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Jonathan Bagger

Publications and source records attributed to Jonathan Bagger.

At least 19 recordsLinked to original sources
arXiv2022

The International Linear Collider: Report to Snowmass 2021

The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community.

physics.acc-ph↗
arXiv2019

The International Linear Collider. A Global Project

A large, world-wide community of physicists is working to realise an exceptional physics program of energy-frontier, electron-positron collisions with the International Linear Collider (ILC). This program will begin with a central focus on high-precision and model-independent measurements of the Higgs boson couplings. This method of searching for new physics beyond the Standard Model is orthogonal to and complements the LHC physics program. The ILC at 250 GeV will also search for direct new physics in exotic Higgs decays and in pair-production of weakly interacting particles. Polarised electron and positron beams add unique opportunities to the physics reach. The ILC can be upgraded to higher energy, enabling precision studies of the top quark and measurement of the top Yukawa coupling and the Higgs self-coupling. The key accelerator technology, superconducting radio-frequency cavities, has matured. Optimised collider and detector designs, and associated physics analyses, were presented in the ILC Technical Design Report, signed by 2400 scientists. There is a strong interest in Japan to host this international effort. A detailed review of the many aspects of the project is nearing a conclusion in Japan. Now the Japanese government is preparing for a decision on the next phase of international negotiations, that could lead to a project start within a few years. The potential timeline of the ILC project includes an initial phase of about 4 years to obtain international agreements, complete engineering design and prepare construction, and form the requisite international collaboration, followed by a construction phase of 9 years.

hep-ex↗
arXiv2012

Multiple Membranes in M-theory

We review developments in the theory of multiple, parallel membranes in M-theory. After discussing the inherent difficulties pertaining to a maximally supersymmetric lagrangian formulation with the appropriate field content and symmetries, we discuss how introducing the concept of 3-algebras allows for such a description. Different choices of 3-algebras lead to distinct classes of 2+1 dimensional theories with varying degrees of supersymmetry. We then describe how these are equivalent to a type of conventional superconformal Chern-Simons gauge theories at level k, coupled to bifundamental matter. Analysing the physical properties of these theories leads to the identification of a certain subclass of models with configurations of M2-branes in Z_k orbifolds of M-theory. In addition these models give rise to a whole new sector of the gauge/gravity duality in the form of an AdS_4/CFT_3 correspondence. We also discuss mass deformations, higher derivative corrections as well as the possibility of extracting information about M5-brane physics.

hep-th↗
arXiv2011

Supersymmetric Nonlinear Sigma Model in AdS_5

We construct the supersymmetric nonlinear sigma model in a fixed AdS_5 background. We use component fields and find that the complex bosons must be the coordinates of a hyper-Kahler manifold that admits a Killing vector satisfying an inhomogeneous tri-holomorphic condition. We propose boundary conditions that map the on-shell bulk hypermultiplets into off-shell chiral multiplets on 3-branes that foliate the bulk. The supersymmetric AdS_5 isometries reduce to superconformal transformations on the brane fields.

hep-th↗
arXiv2011

AdS_5 Supersymmetry in N=1 Superspace

We use N=1 superspace to construct the supersymmetric matter couplings of vector and hyper multiplets in a five-dimensional anti-de Sitter spacetime background. For hypermultiplets, we find that AdS_5 supersymmetry requires the scalar fields to lie on a hyper-Kahler manifold endowed with a certain type of holomorphic Killing vector.

hep-th↗
arXiv2010

Three-Algebras in N = 5, 6 Superconformal Chern-Simons Theories: Representations and Relations

In this work we present 3-algebraic constructions and representations for three-dimensional N = 5 supersymmetric Chern-Simons theories, and show how they relate to theories with additional supersymmetries. The N = 5 structure constants give theories with Sp(2N) \times SO(M) gauge symmetry, as well as more exotic symmetries known from gauged supergravity. We find explicit lifts from N = 6 to 8, and N = 5 to 6 and 8, for appropriate gauge groups.

hep-th↗
arXiv2008

Three-Algebras and N=6 Chern-Simons Gauge Theories

We derive the general form for a three-dimensional scale-invariant field theory with N=6 supersymmetry, SU(4) R-symmetry and a U(1) global symmetry. The results can be written in terms of a 3-algebra in which the triple product is not antisymmetric. For a specific choice of 3-algebra we obtain the N=6 theories that have been recently proposed as models for M2-branes in an R^8/Z_k orbifold background.

hep-th↗
arXiv2007

Comments on Multiple M2-branes

Recently a three-dimensional field theory was derived that is consistent with all the symmetries expected of the worldvolume action for multiple M2-branes. In this note we examine several physical predictions of this model and show that they are in agreement with expected M2-brane dynamics. In particular, we discuss the quantization of the Chern-Simons coefficient, the vacuum moduli space, a massive deformation leading to fuzzy three-sphere vacua, and a possible large n limit. In this large n limit, the fuzzy funnel solution correctly reproduces the mass of an M5-brane.

