Theory Institute in Particle Physics and Cosmology

Europe/Warsaw
Room 4.50 (Faculty of Physics, University of Warsaw)

Room 4.50

Faculty of Physics, University of Warsaw

https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 15:00 17:00
      Welcome coffee 2h 4.49 ()

      4.49

      Ludwika Pasteura 5, 02-093 Warszawa https://goo.gl/maps/Td8ipmZmZPtQ4DYL9

      Coffee and get together afternoon

    • 10:30 11:15
      Is there a supernova bound on axions? 45m 4.50 ()

      4.50

      We present a critical assessment of the SN1987A supernova cooling bound on axions and other light particles. Core-collapse simulations used in the literature to substantiate the bound omitted from the calculation the envelope exterior to the proto-neutron star (PNS). As a result, the only source of neutrinos in these simulations was, by construction, a cooling PNS. We show that if the canonical delayed neutrino mechanism failed to explode SN1987A, and if the pre-collapse star was rotating, then an accretion disk would form that could explain the late-time (t>~5 sec) neutrino events. Such accretion disk would be a natural feature if SN1987A was a collapse-induced thermonuclear explosion. Axions do not cool the disk and do not affect its neutrino output, provided the disk is optically-thin to neutrinos, as it naturally is. These considerations cast doubt on the supernova cooling bound on axions.

      Based on arXiv:1601.03422, 1811.11178, 1907.05020.

      Speaker: Kfir Blum
    • 11:15 12:00
      Coffee break 45m 4.49 ()

      4.49

    • 14:00 14:45
      Scale invariance and the Standard Model 45m
      Speaker: Graham Garland Ross (University of Oxford (GB))
    • 14:45 15:30
      Coffee break 45m
    • 10:30 11:15
      Anomaly free Froggatt-Nielsen models of flavor 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

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      Speaker: Jure Zupan (University of Cincinnati)
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      Axions are blind to anomalies 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      The axion couplings to SM gauge bosons are derived in various models, and shown to always arise entirely from non-anomalous fermion loops. They are thus independent of the anomaly structure of the model. This fact is without consequence for vector gauge interactions like QCD and QED, but has a major impact for chiral gauge theories. For example, in the DFSZ axion model, the couplings of axions to electroweak gauge bosons do not follow the pattern expected from chiral anomalies, as we prove by an explicit calculation. The reason for this mismatch is traced back to triangle Feynman diagrams sensitive to the anomalous breaking of the vector Ward identity, and is ultimately related to the conservation of baryon and lepton numbers. Though our analyses are entirely done for true axion models, this observation could have important consequences for axion-like particle searches.

      Speaker: Dr Jeremie Quevillon (LPSC, Grenoble (CNRS))
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

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    • 10:30 11:15
      Magnetic compactifications 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Emilian Dudas (Ecole Polytechnique)
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      Partially Composite Supersymmetry 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Tony Gherghetta (University of Minnesota (US))
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 15:30 16:15
      A Realistic U(2) Model of Flavor 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      I will discuss a simple U(2) flavor model compatible with an SU(5) GUT structure.
      All hierarchies in fermion masses and mixings arise from powers of two small
      parameters that control the U(2) breaking pattern. In contrast to previous U(2)
      models this setup can be realized without supersymmetry and provides an excellent
      fit to all SM flavor observables including neutrinos, predicting an upper bound
      on the neutrino mass scale below current cosmological bounds. A variant of this
      model is based on a D_6 x U(1)_F flavor symmetry, which closely resembles
      the U(2) structure, but allows for Majorana neutrino masses from the Weinberg
      operator. Remarkably, in this case the structure of neutrino masses is closely
      tied to the quark sector, and one naturally obtains large mixing in the lepton
      sector from small mixing in the quark sector. Finally the model offers a natural
      option for adressing the Strong CP Problem and Dark Matter by identifying the
      Goldstone boson of the U(1)_F factor as the QCD axion.

      Speaker: Robert Ziegler (CERN)
    • 10:30 11:15
      Supersymmetry, g-2 and gauge coupling unification 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Kazuki Sakurai (University of Warsaw)
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      QCD Instanton Processes at Colliders 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Valentin V Khoze (Durham University)
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 10:30 11:15
      Inflation and Bouncing Models 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      Stochastic background gravitational waves allows to discern between different
      paradigms of the Early Universe.I will start with the most conservative scenario
      of Inflation and show how we can consider different inflationary models as different
      field redefinitions of a fixed Kahler geometry and a fixed superpotential in supergravity.
      Nevertheless, Inflation does not resolve the Big Bang singularity. It therefore makes
      sense to consider alternatives to Inflation. Non-singular bounces, where the scale
      factor never vanishes are such an alternative. I will then describe how slow contraction
      with sourced fluctuations allows for a nearly scale invariant tensor and scalar fluctuations
      that is in principle observable at CMB and LI scales. Finally, in an attempt to construct
      a valid bounce, I will discuss how a Bounce may be achieved close to the fixed point
      of Banks-Zaks/Unparticle theory.
      The talk is based on 1908.07052, 1812.06790, 1604.07899 and work in progress.

