Anatomy of Higgs mass in supersymmetric inverse seesaw models
Energy Technology Data Exchange (ETDEWEB)
Chun, Eung Jin, E-mail: ejchun@kias.re.kr [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of); Mummidi, V. Suryanarayana, E-mail: soori9@cts.iisc.ernet.in [Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012 (India); Vempati, Sudhir K., E-mail: vempati@cts.iisc.ernet.in [Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012 (India)
2014-09-07
We compute the one loop corrections to the CP-even Higgs mass matrix in the supersymmetric inverse seesaw model to single out the different cases where the radiative corrections from the neutrino sector could become important. It is found that there could be a significant enhancement in the Higgs mass even for Dirac neutrino masses of O(30) GeV if the left-handed sneutrino soft mass is comparable or larger than the right-handed neutrino mass. In the case where right-handed neutrino masses are significantly larger than the supersymmetry breaking scale, the corrections can utmost account to an upward shift of 3 GeV. For very heavy multi TeV sneutrinos, the corrections replicate the stop corrections at 1-loop. We further show that general gauge mediation with inverse seesaw model naturally accommodates a 125 GeV Higgs with TeV scale stops.
Ahriche, Amine; Nasri, Salah
2016-01-01
We present a minimal model that simultaneously accounts for neutrino masses and the origin of dark matter (DM) and where the electroweak phase transition is strong enough to allow for electroweak baryogenesis. The Standard Model is enlarged with a Majorana fermion, three generations of chiral fermion pairs, and a single complex scalar that plays a central role in DM production and phenomenology, neutrino masses, and the strength of the phase transition. All the new fields are singlets under the SM gauge group. Neutrino masses are generated via a new variant of radiative inverse seesaw where the required small mass term is generated via loops involving DM and no large hierarchy is assumed among the mass scales. The model offers all the advantage of low-scale neutrino mass models as well as a viable dark matter candidate that is testable with direct detection experiments.
Higgs Boson Mass and Complex Snuetrino Dark Matter in the Supersymmetric Inverse Seesaw Models
Guo, Jun; Li, Tianjun; Liu, Yandong
2014-01-01
The discovery of a relatively heavy Standard Model (SM) -like Higgs boson challenges naturalness of the minimal supersymmetric standard model (MSSM) from both Higgs and dark matter (DM) sectors. We study these two aspects in the MSSM extended by the low-scale inverse seesaw mechanism. Firstly, it admits a sizable radiative correction on the Higgs boson mass m_h, up to \\sim 4 GeV in the case of an IR-fixed point of the coupling Y_\
Chowdhury, Debtosh; Vempati, Sudhir K
2011-01-01
Accurate supersymmetric spectra are required to confront data from direct and indirect searches of supersymmetry. \\SUSEFLAV\\ is a numerical tool which is capable of computing supersymmetric spectra accurately for various supersymmetric breaking scenarios applicable even in the presence of flavor violation. The program solves MSSM RGEs with complete $3\\times3$ flavor mixing at 2-loop level and one loop finite threshold corrections to all MSSM parameters by incorporating radiative electroweak symmetry breaking conditions. The program also incorporates the Type-I seesaw mechanism with three massive right handed neutrinos at user defined mass scales and mixing. It also computes branching ratios of flavor violating processes such as $l_j\\,\\rightarrow\\, l_i\\gamma$, $l_j\\;\\rightarrow\\, 3 ~l_i$, $b \\,\\rightarrow\\,s\\gamma$ and supersymmetric contributions to flavor conserving quantities such as $(g_{\\mu}-2)$. A large choice of executables suitable for various operations of the program are provided.
Radiative seesaw and degenerate neutrinos
Bajc, B; Bajc, Borut; Senjanovic, Goran
2005-01-01
The radiative see-saw mechanism of Witten generates the right-handed neutrino masses in SO(10) with the spinorial 16_H Higgs field. We study here analytically the 2nd and 3rd generations for the minimal Yukawa structure containing 10_H and 120_H Higgs representations. In the approximation of small 2nd generation masses and gauge loop domination we find the following results : (1) b-tau unification, (2) natural coexistence between large theta_l and small theta_q, (3) degenerate neutrinos.
Analysis of Leptogenesis in Supersymmetric Triplet Seesaw Model
Chun, E J
2007-01-01
We analyze leptogenesis in a supersymmetric triplet seesaw scenario that explains the observed neutrino masses, adopting a phenomenological approach where the decay branching ratios of the triplets and the amount of CP--violation in its different decay channels are assumed as free parameters. We find that the solutions of the relevant Boltzmann equations lead to a rich phenomenology, in particular much more complex compared to the non--supersymmetric case, mainly due to the presence of an additional Higgs doublet. Several unexpected and counter--intuitive behaviors emerge from our analysis: the amount of CP violation in one of the decay channels can prove to be be irrelevant to the final lepton asymmetry, leading to successful leptogenesis even in scenarios with a vanishing CP violation in the leptonic sector; gauge annihilations can be the dominant effect in the determination of the evolution of the triplet density up to very high values of its mass, leading anyway to a sizeable final lepton asymmetry, which...
