Journal of High Energy Physics

http://link.springer.com/journal/13130

List of Papers (Total 9,333)

Subsystem eigenstate thermalization hypothesis for entanglement entropy in CFT

We investigate a weak version of subsystem eigenstate thermalization hypothesis (ETH) for a two-dimensional large central charge conformal field theory by comparing the local equivalence of high energy state and thermal state of canonical ensemble. We evaluate the single-interval Rényi entropy and entanglement entropy for a heavy primary state in short interval expansion. We verify ...

Multi-soft gluon limits and extended current algebras at null-infinity

In this note we consider aspects of the current algebra interpretation of multisoft limits of tree-level gluon scattering amplitudes in four dimensions. Building on the relation between a positive helicity gluon soft-limit and the Ward identity for a level-zero Kac-Moody current, we use the double-soft limit to define the Sugawara energy-momentum tensor and, by using the triple- ...

Detection prospects of light pseudoscalar Higgs boson at the LHC

The discovery potential of light pseudo scalar Higgs boson for the mass range 10-60 GeV is explored. In the context of the next-to-minimal supersymmetric standard (NMSSM) model, the branching fraction of light pseudo scalar Higgs boson decaying to a pair of photon can be quite large. A pair of light pseudo scalar Higgs boson produced indirectly through the standard model Higgs ...

3d \( \mathcal{N}=2 \) minimal SCFTs from wrapped M5-branes

We study CFT data of 3-dimensional superconformal field theories (SCFTs) arising from wrapped two M5-branes on closed hyperbolic 3-manifolds. Via so-called 3d/3d correspondence, central charges of these SCFTs are related to a SL(2) Chern-Simons (CS) invariant on the 3-manifolds. After developing a state-integral model for the invariant, we numerically evaluate the central charges ...

Feasibility of measuring the magnetic dipole moments of the charm baryons at the LHC using bent crystals

In this paper we revisit the idea of measuring the magnetic dipole moments of the charm baryons and, in particular, of Λ c + by studying the spin precession induced by the strong effective magnetic field inside the channels of a bent crystal. We present a detailed sensitivity study showing the feasibility of such an experiment at the LHC in the coming years.

Strolling along gauge theory vacua

We consider classical, pure Yang-Mills theory in a box. We show how a set of static electric fields that solve the theory in an adiabatic limit correspond to geodesic motion on the space of vacua, equipped with a particular Riemannian metric that we identify. The vacua are generated by spontaneously broken global gauge symmetries, leading to an infinite number of conserved momenta ...

Geodesic description of heavy-light Virasoro blocks

We continue to investigate the dual description of the Virasoro conformal blocks arising in the framework of the classical limit of the AdS3/CFT2 correspondence. To give such an interpretation in previous studies, certain restrictions were necessary. Our goal here is to consider a more general situation available through the worldline approximation to the dual AdS gravity. Namely, ...

Compilation of low-energy constraints on 4-fermion operators in the SMEFT

We compile information from low-energy observables sensitive to flavor-conserving 4-fermion operators with two or four leptons. Our analysis includes data from e + e − colliders, neutrino scattering on electron or nucleon targets, atomic parity violation, parity-violating electron scattering, and the decay of pions, neutrons, nuclei and tau leptons. We recast these data as ...

The supercurrent and Einstein equations in the superconformal formulation

We give a new expression for the supercurrent and its conservation in curved \( \mathcal{N} \) =1, D = 4 superspace using the superconformal approach. The first component of the superfield, whose lowest component is the vector auxiliary field gives the (super)Einstein equations. Its trace and couplings to conformal and non-conformal matter are presented. In a suitable dilatational ...

Time dependence of entanglement entropy on the fuzzy sphere

We numerically study the behaviour of entanglement entropy for a free scalar field on the noncommutative (“fuzzy”) sphere after a mass quench. It is known that the entanglement entropy before a quench violates the usual area law due to the non-local nature of the theory. By comparing our results to the ordinary sphere, we find results that, despite this non-locality, are compatible ...

Singularity development and supersymmetry in holography

We study the effects of supersymmetry on singularity development scenario in holography presented in [1] (BBL). We argue that the singularity persists in a supersymmetric extension of the BBL model. The challenge remains to find a string theory embedding of the singularity mechanism.

Carving out the end of the world or (superconformal bootstrap in six dimensions)

We bootstrap \( \mathcal{N}=\left(1,0\right) \) superconformal field theories in six dimensions, by analyzing the four-point function of flavor current multiplets. Assuming E 8 flavor group, we present universal bounds on the central charge C T and the flavor central charge C J . Based on the numerical data, we conjecture that the rank-one E-string theory saturates the universal ...

Higgsed Gauge-flation

We study a variant of Gauge-flation where the gauge symmetry is spontaneously broken by a Higgs sector. We work in the Stueckelberg limit and demonstrate that the dynamics remain (catastrophically) unstable for cases where the gauge field masses satisfy γ < 2, where γ = g 2 ψ 2/H 2, g is the gauge coupling, ψ is the gauge field vacuum expectation value, and H is the Hubble rate. We ...

