Revisiting scalar and pseudoscalar couplings with nucleons

By Hai-Yang Cheng, C. Chiang. 2012

135 citations recorded by the source corpus.

A bstractCertain dark matter interactions with nuclei are mediated possibly by a scalar or pseudoscalar Higgs boson. The estimation of the corresponding cross sections requires a correct evaluation of the couplings between the scalar or pseudoscalar Higgs boson and the nucleons. Progress has been made in two aspects relevant to this study in the past few years. First, recent lattice calculations show that the strange-quark sigma term σs and the strange-quark content in the nucleon are much smaller than what are expected previously. Second, lattice and model analyses imply sizable SU(3) breaking effects in the determination on the axial-vector coupling constant $ g_A^8 $ that in turn affect the extraction of the isosinglet coupling $ g_A^0 $ and the strange quark spin component Δs from polarized deep inelastic scattering experiments. Based on these new developments, we re-evaluate the relevant nucleon matrix elements and compute the scalar and pseudoscalar couplings of the proton and neutron. We also find that the strange quark contribution in both types of couplings is smaller than previously thought.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/ae1c08f280484a631875d229aa5b095e4430c4f5

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In Nuclear and High Energy Physics

Citations in the corpus

A taste of dark matter: flavour constraints on pseudoscalar mediators (2014, unknown): “0=u;:::;t c q0 m m q0 3 5 (N) : (D.3) Here m= hP q=u;d;s m 1 i 1 and (N) q give the quark spin content of a nucleon: we use the values (p) u = (n) d = 0:84, (p) d = (n) u = 0:44, (p) s = (n) s = 0:03 [163]. Taking the non-relativistic limit of Eq. (D.2) yields L N = 4c N(~s ˜~q) (~s N~q) 4c NO 6 NR ”
Extended gamma-ray emission from Coy Dark Matter (2014, methodology): “with m̄ = (1/mu + 1/md + 1/ms) −1 [96].”
Constraining Dark Sectors at Colliders: Beyond the Effective Theory Approach (2014, background): “43 [8,61], assuming democratic couplings to all quark flavors.”
Characterising dark matter searches at colliders and direct detection experiments: vector mediators (2014, unknown): “08 [99].”