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Related papers: FCNC Processes from D-brane Instantons

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We examine the fluctuations around a Dp-brane solution in an unstable D-brane system using boundary states and also boundary string field theory. We show that the fluctuations correctly reproduce the fields on the Dp-brane. Plugging these…

High Energy Physics - Theory · Physics 2009-11-07 Tsuguhiko Asakawa , Shigeki Sugimoto , Seiji Terashima

This article discusses the status of string physics where the string tension is around the TeV scale. The article covers model building basics for perturbative strings, based on D-brane configurations. The effective low energy physics…

High Energy Physics - Theory · Physics 2015-06-18 David Berenstein

We develop the general formalism of string scattering from decaying D-branes in bosonic string theory. In worldsheet perturbation theory, amplitudes can be written as a sum of correlators in a grand canonical ensemble of unitary random…

High Energy Physics - Theory · Physics 2009-11-10 Vijay Balasubramanian , Esko Keski-Vakkuri , Per Kraus , Asad Naqvi

We discuss tree level three and four point scattering amplitudes in type II string models with matter fields localized at the intersections of D-brane wrapping cycles. Using conformal field theory techniques we calculate the four fermion…

High Energy Physics - Theory · Physics 2009-11-10 S. A. Abel , A. W. Owen

We show that the recent anomalies in $b \to s \ell^+ \ell^-$ transitions observed by the LHCb collaboration can be accommodated within string motivated models with a low mass $Z^{\prime}$ gauge boson. Such $Z^{\prime}$ gauge boson can be…

High Energy Physics - Phenomenology · Physics 2016-02-05 Alejandro Celis , Wan-Zhe Feng , Dieter Lust

One-loop corrections to the gauge coupling and the gauge kinetic function in certain classes of four-dimensional D-brane models are computed. It is described how to determine D-instanton corrections to the superpotential and the gauge…

High Energy Physics - Theory · Physics 2009-09-18 Maximilian Schmidt-Sommerfeld

We systematically search intersecting D-brane models, which just realize the Standard Model chiral matter contents and gauge symmetry. We construct new classes of non-supersymmetric Standard Model-like models. We also study gauge coupling…

High Energy Physics - Theory · Physics 2015-12-09 Yuta Hamada , Tatsuo Kobayashi , Shohei Uemura

We derive pomeron vertex operators for bosonic strings and superstrings in the presence of D-branes. We demonstrate how they can be used in order to compute the Regge behavior of string amplitudes on D-branes and the amplitude of…

High Energy Physics - Theory · Physics 2011-03-07 Angelos Fotopoulos , Nikolaos Prezas

A common way to obtain standard-model-like Lagrangians in string theory is to place D3-branes inside flux compactifications. The bosonic and fermionic masses and couplings of the resulting gauge theory are determined by the ten-dimensional…

High Energy Physics - Theory · Physics 2016-04-13 Iosif Bena , Mariana Graña , Stanislav Kuperstein , Praxitelis Ntokos , Michela Petrini

D-branes intersecting at an arbitrary fixed angle generically constitute a configuration unstable toward recombination. The reconnection of the branes nucleates at the intersection point and involves a generalization of the process of brane…

High Energy Physics - Theory · Physics 2009-11-10 Nicholas T. Jones , S. -H. Henry Tye

We consider string realizations of the Randall-Sundrum effective theory for electroweak symmetry breaking and explore the search for the lowest massive Regge excitation of the gluon and of the extra (color singlet) gauge boson inherent of…

High Energy Physics - Phenomenology · Physics 2010-12-23 Luis A. Anchordoqui , Haim Goldberg , Xing Huang , Tomasz R. Taylor

We clarify certain aspects and discuss extensions of the recently introduced string D-instanton calculus (hep-th/0609191). The one-loop determinants are related to one-loop open string threshold corrections in intersecting D6-brane models.…

High Energy Physics - Theory · Physics 2009-10-07 Nikolas Akerblom , Ralph Blumenhagen , Dieter Lust , Maximilian Schmidt-Sommerfeld

We review for non-experts possible phenomenological scenari in String Theory. In particular we focus on vacuum configurations with intersecting and/or magnetized unoriented D-branes. We will show how a TeV scale tension may be compatible…

High Energy Physics - Theory · Physics 2009-09-10 Massimo Bianchi

We study a class of type I string models with supersymmetry broken on the world-volume of some D-branes and vanishing tree-level potential. Despite the non-supersymmetric spectrum, supersymmetry is non-linearly realized on these D-branes,…

High Energy Physics - Theory · Physics 2015-06-26 I. Antoniadis , K. Benakli , A. Laugier

Intersecting D-brane models provide an attractive explanation of family replication in the context of string theory. We show, however, that the localization of fermion families at different brane intersections in the extra dimensions…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Abel , M. Masip , J. Santiago

The minimal embedding of the Standard Model in type I string theory is described. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The correct prediction of the weak angle is obtained for a string…

High Energy Physics - Theory · Physics 2015-06-26 I. Antoniadis , E. Kiritsis , T. Tomaras

Generic D-brane string models of particle physics predict the existence of extra U(1) gauge symmetries beyond hypercharge. These symmetries are not of the E_6 class but rather include the gauging of Baryon and Lepton numbers as well as…

High Energy Physics - Phenomenology · Physics 2011-09-29 D. M. Ghilencea , L. E. Ibanez , N. Irges , F. Quevedo

In this review we describe our current understanding of the properties of open string tachyons on an unstable D-brane or brane-antibrane system in string theory. The various string theoretic methods used for this study include techniques of…

High Energy Physics - Theory · Physics 2009-09-15 Ashoke Sen

We present a consistent string theory model which reproduces the Standard Model, consisting of a D3-brane at a simple orbifold singularity. We study some simple features of the phenomenology of the model. We find that the scale of stringy…

High Energy Physics - Phenomenology · Physics 2009-11-07 David Berenstein , Vishnu Jejjala , Robert G. Leigh

We calculate the leading order interactions of massless D-brane excitations. Their 4-point functions are found to be identical to those found in type I theory. The amplitude for two massless D-brane fluctuations to produce a massless closed…

High Energy Physics - Theory · Physics 2016-09-06 Akikazu Hashimoto , Igor R. Klebanov