Lepton flavor violation in supersymmetric low-scale seesaw models
Popov, Luka
2013-01-01
The minimal supersymmetric standard model with a low scale see-saw mechanism is presented. Within this framework, the lepton flavour violation in the charged lepton sector is thoroughly studied. Special attention is paid to the individual loop contributions due to the heavy neutrinos $N_{1,2,3}$, sneutrinos $\\tilde{N}_{1,2,3}$ and soft SUSY-breaking terms. For the first time, the complete set of box diagrams is included, in addition to the photon and $Z$-boson mediated interactions. The complete set of chiral amplitudes and their associate form-factors related to the neutrinoless three-body charged lepton flavor violating decays of the muon and tau, such as $\\mu \\to eee$, $\\tau \\to \\mu\\mu\\mu$, $\\tau \\to e\\mu\\mu$ and $\\tau \\to ee\\mu$, as well as the coherent $\\mu \\to e$ conversion in nuclei, were derived. The obtained analytical results are general and can be applied to most of the New Physics models with charged lepton flavor violation. This systematic analysis has revealed the existence of two new box form f...
Weiland, Cédric
2012-01-01
We study the impact of the inverse seesaw mechanism on several leptonic and hadronic low-energy flavour-violating observables in the context of the Minimal Supersymmetric Standard Model. Indeed, the contributions of the light right-handed sneutrinos from the inverse seesaw significantly enhance the Higgs-mediated penguin diagrams. We find that this can increase the different branching ratios by as much as two orders of magnitude.
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
Pires, C A de S; da Silva, P S Rodrigues
2016-01-01
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw mechanism, on the other it is a challenge to find scenarios capable of realizing it. In this work we propose a scenario, based on the framework of R-parity violation, that realizes minimally the supersymmetric inverse seesaw mechanism. In it the energy scale parameters involved in the mechanism are recognized as the vacuum expectation values of the scalars that compose the superfields $\\hat N^C$ and $\\hat S$. We develop also the scalar sector of the model and show that the Higgs mass receives a new tree-level contribution that, when combined with the standard contribution plus loop correction, is capable of attaining $125$GeV without resort to heavy stops.
Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation
de S. Pires, C. A.; Rodrigues, J. G.; Rodrigues da Silva, P. S.
2016-08-01
If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw mechanism, on the other it is a challenge to find scenarios capable of realizing it. In this work we propose a scenario, based on the framework of R-parity violation, that realizes minimally the supersymmetric inverse seesaw mechanism. In it the energy scale parameters involved in the mechanism are recognized as the vacuum expectation values of the scalars that compose the singlet superfields NˆC and S ˆ . We develop also the scalar sector of the model and show that the Higgs mass receives a new tree-level contribution that, when combined with the standard contribution plus loop correction, is capable of attaining 125 GeV without resort to heavy stops.
Type III Seesaw and Dark Matter in a Supersymmetric Left-Right Model
Borah, Debasish
2009-01-01
We propose a new supersymmetric left right model with Higgs doublets carrying odd B-L charge, higgs bidoublet and heavy Higgs triplets with zero B-L charge and a set of sterile neutrinos which are singlet under the gauge group. We show that spontaneous parity violation can be achieved naturally in this model and the neutrino masses arise from the so called type III seesaw mechanism. We also discuss the possible phenomenology in the context of neutrino masses and dark matter.
Supersymmetric Lepton Flavour Violation in Low-Scale Seesaw Models
Ilakovac, Amon
2009-01-01
We study a new supersymmetric mechanism for lepton flavour violation in \\mu and \\tau decays and \\mu -> e conversion in nuclei, within a minimal extension of the MSSM with low-mass heavy singlet neutrinos and sneutrinos. We find that the decays \\mu -> e\\gamma$, \\tau -> e\\gamma and \\tau -> \\mu\\gamma are forbidden in the supersymmetric limit of the theory, whereas other processes, such as \\mu -> eee, \\mu -> e conversion, \\tau -> eee and \\tau -> e\\mu\\mu, are allowed and can be dramatically enhanced several orders of magnitude above the observable level by potentially large neutrino Yukawa coupling effects. The profound implications of supersymmetric lepton flavour violation for present and future experiments are discussed.
The B ‑ L supersymmetric standard model with inverse seesaw at the large hadron collider
Khalil, S.; Moretti, S.
2017-03-01
We review the TeV scale B ‑ L extension of the minimal supersymmetric standard model (BLSSM) where an inverse seesaw mechanism of light neutrino mass generation is naturally implemented and concentrate on its hallmark manifestations at the large hadron collider (LHC).
Oscillating asymmetric sneutrino dark matter from the maximally U(1L supersymmetric inverse seesaw
Directory of Open Access Journals (Sweden)
Shao-Long Chen
2016-10-01
Full Text Available The inverse seesaw mechanism provides an attractive approach to generate small neutrino mass, which origins from a tiny U(1L breaking. In this paper, we work in the supersymmetric version of this mechanism, where the singlet-like sneutrino could be an asymmetric dark matter (ADM candidate in the maximally U(1L symmetric limit. However, even a tiny δm, the mass splitting between sneutrino and anti-sneutrino as a result of the tiny U(1L breaking effect, could lead to fast oscillation between sneutrino and anti-sneutrino and thus spoils the ADM scenario. We study the evolution of this oscillation and find that a weak scale sneutrino, which tolerates a relatively larger δm∼10−5 eV, is strongly favored. We also investigate possible natural ways to realize that small δm in the model.
