# Scalars 2017

from 30 November 2017 to 3 December 2017 (Europe/Warsaw)
University of Warsaw
Europe/Warsaw timezone
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Displaying 81 contributions out of 81
It is known that the CP-even and CP-odd scalars contribute with an opposite sign to the anomalous magnetic moment of the muon. We study popular scalar extensions of the Standard Model, namely the singlet extension, the 2-Higgs doublet model (2HDM) and the doublet plus singlet extension. We show that these models are incapable of explaining the observed discrepancy in (g−2)_\mu, with the exce ... More
Presented by Venus KEUS on 2 Dec 2017 at 17:00
Session: session 6
We embed a thermal dark matter (DM) candidate within the clockwork framework. This mechanism allows to stabilize the DM particle over cosmological time because it suppresses its decay into Standard Model (SM) particles. At the same time, pair annihilations are unsuppressed, so that the relic density is set by the usual freeze-out of the DM particle from the thermal bath. The slow decay of the DM c ... More
Presented by Michel TYTGAT on 1 Dec 2017 at 11:30
In this talk we analyze the sources of lepton flavor violation in the Minimal Supersymmetric Standard Model (MSSM) in the processes $l → l’ \gamma$ and $h → ll’$. Using the Flavor Expansion Theorem, a recently developed technique of a purely algebraic mass-insertion expansion of the amplitudes, we recover the direct analytic dependence of the results on the MSSM Lagrangian parameters. Both ... More
Presented by Zofia FABISIEWICZ on 2 Dec 2017 at 14:00
Session: session 7
Presented by Thomas HAMBYE on 1 Dec 2017 at 14:00
The latest Planck CMB data seem to strongly constrain the Hot Dark Matter scenarios, although they stay in tension with direct Hubble constant measurements. However, one can believe that in near future the experimental uncertainly for the effective number of neutrino species N_{eff} will shrink vastly. Therefore, in order to estimate the allowed parameter space of models predicting a Hot Dark Matt ... More
Presented by Paweł SZCZERBIAK on 2 Dec 2017 at 14:30
Session: session 1
Presented by Greg LANDSBERG on 30 Nov 2017 at 09:00
Session: session 13
We explore the phenomenology of a unique three-Higgs-doublet model based on the single CP symmetry of order 4 (CP4) without any accidental symmetries. The CP4 symmetry is imposed on the scalar potential and Yukawa interactions, strongly shaping both sectors of the model and leading to a very characteristic phenomenology. Although the model is very constrained by CP4, we find points in the par ... More
Presented by Igor IVANOV on 3 Dec 2017 at 15:00
We study the discovery prospects of heavy neutral higgs bosons in Beyond the Standard Model scenarios where it cascade decays to a lighter scalar eigenstate which subsequently decays to the Standard Model Higgs. We consider either of 4 leptons and 2 b-jets or of 2 leptons + 4 b-jets final states. We find that these two signatures allows us to both optimally reduce the Standard Model backgrounds an ... More
Presented by SHIBANANDA SAHOO on 2 Dec 2017 at 15:30
We set the cosmological constant \Lambda is not canstant but a function of Hubble parameter, and \Lambda can decay with matter and radiation in the expansion universe. We examine the running vacuum model with \Lambda(H) = 3\nuH^2 + \Lambda_0, where \nu is the model parameter and \Lambda_0 is the cosmological constant. From the data of the cosmic microwave background radiation, weak lensing and bar ... More
Presented by Lu YIN on 2 Dec 2017 at 15:30
We study the correlation between the loop-induced decays $h^0$ to photon photon and $h^0$ to gluon gluon in the Minimal Supersymmetric Standard Model (MSSM) with non-minimal quark flavour violation assuming that $h^0$ has a mass of the Higgs boson measured at LHC. We perform a MSSM parameter scan respecting theoretical and experimental constraints. The deviations of these two decay widths from th ... More
Presented by Helmut EBERL on 2 Dec 2017 at 14:45
Session: session 4
Presented by Maxim POSPELOV on 30 Nov 2017 at 17:00
Session: session 7
Cosmological relaxation is a mechanism that can explain the smallness of the EW scale without the need of new dynamics at the TeV scale. We discuss how to realize this mechanism during the radiation dominated era, where the role of Hubble friction is played by the production of SM gauge bosons.