hep-th↗
arXiv2007

Gauge Symmetry and Supersymmetry of Multiple M2-Branes

In previous work we proposed a field theory model for multiple M2-branes based on an algebra with a totally antisymmetric triple product. In this paper we gauge a symmetry that arises from the algebra's triple product. We then construct a supersymmetric theory that is consistent with all the symmetries expected of a multiple M2-brane theory: 16 supersymmetries, conformal invariance, and an SO(8) R-symmetry that acts on the eight transverse scalars. The gauge field is not dynamical. The result is a new type of maximally supersymmetric gauge theory in three dimensions.

hep-th↗
arXiv2007

Modeling Multiple M2's

We investigate the worldvolume theory that describes N coincident M2-branes ending on an M5 brane. We argue that the fields that describe the transverse spacetime coordinates take values in a non-associative algebra. We postulate a set of supersymmetry transformations and find that they close into a novel gauge symmetry. We propose a three-dimensional N=2 supersymmetric action to describe the truncation of the full theory to the scalar and spinor fields, and show how a Basu-Harvey fuzzy funnel arises as the BPS solution to this theory.

hep-th↗
arXiv2006

N=2 Nonlinear Sigma Models in N=1 Superspace: Four and Five Dimensions

We formulate four-dimensional N=2 supersymmetric nonlinear sigma models in N=1 superspace. We show how to add superpotentials consistent with N=2 supersymmetry. We lift our construction to higher-dimensional spacetime and write five-dimensional nonlinear sigma models in N=1 superspace.

hep-th↗
arXiv2005

SuperHiggs Mechanism in String Theory

We exhibit the superHiggs effect in heterotic string theory by turning on a background NS-NS field and deforming the BRST operator consistent with superconformal invariance. The NS-NS field spontaneously breaks spacetime supersymmetry. We show how the gravitini and the physical dilatini gain mass by eating the would-be Goldstone fermions.

hep-th↗
arXiv2004

Radion effective theory in the detuned Randall-Sundrum model

We compute the two-derivative low-energy effective action for the radion in the (supersymmetric) Randall-Sundrum scenario with detuned brane tensions. At the classical level, a potential automatically stabilizes the distance between the branes. In the supersymmetric case, supersymmetry can be broken spontaneously by a vacuum expectation value for the fifth component of the graviphoton.

hep-th↗
arXiv2003

Supersymmetry breaking by Wilson lines in AdS$_5$

In the Randall-Sundrum compactification of AdS$_5$ with detuned brane tensions, supersymmetry can be spontaneously broken by a non-trivial Wilson line for the graviphoton. The supersymmetry breaking vanishes in the tuned limit. This effect is equivalent to supersymmetry breaking by Scherk-Schwarz boundary conditions.

hep-th↗
arXiv2003

Boundary Conditions in Brane-World Supergravity

Bulk supergravity on a manifold with boundary must be supplemented by boundary conditions that preserve local supersymmetry. This "downstairs" picture has certain advantages over the equivalent "upstairs" picture, expressed in terms of orbifolds. In particular, Scherk-Schwarz supersymmetry breaking can be described much more simply in the downstairs picture. Nevertheless, physics on the fundamental domain can always be lifted upstairs, so long as fields are allowed to be discontinuous across the boundary. In this talk we apply these considerations to five-dimensional supergravity in a warped Randall-Sundrum background.

hep-th↗
arXiv2003

Twisting Warped Supergravity

We study gauged five-dimensional supergravity on the interval [0,πR]. We find a set of boundary conditions with respect to which the theory is locally supersymmetric. For theories with detuned brane tensions (Λ_4<0), we show that these boundary conditions can be used to spontaneously break global supersymmetry. For the original, tuned Randall-Sundrum scenario (Λ_4=0), we prove that the locally supersymmetric boundary conditions are also globally supersymmetric. We lift the theory from [0,πR] to S^1 and R, with arbitrary twists for the fermions, and cast these results in the language of the Scherk-Schwarz mechanism.

hep-th↗
arXiv2002

Supersymmetric branes with (almost) arbitrary tensions

We present a supersymmetric version of the two-brane Randall-Sundrum scenario, with arbitrary brane tensions T_1 and T_2, subject to the bound |T_{1,2}| \leq \sqrt{-6\Lambda_5}, where \Lambda_5 < 0 is the bulk cosmological constant. Dimensional reduction gives N=1, D=4 supergravity, with cosmological constant \Lambda_4 in the range \half\Lambda_5 \leq \Lambda_4 \leq 0. The case with \Lambda_4 = 0 requires T_1 = -T_2 = \sqrt{-6\Lambda_5}. This work unifies and generalizes previous approaches to the supersymmetric Randall-Sundrum scenario. It also shows that the Randall-Sundrum fine-tuning is not a consequence of supersymmetry.

hep-th↗