Related papers: Common origin of the strong CP and CKM phases in s…
We propose a scenario for realizing super-Planckian axion decay constants in Calabi-Yau orientifolds of type IIB string theory, leading to large-field inflation. Our construction is a simple embedding in string theory of the mechanism of…
We uncover a Kawai-Lewellen-Tye (KLT)-type factorization of closed string amplitudes into open string amplitudes for closed string states carrying winding and momentum in toroidal compactifications. The winding and momentum closed string…
A small upper-bound is obtained for the CP phase $\delta$ in a CKM matrix, $|\sin\delta| \le 0.44$ based on CP independent data on $|V_{ub}/V_{cb}|$ alone. Potential inconsistencies with the CKM model in existing data which need a theory…
CP-violating asymmetries in $B \to \pi \pi$ and $B \to \rho \rho$ decays can help specify the weak phase $\phi_2 = \alpha$ of the Cabibbo-Kobayashi-% Maskawa (CKM) matrix. We discuss the impact of improved measurements of these processes…
Cosmic strings in the brane Universe have recently gained a great interest. I think the most interesting story is that future cosmological observations distinguish them from the conventional cosmic strings. If the strings are the…
Effective type I string models allow stabilization of the dilaton and moduli fields with only a single gaugino condensate. We show that, as well as breaking supersymmetry, the stabilization can spontaneously break CP. We find that this…
We use recently obtained 2-loop string coupling constants to analyze a class of string models based on orbifold compactification. Assuming weak coupling at the string scale and single-scale unification leads to restrictions on the spectrum…
We review recent progress in the construction of four-dimensional vacua of Type II string theory and F-theory which yield the Standard Model of particle physics (SM) or extensions thereof. In Type II orientifold compactifications the SM…
The origin of `invisible' axion in four dimensional effective beyond-standard models from string compactification is discussed and its refined passover through the QCD phase transition is presented toward a reliable estimate of the current…
A variety of CP violating asymmetries in $B^0$ decays is predicted in the Standard Model in terms of CKM (Cabibbo-Kobayashi-Maskawa) complex phases. These phases can also be determined from rate measurements of certain $B^+$ and $B^-$…
The physical motivations and the basic construction rules for Type I strings and M-theory compactifications are reviewed in light of the recent developments. The first part contains the basic theoretical ingredients needed for building…
We investigate the possibility of enhancement of effective axion decay constant in well controlled constructions in string theory. To this end, we study the dynamics of axions arising in the compactifications of type IIA string theory on…
The string landscape satisfies interesting finiteness properties imposed by supersymmetry and string-theoretical consistency conditions. We study N=1 supersymmetric compactifications of Type IIB string theory on smooth elliptically fibered…
Axions, grand unification, and string theory are each compelling extensions of the Standard Model. We show that combining these frameworks imposes strong constraints on the QCD axion mass. Using unitarity arguments and explicit string…
We present a general analysis on charmless B-meson decays $B\to \pi\pi$ and $\pi K$. It is noticed that the final state interactions and inelastic rescattering effects must be significant in order to understand the consistency of the…
We consider type II string compactifications on Calabi-Yau orientifolds with fluxes and D-branes, and analyse the F-term scalar potential that simultaneously involves closed and open string modes. In type IIA models with D6-branes such…
If nature is described by string theory, and if the compactification radius is large (as suggested by the unification of couplings), then the theory is in a regime best described by the low energy limit of $M$-theory. We discuss some…
A certain topological field theory is shown to be equivalent to the compactified c=1 string. This theory is described in both Kazama-Suzuki coset and Landau-Ginzburg formulations. The genus-g partition function and genus-0 multi-tachyon…
We construct stringy cosmic string solutions corresponding to compactifications of F-theory on several elliptic Calabi-Yau manifolds by solving the equations of motion of low energy effective action of ten dimensional type IIB superstring…
We show that EDMs obey a simple approximate scaling under the transformation $m_0\to \lambda m_0,m_{{1/2}}\to \lambda m_{{1/2}}$ in the large $\mu$ region when $\mu$ itself obeys the same scaling, ie., $\mu \to \lambda \mu$. In the scaling…