SwePub - search: WFRF:(Ferretti Gabriele 1963)

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1.	Agarwal, Abhishek, et al. (author) Higher charges in dynamical spin chains for SYM theory 2005 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; :10, s. 1291-1302 Journal article (peer-reviewed)abstract We construct, to the first two non-trivial orders, the next conserved charge in the su(2\|3) sector of N=4 Super Yang-Mills theory. This represents a test of integrability in a sector where the interactions change the number of sites of the chain. The expression for the charge is completely determined by the algebra and can be written in a diagrammatic form in terms of the interactions already present in the Hamiltonian. It appears likely that this diagrammatic expression remains valid in the full theory and can be generalized to higher loops and higher charges thus helping in establishing complete integrability for these dynamical chains.
2.	Argurio, Riccardo, 1972, et al. (author) Collider signatures of goldstini in gauge mediation 2012 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2012:6 Journal article (peer-reviewed)abstract We investigate the collider signatures of the multiple goldstini scenario in the framework of gauge mediation. This class of models is characterized by a visible sector (e.g. the MSSM or any extension) coupled by gauge interactions to more than one SUSY breaking sector. The spectrum consists of a light gravitino LSP, behaving as a goldstino, and a number of neutral fermions (the pseudo-goldstini) with a mass between that of the LSP and that of the lightest particle of the observable sector (LOSP). We consider the two situations where the LOSP is either a gaugino-like neutralino or a stau and we assume only one pseudo-goldstino of a mass of O(100) GeV. The coupling of the LOSP to the pseudo-goldstino can be enhanced with respect to those of the gravitino giving rise to characteristic signatures. We show that the decay modes of the LOSP into a SM particle and a pseudo-goldstino can be significant. For both LOSP scenarios we analyze (pseudo)-goldstini production at colliders. Compared to standard gauge mediation the final state spectrum is softer and more structured.
3.	Argurio, Riccardo, 1972, et al. (author) Massless fermionic bound states and the gauge/gravity correspondence 2006 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 03:2006, s. 043- Journal article (peer-reviewed)abstract We study the equations of motion of fermions in type IIB supergravity in the context of the gauge/gravity correspondence. The main motivation is the search for normalizable fermionic zero modes in such backgrounds, to be interpreted as composite massless fermions in the dual theory. We specialize to backgrounds characterized by a constant dilaton and a self-dual three-form. In the specific case of the Klebanov-Strassler solution we construct explicitly the fermionic superpartner of the Goldstone mode associated with the broken baryonic symmetry. The fermionic equations could also be used to search for goldstinos in theories that break supersymmetry dynamically.
4.	Argurio, Riccardo, 1972, et al. (author) Natural semidirect gauge mediation and D-branes at singularities 2009 In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 80:4, s. 045001- Journal article (peer-reviewed)abstract We consider semidirect gauge mediation models of supersymmetry breaking where the messengers are composite fields and their supersymmetric mass is naturally generated through quartic superpotential couplings. We show that such composite messenger models can be easily embedded in quiver gauge theories arising from D-branes at Calabi-Yau singularities, and argue that semidirect gauge mediation is in fact a very natural option for supersymmetry breaking in D-brane models. We provide several explicit examples and discuss their salient phenomenological properties.
5.	Argurio, Riccardo, 1972, et al. (author) Stringy instantons at orbifold singularities 2007 In: Journal of High Energy Physics. ; 0607 Journal article (peer-reviewed)abstract We study the effects produced by D-brane instantons on the holomorphic quantities of a D-brane gauge theory at an orbifold singularity. These effects are not limited to reproducing the well known contributions of the gauge theory instantons but also generate extra terms in the superpotential or the prepotential. On these brane instantons there are some neutral fermionic zero-modes in addition to the ones expected from broken supertranslations. They are crucial in correctly reproducing effects which are dual to gauge theory instantons, but they may make some other interesting contributions vanish. We analyze how orientifold projections can remove these zero-modes and thus allow for new superpotential terms. These terms contribute to the dynamics of the effective gauge theory, for instance in the stabilization of runaway directions.
6.	Banerjee, Avik, 1992, et al. (author) Modelling vector-like quarks in partial compositeness framework 2022 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2022:3 Journal article (peer-reviewed)abstract Composite Higgs models, together with partial compositeness, predict the existence of new scalars and vector-like quarks (partners) at and above the TeV scale. Generically, the presence of these additional scalars opens up new decay topologies for the partners. In this paper we show how to systematically construct the general low energy Lagrangian to capture this feature. We emphasize the specific pattern in the top-partner spectrum arising in this class of models. We then present a concrete realization in the context of the SU(5)/SO(5) coset. We show that the top-partners in this model can have significant branching ratios to the additional scalars and a third generation quark, compared to the usual Standard Model channels. Amongst the most promising signatures at the LHC are final states containing a diphoton resonance along with a top quark.
