An Effective Field Theory Calculation of the Parity Violating Asymmetry
نویسندگان
چکیده
Weak interactions are expected to induce a parity violating pion-nucleon coupling, h (1) πNN . This coupling should be measurable in a proposed experiment to study the parity violating asymmetry Aγ in the process ~n + p → d + γ. We compute the leading dependence of Aγ on the coupling h (1) πNN using recently developed effective field theory techniques and find an asymmetry of Aγ = +0.17 h (1) πNN at leading order. This asymmetry has the opposite sign to that given by Desplanques, Donoghue and Holstein. ∗On leave from the Department of Physics, Duke University, Durham NC 27708.
منابع مشابه
Parity-violating nucleon-nucleon interaction from different approaches
Two-pion exchange parity-violating nucleon-nucleon interactions from recent effective field theories and earlier fully covariant approaches are investigated. The potentials are compared with the idea to obtain better insight on the role of low-energy constants appearing in the effective field theory approach and the convergence of this one in terms of a perturbative series. The results are illu...
متن کاملX iv : n uc l - th / 9 30 70 13 v 1 1 4 Ju l 1 99 3 Parity – violating electron scattering from the pion – correlated relativistic Fermi gas ∗
Parity–violating quasielastic electron scattering is studied within the context of the relativistic Fermi gas and its extensions to include the effects of pionic correlations and meson–exchange currents. The work builds on previous studies using the same model; here the part of the parity–violating asymmetry that contains axial–vector hadronic currents is developed in detail using those previou...
متن کاملParity-violating two-pion exchange nucleon-nucleon interaction
We calculate in chiral perturbation theory the parity-violating two-pion exchange nucleon-nucleon potentials at leading one-loop order. At a distance of r = m−1 π ≃ 1.4 fm they amount to about ±16% of the parity-violating 1π-exchange potential. We evaluate also the parity-violating effects arising from 2π-exchange with excitation of virtual ∆(1232)-isobars. These come out to be relatively small...
متن کاملParity Violation in γ−→p Compton Scattering
A measurement of parity-violating spin-dependent γ−→p Compton scattering will provide a theoretically clean determination of the parity-violating pionnucleon coupling constant h (1) πNN . We calculate the leading parity-violating amplitude arising from one-loop pion graphs in chiral perturbation theory. An asymmetry of ∼ 5×10−8 is estimated for Compton scattering of 100 MeV photons.
متن کاملParity-Violating Interaction Effects in the np System
We investigate parity-violating observables in the np system, including the longitudinal asymmetry and neutron-spin rotation in ~np elastic scattering, the photon asymmetry in ~np radiative capture, and the asymmetries in deuteron photo-disintegration d(~γ, n)p in the threshold region and electrodisintegration d(~e, e)np in quasi-elastic kinematics. To have an estimate of the model dependence f...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998