| 1. |
- Abdallah, Waleed, et al.
(författare)
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Reinterpretation of LHC results for new physics: Status and recommendations after run 2
- 2020
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Ingår i: SciPost Physics. - 2542-4653. ; 9:2, s. 1-45
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Tidskriftsartikel (refereegranskat)abstract
- We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpretation Forum. We detail current experimental offerings in direct searches for new particles, measurements, technical implementations and Open Data, and provide a set of recommendations for further improving the presentation of LHC results in order to better enable reinterpretation in the future. We also provide a brief description of existing software reinterpretation frameworks and recent global analyses of new physics that make use of the current data. © 2020 SciPost Foundation. All right reserved
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| 2. |
- Banerjee, Souvik, et al.
(författare)
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A bound on thermal relativistic correlators at large spacelike momenta
- 2020
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Ingår i: SciPost Physics. - : SCIPOST FOUNDATION. - 2542-4653. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- We consider thermal Wightman correlators in a relativistic quantum field theory in the limit where the spatial momenta of the insertions become large while their frequencies stay fixed. We show that, in this limit, the size of these correlators is bounded by e(-beta R), where R is the radius of the smallest sphere that contains the polygon formed by the momenta. We show that perturbative quantum field theories can saturate this bound through suitably high-order loop diagrams. We also consider holographic theories in d-spacetime dimensions, where we show that the leading two-point function of generalized free-fields saturates the bound in d = 2 and is below the bound for d > 2. We briefly discuss interactions in holographic theories and conclude with a discussion of several open problems.
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| 3. |
- Bierlich, Christian, et al.
(författare)
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Robust independent validation of experiment and theory : RIVET version 3
- 2020
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Ingår i: SciPost Physics. - 2542-4653. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- First released in 2010, the RIVET library forms an important repository for analysis code, facilitating comparisons between measurements of the final state in particle collisions and theoretical calculations of those final states. We give an overview of RIVET’s current design and implementation, its uptake for analysis preservation and physics results, and summarise recent developments including propagation of MC systematic-uncertainty weights, heavy-ion and ep physics, and systems for detector emulation. In addition, we provide a short user guide that supplements and updates the RIVET user manual.
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| 4. |
- Buarque Franzosi, Diogo, 1983, et al.
(författare)
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Pseudoscalar pair production via off-shell Higgs in composite Higgs models
- 2020
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Ingår i: SciPost Physics. - 2542-4653. ; 9:077
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Tidskriftsartikel (refereegranskat)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.
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| 5. |
- de Boer, Jan, et al.
(författare)
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Non-boost invariant fluid dynamics
- 2020
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Ingår i: SciPost Physics. - : Stichting SciPost. - 2542-4653. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- We consider uncharged fluids without any boost symmetry on an arbitrary curved background and classify all allowed transport coefficients up to first order in derivatives. We assume rotational symmetry and we use the entropy current formalism. The curved background geometry in the absence of boost symmetry is called absolute or Aristotelian spacetime. We present a closed-form expression for the energy-momentum tensor in Landau frame which splits into three parts: a dissipative (10), a hydrostatic non-dissipative (2) and a non-hydrostatic non-dissipative part (4), where in parenthesis we have indicated the number of allowed transport coefficients. The non-hydrostatic non-dissipative transport coefficients can be thought of as the generalization of coefficients that would vanish if we were to restrict to linearized perturbations and impose the Onsager relations. For the two hydrostatic and the four non-hydrostatic non-dissipative transport coefficients we present a Lagrangian description. Finally when we impose scale invariance, thus restricting to Lifshitz fluids, we find 7 dissipative, 1 hydrostatic and 2 non-hydrostatic non-dissipative transport coefficients.
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| 6. |
- Gran, Ulf, 1973, et al.