Oscillating asymmetric sneutrino dark matter from the maximally U(1)L supersymmetric inverse seesaw
Chen, Shao-Long; Kang, Zhaofeng
2016-10-01
The inverse seesaw mechanism provides an attractive approach to generate small neutrino mass, which origins from a tiny U(1)L breaking. In this paper, we work in the supersymmetric version of this mechanism, where the singlet-like sneutrino could be an asymmetric dark matter (ADM) candidate in the maximally U(1)L symmetric limit. However, even a tiny δm, the mass splitting between sneutrino and anti-sneutrino as a result of the tiny U(1)L breaking effect, could lead to fast oscillation between sneutrino and anti-sneutrino and thus spoils the ADM scenario. We study the evolution of this oscillation and find that a weak scale sneutrino, which tolerates a relatively larger δm ∼10-5 eV, is strongly favored. We also investigate possible natural ways to realize that small δm in the model.
Radiative Type III Seesaw Model and its collider phenomenology
von der Pahlen, Federico; Restrepo, Diego; Zapata, Oscar
2016-01-01
We analyze the present bounds of a scotogenic model, the Radiative Type III Seesaw (RSIII), in which an additional scalar doublet and at least two fermion triplets of $SU(2)_L$ are added to the Standard Model (SM). In the RSIII the new physics (NP) sector is odd under an exact global $Z_2$ symmetry. This symmetry guaranties that the lightest NP neutral particle is stable, providing a natural dark matter (DM) candidate, and leads to naturally suppressed neutrino masses generated by a one-loop realization of an effective Weinberg operator. We focus on the region with the highest sensitivity in present and future LHC searches, with light scalar DM and at least one NP fermion triplet at the sub-TeV scale. This region allows for significant production cross-sections of NP fermion pairs at the LHC. We reinterpret a set of searches for supersymmetric particles at the LHC obtained using the package CheckMATE, to set limits on our model as a function of the masses of the NP particles and their Yukawa interactions. The...
Radiative and seesaw threshold corrections to the S3 symmetric neutrino mass matrix
Directory of Open Access Journals (Sweden)
Shivani Gupta
2015-01-01
Full Text Available We systematically analyze the radiative corrections to the S3 symmetric neutrino mass matrix at high energy scale, say the GUT scale, in the charged lepton basis. There are significant corrections to the neutrino parameters both in the Standard Model (SM and Minimal Supersymmetric Standard Model (MSSM with large tanβ, when the renormalization group evolution (RGE and seesaw threshold effects are taken into consideration. We find that in the SM all three mixing angles and atmospheric mass squared difference are simultaneously obtained in their current 3σ ranges at the electroweak scale. However, the solar mass squared difference is found to be larger than its allowed 3σ range at the low scale in this case. There are significant contributions to neutrino masses and mixing angles in the MSSM with large tanβ from the RGEs even in the absence of seesaw threshold corrections. However, we find that the mass squared differences and the mixing angles are simultaneously obtained in their current 3σ ranges at low energy when the seesaw threshold effects are also taken into account in the MSSM with large tanβ.
Constraints on the rare tau decays from {mu} {yields} e{gamma} in the supersymmetric see-saw model
Energy Technology Data Exchange (ETDEWEB)
Ibarra, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Simonetto, C. [Technische Univ., Muenchen (Germany). Physik-Department
2008-02-15
It is now a firmly established fact that all family lepton numbers are violated in Nature. In this paper we discuss the implications of this observation for future searches for rare tau decays in the supersymmetric see-saw model. Using the two loop renormalization group evolution of the soft terms and the Yukawa couplings we show that there exists a lower bound on the rate of the rare process {mu}{yields}e{gamma} of the form BR({mu}{yields}e{gamma})>or similar C x BR({tau}{yields}{mu}{gamma})BR({tau}{yields}e{gamma}), where C is a constant that depends on supersymmetric parameters. Our only assumption is the absence of cancellations among the high-energy see-saw parameters. We also discuss the implications of this bound for future searches for rare tau decays. In particular, for large regions of the mSUGRA parameter space, we show that present B-factories could discover either {tau}{yields}{mu}{gamma} or {tau}{yields}e{gamma}, but not both. (orig.)
Two radiative inverse seesaw models, dark matter, and baryogenesis
Baldes, Iason; Petraki, Kalliopi; Volkas, Raymond R
2013-01-01
The inverse seesaw mechanism allows the neutrino masses to be generated by new physics at an experimentally accessible scale, even with O(1) Yukawa couplings. In the inverse seesaw scenario, the smallness of neutrino masses is linked to the smallness of a lepton number violating parameter. This parameter may arise radiatively. In this paper, we study the cosmological implications of two contrasting radiative inverse seesaw models, one due to Ma and the other to Law and McDonald. The former features spontaneous, the latter explicit lepton number violation. First, we examine the effect of the lepton-number violating interactions introduced in these models on the baryon asymmetry of the universe. We investigate under what conditions a pre-existing baryon asymmetry does not get washed out. While both models allow a baryon asymmetry to survive only once the temperature has dropped below the mass of their heaviest fields, the Ma model can create the baryon asymmetry through resonant leptogenesis. Then we investigat...
