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Starobinsky-Like Inflation and Neutrino Masses in a No-Scale SO(10) Model
http://cds.cern.ch/record/2216709
Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.Ellis, JohnGarcia, Marcos A GNagata, NatsumiNanopoulos, Dimitri VOlive, Keith ATue, 20 Sep 2016 05:48:53 GMT19 Sep 2016arXiv:1609.05849http://cds.cern.ch/record/2216709['arXiv:1609.05849']arXiv:1609.05849A Higgs in the Warped Bulk and LHC signals
http://cds.cern.ch/record/2210901
Warped models with the Higgs in the bulk can generate light Kaluza-Klein (KK) Higgs modes consistent with the electroweak precision analysis. The first KK mode of the Higgs (h_{1}) could lie in the 1-2 TeV range in the models with a bulk custodial symmetry. We find that the h_{1} is gaugephobic and decays dominantly into a t\bar{t} pair. We also discuss the search strategy for h_{1} decaying to t\bar{t} at the Large Hadron Collider. We used substructure tools to suppress the large QCD background associated with this channel. We find that h_{1} can be probed at the LHC run-2 with an integrated luminosity of 300 fb^{-1}.Mahmoudi, FMaitra, UManglani, NSridhar, KMon, 29 Aug 2016 05:48:20 GMT26 Aug 2016arXiv:1608.07407http://cds.cern.ch/record/2210901['arXiv:1608.07407']arXiv:1608.07407Glauber theory and the quantum coherence of curvature inhomogeneities
http://cds.cern.ch/record/2209738
The curvature inhomogeneities are systematically scrutinized in the framework of the Glauber approach. The amplified quantum fluctuations of the scalar and tensor modes of the geometry are shown to be first-order coherent while the interference of the corresponding intensities is larger than in the case of Bose-Einstein correlations. After showing that the degree of second-order coherence does not suffice to characterize unambiguously the curvature inhomogeneities, we argue that direct analyses of the degrees of third and fourth-order coherence are necessary to discriminate between different correlated states and to infer more reliably the statistical properties of the large-scale fluctuations. We speculate that the moments of the multiplicity distributions of the relic phonons might be observationally accessible thanks to new generations of instruments able to count the single photons of the Cosmic Microwave Background in the THz region.Giovannini, MassimoWed, 24 Aug 2016 06:09:22 GMT20 Aug 2016arXiv:1608.05843http://cds.cern.ch/record/2209738['arXiv:1608.05843']arXiv:1608.05843The Super-GUT CMSSM Revisited
http://cds.cern.ch/record/2208907
We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the supersymmetric gauge coupling unification scale, $M_{GUT}$. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$, as do the trilinear soft supersymmetry-breaking parameters $A_0$. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and the LHC measurement of the Higgs mass, $m_h$. We find regions of $m_0$, $m_{1/2}$, $A_0$ and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for $m_0$ and $m_{1/2}$ in the multi-TeV region, for suitable values of the unknown SU(5) GUT-scale phases and superpotential couplings, and with the ratio of supersymmetric Higgs vacuum expectation values $\tan \beta \lesssim 6$.Ellis, JohnEvans, Jason LMustafayev, AzarNagata, NatsumiOlive, Keith AFri, 19 Aug 2016 06:23:44 GMT18 Aug 2016arXiv:1608.05370http://cds.cern.ch/record/2208907['arXiv:1608.05370']arXiv:1608.05370Two-loop scale-invariant scalar potential and quantum effective operators
http://cds.cern.ch/record/2208904
