Unparticle Induced Baryon Number Violating Nucleon Decays

TL;DR

This paper investigates how unparticle physics could induce baryon number violating nucleon decays, deriving operator dimensions and setting experimental bounds on unparticle interaction scales.

Contribution

It identifies the lowest dimension operators for unparticle-induced nucleon decays and constrains unparticle physics scales using experimental decay bounds.

Findings

Unparticle interactions can induce nucleon decays at specific operator dimensions.

Experimental bounds require unparticle physics scale >10^{10} GeV for certain parameters.

Scalar and vector unparticles have lower bounds of 10^{7} and 10^{5} GeV, respectively.

Abstract

We study baryon number violating nucleon decays induced by unparticle interactions with the standard model particles. We find that the lowest dimension operators which cause nucleon decays can arise at dimension 6 + (d_s-3/2) with the unparticles being a spinor of dimension d_s=d_\U +1/2. For scalar and vector unparticles of dimension d_\U, the lowest order operatoers arise at 6+d_\U and 7+d_\U dimensions,respectively. Comparing the spinor unparticle induced n \to O^s_\U and experimental bound on invisible decay of a neutron from KamLAND, we find that the scale for unparticle physics is required to be larger than 10^{10} GeV for d_\U < 2 if the couplings are set to be of order one. For scalar and vector unparticles, the dominant baryon number violating decay modes are n\to \bar \nu + O_\U (O^\mu_\U) and p \to e^+ + O_\U (O^\mu_\U). The same experimental bound puts the scales for scalar and vector unparticle to be larger than 10^{7} and 10^{5} GeV for d_\U <2 with couplings set to be of order one. Data on, p \to e^+ invisible, puts similar constraints on unparticle interactions.