7.	Banerjee, Avik, 1992, et al. (author) Vacuum misalignment in presence of four-Fermi operators 2023 In: Physical Review D. - 2470-0010 .- 2470-0029. ; 107:9 Journal article (peer-reviewed)abstract We consider the issue of vacuum misalignment induced by four-Fermi couplings in a generic strongly coupled four-dimensional gauge theory. After briefly reviewing the general formalism, we focus on the case of partial compositenesslike operators at leading order, which is relevant in applications to phenomenology. We show that the interactions between an elementary fermion and composite spin-1/2 operators in various representations contribute to the effective potential with relative sign differences. Thus the correct sign required to misalign the vacuum is guaranteed to occur for some representations but not all of them. The overall sign dictating the specific representations responsible for misalignment can in principle be determined on the lattice. We also comment on the likely sign for some simple cases.
8.	Beisert, Niklas, et al. (author) One-loop QCD spin chain and its spectrum 2005 In: Nuclear Physics B. - : Elsevier BV. - 0550-3213. ; 717:1-2, s. 137-189 Journal article (peer-reviewed)abstract We study the renormalization of gauge invariant operators in large Nc QCD. We compute the complete matrix of anomalous dimensions to leading order in the 't Hooft coupling and study its eigenvalues. Thinking of the mixing matrix as the Hamiltonian of a generalized spin chain we find a large integrable sector consisting of purely gluonic operators constructed with self-dual field strengths and an arbitrary number of derivatives. This sector contains the true ground state of the spin chain and all the gapless excitations above it. The ground state is essentially the anti-ferromagnetic ground state of a XXX1 spin chain and the excitations carry either a chiral spin quantum number with relativistic dispersion relation or an anti-chiral one with non-relativistic dispersion relation.
9.	Belyaev, Alexander, et al. (author) Di-boson signatures as standard candles for partial compositeness 2017 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2017:1 Journal article (peer-reviewed)abstract Composite Higgs Models are often constructed including fermionic top partners with a mass around the TeV scale, with the top partners playing the role of stabilizing the Higgs potential and enforcing partial compositeness for the top quark. A class of models of this kind can be formulated in terms of fermionic strongly coupled gauge theories. A common feature they all share is the presence of specific additional scalar resonances, namely two neutral singlets and a colored octet, described by a simple effective Lagrangian. We study the phenomenology of these scalars, both in a model independent and model dependent way, including the bounds from all the available searches in the relevant channels with di-boson and di-top final states. We develop a generic framework which can be used to constrain any model containing pseudo-scalar singlets or octets. Using it, we find that such signatures provide strong bounds on the compositeness scale complementary to the traditional EWPT and Higgs couplings deviations. In many cases a relatively light scalar can be on the verge of discovery as a first sign of new physics.
10.	Benbrik, R., et al. (author) Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons 2020 In: Journal of High Energy Physics. - : Springer Nature. - 1029-8479 .- 1126-6708. ; 2020:5 Journal article (peer-reviewed)abstract We explore the phenomenology of models containing one Vector-Like Quark (VLQ), t′, which can decay into the Standard Model (SM) top quark, t, and a new spin-0 neutral boson, S, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the t′ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming t′ pair production via strong interactions, we design signal regions optimised for one t′ → S t transition (while being inclusive on the other t¯ ′ decay, and vice versa), followed by the decay of S into the two very clean experimental signatures S → γ γ and S → Z (→ ℓ+ℓ−)γ. We perform a dedicated signal- to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR(t′ → S t) = 100%, we are therefore able to realistically quantify the sensitivity of the LHC to both the t′ and S masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on t′ decays into SM bosons (W±, Z , h). © 2020, The Author(s).
11.	Bertolini, Matteo, et al. (author) BPS three-brane solution on smooth ALE manifolds with flux 2002 In: Fortsch. Phys.. ; 50, s. 802- Journal article (peer-reviewed)abstract In the present talk I review the construction of a new supersymmetric 3-brane solution of type IIB supergravity on an ALE transverse space in presence of a non trivial flux of the complex 2-form across the ALE cycles. After introducing the ansatz for the solution I will show how the supergravity field equations reduce to a differential equation of Heun type in the non-conformal warp factor H of the metric. Although our analysis is worked out purely at a macroscopic level comments will be made on the general features of the (non-conformal) gauge theory dual to this solution
12.	Bertolini, Matteo, et al. (author) Fractional branes and N = 1 gauge theories 2002 In: Nuclera Physics. ; B:630, s. 222- Journal article (peer-reviewed)abstract We discuss fractional D3-branes on the orbifold C^3/Z_2Z_2. We study the open and the closed string spectrum on this orbifold. The corresponding N=1 theory on the brane has, generically, a U(N_1)U(N_2)U(N_3)U(N_4) gauge group with matter in the bifundamental. In particular, when only one type of brane is present, one obtains pure N=1 Yang-Mills. We study the coupling of the branes to the bulk fields and present the corresponding supergravity solution, valid at large distances. By using a probe analysis, we are able to obtain the Wilsonian beta-function for those gauge theories that possess some chiral multiplet. Although, due to the lack of moduli, the probe technique is not directly applicable to the case of pure N=1 Yang-Mills, we point out that the same formula gives the correct result also for this case.
