Journal of High Energy Physics

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

List of Papers (Total 11,631)

Black holes and fourfolds

We establish a relation between the structure governing four- and five- dimensional black holes and multicenter solutions on the one hand and Calabi-Yau flux compactifications of M-theory and type IIB string theory on the other hand, for both supersymmetric and non-supersymmetric solutions. We find that the known BPS and almost-BPS multicenter black hole solutions can be...

Higher-spin fermionic gauge fields and their electromagnetic coupling

We study the electromagnetic coupling of massless higher-spin fermions in flat space. Under the assumptions of locality and Poincaré invariance, we employ the BRST-BV cohomological methods to construct consistent parity-preserving off-shell cubic 1 − s − s vertices. Consistency and non-triviality of the deformations not only rule out minimal coupling, but also restrict the...

Higgs mass and vacuum stability in the Standard Model at NNLO

We present the first complete next-to-next-to-leading order analysis of the Standard Model Higgs potential. We computed the two-loop QCD and Yukawa corrections to the relation between the Higgs quartic coupling (λ) and the Higgs mass (M h ), reducing the theoretical uncertainty in the determination of the critical value of M h for vacuum stability to 1 GeV. While λ at the Planck...

On flux quantization in F-theory II: unitary and symplectic gauge groups

We study the quantization of the M-theory G-flux on elliptically fibered Calabi-Yau fourfolds with singularities giving rise to unitary and symplectic gauge groups. We seek and find its relation to the Freed-Witten quantization of worldvolume fluxes on 7-branes in type IIB orientifold compactifications on Calabi-Yau threefolds. By explicitly constructing the appropriate four...

Anatomy of maximal stop mixing in the MSSM

A Standard Model-like Higgs near 125 GeV in the MSSM requires multi-TeV stop masses, or a near-maximal contribution to its mass from stop mixing. We investigate the maximal mixing scenario, and in particular its prospects for being realized it in potentially realistic GUT models. We work out constraints on the possible GUT-scale soft terms, which we compare with what can be...

Supersymmetric constraints from B s → μ + μ − and B → K * μ + μ − observables

We study the implications of the recent LHCb limit and results on B s → μ + μ − and B → K * μ + μ − observables in the constrained SUSY scenarios. After discussing the Standard Model predictions and carefully estimating the theoretical errors, we show the constraining power of these observables in CMSSM and NUHM. The latest limit on BR(B s → μ + μ −), being very close to the SM...

Future prospects for the determination of the Wilson coefficient \( C_{{^{{7\gamma }}}}^{\prime } \)

We discuss the possibilities of assessing a non-zero \( C_{{^{{7\gamma }}}}^{\prime } \) from the direct and the indirect measurements of the photon polarization in the exclusive b → sγ(*) decays. We focus on three methods and explore the following three decay modes: B → K * (→ K S π 0)γ, B → K 1(→ Kππ)γ, and B → K * (→ Kπ)ℓ + ℓ −. By studying different New Physics scenarios we...

Stringy stability of charged dilaton black holes with flat event horizon

Electrically charged black holes with flat event horizon in anti-de Sitter space have received much attention due to various applications in Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, from modeling the behavior of quark-gluon plasma to superconductor. Crucial to the physics on the dual field theory is the fact that when embedded in string theory, black holes...

Mellin amplitudes for dual conformal integrals

Motivated by recent work on the utility of Mellin space for representing conformal correlators in AdS/CFT, we study its suitability for representing dual conformal integrals of the type which appear in perturbative scattering amplitudes in super-Yang-Mills theory. We discuss Feynman-like rules for writing Mellin amplitudes for a large class of integrals in any dimension, and find...

Implications of a modified Higgs to diphoton decay width

Motivated by recent results from Higgs searches at the Large Hadron Collider, we consider possibilities to enhance the diphoton decay width of the Higgs boson over the Standard Model expectation, without modifying either its production rate or the partial widths in the WW and ZZ channels. Studying effects of new charged scalars, fermions and vector bosons, we find that...

Study of Monte Carlo approach to experimental uncertainty propagation with MSTW 2008 PDFs

We investigate the Monte Carlo approach to propagation of experimental uncertainties within the context of the established “MSTW 2008” global analysis of parton distribution functions (PDFs) of the proton at next-to-leading order in the strong coupling. We show that the Monte Carlo approach using replicas of the original data gives PDF uncertainties in good agreement with the...

Supersymmetric vacua in N = 2 supergravity

We use the embedding tensor formalism to analyse maximally symmetric backgrounds of N = 2 gauged supergravities which have the full N = 2 supersymmetry. We state the condition for N = 2 vacua and discuss some of their general properties. We show that if the gauged isometries leave the SU(2) R-symmetry invariant, then the N = 2 vacuum must be Minkowski. This implies that there are...

