ALPS2019 -- Fourth Alpine LHC Physics Summit

UZ Obergurgl

UZ Obergurgl

University Center Obergurgl Gaisbergweg 5 6456 Obergurgl Austria
Alberto Escalante Del Valle (Austrian Academy of Sciences (AT)), Axel Torsten Maas (University of Graz), Brigitte DeMonte, Florian Reindl (HEPHY & TU Vienna), Martin Flechl, Robert Schoefbeck (Austrian Academy of Sciences (AT)), Suchita Kulkarni (chair), Wolfgang Lucha (Austrian Academy of Sciences)

Continuing the tradition of 2018, 2017 and 2016, we will meet in the Austrian Alps to discuss recent results and developments in experimental and theoretical particle physics. The dates of the meeting are April 22 - 27, 2019 and the following topics are at the focus of the meeting:

  • Flavour and hadron physics
  • Beyond the Standard Model physics
  • Higgs and Standard Model physics
  • Neutrino physics
  • Dark matter
  • Future colliders

The days are divided into morning sessions with keynote talks, and  late afternoon sessions that will comprise shorter presentations on more specialized topics and the Young Scientist Forum. The meeting will take place at the Obergurgl University Centre, in the ski-resort town of Obergurgl, located in the upper Oetztal Valley in Tyrol, Austria.

Opening speaker:

  • Jessie Shelton (University of Illinois)

Confirmed invited speakers: 

  • Several representatives of ATLAS and CMS collaborations
  • Paula Alvarez Cartelle (Imperial College London)
  • Francesca Calore (LAPTh, Annecy)
  • John Paul Chou (Rutgers University)
  • Sébastien Descotes-Genon (Université Paris-Sud)
  • Luca Doria (JGU, Mainz)
  • Astrid Eichhorn (University of Southern Denmark)
  • Torben Ferber (DESY Hamburg)
  • Jules Gascon (Institut de Physique Nucléaire de Lyon) 
  • Martin Hirsch (IFIC, Valencia)
  • Manfred Jeitler (HEPHY, Vienna)
  • Ken Mimasu (CP3, Louvain)
  • Mihoko Nojiri (KEK, Japan)
  • Federica Petricca (MPI, Munich)
  • Justin Read (University of Surrey, UK)
  • Werner Riegler (CERN)
  • Lesya Shchutska (ETH Zürich)
  • Tim Stefaniak (DESY Hamburg)
  • Walter Winter (DESY Zeuthen)
  • Oliver Witzel (The University of Edinburgh)
  • Dieter Zeppenfeld (KIT, Karlsruhe)

Scientific Advisory Board:

  • Freya Blekman (Vrije Universiteit Brussel)
  • Frank Deppisch (UCL London)
  • Graciela Gelmini (UCLA)
  • Stefania Gori (University of Cincinati)
  • Kai Schmidt Hoberg (DESY Hamburg)
  • Jenny List (DESY Hamburg)
  • Steven Lowette (Vrije Universiteit Brussel)
  • Franz Muheim (University of Edinburgh)
  • Reisaburo Tanaka (LAL Orsay)
  • Roman Zwicky (University of Edinburgh)

Local Organizers (HEPHY):

  • Alberto Escalante del Valle
  • Martin Flechl
  • Gianluca Inguglia
  • Suchita Kulkarni (chair)
  • Wolfgang Lucha
  • Robert Schoefbeck
  • Florian Reindl
  • Brigitte De Monte (secretary)

Local Organizers (University of Graz):

  • Axel Maas
    • Overview talks: Flavour and hadron physics; session chair: Jessie Shelton
      • 2
        Quantum gravity implications for particle physics
        Speaker: Astrid Eichhorn
      • 3
        High energy neutrinos
        Speaker: Walter Winter (DESY)
      • 9:40 AM
        Hot beverages
      • 4
        B-physics anomalies, fluctuations and patterns: a status report
        Speaker: Sebastien Descotes-Genon (Laboratoire de Physique Théorique d'Orsay)
      • 5
        Dark sectors at low energy colliders
        Speaker: Torben Ferber (DESY)
      • 6
        Recent results from LHCb
        Speaker: Paula Alvarez Cartelle (Imperial College (GB))
    • Overview talks: The standard model and Higgs physics; session chair: Tim Stefaniak
      • 7
        Electroweak diboson - LHC measurements and theory
        Speaker: Dieter Zeppenfeld
      • 5:20 PM
        Hot beverages
    • Contributed talks: Flavour and hadron physics; session chair: Tim Stefaniak
      • 8
        Results from the CUORE experiment