13.	Bertolini, Matteo, et al. (author) Supersymmetric 3-branes on smooth ALE manifolds with flux 2001 In: Nuclear Physics. ; B:617, s. 3- Journal article (peer-reviewed)abstract We construct a new family of classical BPS solutions of type IIB supergravity describing 3-branes transverse to a 6-dimensional space with topology R^2*ALE. They are characterized by a non-trivial flux of the supergravity 2-forms through the homology 2-cycles of a generic smooth ALE manifold. Our solutions have two Killing spinors and thus preserve N=2 supersymmetry. They are expressed in terms of a quasi harmonic function H (the ``warp factor''), whose properties we study in the case of the simplest ALE, namely the Eguchi-Hanson manifold. The equation for H is identified as an instance of the confluent Heun equation. We write explicit power series solutions and solve the recurrence relation for the coefficients, discussing also the relevant asymptotic expansions. While, as in all such N=2 solutions, supergravity breaks down near the brane, the smoothing out of the vacuum geometry has the effect that the warp factor is regular in a region near the cycle. We interpret the behavior of the warp factor as describing a three-brane charge ``smeared'' over the cycle and consider the asymptotic form of the geometry in that region, showing that conformal invariance is broken even when the complex type IIB 3-form field strength is assumed to vanish. We conclude with a discussion of the basic features of the gauge theory dual.
14.	Borsato, M., et al. (author) Unleashing the full power of LHCb to probe stealth new physics 2022 In: Reports on Progress in Physics. - : IOP Publishing. - 0034-4885 .- 1361-6633. ; 85:2 Journal article (peer-reviewed)abstract In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.
15.	Buarque Franzosi, Diogo, 1983, et al. (author) Anomalous dimensions of potential top-partners 2019 In: SciPost Physics. - 2542-4653. ; 7:3 Journal article (peer-reviewed)abstract We discuss anomalous dimensions of top-partner candidates in theories of Partial Compositeness. First, we revisit, confirm and extend the computation by DeGrand and Shamir of anomalous dimensions of fermionic trilinears. We present general results applicable to all matter representations and to composite operators of any allowed spin. We then ask the question of whether it is reasonable to expect some models to have composite operators of sufficiently large anomalous dimension to serve as top-partners. While this question can be answered conclusively only by lattice gauge theory, within perturbation theory we find that such values could well occur for some specific models. In the Appendix we collect a number of practical group theory results for fourth-order invariants of general interest in gauge theories with many irreducible representations of fermions.
16.	Buarque Franzosi, Diogo, 1983, et al. (author) Electroweak signatures of gauge-mediated supersymmetry breaking in multiple hidden sectors 2022 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 01 Journal article (peer-reviewed)abstract This paper discusses electroweak collider signatures of the NMSSM with multiple-sector gauge mediation. We focus on the production of neutralinos and charginos which cascade decay into standard model particles and lighter supersymmetric particles, with special emphasis on final states with multiple photons. A search strategy for signatures with at least three photons is presented and compared with current exclusion limits based on two-photon searches. We show that in many regions of the parameter space our strategy gives stronger constraints than the existing two-photon analysis for these models.
17.	Buarque Franzosi, Diogo, 1983, et al. (author) Exploring new possibilities to discover a light pseudo-scalar at LHCb 2022 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 82:1 Journal article (peer-reviewed)abstract We study the possibility of observing a light pseudo-scalar a at LHCb. We target the mass region 2.5GeV less than or similar to m(a) less than or similar to 60 GeV and various decay channels, some of which have never been considered before: muon pairs, tau pairs, D meson pairs, and di-photon. We interpret the results in the context of models of 4D Composite Higgs and Partial Compositeness in particular.
18.	Buarque Franzosi, Diogo, 1983, et al. (author) Pseudoscalar pair production via off-shell Higgs in composite Higgs models 2020 In: SciPost Physics. - 2542-4653. ; 9:077 Journal article (peer-reviewed)abstract We propose a new type of search for a pseudoscalar particle η pair produced via an off-shell Higgs, pp→h∗→ηη. The search is motivated by a composite Higgs model in which the η is extremely narrow and decays almost exclusively into Zγ in the mass range 65 GeV≲mη≲160 GeV. We devise an analysis strategy to observe the novel ZγZγ channel and estimate potential bounds on the Higgs-η coupling. The experimental sensitivity to the signatures depends on the power to identify fake photons and on the ability to predict large photon multiplicities. This search allows us to exclude large values of the compositeness scale f, being thus complementary to other typical processes.