Sigma terms and strangeness content of the nucleon with N f  = 2 + 1 + 1 twisted mass fermions

We study the nucleon matrix elements of the quark scalar-density operator using maximally twisted mass fermions with dynamical light (u,d), strange and charm degrees of freedom. We demonstrate that in this setup the nucleon matrix elements of the light and strange quark densities can be obtained with good statistical accuracy, while for the charm quark counterpart only a bound...

Non-supersymmetric conifold

We find a new family of non-supersymmetric numerical solutions of IIB supergravity which are dual to the \( \mathcal{N} = 1 \) cascading “conifold” theory perturbed by certain combinations of relevant single trace and marginal double trace operators with non infinitesimal couplings. The SUSY is broken but the resulting ground states, and their gravity duals, remain stable, at...

Massive hermitian gravity

Einstein-Strauss Hermitian gravity was recently formulated as a gauge theory where the tangent group is taken to be the pseudo-unitary group instead of the orthogonal group. A Higgs mechanism for massive gravity was also formulated. We generalize this construction to obtain massive Hermitian gravity with the use of a complex Higgs multiplet. We show that both the graviton and...

Search for leptonic decays of W′ bosons in pp collisions at \( \sqrt {s} = {7} \) TeV

A search for a new heavy gauge boson W′ decaying to an electron or muon, plus a low mass neutrino, is presented. This study uses data corresponding to an integrated luminosity of 5.0 fb−1, collected using the CMS detector in pp collisions at a centre-of-mass energy of 7 TeV at the LHC. Events containing a single electron or muon and missing transverse momentum are analyzed. No...

Discrete flavour groups, θ 13 and lepton flavour violation

Discrete flavour groups have been studied in connection with special patterns of neutrino mixing suggested by the data, such as Tri-Bimaximal mixing (groups A 4, S 4…) or Bi-Maximal mixing (group S 4…) etc. We review the predictions for sin θ 13 in a number of these models and confront them with the experimental measurements. We compare the performances of the different classes...

Alleviating the non-ultralocality of coset σ-models through a generalized Faddeev-Reshetikhin procedure

The Faddeev-Reshetikhin procedure corresponds to a removal of the non-ultralocality of the classical SU(2) principal chiral model. It is realized by defining another field theory, which has the same Lax pair and equations of motion but a different Poisson structure and Hamiltonian. Following earlier work of M. Semenov-Tian-Shansky and A. Sevostyanov, we show how it is possible to...

Hiding a heavy Higgs boson at the 7 TeV LHC

A heavy Standard Model Higgs boson is not only disfavored by electroweak precision observables but is also excluded by direct searches at the 7 TeV LHC for a wide range of masses. Here, we examine scenarios where a heavy Higgs boson can be made consistent with both the indirect constraints and the direct null searches by adding only one new particle beyond the Standard Model...

Reach the bottom line of the sbottom search

We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two b-jets besides the initial state radiation...

Building SO(10) models from F-theory

We revisit local F-theory SO(10) and SU(5) GUTs and analyze their properties within the framework of the maximal underlying E 8 symmetry in the elliptic fibration. We consider the symmetry enhancements along the intersections of seven-branes with the GUT surface and study in detail the embedding of the abelian factors undergoing monodromies in the covering gauge groups. We...

Cross section ratios between different CM energies at the LHC: opportunities for precision measurements and BSM sensitivity

The staged increase of the LHC beam energy provides a new class of interesting observables, namely ratios and double ratios of cross sections of various hard processes. The large degree of correlation of theoretical systematics in the cross section calculations at different energies leads to highly precise predictions for such ratios. We present in this letter few examples of...

Inverted sfermion mass hierarchy and the Higgs boson mass in the MSSM

Abstract It is shown that MSSM with first two generations of squarks and sleptons much heavier than the third one naturally predicts the maximal stop mixing as a consequence of the RG evolution, with vanishing (or small) trilinear coupling at the high scale. The Higgs boson is generically heavy, in the vicinity of 125 GeV. In this inverted hierarchy scenario, motivated by the...

Wavefunctions and the point of E 8 in F-theory

AbstractIn F-theory GUTs interactions between fields are typically localised at points of enhanced symmetry in the internal dimensions implying that the coefficient of the associated operator can be studied using a local wavefunctions overlap calculation. Some F-theory SU(5) GUT theories may exhibit a maximum symmetry enhancement at a point to E 8, and in this case all the...