Neutrino masses from SUSY breaking in radiative seesaw models
Energy Technology Data Exchange (ETDEWEB)
Figueiredo, Antonio J.R. [University of Lisbon, Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Lisbon (Portugal)
2015-03-01
Radiatively generated neutrino masses (m{sub ν}) are proportional to supersymmetry (SUSY) breaking, as a result of the SUSY non-renormalisation theorem. In this work, we investigate the space of SUSY radiative seesaw models with regard to their dependence on SUSY breaking (SUSY). In addition to contributions from sources of SUSY that are involved in electroweak symmetry breaking (SUSY{sub EWSB} contributions), and which are manifest from left angle F{sub H}{sup †} right angle = μ left angle anti H right angle ≠ 0 and left angle D right angle = g sum {sub H} left angle H{sup †} x {sub H} H right angle ≠ 0, radiatively generated m{sub ν} can also receive contributions from SUSY sources that are unrelated to EWSB (SUSY{sub EWS} contributions). We point out that recent literature overlooks pure-SUSY{sub EWSB} contributions (∝ μ/M) that can arise at the same order of perturbation theory as the leading order contribution from SUSY{sub EWS}. We show that there exist realistic radiative seesaw models in which the leading order contribution to m{sub ν} is proportional to SUSY{sub EWS}. To our knowledge no model with such a feature exists in the literature. We give a complete description of the simplest model topologies and their leading dependence on SUSY. We show that in one-loop realisations LLHH operators are suppressed by at least μ m{sub soft}/M{sup 3} or m{sub soft}{sup 2}/M{sup 3}. We construct a model example based on a oneloop type-II seesaw. An interesting aspect of these models lies in the fact that the scale of soft-SUSY effects generating the leading order m{sub ν} can be quite small without conflicting with lower limits on the mass of new particles. (orig.)
Supersymmetric radiative corrections at large tan {beta}
Energy Technology Data Exchange (ETDEWEB)
Logan, H.E.
2001-02-20
In the minimal supersymmetric extension of the Standard Model (MSSM), fermion masses and Yukawa couplings receive radiative corrections at one loop from diagrams involving the supersymmetric particles. The corrections to the relation between down-type fermion masses and Yukawa couplings are enhanced by tan {beta}, which makes them potentially very significant at large tan {beta}. These corrections affect a wide range of processes in the MSSM, including neutral and charged Higgs phenomenology, rare B meson decays, and renormalization of the CKM matrix. We give a pedagogical review of the sources and phenomenological effects of these corrections.
Supersymmetric Scenarios with Dominant Radiative Neutralino Decay
Ambrosanio, S; Ambrosanio, Sandro; Mele, Barbara
1997-01-01
The radiative decay of the next-to-lightest neutralino into a lightest neutralino and a photon is analyzed in the MSSM. We find that significant regions of the supersymmetric parameter space with large radiative BR's (up to about 100%) do exist. The radiative channel turns out to be enhanced when the neutralino tree-level decays are suppressed either `kinematically' or `dynamically'. In general, in the regions allowed by LEP data and not characterized by asymptotic values of the SuSy parameters, the radiative enhancement requires tan beta ~= 1 and/or M_1 ~= M_2, and negative values of relaxing the usual relation M_1=(5/3)*tan^2(th_W)*M_2, i.e. gaugino mass unification at the GUT scale. The influence of varying the stop masses and mixing angle when the radiative decay is enhanced is also considered. Some phenomenological consequences of the above picture are discussed.
Radiative see-saw formula in nonsupersymmetric (10) with dark matter
Indian Academy of Sciences (India)
Mina K Parida
2012-11-01
In (10), the type-I and type-II see-saw scales ≥ 1012 GeV are far away from being probed by direct experimental tests. In the absence of supersymmetry, we show how experimentally verifiable radiative see-saw formula of Ma type is realized in non-SUSY (10) while fulfilling the twin objectives: precision gauge coupling unification and dark matter. This model is expected to have a dramatic impact on neutrino physics, dark matter and all fermion masses and mixings.
Radiatively Induced Type II seesaw and Vector-like 5/3 Charge Quarks
Franceschini, R
2013-01-01
Understanding small neutrino masses in type II seesaw models with TeV scale SM triplet Higgs bosons requires that its coupling with the standard model Higgs doublet H be dialed down to be order eV to KeV, which is a fine-tuning by a factor of $10^{-11}-10^{-8}$ with respect to the weak scale. We present a SUSY extension of the type II seesaw model where this dimensionful small coupling is radiatively induced, thus making its smallness natural. This model has an exotic vector-like quark doublet which contains a quark X with electric charge 5/3 and a top partner t'. We discuss in details the phenomenology of the model paying special attention to the consequences of the interactions of the the exotic heavy quarks and the scalars of the model. Implications for neutrinoless double beta decay and for the LHC experiments are discussed in detail. Remarkably, in this model both the seesaw triplet and the heavy quarks can manifest at colliders in a host of different signatures, including some that significantly differ ...
Radiative fermion mass matrix generation in supersymmetric models
Energy Technology Data Exchange (ETDEWEB)
Papantonopoulos, E.; Zoupanos, G.