19.	Cacciapaglia, Giacomo, et al. (author) Light scalars in composite Higgs models 2019 In: Frontiers of Physics. - : Frontiers Media SA. - 2296-424X. ; 7:12 Journal article (peer-reviewed)abstract A composite Higgs boson is likely to be accompanied by additional light states generated by the same dynamics. This expectation is substantiated when realising the composite Higgs mechanism by an underlying gauge theory. We review the dynamics of such objects, which may well be the first sign of compositeness at colliders. We also update our previous analysis of the bounds from LHC searches to the latest results, and discuss the projected reach of the High-Luminosity run.
20.	Cacciapaglia, Giacomo, et al. (author) Revealing timid pseudo-scalars with taus at the LHC 2018 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 78:9 Journal article (peer-reviewed)abstract A light pseudo-scalar that is copiously produced at the LHC may still be allowed by present searches. While masses above 65 GeV are effectively covered by di-photon searches, the lower mass window can be tested by a new search for boosted di-tau resonances. We test this strategy on a set of composite Higgs models with top partial compositeness, where most models can be probed with an integrated luminosity below 300 fb−1
21.	Calibbi, Lorenzo, et al. (author) Constraints on baryon number violation in supersymmetry from searches for neutron-antineutron oscillations and other observables 2016 In: Proceedings of Science. - 1824-8039. ; Part F128560 Conference paper (peer-reviewed)abstract Baryon number violation (BNV) in R-parity violating (RPV) supersymmetry is studied with a focus on ΔB = 2 processes which allow neutron-anti-neutron (n-n) oscillations. Simplified RPV-SUSY models, including only the relevant superpartners and couplings, are considered. Constraints from flavour physics, searches at the Large Hadron Collider and searches at dedicated BNV experiments are quantified for the various scenarios at the TeV scale. It is also shown that a proposed n-n experiment at the European Spallation Source has a sensitivity to a mass scale for new physics that goes beyond all other experiments and up to the PeV scale for certain regions of parameter space.
22.	Campos, Vanicson, 1972, et al. (author) The non-Abelian self dual string on the light cone 2000 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 0012, s. 11- Journal article (peer-reviewed)abstract We construct the scalar profile for the non-abelian self dual string connecting two M5-branes compactified on a light-like circle. The construction is based on a conjectured modified version of Nahm's equations describing a D2-brane, with a magnetic field on it, suspended between two D4-branes. Turning on a constant magnetic field on the D2-brane corresponds to a boost in the eleventh direction. In the limit of infinite boost the D4-branes correspond to light-like compactified M5-branes. The solution for the scalar profile of the brane remains finite in this limit and displays all the correct expected features such as smooth interpolation between the unbroken and broken phase with the correct value for the Higgs field at infinity.
23.	Cederwall, Martin, 1961, et al. (author) Higher-dimensional loop algebras, non-abelian extensions and p-branes 1994 In: Nucl.Phys.B424 (1994) 97. Journal article (peer-reviewed)abstract We postulate a new type of operator algebra with a non-abelian extension. This algebra generalizes the Kac-Moody algebra in string theory and the Mickelsson-Faddeev algebra in three dimensions to higher-dimensional extended objects (p-branes). We then construct new BRST operators, covariant derivatives and curvature tensors in the higher-dimensional generalization of loop space.
24.	Cederwall, Martin, 1961, et al. (author) Low energy dynamics of monopoles in N=2 SYM with matter 1995 In: Mod.Phys.Lett. A11 (1996) 367. Journal article (peer-reviewed)abstract We derive, for N=2 super-Yang-Mills with gauge group SU(2) and massless matter, the supersymmetric quantum mechanical models describing the time evolution of multi-monopole configurations in the low energy approximation. This is a first step towards identifying the solitonic states mapped to fundamental excitations by duality in the model with four hypermultiplets in the fundamental representation.
25.	Cederwall, Martin, 1961, et al. (author) Schwinger terms and cohomology of pseudodifferential operators 1994 In: Commun.Math.Phys. 175 (1996) 203. Journal article (peer-reviewed)abstract We study the cohomology of the Schwinger term arising in second quantization of the class of observables belonging to the restricted general linear algebra. We prove that, for all pseudodifferential operators in 3+1 dimensions of this type, the Schwinger term is equivalent to the ``twisted'' Radul cocycle, a modified version of the Radul cocycle arising in non-commutative differential geometry. In the process we also show how the ordinary Radul cocycle for any pair of pseudodifferential operators in any dimension can be written as the phase space integral of the star commutator of their symbols projected to the appropriate asymptotic component.