Presented by Enrico MORGANTE on 1 Dec 2017 at 15:00
We analyse new signals of Dark Matter (DM) at the LHC, in a 3-Higgs Doublet Model (3HDM) in which only one doublet acquires a Vacuum Expectation Value (VEV), preserving a Higgs parity Z_2. The other two doublets are inert and do not develop a VEV, leading to a dark scalar sector controlled by the Higgs parity and a Dark Matter (DM) candidate provided by the lightest CP-even dark scalar H1. This le ... More
Presented by Dorota SOKOLOWSKA on 2 Dec 2017 at 14:15
Session: session 5
Dark pion in the strongly interacting dark sector could be a good DM candidate with some assumptions. One can realize either WIMP or SIMP scenario within this setup. I discuss each scenario including the dark resonances.
Presented by Pyungwon KO on 1 Dec 2017 at 09:00
Session: session 5
Discovering DM can be challenging in situation when the spectrum of new physics is compressed. I will show how to distinguish between scalar and fermion DM using dileptons produce through loops of new physics states.
Presented by Antonio DELGADO on 1 Dec 2017 at 10:00
Session: session 13
We assume that the origin of the electroweak (EW) scale is a gauge-invariant scalar-bilinear condensation in a strongly interacting non-abelian gauge sector. The dynamical scale genesis appears as a phase transition at finite temperature, and it can produce a gravitational wave (GW) background in the early Universe.
Presented by Jisuke KUBO on 3 Dec 2017 at 14:00
We consider the electroweak production of multiple Higgs bosons at the LHC in the two-Higgs doublet model (2HDM). We show that in realistic models the electroweak cross sections for production of 2 or 3 Higgs bosons can dominate over QCD production. This is because in a gg-initiated process, production via a resonant Z in the s-channel is prohibited according to the Landau-Yang theorem, which is n ... More
Presented by Rikard ENBERG on 2 Dec 2017 at 16:15
We examine the observability of heavy neutrino (nu_h) signatures of a U(1)' enlarged Standard Model (SM) encompassing three heavy Majorana neutrinos alongside the known light neutrino states at the the Large Hadron Collider (LHC). We show that heavy neutrinos can be rather long-lived particles producing distinctive displaced vertices that can be accessed in the CERN LHC detectors. We concentrate h ... More
Presented by Luigi DELLE ROSE on 2 Dec 2017 at 14:30
Twin Higgs models are the prime illustration of neutral naturalness, where the new particles of the twin sector, gauge singlets of the Standard Model, ameliorate the little hierarchy problem. I will discuss the phenomenological implications of the heavy Higgs of the Mirror Twin Higgs and Fraternal Twin Higgs models at the LHC. In particular, I will show how the scalar sector of the Twin Higgs mode ... More
Presented by Aqeel AHMED on 2 Dec 2017 at 14:00
We investigate decay modes of spin-1 heavy vector bosons (V') from the viewpoint of perturbative unitarity in a model-independent manner. Our findings are: [1] Br(W'->WZ) is less than 2% in the system that contains V' and CP-even scalars as well as the SM particles. [2] Contributions of CP-odd scalars help to make Br(W'->WZ) larger than Br(W'->ff) as long as the CP-odd scalars couple to both the S ... More
Presented by Ryo NAGAI on 2 Dec 2017 at 17:45
The models with the gauge group $SU(3)_c\times SU(3)_L\times U(1)_X$ (331-models) have been advocated to explain why there are three fermion generations in Nature. As such they provide partial understanding of the flavour sector. The hierarchy of fermion masses in the Standard Model is another puzzle which remains without compelling explanation. In this talk I present a model that incorporates Fro ... More
Presented by Niko KOIVUNEN on 2 Dec 2017 at 15:00
A straightforward method to translate the potential parameters of the 2HDM into physical masses and couplings is presented. The method is applied to CP-odd and CP-even weak-basis invariants of the model in order to express them exclusively in terms of the physical observable masses and couplings.
