Muon g-2 Discrepancy Within D-brane String Compactifications

Anchordoqui, Luis A.; Antoniadis, Ignatios; Huang, Xing; Luest, Dieter und Taylor, Tomasz R. (2021): Muon g-2 Discrepancy Within D-brane String Compactifications. In: Fortschritte der Physik-Progress of Physics, Bd. 69, Nr. 8-9, 2100084

Abstract

Very recently, the Muon g - 2 experiment at Fermilab has confirmed the E821 Brookhaven result, which hinted at a deviation of the muon anomalous magnetic moment from the Standard Model (SM) expectation. The combined results from Brookhaven and Fermilab show a difference with the SM prediction delta a(mu) = (251 +/- 59) x 10(-11) at a significance of 4.2 sigma, strongly indicating the presence of new physics. Motivated by this new result we reexamine the contributions to delta a(mu) from both: (i) the ubiquitous U(1) gauge bosons of D-brane string theory constructions and (ii) the Regge excitations of the string. We show that, for a string scale O(PeV), the contribution from anomalous U(1) gauge bosons which couple to hadrons could help to reduce (though not fully eliminate) the discrepancy reported by the Muon g - 2 Collaboration. Consistency with null results from LHC searches of new heavy vector bosons imparts the dominant constraint. We demonstrate that the contribution from Regge excitations is strongly suppressed as it was previously conjectured. We also comment on contributions from Kaluza-Klein (KK) modes, which could help resolve the delta a(mu) discrepancy. In particular, we argue that for 4-stack intersecting D-brane models, the KK excitations of the U(1) boson living on the lepton brane would not couple to hadrons and therefore can evade the LHC bounds while fully bridging the delta a(mu) gap observed at Brookhaven and Fermilab.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0015-8208
• Sprache: Englisch