Matti Antola

Publications (6)9.46 Total impact

• Article: Minimal supersymmetric technicolor

  Matti Antola, Stefano Di Chiara, Francesco Sannino, Kimmo Tuominen
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  ABSTRACT: We introduce novel extensions of the Standard Model featuring a supersymmetric technicolor sector. First we consider N=4\mathcal{N}=4 Super Yang–Mills which breaks to N=1\mathcal{N}=1 via the electroweak (EW) interactions and coupling to the MSSM. This is a well defined, economical and calculable extension of the SM involving the smallest number of fields. It constitutes an explicit example of a natural supersymmetric conformal extension of the Standard Model featuring a well defined connection to string theory. It allows us to interpolate, depending on how we break the underlying supersymmetry, between unparticle physics and Minimal Walking Technicolor. As a second alternative we consider other N = 1\mathcal{N} =1 extensions of the Minimal Walking Technicolor model. The new models allow all the standard model matter fields to acquire a mass.
  European Physical Journal C 05/2012; 71(11):1-13. · 3.63 Impact Factor
• Source

  Available from: K. Tuominen

  Article: Unnatural origin of fermion masses for technicolor

  Matti Antola, Matti Heikinheimo, Francesco Sannino, Kimmo Tuominen
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  ABSTRACT: We explore the scenario in which the breaking of the electroweak symmetry is due to the simultaneous presence and interplay of a dynamical sector and an unnatural elementary Higgs. We introduce a low energy effective Lagrangian and constrain the various couplings via direct search limits and electroweak and flavor precision tests. We find that the model we study is a viable model of dynamical breaking of the electroweak symmetry. KeywordsBeyond Standard Model-Technicolor and Composite Models
  Journal of High Energy Physics 04/2012; 2010(3):1-22. · 5.83 Impact Factor
• Source

  Available from: Francesco Sannino

  Article: Supersymmetric Extension of Technicolor & Fermion Mass Generation

  Matti Antola, Stefano Di Chiara, Francesco Sannino, Kimmo Tuominen
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  ABSTRACT: We provide a complete extension of Minimal Walking Technicolor able to account for the standard model fermion masses. The model is supersymmetric at energies greater or equal to the technicolor compositeness scale. We integrate out, at the supersymmetry breaking scale, the elementary Higgses. We use the resulting four-fermion operators to derive the low energy effective theory. We then determine the associated tree-level vacuum and low energy spectrum properties. Furthermore we investigate the phenomenological viability of the model by comparing its predictions with electroweak precision tests and experimental bounds on the mass spectrum. We then turn to the composite Higgs phenomenology at the LHC and show that current data are already constraining the parameter space of the model.
  11/2011;
• Source

  Available from: K. Tuominen

  Article: Naive Dimensional Analysis and Irrelevant Operators

  Matti Antola, Kimmo Tuominen
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  ABSTRACT: We derive a set of easy rules to follow when estimating the coefficients of operators in an effective Lagrangian. In particular, we emphasize how to estimate the size of coefficients originating from irrelevant interactions in the underlying Lagrangian.
  05/2011;
• Source

  Available from: Francesco Sannino

  Article: N=4 Extended MSSM

  Matti Antola, Stefano Di Chiara, Francesco Sannino, Kimmo Tuominen
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  ABSTRACT: We investigate a perturbative N=4 sector coupled to the MSSM and show that it allows for a stable vacuum correctly breaking the electroweak symmetry. The particle spectrum of the MSSM is enrichened by several new particles stemming out from the new N=4 sector of the theory, and a new lepton doublet required to cancel global and gauge anomalies of the theory. Even if the conformal invariance of the N=4 sector is explicitly broken, a nontrivial UV behavior of the coupling constants is possible: by studying the renormalization group equations at two loops we find that the Yukawa couplings of the heavy fermionic states flow to a common fixed point at a scale of a few TeVs. The parameter space of the new theory is reduced imposing naturalness of the couplings and soft supersymmetry breaking masses, perturbativity of the model at the EW scale as well as phenomenological constraints. Our preliminary results on the spectrum of the theory suggest that the LHC can rule out a significant portion of the parameter space of this model.
  Nucl.Phys. 09/2010; B856.
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  Available from: doria.fi

