118565896
Partonic description of a supersymmetric p-brane
We consider supersymmetric extensions of a recently proposed partonic description of a bosonic p-brane which reformulates the Nambu-Goto action as an interacting multi-particle action with Filippov-Lie algebra gauge symmetry. We construct a worldline supersymmetric action by postulating, among others, a p-form fermion. Demanding a local worldline supersymmetry rather than the full worldvolume supersymmetry, we circumvent a known no-go theorem against the construction of a Ramond-Neveu-Schwarz supersymmetric action for a p-brane of p > 1. We also derive a spacetime supersymmetric Green-Schwarz extension from the preexisting kappa-symmetric action.
15885764
Three-algebra for supermembrane and two-algebra for superstring
While string or Yang-Mills theories are based on Lie algebra or two-algebra structure, recent studies indicate that -theory may require a one higher, three-algebra structure. Here we construct a covariant action for a supermembrane in eleven dimensions, which is invariant under global supersymmetry, local fermionic symmetry and worldvolume diffeomorphism. Our action is classically on-shell equivalent to the celebrated Bergshoeff-Sezgin-Townsend action. However, the novelty is that we spell the action genuinely in terms of Nambu three-brackets: All the derivatives appear through Nambu brackets and hence it manifests the three-algebra structure. Further the double dimensional reduction of our action gives straightforwardly to a type IIA string action featuring two-algebra. Applying the same method, we also construct a covariant action for type IIB superstring, leading directly to the IKKT matrix model.
119309124
Ramond-Ramond cohomology and O(D, D) T-duality
A bstractIn the name of supersymmetric double field theory, superstring effective actions can be reformulated into simple forms. They feature a pair of vielbeins corresponding to the same spacetime metric, and hence enjoy double local Lorentz symmetries. In a manifestly covariant manner — with regard to O(D, D) T-duality, diffeomorphism, B-field gauge symmetry and the pair of local Lorentz symmetries — we incorporate R-R potentials into double field theory. We take them as a single object which is in a bi-fundamental spinorial representation of the double Lorentz groups. We identify cohomological structure relevant to the field strength. A priori, the R-R sector as well as all the fermions are O(D, D) singlet. Yet, gauge fixing the two vielbeins equal to each other modifies the O(D, D) transformation rule to call for a compensating local Lorentz rotation, such that the R-R potential may turn into an O(D, D) spinor and T-duality can flip the chirality exchanging type IIA and IIB supergravities.
118474061
Supersymmetric M5 brane theories on R × CP2
A bstractWe propose 4 and 12 supersymmetric conformal Yang-Mills-Chern-Simons theories on R × CP2 as multiple representations of the theory on M5 branes. These theories are obtained by twisted Zk modding and dimensional reduction of the 6d (2,0) superconformal field theory on R × S5 and have a discrete coupling constant $ \frac{1}{{g_{{Y\;M}}^2}}=\frac{k}{{4{\pi^2}}} $ with natural number k. Instantons in these theories are expected to represent the Kaluza-Klein modes. For the k = 1, 2 cases, we argue that the number of supersymmetries in our theories should be enhanced to 32 and 16, respectively. For the k = 3 case, only the 4 supersymmetric theory gets the supersymmetric enhancement to 8. For the 4 supersymmetric case, the vacuum structure becomes more complicated as there are degenerate supersymmetric vacua characterized by fuzzy spheres. We calculate the perturbative part of the SU(N ) gauge group Euclidean path integral for the index function at the symmetric phase of the 4 supersymmetric case and confirm it with the known half-BPS index. From the similar twisted Zk modding of the AdS7 × S4 geometry, we speculate that the M region is for k ≲ N1/3 and the type IIA region is N1/3 ≲ k ≲ N. When nonperturbative corrections are included, our theories are expected to produce the full index of the 6d (2,0) theory.
10365060
The Chern-Simons coefficient in supersymmetric Yang-Mills Chern-Simons theories
We study one-loop corrections to the Chern-Simons coefficient κ = k4π in N = 1, 2, 3 supersymmetric Yang-Mills Chern-Simons systems. In the pure bosonic case, the shift of the parameter k is known to be k → k + cv, where cv is the quadratic Casimir of the gauge group. In the N = 1 case, the fermionic contribution cancels the bosonic contribution by half and the shift is k → k + cv2, making the theory anomalous if cv is odd. In the N = 2, 3 cases, the fermionic contribution cancels the bosonic contribution completely and there is no correction. We also calculate the mass corrections, and show that the supersymmetry is preserved. As the matter fields decouple from the gauge field in the pure Chern-Simons limit, this work sheds some light on the regularization dependency of the correction in pure Chern-Simons systems. We also discuss the implication to the case when the gauge symmetry is spontaneously broken by the Higgs mechanism.
124365920
A statistical model analysis of the rapidity distribution of hadrons
123382046
Tunnelling without barriers in curved space-time
Abstract The evolution in curved space-time of quantum fields in theories with relatively flat potentials is considered. It is known that bubble nucleation, a quantum mechanical tunneling process, may occur in flat space-time even if V ( φ ) has no barrier. It is shown that bubble nucleation can also occur in curved space-time even though there is no bounce solution in the standard formalism for the bubble nucleation rate in curved space-time. Some implications for inflationary scenarios are discussed.
14337412
Implications of the muon anomalous magnetic moment and Higgs-mediated flavor changing neutral currents
Abstract In the light of the recent measurement of the muon anomalous magnetic moment a μ by the Muon ( g −2) Collaboration, we examine the contribution to a μ from the exchange of flavor changing scalars. Assuming that the heavier generations have larger flavor changing couplings, we obtain a bound on the μ – τ Yukawa coupling for a given scalar mass. Constraints on other individual flavor changing/conserving couplings are also obtained from the lepton flavor violating decays of the muon and tau leptons, and bounds on the branching ratio of τ →3 e , μ →3 e and τ → eμe processes are predicted. In addition, we study the implications of the lepton flavor violating pair production at e + e − colliders.