1984-01-01
Supersymmetric SU(2)sub(L)xU(1) horizontal models are studied. The non-renormalisation theorems of sypersymmetry are used to make the mass generation and flavour mixing natural. For three families, the fermion mass matrix generation mechanism is studied as a radiative effect due to horizontal interactions, using various representations of the gauge horizontal groups SU(2)sub(H) and SU(3)sub(H). An attractive possibility leading to a realistic mass matrix is found.
Radiative seesaw-type mechanism of fermion masses and non-trivial quark mixing
Energy Technology Data Exchange (ETDEWEB)
Arbelaez, Carolina; Hernandez, A.E.C.; Kovalenko, Sergey; Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Centro Cientifico-Tecnologico de Valparaiso-CCTVal, Valparaiso (Chile)
2017-06-15
We propose a predictive inert two-Higgs doublet model, where the standard model (SM) symmetry is extended by S{sub 3} x Z{sub 2} x Z{sub 12} and the field content is enlarged by extra scalar fields, charged exotic fermions and two heavy right-handed Majorana neutrinos. The charged exotic fermions generate a non-trivial quark mixing and provide one-loop-level masses for the first- and second-generation charged fermions. The masses of the light active neutrinos are generated from a one-loop-level radiative seesaw mechanism. Our model successfully explains the observed SM fermion mass and mixing pattern. (orig.)
Radiative seesaw-type mechanism of fermion masses and non-trivial quark mixing
Arbeláez, Carolina; Hernández, A. E. Cárcamo; Kovalenko, Sergey; Schmidt, Ivan
2017-06-01
We propose a predictive inert two-Higgs doublet model, where the standard model (SM) symmetry is extended by S3⊗ Z2⊗ Z_{12} and the field content is enlarged by extra scalar fields, charged exotic fermions and two heavy right-handed Majorana neutrinos. The charged exotic fermions generate a non-trivial quark mixing and provide one-loop-level masses for the first- and second-generation charged fermions. The masses of the light active neutrinos are generated from a one-loop-level radiative seesaw mechanism. Our model successfully explains the observed SM fermion mass and mixing pattern.
Soft See-Saw: Radiative Origin of Neutrino Masses in SUSY Theories
Megrelidze, Luka
2016-01-01
Radiative neutrino mass generation within supersymmetric (SUSY) construction is studied. The mechanism is considered where the lepton number violation is originating from the soft SUSY breaking terms. This requires extensions of the MSSM with states around the TeV scale. We present several explicit realizations based on extensions either by MSSM singlet or SU(2)_w triplet states. Besides some novelties of the proposed scenarios, various phenomenological implications are also discussed.
Soft see-saw: Radiative origin of neutrino masses in SUSY theories
Directory of Open Access Journals (Sweden)
Luka Megrelidze
2017-01-01
Full Text Available Radiative neutrino mass generation within supersymmetric (SUSY construction is studied. The mechanism is considered where the lepton number violation is originating from the soft SUSY breaking terms. This requires MSSM extensions with states around the TeV scale. We present several explicit realizations based on extensions either by MSSM singlet or SU(2w triplet states. Besides some novelties of the proposed scenarios, various phenomenological implications are also discussed.
A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
Ko, P.; Nomura, Takaaki; Okada, Hiroshi
2017-09-01
We propose a predictive radiative seesaw model at one-loop level with a flavor dependent gauge symmetry U(1) xB3 - xe - μ + τ and Majorana fermion dark matter. For the neutrino mass matrix, we obtain an A1 type texture (with two zeros) that provides us several predictions such as the normal ordering for the neutrino masses. We analyze the constraints from lepton flavor violations, relic density of dark matter, and collider physics for the new U(1) xB3 - xe - μ + τ gauge boson. Within the allowed region, the LHCb anomalies in B →K*μ+μ- and B → Kℓ+ℓ- with ℓ = e or μ can be resolved, and such Z‧ could be also observed at the LHC.
Direct detection of fermion dark matter in the radiative seesaw model
Ibarra, Alejandro; Zapata, Oscar
2016-01-01
We consider the scenario in the radiative seesaw model where the dark matter particle is the lightest $Z_2$-odd fermion. We identify the regions of the parameter space of the model compatible with neutrino oscillation data, with the upper limits from rare charged lepton decays and with the observed dark matter abundance via thermal freeze-out, and we compute the dark matter scattering cross section with nuclei via the one-loop exchange of a photon, a $Z^0$-boson or a Higgs boson. We find that the predicted spin-independent cross section lies below the current LUX limit, although, for some choices of parameters, above the expected sensitivity of XENON1T or LZ.
A flavor dependent gauge symmetry, predictive radiative seesaw and LHCb anomalies
Directory of Open Access Journals (Sweden)
P. Ko
2017-09-01
Full Text Available We propose a predictive radiative seesaw model at one-loop level with a flavor dependent gauge symmetry U(1xB3−xe−μ+τ and Majorana fermion dark matter. For the neutrino mass matrix, we obtain an A1 type texture (with two zeros that provides us several predictions such as the normal ordering for the neutrino masses. We analyze the constraints from lepton flavor violations, relic density of dark matter, and collider physics for the new U(1xB3−xe−μ+τ gauge boson. Within the allowed region, the LHCb anomalies in B→K⁎μ+μ− and B→Kℓ+ℓ− with ℓ=e or μ can be resolved, and such Z′ could be also observed at the LHC.
