattering length) and $r_{ηN}$ (effective range) because the $η$-nucleon elastic scattering is significantly enhanced. We show that if a ratio $R$, the $γd\toηpn$ cross section divided by the $γp\toηp$ cross section convoluted with the proton momentum distribution in the deuteron, is measured with 5% error, ${\rm Re}[a_{ηN}]$ (${\rm Re}[r_{ηN}]$) can be determined at the precision of $\sim\pm$0.1 fm ($\sim\pm$0.5 fm), significantly narrowing down the currently estimated range of the parameters. The measurement is ongoing at the Research Center for Electron Photon Science (ELPH), Tohoku University.

nucl-th↗

arXiv2018

Nuclear applications of ANL-Osaka amplitudes: pion photo-productions on deuteron

The Argonne National Laboratory-Osaka University (ANL-Osaka) amplitudes (http://www.phy.anl.gov/theory/research/anl-osaka-pwa/) are applied to study pion photo-production reactions on the deuteron target. Within the multiple scattering formulation, we predict the cross sections of $d(γ,π)NN$ in the nucleon resonance region. The calculations include the impulse term and the final-state interaction (FSI) terms due to pion-exchange and nucleon-exchange. We show that the off-shell effects, calculated from the meson-exchange mechanisms, on the propagations of the exchanged nucleon and pion are significant in determining the reaction amplitudes. The FSI effects on the predicted cross sections are found to be important at energies near the $Δ$(1232) resonance, and are still significant at higher energies. The results are in good agreement with most of the available data of $d(γ,π^0)np$ and $d(γ,π^-)pp$ reactions.

nucl-th↗

arXiv2018

Nucleon Excited States from Lattice QCD and Hamiltonian Effective Field Theory

An approach for relating the nucleon excited states extracted from lattice QCD and the nucleon resonances of experimental data has been developed using the Hamiltonian effective field theory (HEFT) method. By formulating HEFT in the finite volume of the lattice, the eigenstates of the Hamiltonian model can be related to the energy eigenstates observed in Lattice simulations. By taking the infinite-volume limit of HEFT, information from the lattice is linked to experiment. The approach opens a new window for the study of experimentally-observed resonances from the first principles of lattice QCD calculations. With the Hamiltonian approach, one not only describes the spectra of lattice-QCD eigenstates through the eigenvalues of the finite-volume Hamiltonian matrix, but one also learns the composition of the lattice-QCD eigenstates via the eigenvectors of the Hamiltonian matrix. One learns the composition of the states in terms of the meson-baryon basis states considered in formulating the effective field theory. One also learns the composition of the resonances observed in Nature. In this paper, we will focus on recent breakthroughs in our understanding of the structure of the $N^*(1535)$, $N^*(1440)$ and $Λ^*(1405)$ resonances using this method.

nucl-th↗

arXiv2017

Low-energy $η$-nucleon interaction studied with $η$ photoproduction off the deuteron

We develop a reaction model for $η$ photoproduction off the deuteron ($γd\toηpn$), and study the reaction at a special kinematics, where the photon beam energy is $\sim 0.94$ GeV and the scattered proton is detected at $\sim 0^\circ$, for the purpose of determining the $η$-nucleon scattering length ($a_{ηN}$) and effective range ($r_{ηN}$). In this kinematics, the $η$-nucleon elastic rescattering is significantly enhanced while other background mechanisms being suppressed. We show that a ratio $R$, the $γd\toηpn$ cross section divided by the $γp\toηp$ cross section convoluted with the proton momentum distribution in the deuteron, has a very good resolving power of $a_{ηN}$ and $r_{ηN}$. We conclude that the $R$ data with 5% error, binned in 1 MeV width of the $η$-neutron invariant mass, can determine ${\rm Re}[a_{ηN}]$ (${\rm Re}[r_{ηN}]$) at the precision of $\sim\pm$0.1 fm ($\sim\pm$0.5 fm), significantly narrowing down the previously estimated ranges of the parameters. To arrive at the conclusion, it is essential to use the $γd\toηpn$ reaction model equipped with elementary amplitudes that are well constrained by $πN$ and $γN$ reaction data through a sophisticated coupled-channels analysis. This result strongly motivates the Research Center for Electron Photon Science (ELPH) at Tohoku University to measure $R$.

