Matter–Antimatter Segregation Across Charge-Conjugate Branes: Baryogenesis and Dark Matter by Transport at Conserved Global Baryon Number

Abstract

This paper proposes CCBS (charge-conjugate brane segregation), a construction in which theobserved baryon asymmetry arises without any violation of global baryon number. Two branesare exchanged by an exact discrete symmetry combining a spatial reflection with chargeconjugation. The configuration in which one brane carries a baryon excess and the other anequal antibaryon excess is a fixed point of that symmetry, so the equality of the twomagnitudes is enforced geometrically rather than tuned, and no domain-wall problem arises. The per-brane excess is generated by an Akhmedov–Rubakov–Smirnov type oscillation mechanismtransposed from flavour space to "brane space": two colour-singlet bulk messengers oscillateand deposit opposite-sign asymmetries on the two branes through a renormalisable neutronportal closed by a colour-triplet scalar diquark. Baryon number is conserved at everyvertex, so the proton is automatically stable and no neutron–antineutron oscillation isinduced — a clean discriminator against Majorana neutron-portal models. The portal couplingis fixed by a warped overlap, so the small coupling usually postulated in freeze-inbaryogenesis is delivered by an order-one bulk-mass parameter. Two-phase quantum kinetic equations — resonant generation followed by a washout window downto the mediator mass — reproduce the observed baryon-to-entropy ratio along a contour with arobust floor on the coloured mediator, of order 1 to 45 TeV depending on the messengersplitting, and independent of the thermal rate coefficient, which cancels between generationand survival. The geometry then predicts a definite bulk-mass parameter. A dark baryonco-segregated by the same mechanism is proposed to complete the dark matter as asymmetricdark matter, with a bulk parity protecting the messenger localisation and giving a darkmass in the 1–4 GeV range; self-interaction bounds disfavour a massless dark mediator andpoint instead to a massive one, with a direct-detection signal. The rate coefficient is derived from the collision integral of the diquark portal andtriple-validated against independent formulations. Open issues, including the reduction ofthe full collision integral and the flavour structure of the diquark, are stated explicitly.