Semi-abelian Z-theory: NLSM+ϕ 3 from the open string

We continue our investigation of Z-theory, the second double-copy component of open-string tree-level interactions besides super-Yang-Mills (sYM). We show that the amplitudes of the extended non-linear sigma model (NLSM) recently considered by Cachazo, Cha, and Mizera are reproduced by the leading α ′-order of Z-theory amplitudes in the semi-abelian case. The extension refers to a ...

S-matrix singularities and CFT correlation functions

In this note, we explore the correspondence between four-dimensional flat space S-matrix and two-dimensional CFT proposed by Pasterski et al. We demonstrate that the factorisation singularities of an n-point cubic diagram reproduces the AdS Witten diagrams if mass conservation is imposed at each vertex. Such configuration arises naturally if we consider the 4-dimensional S-matrix ...

Phenomenology of \( {\Lambda}_b\to {\Lambda}_c\tau {\overline{\nu}}_{\tau } \) using lattice QCD calculations

In a recent paper we studied the effect of new-physics operators with different Lorentz structures on the semileptonic \( {\Lambda}_b\to {\Lambda}_c\tau {\overline{\nu}}_{\tau } \) decay. This decay is of interest in light of the R(D (*)) puzzle in the semileptonic \( \overline{B}\to {D}^{\left(\ast \right)}\tau {\overline{\nu}}_{\tau } \) decays. In this work we add tensor ...

All (4,0): Sigma models with (4,0) off-shell supersymmetry

Off-shell (4, 0) supermultiplets in 2-dimensions are formulated. These are used to construct sigma models whose target spaces are vector bundles over manifolds that are hyperkähler with torsion. The off-shell supersymmetry implies that the complex structures are simultaneously integrable and allows us to write actions using extended superspace and projective superspace, giving an ...

Combinatorics and topology of Kawai-Lewellen-Tye relations

We revisit the relations between open and closed string scattering amplitudes discovered by Kawai, Lewellen, and Tye (KLT). We show that they emerge from the un-derlying algebro-topological identities known as the twisted period relations. In order to do so, we formulate tree-level string theory amplitudes in the language of twisted de Rham theory. There, open string amplitudes are ...

Rare radiative charm decays within the standard model and beyond

We present standard model (SM) estimates for exclusive c → uγ processes in heavy quark and hybrid frameworks. Measured branching ratios \( \mathrm{\mathcal{B}}\left({D}^0\to\ \left(\phi, {\overline{K}}^{\ast 0}\right)\gamma \right) \) are at or somewhat exceeding the upper range of the SM and suggest slow convergence of the 1/m D , α s -expansion. Model-independent constraints on ...

Gravitational wave, collider and dark matter signals from a scalar singlet electroweak baryogenesis

We analyse a simple extension of the SM with just an additional scalar singlet coupled to the Higgs boson. We discuss the possible probes for electroweak baryogenesis in this model including collider searches, gravitational wave and direct dark matter detection signals. We show that a large portion of the model parameter space exists where the observation of gravitational waves ...

Higher spin currents in the critical O(N) vector model at 1/N 2

We calculate the anomalous dimensions of higher spin singlet currents in the critical O(N ) vector model at order 1/N 2. The results are shown to be in agreement with the four-loop perturbative computation in ϕ 4 theory in 4 − 2ϵ dimensions. It is known that the order 1/N anomalous dimensions of higher-spin currents happen to be the same in the Gross-Neveu and the critical vector ...

A leptoquark model to accommodate R K exp < R K SM and \( {R}_{K^{\ast}}^{\exp }<{R}_{K^{\ast}}^{\mathrm{SM}} \)

We show that a modification of the model with a low energy scalar leptoquark state carrying hypercharge Y = 7/6 allows to accommodate both R K < 1 and R K ∗ < 1, through loop effects, consistent with recent observations made at LHCb. We describe details of the model, compute the relevant Wilson coefficient and, after discussing a number of constraints, we examine the ...

An electroweak basis for neutrinoless double β decay

A discovery of neutrinoless double-β decay would be profound, providing the first direct experimental evidence of ΔL = 2 lepton number violating processes. While a natural explanation is provided by an effective Majorana neutrino mass, other new physics interpretations should be carefully evaluated. At low-energies such new physics could man-ifest itself in the form of color and ...

BPS black hole horizons from massive IIA

The maximal four-dimensional supergravity with a dyonic ISO(7) gauging that arises from the reduction of massive IIA on a six-sphere has recently been shown to accommodate static BPS black holes with hyperbolic horizons. When restricted to the \( \mathcal{N}=2 \) subsector that retains one vector multiplet and the universal hypermultiplet, the attractor mechanism was shown to fix ...

Log corrections to entropy of three dimensional black holes with soft hair

We calculate log corrections to the entropy of three-dimensional black holes with “soft hairy” boundary conditions. Their thermodynamics possesses some special features that preclude a naive direct evaluation of these corrections, so we follow two different approaches. The first one exploits that the BTZ black hole belongs to the spectrum of Brown-Henneaux as well as soft hairy ...