26.	Cederwall, Martin, 1961, et al. (author) The Chiral Ring of D=4, N=1 SYM with Exceptional Gauge Groups 2024 In: Fortschritte der Physik. - 0015-8208 .- 1521-3978. ; 72:5 Journal article (peer-reviewed)abstract The Cachazo-Douglas-Seiberg-Witten conjecture, concerning the algebraic structure of the chiral ring in N=1, D=4 supersymmetric Yang-Mills theory, is proven for exceptional gauge groups. This completes the proof of the conjecture.
27.	Eerola, Paula, et al. (author) Accelerator-based infrastructures in the fields of particle and nuclear physics 2020 Reports (other academic/artistic)abstract The Council for Research Infrastructures (RFI) within the Swedish Research Council (Vetenskapsrådet) commits a significant part of its annual budget to accelerator-based infrastructures in particle and nuclear physics. The funding covers membership fees, running costs and investments. The Swedish activities in these fields are mainly focused on CERN (Geneva, Switzerland) and FAIR (Darmstadt, Germany). In 2019, RFI decided to commission an investigation and landscape analysis of the research infrastructures they fund in these fields. The report is meant to support the Council’s work in ensuring that these funds are strategically well-spent and of maximum benefit to the research community. A panel of seven experts from the Nordic countries have worked on the task with the aid of data from relevant documentation, hearings, interviews and questionnaires. The report contains several concrete recommendations given from the authors to RFI.
28.	Englert, Christoph, et al. (author) Jet-associated resonance spectroscopy 2017 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 77:12, s. 842- Journal article (peer-reviewed)abstract We present a model-independent study aimed at characterising the nature of possible resonances in the jet-photon or jet-Z final state at hadron colliders. Such resonances are expected in many models of compositeness and would be a clear indication of new physics. At leading order, in the narrow width approximation, the matrix elements are parameterised by just a few constants describing the coupling of the various helicities to the resonance. We present the full structure of such amplitudes up to spin 2 and use them to simulate relevant kinematic distributions that could serve to constrain the coupling structure. This also generalises the signal generation strategy that is currently pursued by ATLAS and CMS to the most general case in the considered channels. While the determination of the P/CP properties of the interaction seems to be out of reach within this framework, there is a wealth of information to be gained about the spin of the resonance and the relative couplings of the helicities.
29.	Ferretti, Gabriele, 1963, et al. (author) Baryon number violation in supersymmetry: n - (n)over-bar oscillations as a probe beyond the LHC 2016 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 5:5, s. Art. no. 144- Journal article (peer-reviewed)abstract We summarize the current status of baryon number violation in supersymmetry and provide prospects for going beyond the present reach by means of a new search for neutron-antineutron oscillations. The main motivation is the recently proposed neutron-antineutron oscillation experiment at the European Spallation Source in Lund, Sweden, which is projected to be able to improve the current bound on the transition probability in the quasi-free regime by three orders of magnitude. We consider various processes involving superpartners that give rise to neutron-antineutron oscillations and extract the corresponding simplified models, including only the most relevant superpartners and couplings. In terms of these models we recast and determine the exclusion limits from LHC searches as well as from searches for flavor transitions, CP violation and di-nucleon decays. We find that, for certain regions of the parameter space, the proposed neutron-antineutron experiment has a reach that goes beyond all other experiments, as it can probe gluino and squark masses in the multi-TeV range.
30.	Ferretti, Gabriele, 1963, et al. (author) Beyond the Standard Model Physics at the HL-LHC and HE-LHC 2018 Reports (other academic/artistic)abstract This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of the High Luminosity (HL) phase of the LHC, defined as 3 ab−1 of data taken at a centre-of-mass energy of 14 TeV, and of a possible future upgrade, the High Energy (HE) LHC, defined as 15 ab−1 of data at a centre-of-mass energy of 27 TeV. We consider a large variety of new physics models, both in a simplified model fashion and in a more model-dependent one. A long list of contributions from the theory and experimental (ATLAS, CMS, LHCb) communities have been collected and merged together to give a complete, wide, and consistent view of future prospects for BSM physics at the considered colliders. On top of the usual standard candles, such as supersymmetric simplified models and resonances, considered for the evaluation of future collider potentials, this report contains results on dark matter and dark sectors, long lived particles, leptoquarks, sterile neutrinos, axion-like particles, heavy scalars, vector-like quarks, and more. Particular attention is placed, especially in the study of the HL-LHC prospects, to the detector upgrades, the assessment of the future systematic uncertainties, and new experimental techniques. The general conclusion is that the HL-LHC, on top of allowing to extend the present LHC mass and coupling reach by 20−50% on most new physics scenarios, will also be able to constrain, and potentially discover, new physics that is presently unconstrained. Moreover, compared to the HL-LHC, the reach in most observables will generally more than double at the HE-LHC, which may represent a good candidate future facility for a final test of TeV-scale new physics.