Atomki anomaly and dark matter in a radiative seesaw model with gauged $B-L$ symmetry
Seto, Osamu
2016-01-01
Motivated by recently reported anomalies in a decay of an excited state of beryllium by the Atomki collaboration, we study a radiative seesaw model with gauged $B-L$ symmetry and a $Z_2$ parity. Assuming that the anomalies originate from the decay of the $B-L$ gauge boson followed by the nuclear decay, the mass of the lightest right-handed neutrino or the dark matter candidate can be determined below $10$ GeV. We show that for this mass range, the model can explain the anomalies in the beryllium decay and the relic dark matter abundance consistent with neutrino masses. We also predict its spin-independent cross section in direct detection experiments for this mass range.
Testing Type II Radiative Seesaw Model: from Dark Matter Detection to LHC Signatures
Guo, Shu-Yuan; Liao, Yi
2016-01-01
We analyse the testability of the type II radiative seesaw in which neutrino mass and dark matter (DM) are related at one-loop level. Under the constraints from DM relic density, direct and indirect detection, and invisible Higgs decays, we find three possible regions of DM mass $M_{s_1}$ that can survive the present and even the future experiments: (1) the Higgs resonance region with $M_{s_1}\\sim M_h/2$, (2) the Higgs region with $M_{s_1}\\sim M_h$, and (3) the coannihilation region with $M_{s_2}\\sim M_{s_1}$. Here $s_{1,2}$ are two scalar singlets with the lighter $s_1$ being the DM candidate. Based on DM properties and direct collider constraints, we choose three benchmark points to illustrate the testability of this model at LHC. We perform a detailed simulation of the four-lepton and tri-lepton signatures at 13 (14) TeV LHC. While both signatures are found to be promising at all benchmark points, the tri-lepton one is even better: it is possible to reach the $5\\sigma$ significance with an integrated lumin...
Testing the type II radiative seesaw model: From dark matter detection to LHC signatures
Guo, Shu-Yuan; Han, Zhi-Long; Liao, Yi
2016-12-01
We analyze the testability of the type II radiative seesaw in which neutrino mass and dark matter (DM) are related at one-loop level. Under the constraints from DM relic density, direct and indirect detection, and invisible Higgs decays, we find three possible regions of DM mass Ms1that can survive the present and even the future experiments: (1) the Higgs resonance region with Ms 1˜Mh/2 , (2) the Higgs region with Ms1˜Mh, and (3) the coannihilation region with Ms 2˜Ms 1. Here s1 ,2 are two scalar singlets with the lighter s1 being the DM candidate. Based on DM properties and direct collider constraints, we choose three benchmark points to illustrate the testability of this model at the LHC. We perform a detailed simulation of the four-lepton and trilepton signatures at 13(14) TeV LHC. While both signatures are found to be promising at all benchmark points, the trilepton one is even better: it is possible to reach the 5 σ significance with an integrated luminosity of 100 fb-1.
Ahn, Y H
2012-01-01
We propose a new scenario in a radiative seesaw model based on A_4 flavor symmetry. In this model, we explore a possibility of linking non-zero \\theta_{13} to dark matter. And we analyze the lepton sector to predict the observed neutrinos and mixings, especially obtaining a lower bound of \\theta_{13}~3.5 [Deg.]. We show that the non-zero \\theta_{13} is correlated with our heavy Majorana type of dark matter. Also we predict that the mass be O(1-10) TeV, as a result of analyzing the Wilkinson-Microwave-Anisotropy-Probe and lepton flavor violation.
Radiative Effects and Electroweak Symmetry Breaking in a Supersymmetric Preon Model
Kim, Jongbae
We construct the low energy effective theory of composite quarks, leptons, and Higgs bosons for a supersymmetric preon model and study the effects of renormalization-group based radiative corrections. The study on the evolution of scalar masses for avoiding color and charge breakings leads us to conclude that Yukawa couplings are bounded from above. The implementation of electroweak symmetry breaking requires that only the purely dynamical symmetry breaking should be needed for the model, but the combined scheme of dynamical and radiative symmetry breaking as well as the purely radiative symmetry breaking scheme be disfavored. Our analysis of (mb)/(m_τ ) including radiative effects shows that, should a discrepancy be found between the observed and the theoretical value of (mb)/(m_τ ) after experimental determination of supersymmetric particle masses, it would imply that the complete quark-lepton universality in the supersymmetric preon model does not hold either for the Yukawa couplings, or for the condensates, or for both.
Dark radiation and dark matter in supersymmetric axion models with high reheating temperature
Graf, Peter; Steffen, Frank Daniel
2013-01-01
Recent studies of the cosmic microwave background, large scale structure, and big bang nucleosynthesis (BBN) show trends towards extra radiation. Within the framework of supersymmetric hadronic axion models, we explore two high-reheating-temperature scenarios that can explain consistently extra radiation and cold dark matter (CDM), with the latter residing either in gravitinos or in axions. In the gravitino CDM case, axions from decays of thermal saxions provide extra radiation already prior ...