        The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay (0νββ) that has been able to reach the one-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. The construction of the experiment was completed in August 2016 with the installation of all towers in the cryostat. Following a cooldown, diagnostic, and optimization campaign, routine data-taking began in spring 2017. In this talk, we present the 0νββ results of CUORE from examining a total TeO2 exposure of 86.3 kg∙yr, characterized by an average energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV∙kg∙yr). In this physics run, CUORE placed the current best lower limit on the 130Te 0νββ half-life of > 1.3 × 10^25 yr (90% C.L.). We then discuss the additional improvements in the detector performance achieved in 2018, the latest evaluation of the CUORE background budget, and we finally present the most precise measurement of the 130Te 2νββ half-life to date.

        Speaker: Simone Copello (INFN)
      • 9
        Displaced Heavy Neutrinos at the LHC and Beyond

        We investigate the pair production of right-handed neutrinos from the decay of the additional neutral gauge boson Z′ at a gauged B − L model. Analysing such signal can be recasted from dark photon searches with a corresponding factor of its coupling g′, this gives a upper bound for g′ to be 10−4 for mZ′ under 10 GeV and $10^{−3}$ for mZ′ beyond 10 GeV. As the heavy neutrinos can be longlived as distinctive displaced vertices signatures via seesaw mechanism, an simulation based on Monte Carlo event generator is performed, which shows a sensitivities for VμN< 10−5 with 300 fb−1 assuming g′ = 10−3 and MN = 0.3∗mZ′ at MAPP and LHCb detector.

        Speaker: Mr Wei Liu (University College London)
      • 10
        (Semi)-Leptonic $D_{(s)}$ decays at BESIII

        Leptonic and semi-leptonic $D$ decays at BESIII contribute the most precise experimental measurement of $|V_{cs(d)}|$ and form factor $f_{D_{(s)}}$ in the world based on 2.93 fb$^{-1}$ and 3.19 fb$^{-1}$ data taken at center-of-mass energies $\sqrt{s} = 3.773$ and 4.180~GeV, respectively. The largest samples at the mass threshold of the charmed hadrons $D_{(s)}$ also provide chances to extract form factors of some semi-electronic decays for the first time and together with the semi-muonic decays we could understand lepton flavour universality better. This talk would introduce the recent results of leptonic and semi-leptonic $D_{(s)}$ decays at BESIII.

        Speaker: Mr Youhua Yang (Nanjing University)
      • 11
        Flavour anomaly updates from ATLAS and CMS
        Speaker: Alberto Bragagnolo (Università degli Studi di Padova (IT))
      • 12
        Exotic bottomonium-like hadrons

        In recent years, many hadronic states with heavy quarks have been observed which do not fit into the quark model scheme. Investigation of the nature and properties of such exotic states is an important task for the phenomenology of strong interactions. Most intriguing are charged states which at the same time contain a heavy quark-antiquark pair, since their minimal quark contents is four-quark and, therefore, their exotic nature is undoubted. A combined analysis of the existing experimental data on the production and decay channels of the isovector bottomonium-like states Zb(10610) and Zb(10650) (with the quantum number 1+-) is performed in the framework of a coupled-channel approach which respects constraints from unitarity, analyticity and heavy quark spin symmetry. The latter symmetry, inter alia, allows one to relate properties of the Zb's with those of their spin partners WbJ (with the quantum numbers J++, J=0,1,2) which differ from the Zb's by the orientation of the heavy quark spins. As a result, the pole positions and the line shapes in different elastic and inelastic channels are predicted for the WbJ's in a parameter-free way. The developed approach admits a natural generalisation to other exotic states, in particular, to charmonia.