Spontaneous breaking of quantum scale invariance may provide a solution to the hierarchy and cosmological constant problems. In a scale-invariant regularization, we compute the two-loop potential of a higgs-like scalar $\phi$ in theories in which scale symmetry is broken only spontaneously by the dilaton ($\sigma$). Its vev $\langle\sigma\rangle$ generates the DR subtraction scale ($\mu\sim\langle\sigma\rangle$), which avoids the explicit scale symmetry breaking by traditional regularizations (where $\mu$=fixed scale). The two-loop potential contains effective operators of non-polynomial nature as well as new corrections, beyond those obtained with explicit breaking ($\mu$=fixed scale). These operators have the form: $\phi^6/\sigma^2$, $\phi^8/\sigma^4$, etc, which generate an infinite series of higher dimensional polynomial operators upon expansion about $\langle\sigma\rangle\gg \langle\phi\rangle$, where such hierarchy is arranged by {\it one} initial, classical tuning. These operators emerge at the quantum level from evanescent interactions ($\propto\epsilon$) between $\sigma$ and $\phi$ that vanish in $d=4$ but are demanded by classical scale invariance in $d=4-2\epsilon$. The Callan-Symanzik equation of the two-loop potential is respected and the two-loop beta functions of the couplings differ from those of the same theory regularized with $\mu=$fixed scale. Therefore the running of the couplings enables one to distinguish between spontaneous and explicit scale symmetry breaking.Ghilencea, D MLalak, ZOlszewski, PFri, 19 Aug 2016 06:23:44 GMT18 Aug 2016arXiv:1608.05336http://cds.cern.ch/record/2208904['arXiv:1608.05336']arXiv:1608.05336Chiral Heterotic Strings with Positive Cosmological Constant
http://cds.cern.ch/record/2208448
We present explicit examples of semi-realistic heterotic models with spontaneously broken supersymmetry, which dynamically lead to breaking scales much smaller than $M_{\rm Planck}$ and exponentially small positive values for the cosmological constant. Contrary to field theoretic intuition, we find that the global structure of the effective potential is significantly affected by contributions of massive and non-level matched string states and we investigate the conditions that dynamically ensure a number of desired properties.Florakis, IoannisRizos, JohnWed, 17 Aug 2016 07:57:48 GMT16 Aug 2016arXiv:1608.04582http://cds.cern.ch/record/2208448['arXiv:1608.04582']arXiv:1608.04582Simulating V+jet processes in heavy ion collisions with JEWEL
http://cds.cern.ch/record/2207127
Processes in which a jet recoils against an electroweak boson complement studies of jet quenching in heavy ion collisions at the LHC. As the boson does not interact strongly it escapes the dense medium unmodified and thus provides a more direct access to the hard scattering kinematics than can be obtained in di-jet events. First measurements of jet modification in these processes are now available from the LHC experiments and will improve greatly with better statistics in the future. We present an extension of JEWEL to boson-jet processes. JEWEL is a dynamical framework for jet evolution in a dense background based on perturbative QCD, that is in agreement with a large variety of jet observables. We also obtain a good description of the CMS and ATLAS data for y+jet and Z+jet processes at 2.76 TeV and 5.02 TeV.Elayavalli, Raghav KunnawalkamZapp, Korinna ChristineThu, 11 Aug 2016 09:48:25 GMT10 Aug 2016arXiv:1608.03099http://cds.cern.ch/record/2207127['arXiv:1608.03099']arXiv:1608.03099Associated production of a quarkonium and a Z boson at one loop in a quark-hadron-duality approach
http://cds.cern.ch/record/2207118
In view of the large discrepancy about the associated production of a prompt $J/\psi$ and a $Z$ boson between the ATLAS data at $\sqrt{s}=8$ TeV and theoretical predictions for Single Parton Scattering (SPS) contributions, we perform an evaluation of the corresponding cross section at one loop accuracy (Next-to-Leading Order, NLO) in a quark-hadron-duality approach, also known as the Colour-Evaporation Model (CEM). This work is motivated by (i) the extremely disparate predictions based on the existing NRQCD fits conjugated with the absence of a full NLO NRQCD computation and (ii) the fact that we believe that such an evaluation provides a likely upper limit of the SPS cross section. In addition to these theory improvements, we argue that the ATLAS estimation of the Double Parton Scattering (DPS) yield may be underestimated