Universality in radiative corrections for non-supersymmetric heterotic vacua
Angelantonj, C; Tsulaia, Mirian
2016-01-01
Properties of moduli-dependent gauge threshold corrections in non-supersymmetric heterotic vacua are reviewed. In the absence of space-time supersymmetry these amplitudes are no longer protected and receive contributions from the whole tower of string states, BPS and not. Never-theless, the difference of gauge thresholds for non-Abelian gauge groups displays a remarkable universality property, even when supersymmetry is absent. We present a simple heterotic construction that shares this universal behaviour and expose the necessary conditions on the super-symmetry breaking mechanism for universality to occur.
The see-saw mechanism: Neutrino mixing, leptogenesis and lepton flavour violation
Indian Academy of Sciences (India)
Werner Rodejohann
2009-01-01
The see-saw mechanism to generate small neutrino masses is reviewed. After summarizing our current knowledge about the low energy neutrino mass matrix, we consider reconstructing the see-saw mechanism. Indirect tests of see-saw are leptogenesis and lepton flavour violation in supersymmetric scenarios, which together with neutrino mass and mixing define the framework of see-saw phenomenology. Several examples are given, both phenomenological and GUT-related.
Akhmedov, E K
2006-01-01
We consider type I+II seesaw mechanism, where the exchanges of both right-handed neutrinos and isotriplet Higgs bosons contribute to the neutrino mass. Working in the left-right symmetric framework and assuming the mass matrix of light neutrinos $m_\
Xing, Zhi-zhong
2012-01-01
In a simple extension of the standard electroweak theory where the phenomenon of lepton flavor mixing is described by a 3x3 unitary matrix V, the electric and magnetic dipole moments of three active neutrinos are suppressed not only by their tiny masses but also by the Glashow-Iliopoulos-Maiani (GIM) mechanism. We show that it is possible to lift the GIM suppression if the canonical seesaw mechanism of neutrino mass generation, which allows V to be slightly non-unitary, is taken into account. In view of current experimental constraints on the non-unitarity of V, we find that the effective electromagnetic dipole moments of three neutrinos and the rates of their radiative decays can be maximally enhanced by a factor of O(10^2) and a factor of O(10^4), respectively. This nontrivial observation reveals an intrinsic and presumably significant correlation between the electromagnetic properties of massive neutrinos and the origin of their small masses.
Muon anomalous magnetic moment in SUSY B−L model with inverse seesaw
Directory of Open Access Journals (Sweden)
Shaaban Khalil
2016-12-01
Full Text Available Motivated by the tension between the Higgs mass and muon g−2 in minimal supersymmetric standard model (MSSM, we analyze the muon g−2 in supersymmetric B−L extension of the standard model (BLSSM with inverse seesaw mechanism. In this model, the Higgs mass receives extra important radiative corrections proportional to large neutrino Yukawa coupling. We point out that muon g−2 also gets significant contribution, due to the constructive interferences of light neutralino effects. The light neutralinos are typically the MSSM Bino like and the supersymmetric partner of U(1B−L gauge boson (B˜′-ino. We show that with universal soft supersymmetry breaking terms, the muon g−2 resides within 2σ of the measured value, namely ∼20×10−10, with Higgs mass equal to 125 GeV.
Muon anomalous magnetic moment in SUSY B - L model with inverse seesaw
Khalil, Shaaban; Ün, Cem Salih
2016-12-01
Motivated by the tension between the Higgs mass and muon g - 2 in minimal supersymmetric standard model (MSSM), we analyze the muon g - 2 in supersymmetric B - L extension of the standard model (BLSSM) with inverse seesaw mechanism. In this model, the Higgs mass receives extra important radiative corrections proportional to large neutrino Yukawa coupling. We point out that muon g - 2 also gets significant contribution, due to the constructive interferences of light neutralino effects. The light neutralinos are typically the MSSM Bino like and the supersymmetric partner of U(1) B - L gauge boson (B˜‧-ino). We show that with universal soft supersymmetry breaking terms, the muon g - 2 resides within 2σ of the measured value, namely ∼ 20 ×10-10, with Higgs mass equal to 125 GeV.
Large BR(h -> tau mu) in Supersymmetric Models
Hammad, Ahmed; Un, Cem Salih
2016-01-01
We analyze the Lepton Flavor Violating (LFV) Higgs decay h -> tau mu in three supersymmetric models: Minimal Supersymmetric Standard Model (MSSM), Supersymmetric Seesaw Model (SSM), and Supersymmetric B-L model with Inverse Seesaw (BLSSM-IS). We show that in generic MSSM, with non-universal slepton masses and/or trilinear couplings, it is not possible to enhance BR(h -> tau mu) without violating the experimental bound on the BR(tau -> mu gamma). In SSM, where flavor mixing is radiatively generated, the LFV process mu -> e gamma strictly constrains the parameter space and the maximum value of BR(h -> tau mu) is of order 10^-10, which is extremely smaller than the recent results reported by the CMS and ATLAS experiments. In BLSSM-IS, with universal soft SUSY breaking terms at the grand unified scale, we emphasize that the measured values of BR(h -> tau mu) can be accommodated in a wide region of parameter space without violating LFV constraints. Thus, confirming the LFV Higgs decay results will be a clear signa...