31.	Ferretti, Gabriele, 1963, et al. (author) Chiral Extensions of the MSSM 2013 In: Modern Physics Letters A. - 0217-7323. ; 28:8 Journal article (peer-reviewed)abstract We present a class of extensions of the MSSM characterized by a fully chiral field content (no mu-terms) and no baryon or lepton number violating term in the superpotential due to an extra U'(1) gauge symmetry. The minimal model consist of the usual matter sector with family dependent U'(1) charges, six Higgs weak doublets, and three singlets required to give masses to the Higgsinos and cancel anomalies. We discuss its main features such as the tree level mass spectrum and the constraints on flavor changing processes.
32.	Ferretti, Gabriele, 1963 (author) Composite Higgs bosons 2018 In: Proceedings of Science. - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 339:2018 Conference paper (peer-reviewed)abstract I discuss work done in the last few years, together with my collaborators, in classifying, constructing and studying models of partial compositeness based on underlying 4D gauge theories with fermionic matter. The main motivation is trying to solve the hierarchy problem of the standard model. I start with a brief overview of the main ideas, present one particular example based on a SU(4) gauge group and then discuss more recent work on the dynamics of some neutral pseudo-Nambu-Goldstone bosons that are ubiquitous in all of these models and that could be a target for coming LHC runs. I conclude with some general remarks and future directions.
33.	Ferretti, Gabriele, 1963 (author) Compositeness above the electroweak scale and a proposed test at LHCb 2022 In: EPJ Web Conf.. - : EDP Sciences. - 2100-014X. ; 258 Conference paper (peer-reviewed)abstract I review attempts to construct models of partial compositeness from strongly coupled gauge theories. A few minimal assumptions allow one to isolate a small number of representative models. After presenting the main idea, I discuss a recent proposal to detect a light pseudo-scalar, predicted in all these models, at the LHCb detector.
34.	Ferretti, Gabriele, 1963, et al. (author) D-brane probes on G(2) orbifolds 2002 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 03, s. 04- Journal article (peer-reviewed)abstract We consider type-IIB string theory on a seven dimensional orbifold with holonomy in G2. The motivation is to use D1-branes as probes of the geometry. The low energy theory on the D1-brane is a sigma-model with two real supercharges (N = (1,1) in two dimensional language). We study in detail the closed and open string sectors and propose a coupling of the twisted fields to the brane that modifies the vacuum moduli space so that the singularity at the origin is removed. Instead of coming from D-terms, which are not present here, the modification comes from a ``twisted'' mass term for the seven scalar multiplets on the brane. The proposed mechanism involves a generalization of the moment map.
35.	Ferretti, Gabriele, 1963, et al. (author) Fermionic UV completions of composite Higgs models 2014 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2014:3 Journal article (peer-reviewed)abstract We classify the four-dimensional purely fermionic gauge theories that give a UV completion of composite Higgs models. Our analysis is at the group theoretical level, addressing the necessary (but not sufficient) conditions for the viability of these models, such as the existence of top partners and custodial symmetry. The minimal cosets arising are those of type SU(5)/SO(5) and SU(4)/Sp(4). We list all the possible "hyper-color" groups allowed and point out the simplest and most promising ones.
36.	Ferretti, Gabriele, 1963 (author) Gauge theories of Partial Compositeness: Scenarios for Run-II of the LHC 2016 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2016:6 Journal article (peer-reviewed)abstract We continue our investigation of gauge theories in which the Higgs boson arises as a pseudo-Nambu-Goldstone boson (pNGB) and top-partners arise as bound states of three hyperfermions. All models have additional pNGBs in their spectrum that should be accessible at LHC. We analyze the patterns of symmetry breaking and present all relevant couplings of the pNGBs with the gauge fields. We discuss how vacuum misalignment and a mass for the pNGBs is generated by a loop-induced potential. Finally, we paint a very broad, qualitative, picture of the kind of experimental signatures these models give rise to, setting the stage for further analysis.
37.	Ferretti, Gabriele, 1963, et al. (author) Instantons and Toric Quiver Gauge Theories 2008 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2008:7 Journal article (peer-reviewed)abstract We show how to construct the general action coupling (multi)instantons to gauge theories arising from branes probing arbitrary toric singularities. We give a general set of rules for how to construct such an action given the knowledge of the superpotential for the gauge theory. The main idea is to obtain the action by higgsing a theory whose instanton dynamics is known, namely an orbifold of N=4 super Yang-Mills. We find that the couplings of the fermionic zero-modes with the holomorphic fields are dictated by the structure of the superpotential describing the toric singularity. We present explicit examples such as the Suspended Pinch Point, the Conifold and the first three del Pezzo's. We perform various checks on these results by further higgsing to smaller orbifolds and present some applications, including both gauge theory and stringy instantons.