        Speaker: Dr Alexey Nefediev (P.N.Lebedev Institute of RAS)
      • 13
        Angular analysis of the $e^{+}e^{-} \to D^{(*)}D^{*}$ process near the open-charm threshold using initial-state radiation at Belle

        Until recently, parameters of vector charmonia lying above the open-charm threshold were determined from the inclusive cross section of the electron-positron annihilation to hadronic final states. However, the parameters of the resonances obtained this way are model-dependent and they suffer from large uncertainties. On the other hand, measurements of exclusive cross sections of the e^+e^- annihilation to charm hadrons should provide important missing information about strong interaction in this region so that the results of such measurements are of large interest both for developments of experimental methods, and theory.
        In particular, the aforementioned measurements should shed light on the nature on the charminium states with quantum numbers $1^{--}$, which are not fully understood yet. Determination of the masses and widths of these resonances in a model-independent way and extraction of their coupling constant to elastic open-charm channels will allow to obtain information on the wave functions of the vector charmonia and to verify the phenomenological models for heavy hadrons.
        New results are obtained for the exclusive cross sections of the $e^+e^−$ annihilation into charmed hadron pairs with initial state radiation. The analysis is based on the data sample collected with the Belle detector with the integrated luminosity of 951 fb$^{−1}$. The accuracy of the cross section measurement is increased by a factor of 2 compared with the previous Belle study and, for the first time, the $e^+e^- \to D^∗D^∗$ cross section is decomposed into three components corresponding to different helicities of the $D^∗$’s in the final state.

        Speaker: Valentina Zhukova (Lebedev Physical Institute)
    • Overview talks: Dark matter; session chair: Pat Scott
      • 14
        Dark matter searches at the intensity frontier
        Speaker: Luca Doria (University of Mainz)
      • 15
        Direct detection searches: an overview
        Speaker: Federica Petricca (Max-Planck-Institut für Physik)
      • 9:40 AM
        Hot beverages
      • 16
        Multi-messenger probes for dark matter
        Speakers: Francesca Calore (LAPTh, CNRS), Francesca Calore (Unite Reseaux du CNRS (FR))
      • 17
        Dark matter: Between astronomy and particle physics
        Speaker: Justin Read (University of Surrey)
    • Contributed talks: session chair: Pat Scott
      • 18
        Dark matter searches at the LHC
        Speakers: Renjie Wang (Johannes Gutenberg-Universität Mainz (DE)), Renjie Wang (Johannes Gutenberg-Universität Mainz (DE))
      • 19
        Coloured coannihilations: Dark matter phenomenology meets non-relativistic EFTs

        We investigate the phenomenology of a simplified model with a Majorana fermion as dark matter candidate which interacts with Standard Model quarks via a colour-charged coannihilation partner. Recently it has been realized that non-perturbative dynamics, including the Sommerfeld effect, bound state formation/dissociation and thermal corrections, play an important role in coannihilations with coloured mediators. This calls for a careful analysis of thermal freeze-out and a new look at the experimental signatures expected for a thermal relic. We employ a state of the art calculation of the relic density which makes use of a non-relativistic effective theory framework and calculate the effective annihilation rates by solving a plasma-modified Schrödinger equation. We determine the cosmologically preferred parameter space and confront it with current experimental limits and future prospects for dark matter detection.

        Speaker: Stefan Vogl (Max Planck Institute for Nuclear Physics)
    • Contributed talks: Dark matter; session chair: Federica Petricca
      • 20
        Dark matter/ new physics searches at BESIII

        Many extensions of the Standard Model, motivated by recent astrophysical observations, include the possibility of a new type of weak-interacting degrees of freedom. The typical models include the Next-to-Minimal Supersymmetric Standard Model and Light Hidden Dark-sector model that predict the low-mass Higgs and dark bosons, respectively. The masses of these particles are expected to be a few GeV and thus making them reachable at the BESIII experiment. The BESIII has recently explored the possibility of light Higgs and dark bosons in several decay modes using the data collected at J/psi, psi(3686) and psi(3770) resonances. The large dataset corresponding to the J/psi resonance has also been utilized to perform the searches for invisible decays of light vector (V=omega, phi) and pseudo-scalar (P=eta, eta') mesons via J/psi --> VP decays. This talk will summarize the recent results of the BESIII experiment on these topics.

        Speaker: Vindhyawasini Prasad
      • 21
        Status of supersymmetric models with GAMBIT

        I will review the latest constraints on SUSY models from the GAMBIT global fitting collaboration, with a focus on combined collider constraints on neutralinos and charginos. Several tantalising excesses are observed in these searches, and I will discuss their combined statistical significance and possible new physics interpretation.

