TY - JOUR
T1 - Abelian instantons and monopole scattering
AU - Csáki, Csaba
AU - Ovadia, Rotem
AU - Telem, Ofri
AU - Terning, John
AU - Yankielowicz, Shimon
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/11
Y1 - 2024/11
N2 - It is usually assumed that 4D instantons can only arise in non-Abelian theories. In this paper we re-examine this conventional wisdom by explicitly constructing instantons in an Abelian gauge theory: QED4 with Nf flavors of Dirac fermions, in the background of a Dirac monopole. This is the low-energy effective field theory for fermions interacting with a ’t Hooft-Polyakov monopole, in the limit where the monopole is infinitely heavy (hence pointlike) and static. This theory, whose non-topological sectors were studied by Rubakov and Callan, has a far richer structure than previously explored. We show how to calculate the topological instanton number, demonstrate the existence of ’t Hooft zero modes localized around such instantons, and show how instantons in the path integral provide the underlying mechanism for the Callan-Rubakov process: monopole-catalyzed baryon decay with a cross section that saturates the unitarity bound. Our computation relies on correctly identifying the relevant 2D EFT for monopole catalysis as Axial QED2 in an effective AdS2 metric.
AB - It is usually assumed that 4D instantons can only arise in non-Abelian theories. In this paper we re-examine this conventional wisdom by explicitly constructing instantons in an Abelian gauge theory: QED4 with Nf flavors of Dirac fermions, in the background of a Dirac monopole. This is the low-energy effective field theory for fermions interacting with a ’t Hooft-Polyakov monopole, in the limit where the monopole is infinitely heavy (hence pointlike) and static. This theory, whose non-topological sectors were studied by Rubakov and Callan, has a far richer structure than previously explored. We show how to calculate the topological instanton number, demonstrate the existence of ’t Hooft zero modes localized around such instantons, and show how instantons in the path integral provide the underlying mechanism for the Callan-Rubakov process: monopole-catalyzed baryon decay with a cross section that saturates the unitarity bound. Our computation relies on correctly identifying the relevant 2D EFT for monopole catalysis as Axial QED2 in an effective AdS2 metric.
KW - Effective Field Theories
KW - Field Theories in Lower Dimensions
KW - Nonperturbative Effects
KW - Solitons Monopoles and Instantons
UR - http://www.scopus.com/inward/record.url?scp=85214200163&partnerID=8YFLogxK
U2 - 10.1007/JHEP11(2024)165
DO - 10.1007/JHEP11(2024)165
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:85214200163
SN - 1126-6708
VL - 2024
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 11
M1 - 165
ER -