Measurement of spin observables in neutron-proton elastic scattering

Arnold, J.

doi:10.1007/s100520000464

Cited by 13 publications

(6 citation statements)

References 8 publications

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“…The trend of the new data in the resonance region deviates clearly from that exhibited by the data from previous experiments below and above this region [8][9][10][22][23][24][25][26][27]. The new partial-wave solutions (see below) connect all data within their uncertainties, whereas the SP07 solution obviously fails in the resonance region.…”

Section: Amentioning

confidence: 58%

Neutron-proton scattering in the context of thed*(2380) resonance

Adlarson¹,

Augustyniak²,

Bardan³

et al. 2014

Phys. Rev. C

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New data on quasifree polarized neutron-proton scattering, in the region of the recently observed d * resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, 2 checks of the quasifree character of the scattering process, on all obtained Ay angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the 3 D3-3 G3 coupled partial waves at (2380±10−i40±5) MeV -in accordance with the d * dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at T d = 2.27 GeV is discussed.

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Section: Amentioning

confidence: 58%

Neutron-proton scattering in the context of thed*(2380) resonance

Adlarson¹,

Augustyniak²,

Bardan³

et al. 2014

Phys. Rev. C

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“…The solid symbols denote the results from this work, the open symbols those from previous work [7][8][9][19][20][21][22][23]. For the meaning of the curves see Fig.…”

Section: = 83mentioning

confidence: 93%

Evidence for a New Resonance from Polarized Neutron-Proton Scattering

Adlarson¹,

Augustyniak²,

Bardan³

et al. 2014

Phys. Rev. Lett.

167

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Exclusive and kinematically complete high-statistics measurements of quasifree polarized np scattering have been performed in the energy region of the narrow resonance-like structure d * with 2 I(J P ) = 0(3 + ), M ≈ 2380 MeV and Γ ≈ 70 MeV observed recently in the double-pionic fusion channels pn → dπ 0 π 0 and pn → dπ + π − . The experiment was carried out with the WASA detector setup at COSY having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process dp → np + pspectator. This allowed the np analyzing power, Ay, to be measured over a broad angular range. The obtained Ay angular distributions deviate systematically from the current SAID SP07 NN partial-wave solution. Incorporating the new Ay data into the SAID analysis produces a pole in the 3 D3 − 3 G3 waves in support of the d * resonance hypothesis.

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“…Starting from N 4 LO, we found that setting the maximum fitting energy E max lab ∼ 250 MeV leads to stable results for the LECs and phase shifts for all employed cutoff values in the range of Λ = 350 − 550 MeV. Given the abundance of np spin-observables available at the energies around E lab ∼ 260 MeV and coming from the recent experiments of [94][95][96], we decided to set E max lab = 260 MeV at this chiral order. We will address the sensitivity of our results on the choice of E max lab in section VII E. At N 3 LO, we fit up to E lab = 200 MeV while the maximum energy of included scattering data at LO, NLO and N 2 LO is chosen to be E lab = 25, 100 and 125 MeV.…”

Section: Fitting Proceduresmentioning

confidence: 99%

Semilocal momentum-space regularized chiral two-nucleon potentials up to fifth order

2018

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We introduce new semilocal two-nucleon potentials up to fifth order in the chiral expansion. We employ a simple regularization approach for the pion-exchange contributions which (i) maintains the long-range part of the interaction, (ii) is implemented in momentum space and (iii) can be straightforwardly applied to regularize many-body forces and current operators. We discuss in detail the two-nucleon contact interactions at fourth order and demonstrate that three terms out of fifteen used in previous calculations can be eliminated via suitably chosen unitary transformations. The removal of the redundant contact terms results in a drastic simplification of the fits to scattering data and leads to interactions which are much softer (i.e. more perturbative) than our recent semilocal coordinate-space regularized potentials. Using the pion-nucleon low-energy constants from matching pion-nucleon Roy-Steiner equations to chiral perturbation theory, we perform a comprehensive analysis of nucleon-nucleon scattering and the deuteron properties up to fifth chiral order and study the impact of the leading F-wave two-nucleon contact interactions which appear at sixth order. The resulting chiral potentials lead to an outstanding description of the proton-proton and neutron-proton scattering data from the self-consistent Granada-2013 database below the pion production threshold, which is significantly better than for any other chiral potential. For the first time, the chiral potentials match in precision and even outperform the available high-precision phenomenological potentials, while the number of adjustable parameters is, at the same time, reduced by about ∼ 40%. Last but not least, we perform a detailed error analysis and, in particular, quantify for the first time the statistical uncertainties of the fourth-and the considered sixth-order contact interactions.

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Measurement of spin observables in neutron-proton elastic scattering

Cited by 13 publications

References 8 publications

Neutron-proton scattering in the context of thed*(2380) resonance

Neutron-proton scattering in the context of thed*(2380) resonance

Evidence for a New Resonance from Polarized Neutron-Proton Scattering

Semilocal momentum-space regularized chiral two-nucleon potentials up to fifth order

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