        Speaker: Benjamin Farmer (Imperial College London)
      • 5:25 PM
        Hot beverages
      • 22
        Above-ground direct searches for WIMPs

        Most direct WIMP searches have located their experimental setup under a large rock overburden in order to drastically reduce the backgrounds caused by cosmic-ray interactions. The absence of signal in current searches had led to revisit of the assumption that the WIMP-nucleon cross section is necessarily low enough to justify to neglect a possible attenuation of the WIMP flux as it passes through the rock overburden. I will review recent experiments devoted to the direct search for WIMPs having cross-section large enough to escape detection in an underground site, while still being compatible with cosmological and astrophysical constraints.

        Speaker: Prof. Jules Gascon (IPNL - Universite Lyon and CNRS/IN2P3)
      • 23
        Search for light dark states with electromagnetic form factors

        Light dark particles coupled to the electromagnetic current via higher-dimensional operators can be produced and searched for in various experiments and astrophysics. The talk will discuss relevant intensity frontier experiments with electron beams, as well as astrophysical and cosmological observations. The combination of all considered probes lead to stringent constraints on the electromagnetic form factors of such light dark states.

        Speaker: Xiaoyong Chu (Institute of High Energy Physics (Vienna, Austria))
      • 24
        The Belle II Experiment: Status and Prospects

        The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the matrix elements and their phases, with unprecedented precision and explore flavor physics with $B$ and charmed mesons, and $\tau$ leptons. Belle II has also a unique capability to search for low mass dark matter and low mass mediators. We also expect exciting results in quarkonium physics with Belle II. From February to July of this year, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Regular operations are expected to start in March 2019. In this presentation, we will review the status of the Belle II detector, the results of the commissioning run and the near-term prospects for physics at Belle II.

        Speaker: Chiara La Licata (Universita e INFN, Trieste (IT))
      • 25
        Inert Doublet Model signatures at Future e+e- Colliders

        The Inert Doublet Model (IDM) is one of the simplest extensions of the Standard Model (SM), providing a dark matter candidate. It is a two Higgs doublet model with a discrete $Z_2$ symmetry, that prevents the scalars of the second doublet (inert scalars) from coupling to the SM fermions and makes the lightest of them stable. We study a large statistics of IDM scenarios, which are consistent with current constraints on direct detection, including the most recent bounds from XENON1T experiment and relic density of dark matter, as well as with all collider and low-energy limits. We propose a set of benchmark points with different kinematic features, that promise detectable signals at future $e^+e^-$ colliders. Two inert scalar pair-production processes are considered, $e^{+}e^{-} \rightarrow H^{+}H^{-}$ and $e^{+}e^{-}\rightarrow AH$, followed by decays of $H^\pm$ and $A$ into the final states which include the lightest and stable neutral scalar dark matter candidate $H$. Significance of the expected observations is studied for different benchmark models and different running scenarios, for center of mass energies up to 3 TeV. Numerical results are presented for the signal signatures with two muons or an electron and a muon in the final state, while the qualitative conclusions can also be drawn for the semi-leptonic signatures.

        Speaker: Aleksander Zarnecki (University of Warsaw (PL))
      • 26
        The search for high mass dilepton resonances in Run II data from ATLAS

        Having enabled discoveries of Standard Model resonances in previous decades, the dilepton invariant mass spectrum remains a vital experimental probe of today’s high energy frontier. Multiple benchmark scenarios beyond the Standard Model anticipate high-mass neutral mediators with clean signatures in dilepton final states at the Large Hadron Collider. In my talk I report findings from the latest search for such signatures in 13 TeV collision data recorded by the ATLAS detector.

        Speaker: Etienne Dreyer (Simon Fraser University (CA))
      • 27
        Toward the spectrum of the SU(2) adjoint Higgs model

        Higgs particles in the adjoint representation of a non-Abelian gauge theory play an important role in many scenarios beyond the standard model, especially grand-unified theories, partial compositness models, and (broken) supersymmetric theories. However, recently new analytic results based on gauge-invariant perturbation theory have arisen, which require a reevaluation of the observable, physical spectrum of such theories.
        Lattice methods can be used to determine this spectrum, and test the underlying predictions. To this end, an SU(2) gauge theory with a single adjoint Higgs is simulated. This model, in the Brout-Englert-Higgs phase, has an unbroken U(1) subgroup. It is then expected a massless vector state. This model can then be a well defined way to obtain a low energy QED from a GUT that comprehends it.