(författare)
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Plasmons in holographic graphene
- 2020
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Ingår i: SciPost Physics. - : SCIPOST FOUNDATION. - 2542-4653. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate how self-sourced collective modes - of which the plasmon is a prominent example due to its relevance in modern technological applications - are identified in strongly correlated systems described by holographic Maxwell theories. The characteristic ω ∝ pk plasmon dispersion for 2D materials, such as graphene, naturally emerges from this formalism. We also demonstrate this by constructing the first holographic model containing this feature. This provides new insight into modeling such systems from a holographic point of view, bottom-up and top-down alike. Beyond that, this method provides a general framework to compute the dynamical charge response of strange metals, which has recently become experimentally accessible due to the novel technique of momentum-resolved electron energy-loss spectroscopy (M-EELS). This framework therefore opens up the exciting possibility of testing holographic models for strange metals against actual experimental data.
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| 7. |
- Lindgren, Erik J., et al.
(författare)
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A systematic interpolatory method for an impurity in a one-dimensional fermionic background
- 2020
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Ingår i: SciPost Physics. - : Stichting SciPost. - 2542-4653. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- We explore a new numerical method for studying one-dimensional quantum systems in a trapping potential. We focus on the setup of an impurity in a fermionic background, where a single distinguishable particle interacts through a contact potential with a num-ber of identical fermions. We can accurately describe this system, for various particle numbers, different trapping potentials and arbitrary finite repulsion, by constructing a truncated basis containing states at both zero and infinite repulsion. The results are compared with matrix product states methods and with the analytical result for two particles in a harmonic well.
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| 8. |
- Nguyen, Dung Xuan, et al.
(författare)
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Fracton-elasticity duality of two-dimensional superfluid vortex crystals : defect interactions and quantum melting
- 2020
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Ingår i: SciPost Physics. - : SciPost Foundation. - 2542-4653. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Employing the fracton-elastic duality, we develop a low-energy effective theory of a zero-temperature vortex crystal in a two-dimensional bosonic superfluid which naturally incorporates crystalline topological defects. We extract static interactions between these defects and investigate several continuous quantum transitions triggered by the Higgs condensation of vortex vacancies/interstitials and dislocations. We propose that the quantum melting of the vortex crystal towards the hexatic or smectic phase may occur via a pair of continuous transitions separated by an intermediate vortex supersolid phase.
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| 9. |
- Rose, Felix, et al.
(författare)
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Hall viscosity and conductivity of two-dimensional chiral superconductors
- 2020
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Ingår i: SciPost Physics. - : SciPost Foundation. - 2542-4653. ; 9:1, s. 1-38
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Tidskriftsartikel (refereegranskat)abstract
- We compute the Hall viscosity and conductivity of non-relativistic two-dimensional chi-ral superconductors, where fermions pair due to a short-range attractive potential, e.g. p + ip pairing, and interact via a long-range repulsive Coulomb force. For a logarithmic Coulomb potential, the Hall viscosity tensor contains a contribution that is singular at low momentum, which encodes corrections to pressure induced by an external shear strain. Due to this contribution, the Hall viscosity cannot be extracted from the Hall conductivity in spite of Galilean symmetry. For mixed-dimensional chiral superconductors, where the Coulomb potential decays as inverse distance, we find an intermediate behavior between intrinsic two-dimensional superconductors and superfluids. These results are obtained by means of both effective and microscopic field theory.
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| 10. |
- Tournois, Yoran, et al.
(författare)
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Microscopic derivation of Ginzburg-Landau theories for hierarchical quantum Hall states
- 2020
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Ingår i: SciPost Physics. - : SCIPOST FOUNDATION. - 2542-4653. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- We propose a Ginzburg-Landau theory for a large and important part of the abelian quantum Hall hierarchy, including the prominently observed Jain sequences. By a generalized "flux attachment" construction we extend the Ginzburg-Landau-Chern-Simons composite boson theory to states obtained by both quasielectron and quasihole condensation, and express the corresponding wave functions as correlators in conformal field theories. This yields a precise identification of the relativistic scalar fields entering these correlators in terms of the original electron field.
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