nucl-th↗

arXiv2017

Towards a Unified Model of Neutrino-Nucleus Reactions for Neutrino Oscillation Experiments

A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the reactions over all the energy regions. A description of the neutrino-nucleon reactions follows and, in particular, a dynamical coupled-channels model for meson productions in and beyond the $Δ$(1232) region is discussed in detail. We then discuss the neutrino-nucleus reactions, putting emphasis on our theoretical approaches. We start the discussion with electroweak processes in few-nucleon systems studied with the correlated Gaussian method. Then we describe quasi-elastic scattering with nuclear spectral functions, and meson productions with a $Δ$-hole model. Nuclear modifications of the parton distribution functions determined through a global analysis are also discussed. Finally, we discuss issues to be addressed for future developments.

nucl-th↗

arXiv2016

Toward establishing low-lying $Λ$ and $Σ$ hyperon resonances with the $\bar K + d \to π+ Y + N$ reaction

A model for the $\bar K d \to πY N$ reactions with $Y=Λ, Σ$ is developed, aiming at establishing the low-lying $Λ$ and $Σ$ hyperon resonances through analyzing the forthcoming data from the J-PARC E31 experiment. The off-shell amplitudes generated from the dynamical coupled-channels (DCC) model, which was developed in Kamano et al. [Phys. Rev. C 90, 065204 (2014)], are used as input to the calculations of the elementary $\bar K N \to \bar K N$ and $\bar K N \to πY$ subprocesses in the $\bar K d \to πY N$ reactions. It is shown that the cross sections for the J-PARC E31 experiment with a rather high incoming-$\bar{K}$ momentum, $|\vec p_{\bar K}|= 1$ GeV, can be predicted reliably only when the input $\bar K N \to \bar K N$ amplitudes are generated from a $\bar KN$ model, such as the DCC model used in this investigation, which describes the data of the $\bar K N$ reactions at energies far beyond the $\bar K N$ threshold. We find that the data of the threefold differential cross section $dσ/(dM_{πΣ}dΩ_{p_n})$ for the $K^- d \to πΣn$ reaction below the $\bar K N$ threshold can be used to test the predictions of the resonance poles associated with $Λ(1405)$. We also find that the momentum dependence of the threefold differential cross sections for the $K^- d \to π^- Λp$ reaction can be used to examine the existence of a low-lying $J^P=1/2^+$ $Σ$ resonance with a pole mass $M_R = 1457 -i39$ MeV, which was found from analyzing the $K^-p$ reaction data within the employed DCC model.

nucl-th↗

arXiv2016

Nucleon resonance structure in the finite volume of lattice QCD

An approach for relating the nucleon resonances extracted from $πN$ reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of $πN$ reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance pole positions can be related to the probability $P_{N^*}(E)$ of finding the bare state, $N^*$, in the $πN$ scattering states in infinite volume. We further demonstrate that the probability $P_{N^*}^V(E)$ of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches $P_{N^*}(E)$ as the volume increases. Our findings suggest that the comparison of $P_{N^*}(E)$ and $P_{N^*}^V(E)$ can be used to examine whether the nucleon resonances extracted from the $πN$ reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of $P_{N^*}^V(E)$ directly from lattice QCD. The practical differences between our approach and the approach using the Lüscher formalism to relate LQCD calculations to the nucleon resonance poles embedded in the data are also discussed.

hep-lat↗

arXiv2016

Isospin decomposition of the $γ^{()} N \to N^$ transitions as input for constructing models of neutrino-induced reactions in the nucleon resonance region