        Speaker: Vincenzo Afferrante (University of Graz)
    • Overview talks: Future facilities; session chair: Axel Mass
    • Contributed talks: Future facilities; session chair: Paula Alvarez Cartelle
      • 33
        The XENON Dark Matter Project: Latest Results and Future Prospects

        The XENON1T experiment searches for weakly interacting massive particles (WIMPs) with a dual-phase xenon time projection chamber (TPC). The latest results come from 278.8 days of collected data in an inner fiducial volume of 1.3 tonnes, corresponding to a $\sim$1 tonne-year of exposure. The main aspects of the experiment and the analysis that led to the best 90% exclusion limit on the cross-section of the spin-independent WIMP interaction above 6 GeV/c$^2$ will be presented, together with the effort to explore other detection channels. To probe a lower interaction cross-section, the upgraded experiment, XENONnT, is currently being commissioned. The new systems that will allow the XENONnT detector to be the next step in the search for dark matter will also be shown.

        Speaker: Chiara Capelli
      • 34
        LHCb upgrades

        During the ongoing LHC long shutdown 2, in 2019/2020,
        the LHCb collaboration is performing a major upgrade of the experiment.
        The upgraded detector is designed to operate at a five times higher instantaneous
        luminosity than in Run II and it can be read out at the full bunch-crossing
        frequency of the LHC, abolishing the need for a hardware trigger. This
        talk will present an overview of the upgraded detector systems and
        discuss the physics reach of the upgraded experiment for selected
        physics topics. In addition, plans for future upgrades will be briefly outlined.

        Speaker: Franz Muheim (The University of Edinburgh (GB))
      • 5:25 PM
        Hot beverages
      • 35
        News on the CLIC physics potential

        The Compact Linear Collider (CLIC) is a proposed TeV-scale high-luminosity electron-positron collider. For an optimal exploitation of its physics potential, CLIC is foreseen to be built and operated in three stages, with centre-of-mass energies ranging from 380 GeV up to 3 TeV. Electron beam polarisation is provided at all energies. The initial energy stage will focus on precision measurements of Higgs-boson and top-quark properties. The subsequent energy stages enhance the reach of many direct and indirect searches for new physics Beyond Standard Model and give access to the Higgs self-coupling. Higgs and top-quark projections have been evaluated using full detector simulation studies. Many new phenomenology studies have been undertaken to explore the BSM reach of CLIC, from EFT interpretations of precision measurements through to signature-based searches; these include flavour dynamics, and dark matter and heavy neutrino searches. This talk will review some of the latest results that demonstrate the outstanding potential of CLIC in many physics domains.

        Speaker: Aleksander Zarnecki (University of Warsaw (PL))
      • 36
        The magnetic moments of muon and electron and implications for a large muon EDM

        With the long-standing tension between experiment and Standard-Model (SM) prediction in the anomalous magnetic moment of the muon, $a_\mu=(g-2)_\mu/2$, at the level of $3$--$4\sigma$, it is natural to ask if there could be a sizable effect in the electric dipole moment (EDM) $d_\mu$ as well. In this context it has often been argued that in UV complete models the electron EDM, which is very precisely measured, excludes a large effect in $d_\mu$. However, the recently observed $2.5\sigma$ tension in $a_e=(g-2)_e/2$, if confirmed, requires that the muon and electron sectors effectively decouple to avoid constraints from $\mu\to e\gamma$. I discuss UV complete models that possess such a decoupling and show that, in such scenarios, there is no reason to expect a correlation between the electron and muon EDM. New limits on $d_\mu$ improved by up to two orders of magnitude are expected from the upcoming $(g-2)_\mu$ experiments at Fermilab and J-PARC. Beyond, a proposed dedicated muon EDM experiment at PSI could further advance the limit. In this way, future improved measurements of $a_e$, $a_\mu$, as well as the fine-structure constant $\alpha$ are not only set to provide exciting precision tests of the SM, but, in combination with EDMs, to reveal crucial insights into the flavor structure of physics beyond the SM.

        Speaker: Andreas Crivellin (Paul Scherrer Institut (CH))
      • 37
        Compact Linear Collider sensitivity to measure σ(Hvv) X BR (H->γγ) at the 3 TeV center-of-mass energy

        In this talk we address expected measurement accuracy of the Standard Model Higgs boson decay into two photons at 3 TeV Compact Linear Collider (CLIC). This process is induced via loop exchange of heavy particles either from the Standard Model (SM) or beyond, modifying the SM expectations in the latter case. The study is performed using a full simulation of the CLIC_ILD detector model, considering all relevant physics and beam-induced processes in the full reconstruction chain. It has been shown that the Higgs production cross-section in WW-fusion times branching ratio BR (H→γγ) can be measured with a relative statistical accuracy of 7.5 %, assuming an integrated luminosity of 5 ab-1 and 80% of the data being collected with -80% electron-beam polarization and 20% of the data with +80% electron-beam polarization.