  Article: Technicolor

  Matti Antola
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  ABSTRACT: In technicolor theories the scalar sector of the Standard Model is replaced by a strongly interacting sector. Although the Standard Model has been exceptionally successful, the scalar sector causes theoretical problems that make these theories seem an attractive alternative. I begin my thesis by considering QCD, which is the known example of strong interactions. The theory exhibits two phenomena: confinement and chiral symmetry breaking. I find the low-energy dynamics to be similar to that of the sigma models. Then I analyze the problems of the Standard Model Higgs sector, mainly the unnaturalness and triviality. Motivated by the example of QCD, I introduce the minimal technicolor model to resolve these problems. I demonstrate the minimal model to be free of anomalies and then deduce the main elements of its low-energy particle spectrum. I find the particle spectrum contains massless or very light technipions, and also technibaryons and techni-vector mesons with a high mass of over 1 TeV. Standard Model fermions remain strictly massless at this stage. Thus I introduce the technicolor companion theory of flavor, called extended technicolor. I show that the Standard Model fermions and technihadrons receive masses, but that they remain too light. I also discuss flavor-changing neutral currents and precision electroweak measurements. I then show that walking technicolor models partly solve these problems. In these models, contrary to QCD, the coupling evolves slowly over a large energy scale. This behavior adds to the masses so that even the light technihadrons are too heavy to be detected at current particle accelerators. Also all observed masses of the Standard Model particles can be generated, except for the bottom and top quarks. Thus it is shown in this thesis that, excluding the masses of third generation quarks, theories based on walking technicolor can in principle produce the observed particle spectrum. Teknivärillä viitataan kategoriaan malleja, joissa standardimallin Higgsin sektori korvataan vahvasti vuorovaikuttavalla, QCD:n kaltaisella sektorilla. Vaikka Standardimallin ennusteet on todettu poikkeuksellisen tarkasti paikkaansapitäviksi, Higgsin sektori aiheuttaa teoreettisia ongelmia jotka tekevät tekniväriin perustuvat mallit houkutteleviksi. Aloitan tutkielman selvittämällä QCD:n matalan energian dynamiikkaa. Siinä näkyy kaksi ilmiötä: kaikki havaitut hiukkaset ovat värineutraaleja, ja QCD:n globaali kiraalisymmetria on spontaanisti rikkoutunut. Osoitan, että QCD:n matalan energian dynamiikka on samankaltaista kuin sigma-malleissa. Seuraavaksi tutkin Standardimallin Higgsin sektorin ongelmia, pääasiassa luonnottomuutta ja triviaalisuutta. Näiden korjaamiseksi esittelen QCD:n esimerkin mukaisen minimaalisen teknivärimallin, ja osoitan että mallissa ei ole mitta-anomalioita. Tarkastelen myös teorian matalan energian hiukkasspektriä. Hiukkasspektrissä on massattomia tai kevyitä teknipioneja, sekä yli TeV:n painavia tekni-vektori mesoneja ja teknibaryoneja. Standardimallin fermionit ovat tässä vaiheessa täysin massattomia. Jotta näille fermioneille voidaan generoida massa, täytyy olettaa laajennettu tekniväri. Hiukkasspektri muuttuu massallisiksi, mutta painavimpien standardimallin hiukkasten massoja ei voida selittää. Teoria tuottaa muitakin fenomenologisia ongelmia, kuten makua vaihtavia virtoja. Näiden ongelmien ratkaisemiseksi esittelen kävelevän teknivärin, jossa vastoin QCD:n esimerkkiä kytkentävakio kasvaa hitaasti suuren energiaskaalan ylitse. Tämä nostaa massoja niin suuriksi, että teknihadroneita ei ole voitu havaita nykyisillä kiihdyttimillä. Myös kaikkien Standardimallin fermionien paitsi top ja bottom kvarkkien massat ovat selitettävissä. Siten osoitan tutkielmassani, että lukuunottamatta kolmannen sukupolven kvarkkien suuria massoja, kävelevään tekniväriin perustuvat mallit voivat periaatteessa tuottaa havaitun hiukkasspektrin.