Presented by Odd Magne OGREID on 2 Dec 2017 at 17:30
Session: session 11
SO(5)xU(1) gauge-Higgs EW unification gives almost the same phenomenology as the standard model and is consistent with the data at low energies and at 8 TeV LHC. It gives many predictions to be explored and verified at 14 TeV LHC and 250-500 GeV ILC. In addition to the production of Z' bosons around 7 - 9 TeV with broad widths at 14 TeV LHC, distinct signals are predicted in future $e^+ e^-$ ... More
Presented by Yutaka HOSOTANI on 3 Dec 2017 at 09:00
The fermion spectrum observed in nature exhibits a wide range of hierarchies that go from the sub-eV regime up to hundreds of GeV. In this talk I will introduce a multi-Higgs extension of the Standard Model whose origin is inspired in a recently proposed Grand Unified Theory denoted as Supersymmetric Higgs Unified Trinification (or SHUT model for short). The presence of an SU(3) family symmetry at ... More
Presented by Antonio MORAIS on 2 Dec 2017 at 14:30
I will discuss a simple extension of the SM with just an additional scalar singlet coupling to the Higgs. My main focus will be the possible probes of electroweak baryogenesis in this model including collider searches gravitational wave detection and direct dark matter detection experiments. I will show there are regions in the parameter space where observation of gravitational waves is the most p ... More
Presented by Marek LEWICKI on 2 Dec 2017 at 16:15
Among various scenarios of baryon asymmetry of the Universe, electroweak baryogenesis is directly connected with physics of the Higgs sector. We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. In the Z_3 symmetric singlet scalar mod ... More
Presented by Toshnori MATSUI on 2 Dec 2017 at 16:45
I will present the Idea of an inflaton without direct couplings to any additional fields. I will show a possible mechanisms of reheating via gravity together with implications of such an approach to inflation on predictions of inflation, dark energy, dark matter, thermal history of the Universe, electro-weak phase transition and especially gravitational waves production.
Presented by Michal ARTYMOWSKI on 2 Dec 2017 at 16:30
The absence of confirmed signal in dark matter (DM) direct detection (DD) may suggest a weak coupling between DM and the first generation quarks. In this work we consider a real scalar dark matter $S$ which has new Yukawa interactions with charm $c$ and top quark $t$ via a vector-like fermion mediator $\psi$. By setting the Higgs portal to be negligible, we focus on the new Yukawa interactions. Si ... More
Presented by Peiwen WU on 2 Dec 2017 at 15:15
Session: session 3
Presented by Nazila MAHMOUDI on 30 Nov 2017 at 15:00
The study of the renormalization group improved effective potential of the Standard Model has revealed existence of a local maximum at field strengths of the order of 10^10 GeV. If the Standard Model is valid for very high energy scales, then the possibility of the production of cosmological domain walls in the early Universe occurs. We investigated dynamics of networks of domain walls using l ... More
Presented by Tomasz KRAJEWSKI on 2 Dec 2017 at 17:15
We would like to show how stability, electroweak symmetry breaking and symmetries may be studied in models with various Higgs-boson doublets.