        Speaker: Goran Kacarevic (University of Belgrade (RS))
    • Overview talks: Beyond the Standard Model physics; session chair: Francesca Ungaro
      • 38
        Lattice BSM
        Speaker: Oliver Witzel (University of Edinburgh)
      • 39
        Neutrinos at colliders and connections to lepton number violation
        Speaker: Martin Hirsch (Instituto de Fisica Corpuscular (CSIC, University of Valencia))
      • 9:40 AM
        Hot beverages
      • 40
        LHC searches for heavy neutral leptons and displaced signatures
        Speaker: Lesya Shchutska (ETH Zurich (CH))
      • 41
        Effective field theory
        Speaker: Ken Mimasu (Université Catholique de Louvain)
    • Contributed talks: session chair: Francesca Ungaro
      • 42
        Observation and measurements of vector-boson pair production with ATLAS

        Measurements of electroweak boson pair scattering and inclusive production at the LHC constitute a stringent test of the electroweak sector and provide model-independent means to search for new physics at the TeV scale. They allow to test the gauge structure of the Standard Model.

        In this talk, we present recent results on vector-boson scattering from the ATLAS experiment using proton-proton collisions at √s=13 TeV. This includes the observation of WZ and same-sign-WW production via vector-boson scattering along with a measurement of VV production in semileptonic final states. If available, a measurement of Z𝛾 production via vector-boson scattering will also be presented.

        We also present recent results for inclusive ZZ, Z𝛾, WW and WZ production in proton-proton collisions at √s=13 TeV, including polarisation studies in the WZ final state. The precision measurements are compared to state-of-the-art Standard Model calculations.

        The data are sensitive to anomalous triple and quartic gauge couplings and are reinterpreted in terms of an effective field theory to constrain new physics beyond the Standard Model.

        Speaker: Rebecca Linck (Indiana University (US))
      • 43
        Searches for supersymmetry with the ATLAS detector

        Abstract: Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarizes recent ATLAS results for searches for supersymmetric (SUSY) particles. Weak and strong production in both R-Parity conserving and R-Parity violating SUSY scenarios are considered. The searches use the full Run 2 dataset of proton-proton collisions at sqrt{s} = 13 TeV, and involve final states including jets, missing transverse momentum, light leptons as well as long-lived particle signatures.

        Speaker: Mats Joakim Robert Olsson (University of California Irvine (US))
    • Contributed talks: session chair: Stefan Vogl
      • 44
        Spin correlations: Status of spin correlations in pp->ttbar
        Speaker: Bora Isildak (Ozyegin University (TR))
      • 45
        Anomalous gauge couplings: Status of triple and quartic anomalous gauge couplings
        Speaker: Chav Chhiv Chau (Carleton University (CA))
      • 5:25 PM
        Hot beverages
      • 46
        LHC limits on gluinos and squarks in the minimal Dirac gaugino model.

        Most SUSY searches at the LHC are optimised for the MSSM, where gauginos are Majorana particles. By introducing Dirac gauginos, we obtain an enriched phenomenology, from which considerable differences in the LHC signatures and limits are expected as compared to the MSSM. Concretely, in the minimal Dirac gaugino model (MDGSSM) we have six neutralino and three chargino states. Moreover, production cross sections are enhanced for gluinos, while for squarks they are suppressed. In this talk, we explore the consequences for the current LHC limits on gluinos and squarks. This is based on the recent paper arXiv:1812.09293. We also comment on ongoing work regarding electroweak-ino phenomenology in the MDGSSM.