38.	Ferretti, Gabriele, 1963 (author) Introduktion till speciell relativitetsteori 2018 Other publication (other academic/artistic)abstract Kompendium i speciell relativitetsteori Huvudförfattare: Gabriele Ferretti Medförfattare: Sara-Louise Karlsson, Mikael Lennefors, Sebastian Lundquist, Felix Mattsson, David Schörling (fysik studenter)
39.	Ferretti, Gabriele, 1963 (author) LHC och partikelfysikens framtid 2010 Reports (other academic/artistic)
40.	Ferretti, Gabriele, 1963, et al. (author) Light stop squarks and b-tagging 2014 In: Proceedings of Science. - 1824-8039. ; 2014-September Conference paper (peer-reviewed)abstract A significant part of the parameter space for light stop squarks still remains unconstrained by collider searches. For both R-Parity Conserving (RPC) and R-Parity Violating (RPV) scenarios there are regions in which the stop mass is around or below the top quark mass that are particularly challenging experimentally. Here we review the status of light stop searches, both in RPC and RPV scenarios. We also propose strategies, generally based on exploiting b-tagging, to cover the unconstrained regions.
41.	Ferretti, Gabriele, 1963, et al. (author) Monojetlike Searches for Top Squarks with a b Tag 2015 In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 114:20, s. Art. no. 201801- Journal article (peer-reviewed)abstract The LHC searches for light compressed stop squarks have resulted in considerable bounds in the case where the stop decays to a neutralino and a charm quark. However, in the case where the stop decays to a neutralino, a bottom quark and two fermions via an off-shell W-boson, there is currently a significant unconstrained region in the stop-neutralino mass plane, still allowing for stop masses in the range 90-140 GeV. In this paper we propose a new monojet-like search for light stops, optimized for the four-body decay mode, in which at least one b-tagged jet is required. We show that, already by using the existing 8 TeV LHC data set, such a search would cover the entire unconstrained region. Moreover, in the process of validating our tools against an ATLAS monojet search, we show that the existing limit can be extended to exclude also stop masses below 100 GeV.
42.	Ferretti, Gabriele, 1963, et al. (author) Multiphoton signatures of goldstini at the LHC 2014 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; April 2014:2014:126 Journal article (peer-reviewed)abstract We study models of gauge mediated SUSY breaking with more than one hidden sector. In these models the neutralino sector of the MSSM is supplemented with additional light neutral fermions, the nearly massless gravitino and the massive pseudo-goldstini. For the case where the Bino is the lightest ordinary SUSY particle, its preferred decay is to a photon and the heaviest pseudo-goldstino, which generically cascades down to lighter pseudo-goldstini, or to the gravitino, in association with photons. This gives rise to multiphoton plus missing energy signatures at the LHC. We investigate in detail simplified models where the SUSY spectrum consists of the right-handed sleptons, a Bino-like neutralino, the pseudo-goldstini and the gravitino. We compare against existing LHC searches and show that the sensitivity to our models could be significantly improved by relaxing the kinematic cuts and requiring additional final state particles. We propose inclusive searches in the final state with at least three photons plus missing energy and in the final state with at least two photons plus two leptons plus missing energy, the former being sensitive to any production mode and the latter being optimized for slepton pair production. We show that they could lead to an observation (or strong constraints) already with the data set from LHC Run I, and present prospects for LHC Run II.
43.	Ferretti, Gabriele, 1963, et al. (author) New integrable structures in large-N QCD 2004 In: Physical Review D: Particles and fields. - 0556-2821. ; 70:7, s. 074024- Journal article (peer-reviewed)abstract We study the anomalous dimensions of single trace operators composed of field strengths $F_{\mu\nu}$ in large-N QCD. The matrix of anomalous dimensions is the Hamiltonian of a compact spin chain with two spin one representations at each vertex corresponding to the selfdual and anti-selfdual components of $F_{\mu\nu}$. Due to the special form of the interaction it is possible to study separately renormalization of purely selfdual components. In this sector the Hamiltonian is integrable and can be exactly solved by Bethe ansatz. Its continuum limit is described by the level two SU(2) WZW model.
44.	Ferretti, Gabriele, 1963, et al. (author) Non-Perturbative Effects on a Fractional D3-Brane 2009 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 03:3, s. 040- Journal article (peer-reviewed)abstract In this note we study the N = 1 abelian gauge theory on the world volume of a single fractional D3-brane. In the limit where gravitational interactions are not completely decoupled we find that a superpotential and a fermionic bilinear condensate are generated by a D-brane instanton effect. A related situation arises for an isolated cycle invariant under an orientifold projection, even in the absence of any gauge theory brane. Moreover, in presence of supersymmetry breaking background fluxes, such instanton configurations induce new couplings in the 4-dimensional effective action, including non-perturbative contributions to the cosmological constant and non-supersymmetric mass terms.
