Interpretation of neutral charm mesons near threshold as unparticles

TL;DR

This paper interprets near-threshold neutral charm mesons as unparticles within a nonrelativistic conformal field theory framework, explaining observed spectral peaks and proposing experimental methods to determine their scaling dimensions.

Contribution

It introduces a novel unparticle interpretation of neutral charm mesons near threshold and calculates their scaling dimensions, linking theoretical predictions with experimental observables.

Findings

Unparticles produce observable peaks in decay spectra.

Scaling dimensions can be experimentally determined.

Theoretical framework connects charm mesons with conformal field theory.

Abstract

The existence of the $X(3872)$ resonance extremely close to the $D^{*0} \bar{D}^0$ threshold implies that neutral charm mesons have an approximate nonrelativistic conformal symmetry. Systems consisting of these mesons with small kinetic energies produced in a short-distance reaction are unparticles in the sense that they can be created by operators with definite scaling dimensions in a nonrelativistic conformal field theory. There is a scaling region in which their energy distribution has power-law behavior with an exponent determined by the scaling dimension of the operator. The unparticle associated with two neutral charm mesons produces a peak in the recoil momentum spectrum of $K^\pm$ in inclusive decays of $B^\pm$ that has been observed. The scaling dimensions of the unparticles associated with three neutral charm mesons are calculated. They can be determined experimentally by measuring the invariant mass distributions for $XD^0$ or $X D^{*0}$ in inclusive prompt production at the Large Hadron Collider.