by a factor as large as 3 which then reduces the size of the SPS yield extracted from the ATLAS data. Our NLO SPS evaluation also allows us to set an upper limit on $\sigma_{\rm eff}$ driving the size of the DPS yield. Overall, the discrepancy between theory and experiment may be smaller than expected, which calls for further analyses by ATLAS and CMS, for which we provide predictions, and for full NLO computations in other models. As an interesting side product of our analysis, we have performed the first NLO computation of $d\sigma / dP_T$ for prompt single-$J/\psi$ production in the CEM from which we have fit the CEM non-pertubative parameter at NLO using the most recent ATLAS data.Lansberg, Jean-PhilippeShao, Hua-ShengThu, 11 Aug 2016 09:44:14 GMT10 Aug 2016arXiv:1608.03198http://cds.cern.ch/record/2207118['arXiv:1608.03198']arXiv:1608.03198On gravitational and thermal corrections to vacuum decay
http://cds.cern.ch/record/2206654
We reconsider gravitational corrections to vacuum decay, confirming and simplifying earlier results and extending them allowing for a non-minimal coupling of the Higgs to gravity, finding that leading-order gravitational corrections suppress the vacuum decay rate. Furthermore, we find minor corrections to thermal vacuum decay in the SM adding one-loop corrections to the Higgs kinetic term, two-loop corrections to the Higgs potential and allowing for time-dependent bounces.Salvio, AlbertoStrumia, AlessandroTetradis, NikolaosUrbano, AlfredoWed, 10 Aug 2016 07:19:21 GMT08 Aug 2016arXiv:1608.02555http://cds.cern.ch/record/2206654['arXiv:1608.02555']arXiv:1608.02555Inflation from Supergravity with Gauged R-symmetry in de Sitter Vacuum
http://cds.cern.ch/record/2206494
We study the cosmology of a recent model of supersymmetry breaking, in the presence of a tuneable positive cosmological constant, based on a gauged shift symmetry of a string modulus that can be identified with the string dilaton. The minimal spectrum of the `hidden' supersymmetry breaking sector consists then of a vector multiplet that gauges the shift symmetry of the dilaton multiplet and when coupled to the MSSM leads to a distinct low energy phenomenology depending on one parameter. Here we study the question if this model can also lead to inflation by identifying the dilaton with the inflaton. We find that this is possible if the K\"ahler potential is modified by a term that has the form of NS5-brane instantons, leading to an appropriate inflationary plateau around the maximum of the scalar potential, depending on two extra parameters. This model is consistent with present cosmological observations without modifying the low energy particle phenomenology associated to the minimum of the scalar potential.Antoniadis, IChatrabhuti, AIsono, HKnoops, RWed, 10 Aug 2016 07:14:28 GMT06 Aug 2016arXiv:1608.02121http://cds.cern.ch/record/2206494['arXiv:1608.02121']arXiv:1608.02121Protected couplings and BPS dyons in half-maximal supersymmetric string vacua
http://cds.cern.ch/record/2205505
We analyze four- and six-derivative couplings in the low energy effective action of $D=3$ string vacua with half-maximal supersymmetry. In analogy with an earlier proposal for the $(\nabla\Phi)^4$ coupling, we propose that the $\nabla^2(\nabla\Phi)^4$ coupling is given exactly by a manifestly U-duality invariant genus-two modular integral. In the limit where a circle in the internal torus decompactifies, the $\nabla^2(\nabla\Phi)^4$ coupling reduces to the $D^2 F^4$ and $R^2 F^2$ couplings in $D=4$, along with an infinite series of corrections of order $e^{-R}$, from four-dimensional 1/4-BPS dyons whose wordline winds around the circle. Each of these contributions is weighted by a Fourier coefficient of a meromorphic Siegel modular form, explaining and extending standard results for the BPS index of 1/4-BPS dyons.Bossard, GuillaumeCosnier-Horeau, CharlesPioline, BorisFri, 05 Aug 2016 06:03:23 GMT04 Aug 2016arXiv:1608.01660http://cds.cern.ch/record/2205505['arXiv:1608.01660']arXiv:1608.01660Full mass dependence in Higgs boson production in association with jets at the LHC and FCC