We present our recent efforts to determine the matrix elements associated with the transition between the nucleon and a nucleon resonance induced by the vector current, which are necessary ingredients for models of neutrino-induced reactions in the resonance region. This is accomplished by making the comprehensive analysis of the data for various meson photo- and electro-production reactions off the nucleon within a sophisticated coupled-channels framework, which is known as the ANL-Osaka dynamical coupled-channels model. We also give a brief introduction to our project for constructing a unified neutrino reaction model conducted at the J-PARC Branch of the KEK Theory Center.

nucl-th↗

arXiv2016

Isospin decomposition of $γN \to N^*$ transitions within a dynamical coupled-channels model

By extending the dynamical coupled-channels analysis performed in our previous work [Phys. Rev. C 88, 035209 (2013)] to include the available data of photoproduction of pi meson off the neutron, the transition amplitudes for the photo-excitation of the neutron to nucleon resonances, gamma n --> N*, at the resonance pole positions are determined. The combined fits to the data for both the proton- and neutron-target reactions also revise our results for the resonance pole positions and the gamma p --> N* transition amplitudes. Our results allow an isospin decomposition of the gamma N --> N* transition amplitudes for the isospin I=1/2 N* resonances, which is necessary for testing hadron structure models and gives crucial inputs for constructing models of neutrino-induced reactions in the nucleon resonance region.

nucl-th↗

arXiv2016

Workshop on Physics with Neutral Kaon Beam at JLab (KL2016) Mini-Proceedings

The KL2016 Workshop is following the Letter of Intent LoI12-15-001 "Physics Opportunities with Secondary KL beam at JLab" submitted to PAC43 with the main focus on the physics of excited hyperons produced by the Kaon beam on unpolarized and polarized targets with GlueX setup in Hall D. Such studies will broaden a physics program of hadron spectroscopy extending it to the strange sector. The Workshop was organized to get a feedback from the community to strengthen physics motivation of the LoI and prepare a full proposal. Further details about the Workshop can be found on the web page of the conference: http://www.jlab.org/conferences/kl2016/index.html .

hep-ph↗

arXiv2015

Dynamical coupled-channels model for neutrino-induced meson productions in resonance region

A dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region is developed. Starting from the DCC model that we have previously developed through an analysis of $πN, γN\to πN, ηN, KΛ, KΣ$ reaction data for $W\le 2.1$ GeV, we extend the model of the vector current to $Q^2\le$ 3.0 (GeV/$c$)$^2$ by analyzing electron-induced reaction data for both proton and neutron targets. We derive axial-current matrix elements that are related to the $πN$ interactions of the DCC model through the Partially Conserved Axial Current (PCAC) relation. Consequently, the interference pattern between resonant and non-resonant amplitudes is uniquely determined. We calculate cross sections for neutrino-induced meson productions, and compare them with available data. Our result for the single-pion production reasonably agrees with the data. We also make a comparison with the double-pion production data. Our model is the first DCC model that can give the double-pion production cross sections in the resonance region. We also make comparison of our result with other existing models to reveal an importance of testing the models in the light of PCAC and electron reaction data. The DCC model developed here will be a useful input for constructing a neutrino-nucleus reaction model and a neutrino event generator for analyses of neutrino experiments.

hep-ph↗

arXiv2015

Dynamical coupled-channels model of $K^- p$ reactions (II): Extraction of $Λ^$ and $Σ^$ hyperon resonances

Resonance parameters (pole masses and residues) associated with the excited states of hyperons, Lambda^* and Sigma^*, are extracted within a dynamical coupled-channels model developed recently by us [Phys. Rev. C 90, 065204 (2014)] through a comprehensive partial-wave analysis of the K^- p --> barK N, pi Sigma, pi Lambda, eta Lambda, K Xi data up to invariant mass W = 2.1 GeV. We confirm the existence of resonances corresponding to most, if not all, of the four-star resonances rated by the Particle Data Group. We also find several new resonances, and in particular propose a possible existence of a new narrow J^P=3/2^+ Lambda resonance that couples strongly to the eta Lambda channel. The J^P=1/2^- Lambda resonances located below the barK N threshold are also discussed. Comparing our extracted pole masses with the ones from a recent analysis by the Kent State University group, some significant differences in the extracted resonance parameters are found, suggesting the need of more extensive and accurate data of K^- p reactions including polarization observables to eliminate such an analysis dependence of the resonance parameters. In addition, the determined large branching ratios of the decays of high-mass resonances to the pi Sigma^* and barK^* N channels also suggest the importance of the data of 2 --> 3 reactions such as K^- p --> pi pi Lambda and K^- p --> pi barK N. Experiments on measuring cross sections and polarization observables of these fundamental reactions are highly desirable at hadron beam facilities such as J-PARC for establishing the Lambda^* and Sigma^* spectrum.