      Speaker: Ido Ben-Dayan
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      Origin of CP and flavor 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Hans Peter Nilles (Univ. Bonn)
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 10:30 11:15
      Higgs inflation, unitarity, and emergence of scalaron 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      The vanilla Higgs inflation introduces a large non-minimal coupling between the Ricci scalar and Higgs that causes the tree-level unitarity violation well below the Planck scale. After reviewing the unitarity issue of the Higgs inflation during and after inflation, we show that the unitarity can be restored by summing over vacuum polarization-type diagrams. The scattering amplitude develops a pole after the resummation, which we identify as the scalar component of the metric, or the scalaron. It suggests that the Higgs inflation is actually a multi-field inflation model, i.e. Higgs and the scalaron, and does not suffer from the unitarity problem.

      Speaker: Yohei Ema
    • 11:15 11:45
      Coffee break 30m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 11:45 12:30
      Gravitational wave energy budget in strongly supercooled phase transitions 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      We derive efficiency factors for the production of gravitational waves through bubble collisions and plasma-related sources in strong phase transitions, and find the conditions under which the bubble collisions can contribute significantly to the signal. We illustrate our findings in two examples, the Standard Model with an extra $|H|^6$ interaction and a classically scale-invariant $U(1)_{\rm B-L}$ extension of the Standard Model. The contribution to the GW spectrum from bubble collisions is found to be negligible in the $|H|^6$ model, whereas it can play an important role in parts of the parameter space in the scale-invariant $U(1)_{\rm B-L}$ model. In both cases the sound-wave period is much shorter than a Hubble time, suggesting a significant amplification of the turbulence-sourced signal. We find, however, that the peak of the plasma-sourced spectrum is still produced by sound waves with the slower-falling turbulence contribution becoming important off-peak. We also Investigate another complimentary signal in the form of primordial magnetic fields produced in the transition

      Speaker: Marek Lewicki
    • 14:00 14:45
      Constraints on EFT from neutrino oscillations 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      I will discuss how the existing data from neutrino oscillation
      experiments can be used to constrain Wilson coefficients of effective
      field theories (EFTs) extending the Standard Model. I will also
      clarify the relation between the proper EFT approach and the so-called
      NSI formalism popular in the neutrino literature.

      Speaker: Adam Falkowski (LPT Orsay)
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 10:30 11:15
      Tunneling rates from the Minkowski path integral 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      We present the calculation of the Feynman path integral in real time for tunneling in quantum mechanics and field theory, including the first quantum corrections. For this purpose we use the well-known fact that Euclidean saddle points in terms of real fields can be analytically continued to complex saddles of the action in Minkowski space. We also use Picard-Lefschetz theory in order to determine the middle-dimensional steepest-descent surface in the complex field space, constructed from Lefschetz thimbles, on which the path integral is to be performed. As an alternative to extracting the decay rate from the imaginary part of the ground-state energy of the false vacuum, we use the optical theorem in order to derive it from the real-time amplitude for forward scattering. The latter amplitude is computed from the Minkowski path integral, i.e. evaluating the Gaussian integrals of fluctuations about the relevant complex saddle points. Although the equations for the steepest-descent integration surfaces are not holomorphic, which prevents a straightforward analytic continuation of the Euclidean results, we show how the eigenvalues and eigenfunctions of the fluctuation operators on a thimble can be related to their Euclidean counterparts, and we determine the path-integral measure on thimbles. This way, using real-time methods we recover the one-loop result by Callan and Coleman for the decay rate.

      Speaker: Carlos Tamarit (Technische Universität München)
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      Gauge-protected clockwork and flavourful axions 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      I will discuss the gauge protection of an axion shift-symmetry in two phenomenologically relevant scenarii: axions with a clockwork profile and flaxions/axiflavons arising in Froggatt-Nielsen models. I will mostly focus on the comparison between the original globally-symmetric models and their embeddings in gauged models.

      Speaker: Quentin Bonnefoy
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 10:30 11:15
      Electroweak baryogenesis at colliders 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6

      Motivated by (but not restricted to) models of composite Higgs, I will discuss
      electroweak baryogenesis in different extensions of the Higgs sector. In particular, I
      will focus on smoking gun signatures that -surprisingly- have not yet been studied at colliders.
      I will also stress the complementarity with gravitational wave experiments.

      Speaker: Dr Mikael Chala (IPPP Durham)
    • 11:15 12:00
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:00 14:45
      TBA 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
      Speaker: Kyohei Mukaida (DESY)
    • 14:45 15:30
      Coffee break 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 11:15 12:00
      Coffee 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6
    • 14:45 15:30
      Coffee 45m Room 4.50

      Room 4.50

      Faculty of Physics, University of Warsaw

      https://goo.gl/maps/pDwZPDuTRr2maD1C6