http://cds.cern.ch/record/2205473
The first computation of Higgs production in association with three jets at NLO in QCD has recently been performed using the effective theory, where the top quark is treated as an infinitely heavy particle and integrated out. This approach is restricted to the regions in phase space where the typical scales are not larger than the top quark mass. Here we investigate this statement at a quantitative level by calculating the leading-order contributions to the production of a Standard Model Higgs boson in association with up to three jets taking full top-quark and bottom-quark mass dependence into account. We find that the transverse momentum of the hardest particle or jet plays a key role in the breakdown of the effective theory predictions, and that discrepancies can easily reach an order of magnitude for transverse momenta of about 1 TeV. The impact of bottom-quark loops are found to be visible in the small transverse momentum region, leading to corrections of up to 5 percent. We further study the impact of mass corrections when VBF selection cuts are applied and when the center-of-mass energy is increased to 100 TeV.Greiner, NicolasHoeche, StefanLuisoni, GionataSchonherr, MarekWinter, Jan-ChristopherFri, 05 Aug 2016 06:02:34 GMT03 Aug 2016arXiv:1608.01195http://cds.cern.ch/record/2205473['arXiv:1608.01195']arXiv:1608.01195Solving the Standard Model Problems in Softened Gravity
http://cds.cern.ch/record/2205472
The Higgs naturalness problem is solved if the growth of Einstein's gravitational interaction is softened at an energy $ \lesssim 10^{11}\,$GeV (softened gravity). We work here within an explicit realization where the Einstein-Hilbert Lagrangian is extended to include terms quadratic in the curvature and a non-minimal coupling with the Higgs. We show that this solution is preserved by adding three right-handed neutrinos with masses below the electroweak scale, accounting for neutrino oscillations, dark matter and the baryon asymmetry. The smallness of the right-handed neutrino masses (compared to the Planck scale) and the QCD $\theta$-term are also shown to be natural. We prove that a possible gravitational source of CP violation cannot spoil the model, thanks to the presence of right-handed neutrinos. Starobinsky inflation can occur in this context, even if we live in a metastable vacuum.Salvio, AlbertoFri, 05 Aug 2016 06:02:33 GMT03 Aug 2016arXiv:1608.01194http://cds.cern.ch/record/2205472['arXiv:1608.01194']arXiv:1608.01194Effective Field Theory with Two Higgs Doublets
http://cds.cern.ch/record/2205466
In this article we extend the effective field theory framework describing new physics effects to the case where the underlying low-energy theory is a Two-Higgs-Doublet model. We derive a complete set of independent operators up to dimension six assuming a $Z_2$-invariant CP-conserving Higgs potential. The effects on Higgs and gauge boson masses, mixing angles in the Higgs sector as well as couplings to fermions and gauge bosons are computed. At variance with the case of a single Higgs doublet, we find that pair production of SM-like Higgses, arising through dimension-six operators, is not fixed by fermion-fermion-Higgs couplings and can therefore be sizable.Crivellin, AndreasGhezzi, MargheritaProcura, MassimilianoFri, 05 Aug 2016 06:02:32 GMT02 Aug 2016arXiv:1608.00975http://cds.cern.ch/record/2205466['arXiv:1608.00975']arXiv:1608.00975Baryogenesis and Gravitational Waves from Runaway Bubble Collisions
http://cds.cern.ch/record/2203671