Presented by Prof. Markos MANIATIS on 2 Dec 2017 at 17:15
Minimal scenarios with light (sub-GeV) dark matter whose relic density is obtained from thermal freeze-out must include new light mediators. In particular, a very well-motivated case is that of a new "dark" massive vector gauge boson mediator. The mass term for such mediator is most naturally obtained by a "dark Higgs mechanism" which leads to the presence of an often long-lived dark Higgs boson w ... More
Presented by Soumya RAO on 2 Dec 2017 at 14:45
In theories with spontaneous symmetry breaking it is possible to calculate the critical temperature of the phase transition between the symmetric and broken phases of the theory. In the Standard Model and its extensions, the temperature of the electroweak phase transition is interesting for a number of physical questions – for example when considering the observed matter/antimatter asymmetry, or ... More
Presented by Johan LöFGREN on 2 Dec 2017 at 17:30
It is possible that dark matter consists of two or more particle species with non-negligible contribution to the relic abundance. This scenario leads to a complicated dynamic in the hidden sector where various processes are responsible for the thermal production of dark matter. We discuss the model with fermionic and vector dark matter candidates that interact with the Standard Model through the H ... More
Presented by Mateusz DUCH on 2 Dec 2017 at 14:15
We examine the phenomenology of the full electroweakino sector of the pMSSM without invoking the adhoc but often employed assumption that the heavier ones are decoupled. We identify several generic models which illustrate the importance of the heavier electroweakinos and constrain them with the LHC 3l + missing E_T data. The constraints are usually stronger than that for decoupled heavier electrow ... More
Presented by Manimala CHAKRABORTI on 2 Dec 2017 at 15:15
The off-shell one-loop renormalization of a Higgs effective field theory with a sextic scalar potential is presented. This is achieved by renormalizing the theory once reformulated in terms of two auxiliary fields, allowing to diagrammatically separate the SM and BSM contributions to 1-PI amplitudes. Invariance under an extended Becchi-Rouet-Stora-Tyutin symmetry guarantees the physical equivalenc ... More
Presented by Andrea QUADRI on 2 Dec 2017 at 15:30
With increasing accuracy of CMB data, a thorough, quantitative understanding of the post-inflationary reheating era becomes more and more important for constraining different models of inflation. In particular, a precise computation of the non-homogeneous field evolution during preheating is desirable.In this talk I will present results of such computation for alpha-attractors models of inflation. ... More
Presented by Michal WIECZOREK on 2 Dec 2017 at 17:00
Session: session 8
Predictions for cosmological observables, such as the scalar and tensor power spectra, their spectral indices and their higher order runnings, suffer from the so-called frame problem. They depend on whether the computation has been performed in the Jordan or Einstein frame. In this talk, I will present a frame-covariant formalism which enables one to address the frame problem in the context ... More
Presented by Apostolos PILAFTSIS on 1 Dec 2017 at 16:00
In this presentation we consider doubly charged scalars pair production and decays within the Higgs Triplet Model (HTM) in lepton and hadron colliders. The HTM is an extension of the Standard Model realising the type II seesaw mechanism [1]. The additional scalar triplet contains the doubly charged particle H++, which contributes to lepton flavour violating (LFV) processes. We discu ... More
Presented by Magdalena KORDIACZYNSKA on 2 Dec 2017 at 17:30
In the standard model, the negative mass parameter is introduced in the Higgs potential to occur electroweak symmetry breaking. In a class of models based on classically scale invariance, parameters with mass dimensions in the Lagrangian are prohibited by classically scale invariance and electroweak symmetry breaking dynamically occurs by Coleman and Weinberg mechanism. In this talk, I focus on ... More
Presented by Katsuya HASHINO on 2 Dec 2017 at 17:15
Experimental limits on the masses of SUSY states from searches at the LHC are becoming quite stringent, especially for the gluino of the MSSM. The MRSSM is an alternative supersymmetric model which features an continuous R-symmetry and it leads to a Dirac-type gluino. Compellingly, it is natural for a Dirac gluino to have a large mass outside the current bounds. For an accurate prediction of ... More
Presented by Philip DIESSNER on 2 Dec 2017 at 15:00
Session: session 11
The possibility that alignment arises in 2HDM as a consequence of the high-scale behaviour of the theory is discussed here. Requiring the 2HDM to be bounded from below and perturbative up to scales as low as a few TeV forces the lightest CP-even scalar to have SM-like properties for model Type II. Analogous conclusions are found for model I, if the charged higgs mass is larger than about 400 GeV. ... More
Presented by Pedro FERREIRA on 3 Dec 2017 at 10:00
Dynamical relaxation provides an interesting solution to the hierarchy problem, which allows to produce a large hierarchy of scales without abandoning the naturalness principle. The observed value of the electroweak scale is then a consequence of an interaction between the Higgs boson and a new axion-like field, a relaxion. Attempts at extending this mechanism to a two-doublet scenario (arXiv:1612 ... More
Presented by Adam MARKIEWICZ on 2 Dec 2017 at 16:30
In this talk we present a new method of renormalisation-group (RG) improvement of effective potentials in models with extended scalar sectors. The method amounts to running with the renormalisation scale to a surface in the parameter space where quantum corrections to the effective potential vanish. This can be equivalently understood as fixing the renormalisation scale to a suitably chosen field- ... More
Presented by Bogumila SWIEZEWSKA on 2 Dec 2017 at 15:15
Session: session 4
Tentative evidence for lepton flavor nonuniversality in semileptonic B meson decays from LHCb suggests new physics beyond the standard model. I present some representative models for explaining this observation, simultaneously with other puzzles such as the origin of flavor or dark matter, emphasizing the essential role played by new scalar particles.
