324 research outputs found
Muon Capture on H
No full textThe μ-+H3→νμ+n+n+n capture reaction is studied under full inclusion of final-state interactions. Predictions for the three-body breakup of H3 are calculated with the AV18 potential, augmented by the Urbana IX three-nucleon force. Our results are based on the single-nucleon weak-current operator comprising the dominant relativistic corrections. This work is a natural extension of our investigations of the μ-+He3→νμ+H3,μ-+He3→νμ+n+d and μ-+He3→νμ+n+n+p capture reactions presented in Golak et al. [J. Golak, R. Skibiński, H. Witała, K. Topolnicki, A. E. Elmeshneb, H. Kamada, A. Nogga, and L. E. Marcucci, Phys. Rev. C 90, 024001 (2014)]PRVCAN0556-281310.1103/PhysRevC.90.024001
Orthogonal polynomial approach to calculate the two-nucleon transition operator in three dimensions
No full textWe give a short report on the possibility to use orthogonal polynomials (OP) in calculations that involve the two-nucleon (2N) transition operator. The presented work adds another approach to the set of previously developed methods (described in Phys. Rev. C 81, 034006 (2010); Few-Body Syst. 53, 237 (2012); K. Topolnicki, PhD thesis, Jagiellonian University (2014)) and is applied to the transition operator calculated at laboratory kinetic energy 300MeV. The new results for neutron-neutron and neutron-proton scattering observables converge to the results presented in Few-Body Syst. 53, 237 (2012) and to results obtained using the Arnoldi algorithm (Y. Saad, Iterative methods for sparse linear systems (SIAM Philadelphia, PA, USA 2003)). The numerical cost of the calculations performed using the new scheme is large and the new method can serve only as a backup to cross-check the previously used calculation schemes
Response functions and cross sections for inclusive neutrino scattering off ^{2}H, ^{3}H, and ^{3}He
No full textFor several decades there has been an interest in studying neutrino scattering on light nuclei, with the hope of increasing knowledge about the theory of weak interactions and electroweak unification. A study of several neutrino induced reactions on light nuclei (2H, 3H and 3He) is presented here. The cross section for these reactions is evaluated using the nuclear response functions, which holds the information about the nuclear interactions and structure. This approach has been tested for break-up reactions on the deuteron before and is now extended to three-nucleon break-up reactions
General operator form of the non-local three-nucleon force
No full textThis paper describes a procedure to obtain the general form of the three-nucleon force. The result is an operator form where the momentum space matrix element of the three-nucleon potential is written as a linear combination of 320 isospin-spin-momentum operators and scalar functions of momenta. Any spatial and isospin rotation invariant three-nucleon force can be written in this way and in order for the potential to be Hermitian, symmetric under parity inversion, time reversal and particle exchange, the scalar functions must have definite transformation properties under these discrete operations. A complete list of the isospin-spin-momentum operators and scalar function transformation properties is given
Radiative pion capture in 2H, 3He, and 3H
No full textThe pi(-) + H-2 -> gamma + n + n, pi(-) + He-3 -> gamma + H-3, pi(-) + He-3 -> gamma + n + d, pi(-) + He-3 -> gamma + n + n + p, and pi(-) + H-3 -> gamma + n + n + n capture reactions are studied with the AV18 two-nucleon potential and the Urbana IX three-nucleon potential. We provide for the first time realistic predictions for the differential and total capture rates for all these processes, treating consistently the initial and final nuclear states. Our results are based on the single-nucleon Kroll-Ruderman-type transition operator and concentrate on the full treatment of the nuclear final state interactions. They are compared with older theoretical predictions and experimental data
Muon induced deuteron disintegration in three-dimensions
No full textWe present a three-dimensional (3D) description of muon induced deuteron disintegration. This reaction is treated as the decay of the muonic atom with the muon initially on the lowest K shell. Our aim is to calculate the total and differential decay rates. We work in momentum space and use 3D momentum eigenstates directly. This approach allowed us to calculate the appropriate nuclear matrix elements, necessary building blocks for the differential decay rate, in a single step. For contrast - in classical calculations many partial-waves have to be taken into account. We achieved a very good agreement between the 3D and partial-wave methods for calculations that involve single-nucleon currents. Our result for the total decay rate is also in agreement with experimental values, though these are not very precise. This success motivates us to also include two-nucleon current contributions that include the meson exchange currents. Additionally, our formalism can also be applied to other, so far poorly described, processes like: or
Numerical complexity of helix unraveling algorithm for charged particle tracking
No full textThis paper describes a procedure for estimating the number of iterations in the main loop of a recently proposed algorithm designed to detect helical charged particle tracks in detectors submerged in a magnetic field. The calculations are based on a Monte Carlo simulation of the ATLAS inner detector. The resulting estimates of numerical complexity suggest that using the new procedure for online triggering is not feasible. There are however some areas, such as triggering for particles in a specific sub-domain of the phase space, where using this procedure might be beneficial
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