We propose a novel mechanism for production of baryonic asymmetry in the early Universe. The mechanism takes advantage of the strong first order phase transition that produces runaway bubbles in the hidden sector that propagate almost without friction with ultra-relativistic velocities. Collisions of such bubbles can non-thermally produce heavy particles that further decay out-of-equilibrium into the SM and produce the observed baryonic asymmetry. This process can proceed at the very low temperatures, providing a new mechanism of post-sphaleron baryogenesis. In this paper we present a fully calculable model which produces the baryonic asymmetry along these lines as well as evades all the existing cosmological constraints. We emphasize that the Gravitational Waves signal from the first order phase transition is completely generic and can potentially be detected by the future eLISA interferometer. We also discuss other potential signals, which are more model dependent, and point out the unresolved theoretical questions related to our proposal.Katz, AndreyRiotto, AntonioWed, 03 Aug 2016 08:30:00 GMT01 Aug 2016arXiv:1608.00583http://cds.cern.ch/record/2203671['arXiv:1608.00583']arXiv:1608.00583Two-Loop Scattering Amplitudes from the Riemann Sphere
http://cds.cern.ch/record/2202933
The scattering equations give striking formulae for massless scattering amplitudes at tree level and, as shown recently, at one loop. The progress at loop level was based on ambitwistor string theory, which naturally yields the scattering equations. We proposed that, for ambitwistor strings, the standard loop expansion in terms of the genus of the worldsheet is equivalent to an expansion in terms of nodes of a Riemann sphere, with the nodes carrying the loop momenta. In this paper, we show how to obtain two-loop scattering equations with the correct factorization properties. We adapt genus-two integrands from the ambitwistor string to the nodal Riemann sphere and show that these yield correct answers, by matching standard results for the four-point two-loop amplitudes of maximal supergravity and super-Yang-Mills theory. In the Yang-Mills case, this requires the loop analogue of the Parke-Taylor factor carrying the colour dependence, which includes non-planar contributions.Geyer, YvonneMason, LionelMonteiro, RicardoTourkine, PiotrMon, 01 Aug 2016 06:16:06 GMT29 Jul 2016arXiv:1607.08887http://cds.cern.ch/record/2202933['arXiv:1607.08887']arXiv:1607.08887Sneutrino Inflation with $\alpha$-attractors
http://cds.cern.ch/record/2202895
Sneutrino inflation employs the fermionic partners of the inflaton and stabilizer field as right-handed neutrinos to realize the seesaw mechanism for light neutrino masses. A crucial ingredient in existing constructions for sneutrino (multi-)natural inflation is an unbroken discrete shift symmetry. We demonstrate that a similar construction applies to $\alpha$-attractor models. In this case the hyperbolic geometry protects the neutrino Yukawa couplings to the inflaton field, and the masses of leptons and Higgs fields, from blowing up when the inflaton is super-Planckian. We find that the predictions for $n_s$ and $r$ for $\alpha$-attractor cosmological models, compatible with the current cosmological data, are preserved in the presence of the neutrino sector.Kallosh, RenataLinde, AndreiRoest, DiederikWrase, TimmMon, 01 Aug 2016 06:13:21 GMT29 Jul 2016arXiv:1607.08854http://cds.cern.ch/record/2202895['arXiv:1607.08854']arXiv:1607.08854Interplay of Infrared Divergences and Gauge-Dependence of the Effective Potential
http://cds.cern.ch/record/2202547
The perturbative effective potential suffers infrared (IR) divergences in gauges with massless Goldstones in their minima (like Landau or Fermi gauges) but the problem can be fixed by a suitable resummation of the Goldstone propagators. When the potential minimum is generated radiatively, gauge-independence of the potential at the minimum also requires resummation and we demonstrate that the resummation that solves the IR problem also cures the gauge-dependence issue, showing this explicitly in the Abelian Higgs model in Fermi gauge. In the process we find an IR divergence (in the location of the minimum) specific to Fermi gauge and not appreciated in recent literature. We show that physical observables can still be computed in this gauge and we further show how to get rid of this divergence by a field redefinition. All these results generalize to the Standard Model case.Espinosa, J RGarny, MKonstandin, TFri, 29 Jul 2016 06:30:46 GMT28 Jul 2016arXiv:1607.08432http://cds.cern.ch/record/2202547['arXiv:1607.08432']arXiv:1607.08432Moduli Backreaction on Inflationary Attractors