45.	Ferretti, Gabriele, 1963 (author) Preparing for the physics GRE 2008 Reports (other academic/artistic)abstract The Physics GRE is a standardized multiple-choice test used worldwide as one of the admission criteria to graduate studies. For the last two years we have given a preparatory course to the students wanting to take this test. The main aim of this project was to assess the effectiveness of such a preparatory course. We recorded the results of four trial exams, taken under realistic circumstances, and used them to track the students’ performance as the course progressed. Although the number of students tested was small, the preliminary results were quite encouraging and showed a clear improvement in the students’ performance. We complemented this investigation with an online evaluation form asking the students to assess the course, their undergraduate education as a whole, and to express their opinions about the usefulness of such a standardized test. The feedback received about the course was also very encouraging. However, the students expressed some doubts regarding the effectiveness of the Physics GRE in assessing their preparation or in predicting their future performance.
46.	Ferretti, Gabriele, 1963 (author) Underlying gauge-fermion models of compositeness 2022 In: European Physical Journal: Special Topics. - : Springer Science and Business Media LLC. - 1951-6401 .- 1951-6355. ; 231:7, s. 1265-1272 Research review (peer-reviewed)abstract We review recent advances in the construction of models of compositeness using four-dimensional gauge theories with fermionic matter. We discuss the group theory data needed to fulfill the basic phenomenological requirements and we touch upon the main predictions of these constructions.
47.	Ferretti, Gabriele, 1963 (author) UV Completions of Partial Compositeness: The Case for a SU(4) Gauge Group 2014 In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2014:6, s. Art. no. 142- Journal article (peer-reviewed)abstract We present a model of partial compositeness arising as the IR limit of a SU(4) gauge theory with only fermionic matter. This group is one of the most promising ones among a handful of possible choices allowing a symmetry breaking pattern incorporating custodial symmetry and a top partner candidate, while retaining asymptotic freedom. It is favored for not giving rise to lepto-quarks or Landau poles in the SM gauge couplings. The minimal UV theory consists of five hyperfermions in the anti-symmetric representation and three in the fundamental and anti-fundamental. The IR theory is centered around the coset SU(5)/SO(5), with top partners in the fundamental of SO(5), giving rise to one composite fermion of electric charge 5/3, three of charge 2/3 and one of charge -1/3. Electro-Weak symmetry breaking occurs via top-quark-driven vacuum misalignment. The top quark mass is generated via the mechanism of partial compositeness, while the remaining fermions acquire a mass via a standard quadratic coupling to the Higgs. We compute the top and bottom quark mass matrix and the Electro-Weak currents of the composite fermions. The model does not give rise to unacceptably large deviations from the SM Z\to b \bar b decay width.
48.	Petersson, Christoffer, 1979, et al. (author) An introduction to supersymmetric gauge theories and matrix models 2004 In: International Journal of Modern Physics. ; A:19, s. 2015- Journal article (peer-reviewed)abstract We give an introduction to the recently established connection between supersymmetric gauge theories and matrix models. We begin by reviewing previous material that is required in order to follow the latest developments. This includes the superfield formulation of gauge theories, holomorphy, the chiral ring, the Konishi anomaly and the large N limit. We then present both the diagrammatic proof of the connection and the one based on the anomaly. Our discussion is entirely field theoretical and self contained.
49.	Petersson, Christoffer, 1979, et al. (author) BARYONIC CORRECTIONS TO SUPERPOTENTIALS FROM PERTURBATION THEORY 2003 In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 553:3-4, s. 332-336 Journal article (peer-reviewed)abstract We study the corrections induced by a baryon vertex to the superpotential of SQCD with gauge group SU(N) and N quark flavors. We first compute the corrections order by order using a standard field theory technique and derive the corresponding glueball superpotential by "integrating in" the glueball field. The structure of the corrections matches with the expectations from the recently introduced perturbative techniques. We then compute the first non-trivial contribution using this new technique and find exact quantitative agreement. This involves cancellations between diagrams that go beyond the planar approximation.
50.	Petersson, Christoffer, 1979, et al. (author) Chiral SU(N) gauge theories and the Konishi anomaly 2003 In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2003:07, s. 044- Journal article (peer-reviewed)abstract We study chiral SU(N) supersymmetric gauge theories with matter in the antifundamental and antisymmetric representations. For SU(5) with two families, we show how to reproduce the non-perturbatively generated superpotential, and we discuss dynamical supersymmetry breaking purely in terms of the Konishi anomaly. We apply the same technique in general to SU(N) with one family. We also briefly comment on the chiral ring for these theories.

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