        Speaker: Humberto Reyes-González (LPSC Grenoble)
      • 47
        Latest results from the NA62 experiment at CERN

        The NA62 experiment at CERN SPS is designed to measure BR(K+ -> pi+ nu nu) with 10% accuracy. The high-intensity setup, trigger system flexibility and detector performance make NA62 particularly suitable to search for physics beyond the Standard Model with kaon decays and to perform direct searches for long-lived hidden-sector particles, such as dark photons, dark scalars, axion-like particles, and heavy neutral leptons, using kaon and pion decays as well as operating the
        experiment in dump mode. NA62 took its first physics data in 2016, reaching sensitivity to the K+ -> pi+ nu nu decay at the
        level of the Standard Model BR. The experiment collected 10 times more statistics in 2017 and 2018. The result on K+->pi+nunu from the full 2016 data set will be presented and prospects for future improvements will be discussed.
        The sensitivity to a number of lepton flavour and lepton number violating K+ decays provided by the sample of charged kaon decays into final states with multiple charged particles collected in 2016-2018 is an order of magnitude beyond the current state of the art. Results of the search for these processes with a partial NA62 data sample will be presented. The status of hidden-particle searches will be reviewed together with prospects for future data taking at NA62.

        Speaker: Nicolas Lurkin (University of Birmingham (GB))
      • 48
        Status of non-supersymmetric models with GAMBIT

        I will present the latest analyses of non-supersymmetric models from the GAMBIT global fitting project, covering axions, axion-like particles and scalar, vector and fermionic Higgs portal models stabilised by either a $\mathbb{Z}_2$ or $\mathbb{Z}_3$ discrete symmetry. These results incorporate various combinations of constraints from the LHC, direct and indirect searches for dark matter, dedicated axion experiments, vacuum stability and the observed relic density of dark matter (applied as either an upper limit or a strict requirement). They also include the impacts of theoretical uncertainties ranging from the temperature dependence of the QCD axion mass to nuclear matrix elements, Standard Model parameters and astrophysical halo modelling.

        Speaker: Pat Scott
      • 49
        Bottom and strange Yukawa couplings at the NNLO in the MSSM

        In MSSM scenarios characterised by large tan(beta), bottom-Yukawa-induced processes, such as Higgs decays into bottom pairs and Higgs bremsstrahlung off bottom quarks, play a major role at present and future colliders. Therefore, radiative corrections to the bottom Yukawa coupling are of extreme importance. Currently they are known in a resummed form at the NNLO level. The resummed result can be easily adapted for the strange Yukawa coupling. In this talk, I will review the calculation of the SUSY-QCD two-loop corrections to the strange and bottom Yukawa couplings, which includes the resummation of the dominant corrections for large values of tan(beta), as well as the subleading terms induced by the trilinear Higgs couplings A_b,s. Moreover, preliminary results on the two-loop electroweak corrections to the bottom Yukawa coupling will be presented. The phenomenological impact of the calculation will also be discussed.

        Speaker: Margherita Ghezzi (Universität Tübingen)
      • 50
        Vacuum Stability Constraints in Models with Extended Scalar Sectors

        Constraining physics beyond the Standard Model through theoretical constraints is highly relevant to increase the predictivity of the models for collider searches. Constraints from the stability of the electroweak vacuum are especially important in models with large scalar sectors, such as SUSY models. We developed a highly efficient and numerically reliable approach that enables the application of vacuum stability constraints in large parameter scans. Based on this approach we present our constraints and study the vacuum structure of models beyond the SM.

        Speaker: Jonas Wittbrodt (DESY)
      • 51
        Measurement of top polarization and ttbar spin correlations at CMS 13 TeV

        Measurements of the properties of the top quark can serve as stringent tests of the standard model (SM). To date, all the measurements of its pair and single production cross sections and properties indicate that it is indeed the top quark as predicted by the SM. However, moderate deviations from this expectation still cannot be ruled out. The spin density matrix of top quark pair production consists of coefficients which are affected by various discrete symmetry properties, making it a rich trove of information to search for effects beyond the SM. This talk describes the first measurement of top polarization and ttbar spin correlations at 13 TeV that are encoded in a systematic way into the spin density matrix, using data recorded by the CMS experiment in 2016. The measurements are found to be consistent with the SM prediction derived from Monte Carlo generators and analytic calculations at next to leading order QCD (+weak) accuracy. They are also used to derive the best constraint on the anomalous chromomagnetic moment of the top quark to date.

        Speaker: Afiq Aizuddin Anuar (DESY (DE))
    • Contributed talks: session chair: Lesya Shchutska
      • 52
        Precision EW results from CMS
        Speaker: Marco Cipriani (Sapienza Universita di Roma e INFN Roma 1 (IT))
    • Overview talks: The standard model and Higgs physics; session chair: Lesya Shchutska