http://cds.cern.ch/record/2202275
We investigate the interplay between moduli dynamics and inflation, focusing on the KKLT-scenario and cosmological $\alpha$-attractors. General couplings between these sectors can induce a significant backreaction and potentially destroy the inflationary regime; however, we demonstrate that this generically does not happen for $\alpha$-attractors. Depending on the details of the superpotential, the volume modulus can either be stable during the entire inflationary trajectory, or become tachyonic at some point and act as a waterfall field, resulting in a sudden end of inflation. In the latter case there is a universal supersymmetric minimum where the scalars end up, preventing the decompactification scenario. The observational predictions conform to the universal value of attractors, fully compatible with the Planck data, with possibly a capped number of e-folds due to the interplay with moduli.Roest, DiederikScalisi, MarcoWerkman, PelleThu, 28 Jul 2016 05:34:46 GMT27 Jul 2016arXiv:1607.08231http://cds.cern.ch/record/2202275['arXiv:1607.08231']arXiv:1607.08231Monte Carlo simulations of Higgs-boson production at the LHC with the KrkNLO method
http://cds.cern.ch/record/2201359
We present numerical tests and predictions of the KrkNLO method for matching of NLO QCD corrections to hard processes with LO parton shower Monte Carlo generators. This method was described in detail in our previous publications, where its advantages over other approaches, such as MCatNLO and POWHEG, were pointed out. Here we concentrate on presenting some numerical results (cross sections and distributions) for $Z/\gamma^*$ (Drell-Yan) and Higgs-boson production processes at the LHC. The Drell--Yan process is used mainly to validate the KrkNLO implementation in the Herwig 7 program with respect to the previous implementation in Sherpa. We also show predictions for this process with the new, complete, MC-scheme parton distribution functions and compare them with our previously published results. Then, we present the first results of the KrkNLO method for the Higgs production in gluon--gluon fusion at the LHC and compare them with the predictions of other programs, such as MCFM, MCatNLO, POWHEG and HNNLO, as well as with experimental data from the ATLAS collaboration.Jadach, SNail, GPlaczek, WSapeta, SSiodmok, ASkrzypek, MMon, 25 Jul 2016 05:42:34 GMT22 Jul 2016arXiv:1607.06799http://cds.cern.ch/record/2201359['arXiv:1607.06799']arXiv:1607.06799$SU(2)$ gauge theory with two fundamental flavours: scalar and pseudoscalar spectrum
http://cds.cern.ch/record/2201348
We investigate the scalar and pseudoscalar spectrum of the $SU(2)$ gauge theory with $N_f=2$ flavours of fermions in the fundamental representation using non perturbative lattice simulations. We provide first benchmark estimates of the mass of the lightest $0(0^{+})$ ($\sigma$), $0(0^{-})$ ($\eta'$) and $1(0^+)$ ($a_0$) states, including estimates of the relevant disconnected contributions. We find $m_{a_0}/F_{\rm{PS}}= 16.7(4.9)$, $m_\sigma/F_{\rm{PS}}=19.2(10.8)$ and $m_{\eta'}/F_{\rm{PS}} = 12.8(4.7)$. These values for the masses of light scalar states provide crucial information for composite extensions of the Standard Model from the unified Fundamental Composi te Higgs-Technicolor theory \cite{Cacciapaglia:2014uja} to models of composite dark matter.Arthur, RudyDrach, VincentHietanen, AriPica, ClaudioSannino, FrancescoMon, 25 Jul 2016 05:42:23 GMT22 Jul 2016arXiv:1607.06654http://cds.cern.ch/record/2201348['arXiv:1607.06654']arXiv:1607.06654The S-matrix Bootstrap II: Two Dimensional Amplitudes
http://cds.cern.ch/record/2200938
