F-theory and the classification of little strings

Abstract

Little string theories (LSTs) are UV complete non-local 6D theories decoupled from gravity in which there is an intrinsic string scale. In this paper we present a systematic approach to the construction of supersymmetric LSTs via the geometric phases of F-theory. Our central result is that all LSTs with more than one tensor multiplet are obtained by a mild extension of 6D superconformal field theories (SCFTs) in which the theory is supplemented by an additional, non-dynamical tensor multiplet, analogous to adding an affine node to an ADE quiver, resulting in a negative semidefinite Dirac pairing. We also show that all 6D SCFTs naturally embed in an LST. Motivated by physical considerations, we show that in geometries where we can verify the presence of two elliptic fibrations, exchanging the roles of these fibrations amounts to T-duality in the 6D theory compactified on a circle. *

XYZResonances at Belle

“…As described above, the admixture scenario also gives an explanation for this question. In the χ c1 π + π − mass spectrum in B → χ c1 π + π − K decays, an attempt has been made to look for a peak at 3872 MeV/c 2 or 3920 MeV/c 2 and no significant signal is found, though there is no obvious quantum number conflict [16].…”

Little strings on D n orbifolds

“…The common feature of LSTs is that a ij has precisely one null eigenvector n i [5,6]. The linear combinations of the tensor multiplet fields, B b = n i B i and Φ b = n i Φ i , have vanishing kinetic terms, as being non-dynamical background fields.…”

“…The linear combinations of the tensor multiplet fields, B b = n i B i and Φ b = n i Φ i , have vanishing kinetic terms, as being non-dynamical background fields. The VEV of the nondynamical scalar Φ b defines the mass scale of the theory, Φ b ∼ m 2 s ∼ (α ) −1 , rather than participating into the tensor branch [5]. And also, the non-dynamical 2-form B b cannot participate in the Green-Schwarz mechanism, so the gauge anomaly of one gauge node must vanish by itself [5,6].…”

“…They depend on a scale parameter m s ∼ (α ) −1/2 which determines the tension of little strings. They can be regarded as "affine" extensions of 6d superconformal field theories, which add an extra background tensor multiplet coupled to the little strings [5,6]. There are a vast number of LSTs found from various combinations of branes and/or geometric singularities in the decoupling limit g s → 0 [1][2][3][4][7][8][9][10].…”

“…There are a vast number of LSTs found from various combinations of branes and/or geometric singularities in the decoupling limit g s → 0 [1][2][3][4][7][8][9][10]. Broader classes of LSTs can be constructed from F-theory wrapped on non-compact Calabi-Yau threefolds [5,[11][12][13].…”