Presented by James CLINE on 30 Nov 2017 at 16:00
Session: session 1
Presented by Barr ALAN on 30 Nov 2017 at 09:30
In the framework of the $B-L$ Supersymmetric Standard Model (BLSSM), we assess the ability of ground and space based experiments to establish the nature of its prevalent Dark Matter (DM) candidate, the sneutrino, which could either be CP-even or -odd. Firstly, by benchmarking this theory construct against the results obtained by the Planck spacecraft, we extract the portions of the BLSSM parameter ... More
Presented by Simon KING on 2 Dec 2017 at 15:00
We study a vector dark matter (VDM) model in which the VDM couples to the Standard Model sector via the Higgs portal. As a result, the VDM can be produced via the freeze-in mechanism. In particular, we find that the electroweak phase transition have a great impact on the prediction of the VDM relic density. We further assume that the dark Higgs which gives the VDM mass is so light that it can indu ... More
Presented by Da HUANG on 2 Dec 2017 at 14:00
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter while the other scalar not only helps in making the electroweak vacuum stable but also opens up the low mass window of the scalar singlet dark matter (< 500 GeV ... More
Presented by Abhijit KUMAR SAHA on 2 Dec 2017 at 17:00
Session: session 2
Presented by Howard HABER on 30 Nov 2017 at 11:00
Session: session 8
Presented by Anupam MAZUMDAR on 1 Dec 2017 at 16:30
Session: session 6
Presented by Zackaria CHACKO on 1 Dec 2017 at 11:00
Session: session 6
Presented by Rick S GUPTA on 1 Dec 2017 at 12:00
Session: session 2
Presented by Per OSLAND on 30 Nov 2017 at 12:00
Session: session 3
Presented by Gustavo C BRANCO on 30 Nov 2017 at 14:00
Session: session 3
Presented by Margarida (Gui) N. REBELO on 30 Nov 2017 at 14:30
Session: session 11
Presented by Mariano QUIROS on 3 Dec 2017 at 09:30
Session: session 12
Presented by Ulrich ELLWANGER on 3 Dec 2017 at 11:00
Session: session 12
Presented by Dominik STOECKINGER on 3 Dec 2017 at 12:00
Session: session 14
Presented by Mikolaj MISIAK on 3 Dec 2017 at 16:30
Session: session 9
Presented by Adam FALKOWSKI on 2 Dec 2017 at 09:00
Session: session 9
Presented by Michael TROTT on 2 Dec 2017 at 10:00
Session: session 1
Presented by Christophe GROJEAN on 30 Nov 2017 at 10:00
Session: session 10
Presented by Manfred LINDNER on 2 Dec 2017 at 12:00
Session: session 10
Presented by Andreas RINGWALD on 2 Dec 2017 at 11:30
Session: session 10
Presented by Matthias NEUBERT on 2 Dec 2017 at 11:00
Session: session 9
Presented by Andrea WULZER on 2 Dec 2017 at 09:30
Session: session 2
Presented by Shinya KANEMURA on 30 Nov 2017 at 11:30
Session: session 8
Presented by Vincenzo BRANCHINA on 1 Dec 2017 at 17:00
Session: session 14
Presented by Amarjit SONI on 3 Dec 2017 at 16:00
Session: session 12
Presented by Rui SANTOS on 3 Dec 2017 at 11:30
Session: session 7
I'll discuss recent progress in the Higgs portal framework in relation to dark matter and inflation.