We consider constraints on the S-matrix of any gapped, Lorentz invariant quantum field theory in 1 + 1 dimensions due to crossing symmetry and unitarity. In this way we establish rigorous bounds on the cubic couplings of a given theory with a fixed mass spectrum. In special cases we identify interesting integrable theories saturating these bounds. Our analytic bounds match precisely with numerical bounds obtained in a companion paper where we consider massive QFT in an AdS box and study boundary correlators using the technology of the conformal bootstrap.Paulos, Miguel FPenedones, JoaoToledo, Jonathanvan Rees, Balt CVieira, PedroFri, 22 Jul 2016 05:41:01 GMT20 Jul 2016arXiv:1607.06110http://cds.cern.ch/record/2200938['arXiv:1607.06110']arXiv:1607.06110The S-matrix Bootstrap I: QFT in AdS
http://cds.cern.ch/record/2200937
We propose a strategy to study massive Quantum Field Theory (QFT) using conformal bootstrap methods. The idea is to consider QFT in hyperbolic space and study correlation functions of its boundary operators. We show that these are solutions of the crossing equations in one lower dimension. By sending the curvature radius of the background hyperbolic space to infinity we expect to recover flat-space physics. We explain that this regime corresponds to large scaling dimensions of the boundary operators, and discuss how to obtain the flat-space scattering amplitudes from the corresponding limit of the boundary correlators. We implement this strategy to obtain universal bounds on the strength of cubic couplings in 2D flat-space QFTs using 1D conformal bootstrap techniques. Our numerical results match precisely the analytic bounds obtained in our companion paper using S-matrix bootstrap techniques.Paulos, Miguel FPenedones, JoaoToledo, Jonathanvan Rees, Balt CVieira, PedroFri, 22 Jul 2016 05:41:01 GMT20 Jul 2016arXiv:1607.06109http://cds.cern.ch/record/2200937['arXiv:1607.06109']arXiv:1607.06109Slow running of the Gradient Flow coupling from 200 MeV to 4 GeV in $N_{\rm f}=3$ QCD
http://cds.cern.ch/record/2200917
Using a finite volume Gradient Flow (GF) renormalization scheme with Schr\"odinger Functional (SF) boundary conditions, we compute the non-perturbative running coupling in the range $2.2 \lesssim {\bar g}_\mathrm{GF}^2(L) \lesssim 13$. Careful continuum extrapolations turn out to be crucial to reach our high accuracy. The running of the coupling is always between one-loop and two-loop and very close to one-loop in the region of $200\,{\rm MeV} \lesssim \mu=1/L \lesssim 4\,{\rm GeV}$. While there is no convincing contact to two-loop running, we match non-perturbatively to the SF coupling with background field. In this case we know the $\mu$ dependence up to $\sim 100\,{\rm GeV}$ and can thus connect to the $\Lambda$-parameter.Brida, Mattia DallaFritzsch, PatrickKorzec, TomaszRamos, AlbertoSint, StefanSommer, RainerFri, 22 Jul 2016 05:40:18 GMT21 Jul 2016arXiv:1607.06423http://cds.cern.ch/record/2200917['arXiv:1607.06423']arXiv:1607.06423The moduli spaces of $3d$ ${\cal N} \ge 2$ Chern-Simons gauge theories and their Hilbert series
http://cds.cern.ch/record/2200595
We present a formula for the Hilbert series that counts gauge invariant chiral operators in a large class of 3d ${\cal N} \ge 2$ Yang-Mills-Chern-Simons theories. The formula counts 't Hooft monopole operators dressed by gauge invariants of a residual gauge theory of massless fields in the monopole background. We provide a general formula for the case of abelian theories, where nonperturbative corrections are absent, and consider a few examples of nonabelian theories where nonperturbative corrections are well understood. We also analyze in detail nonabelian ABJ(M) theories as well as worldvolume theories of M2-branes probing Calabi-Yau fourfold and hyperK\"ahler twofold singularities with ${\cal N} = 2$ and ${\cal N} = 3$ supersymmetry.Cremonesi, StefanoMekareeya, NoppadolZaffaroni, AlbertoThu, 21 Jul 2016 06:39:01 GMT19 Jul 2016arXiv:1607.05728http://cds.cern.ch/record/2200595['arXiv:1607.05728']arXiv:1607.05728