nucl-th↗

arXiv2014

Letter of Intent to Construct a nuPRISM Detector in the J-PARC Neutrino Beamline

As long-baseline neutrino experiments enter the precision era, the difficulties associated with understanding neutrino interaction cross sections on atomic nuclei are expected to limit experimental sensitivities to oscillation parameters. In particular, the ability to relate experimental observables to neutrino energy in previous experiments has relied solely on theoretical models of neutrino-nucleus interactions, which currently suffer from very large theoretical uncertainties. By observing charged current $ν_μ$ interactions over a continuous range of off-axis angles from 1 to 4 degrees, the nuPRISM water Cherenkov detector can provide a direct measurement of the far detector lepton kinematics for any given set of oscillation parameters, which largely removes neutrino interaction modeling uncertainties from T2K oscillation measurements. This naturally provides a direct constraint on the relationship between lepton kinematics and neutrino energy. In addition, nuPRISM is a sensitive probe of sterile neutrino oscillations with multiple energy spectra, which provides unique constraints on possible background-related explanations of the MiniBooNE anomaly. Finally, high-precision measurements of neutrino cross sections on water are possible, including $ν_e$ measurements and the first ever measurements of neutral current interactions as a function of neutrino energy. The nuPRISM detector also benefits the proposed Hyper-Kamiokande project. A demonstration that neutrino interaction uncertainties can be controlled will be important to understanding the physics reach of Hyper-K. In addition, nuPRISM will provide an easily accessible prototype detector for many of the new hardware components currently under consideration for Hyper-K. The following document presents the configuration, physics impact, and preliminary cost estimates for a nuPRISM detector in the J-PARC neutrino beamline.

physics.ins-det↗

arXiv2014

Dynamical coupled-channels model of $K^- p$ reactions (I): Determination of partial-wave amplitudes

We develop a dynamical coupled-channels model of K^- p reactions, aiming at extracting the parameters associated with hyperon resonances and providing the elementary antikaon-nucleon scattering amplitudes that can be used for investigating various phenomena in the strangeness sector such as the production of hypernuclei from kaon-nucleus reactions. The model consists of (a) meson-baryon (MB) potentials v_{M'B',MB} derived from the phenomenological SU(3) Lagrangian, and (b) vertex interactions Gamma_{MB,Y*} for describing the decays of the bare excited hyperon states (Y*) into MB states. The model is defined in a channel space spanned by the two-body barK N, pi Sigma, pi Lambda, eta Lambda, and K Xi states and also the three-body pi pi Lambda and pi barK N states that have the resonant pi Sigma* and barK* N components, respectively. The resulting coupled-channels scattering equations satisfy the multichannel unitarity conditions and account for the dynamical effects arising from the off-shell rescattering processes. The model parameters are determined by fitting the available data of the unpolarized and polarized observables of the K^- p --> barK N, pi Sigma, pi Lambda, eta Lambda, K Xi reactions in the energy region from the threshold to invariant mass W=2.1 GeV. Two models with equally good chi^2 fits to the data have been constructed. The partial-wave amplitudes obtained from the constructed models are compared with the results from a recent partial-wave analysis by the Kent State University group. We discuss the differences between these three analysis results. Our results at energies near the threshold suggest that the higher partial waves should be treated on the same footing as the S wave if one wants to understand the nature of Lambda(1405)1/2^- using the data below the barK N threshold, as will be provided by the J-PARC E31 experiment.

nucl-th↗