Presented by Oleg LEBEDEV on 1 Dec 2017 at 14:30
We show that the well known Georgi-Machacek (GM) model can be realized as a limit of the recently constructed Supersymmetric Custodial Higgs Triplet Model (SCTM) which in general contains a significantly more complex scalar spectrum. We dub this limit of the SCTM the Supersymmetric GM (SGM) model. We derive a mapping between the SGM and GM models using it to show supersymmetry implies constrain ... More
Presented by Roberto VEGA on 2 Dec 2017 at 16:15
We find exact solutions to the wave equation of scalar field in the background of five-dimensional Einstein-Maxwell theory with cosmological constant where the scalar field couples to the electromagnetic field as well as to the cosmological term with two different coupling constants. We find that the five-dimensional spacetime is non-stationary and is a conformally regular spacetime, everywhere. ... More
Presented by Masoud GHEZELBASH on 2 Dec 2017 at 17:45
I will present the phenomenology of twin photon and twin sector Higgs in the Mirror Twin Higgs framework. I will show the experimental constraints on the parameters of the model and discuss how that will allow us to confirm the Twin Higgs mechanism at colliders.
Presented by Saereh NAJJARI on 2 Dec 2017 at 14:15
A general Two Higgs Doublet Model includes uncontrolled sources of tree level flavour violation in neutral couplings. In popular cases like type I or II, the imposition of a symmetry forbids them. We explore scenari where a symmetry requirement, rather than removing them, allows for their presence in a controlled manner. Phenomenological consequences of those controlled tree level FCNC are explore ... More
Presented by Miguel NEBOT GóMEZ on 2 Dec 2017 at 16:45
We discuss composite two Higgs doublet models based on the global symmetry breaking SO(6) to SO(4)*SO(2). We construct two Higgs doublets emerging from 8 pseudo Nambu-Goldstone bosons, and then show how the scalar potential is generated through the Coleman-Weinberg mechanism at one-loop level. We also show several phenomenologically viable scenarios, a mass spectrum of Higgs bosons, their couplin ... More
Presented by Kei YAGYU on 2 Dec 2017 at 16:30
Session: session 5
Presented by Hooman DAVOUDIASL on 1 Dec 2017 at 09:30
We show that a universal texture zero in the (1,1) position of all fermionic mass matrices, including heavy right-handed Majorana neutrinos driving a type-I see-saw mechanism, can lead to a viable spectrum of mass, mixing and CP violation for both quarks and leptons, including (but not limited to) three important postdictions: the Cabibbo angle, the charged lepton masses, and the leptonic `reacto ... More
Presented by Ivo DE MEDEIROS VARZIELAS on 2 Dec 2017 at 14:45
We consider three different series of problems 1. The t–channel singularity in small angle scattering (almost solved). In the processes like \mu^+\mu^-\to W e\nu with effective mass e\nu lower than m_\mu transferred momentum of \nu can be both space-like and time-like. In the naive approach it gives divergent cross section. This difficulty is eliminated when treat initial states as wave pack ... More
Presented by Ilya GINZBURG on 2 Dec 2017 at 16:45
The Two-Higgs-doublet model (2HDM) is one of the most studied extensions of the Standard Model. But just as the other popular "New Physics" models, it gets more and more constrained by recent experimental progress, especially by the LHC data. For all four 2HDM types with a softly broken Z2 symmetry, we present updated results of global analyses obtained with the open-source HEPfit code. We obtain ... More
Presented by Debtosh CHOWDHURY on 2 Dec 2017 at 17:45