Dark radiation and dark matter in supersymmetric axion models with high reheating temperature
Energy Technology Data Exchange (ETDEWEB)
Graf, Peter; Steffen, Frank Daniel, E-mail: graf@mpp.mpg.de, E-mail: steffen@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, D–80805 Munich (Germany)
2013-12-01
Recent studies of the cosmic microwave background, large scale structure, and big bang nucleosynthesis (BBN) show trends towards extra radiation. Within the framework of supersymmetric hadronic axion models, we explore two high-reheating-temperature scenarios that can explain consistently extra radiation and cold dark matter (CDM), with the latter residing either in gravitinos or in axions. In the gravitino CDM case, axions from decays of thermal saxions provide extra radiation already prior to BBN and decays of axinos with a cosmologically required TeV-scale mass can produce extra entropy. In the axion CDM case, cosmological constraints are respected with light eV-scale axinos and weak-scale gravitinos that decay into axions and axinos. These decays lead to late extra radiation which can coexist with the early contributions from saxion decays. Recent results of the Planck satellite probe extra radiation at late times and thereby both scenarios. Further tests are the searches for axions at ADMX and for supersymmetric particles at the LHC.
Axions and saxions from the primordial supersymmetric plasma and extra radiation signatures
Energy Technology Data Exchange (ETDEWEB)
Graf, Peter; Steffen, Frank Daniel, E-mail: graf@mpp.mpg.de, E-mail: steffen@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, D–80805 Munich (Germany)
2013-02-01
We calculate the rate for thermal production of axions and saxions via scattering of quarks, gluons, squarks, and gluinos in the primordial supersymmetric plasma. Systematic field theoretical methods such as hard thermal loop resummation are applied to obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling. We calculate the thermally produced yield and the decoupling temperature for both axions and saxions. For the generic case in which saxion decays into axions are possible, the emitted axions can constitute extra radiation already prior to big bang nucleosynthesis and well thereafter. We update associated limits imposed by recent studies of the primordial helium-4 abundance and by precision cosmology of the cosmic microwave background and large scale structure. We show that the trend towards extra radiation seen in those studies can be explained by late decays of thermal saxions into axions and that upcoming Planck results will probe supersymmetric axion models with unprecedented sensitivity.
Radiative symmetry breaking on D-branes at non-supersymmetric singularities
Kitazawa, Noriaki
2006-10-01
The possibility of radiative gauge symmetry breaking on D3-branes at non-supersymmetric orbifold singularities is examined. As an example, a simple model of D3-branes at non-supersymmetric C/Z singularity with some D7-branes for the cancellations of RR tadpoles in twisted sectors is analyzed in detail. We find that there are no tachyon modes in twisted sectors, and NS-NS tadpoles in twisted sectors are canceled out, though uncanceled tadpoles and tachyon modes exist in untwisted sectors. This means that this singularity background is a stable solution of string theory at tree level, though some specific compactification of six-dimensional space should be considered for a consistent untwisted sector. On D3-brane three massless "Higgs doublet fields" and three family "up-type quarks" are realized at tree level. Other fermion fields, "down-type quarks" and "leptons", can be realized as massless modes of the open strings stretching between D3-branes and D7-branes. The Higgs doublet fields have Yukawa couplings with up-type quarks, and they also have self-couplings which give a scalar potential without flat directions. Since there is no supersymmetry, the radiative corrections may naturally develop negative Higgs mass squared and "electroweak symmetry breaking". We explicitly calculate the open string one-loop correction to the Higgs mass squared from twisted sectors, and find that the negative value is indeed realized in this specific model.
Muon Anomalous Magnetic Moment in SUSY B-L Model with Inverse Seesaw
Khalil, Shaaban
2015-01-01
Motivated by the tension between the Higgs mass and muon g-2 in minimal supersymmetric standard model (MSSM), we analyze the muon g-2 in supersymmertic B-L extension of the standard model (BLSSM) with inverse seesaw mechanism. In this model, the Higgs mass receives extra important radiative corrections proportional to large neutrino Yukawa coupling. We point out that muon g-2 also gets significant contribution, due to the constructive interferences of light neutralino effects. The light neutralinos are typically the MSSM Bino like and the supersymmetric partner of U(1)_B-L gauge boson (B'-ino). We show that with universal soft supersymmetry breaking terms, the muon g-2 resides within 2 sigma of the measured value, namely ~17 x 10^-10, with Higgs mass equal to 125 GeV .
Two Loop Radiative Seesaw and X-ray line Dark Matter with Global U(1) Symmetry
Okada, Hiroshi
2015-01-01
We study a two loop induced radiative neutrino model with global $U(1)$ symmetry at 0.1 GeV scale, in which we consider a keV scale of dark matter candidate recently reported by XMN-Newton X-ray observatory using data of various galaxy clusters and Andromeda galaxy. We also discuss the vacuum stability of singly charged bosons, lepton flavor violation processes, and a role of Goldstone boson.
Radiative Symmetry Breaking in the Supersymmetric Minimal B-L Extended Standard Model
Burell, Zachary
2016-01-01
The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others). There is no reason to expect the validity of the ad hoc SM to remain intact at energy scales above a few TeV, thus a more fundamental theory will almost certainly be required. Motivated by these considerations, we investigate a Supersymmetric version of a natural extension of the SM, the $U(1)_{B-L}$ model, that is obtained by gauging the accidental B-L symmetry that exists in the ordinary SM. The Supersymmetric $U(1)_{B-L}$ extended SM can resolve the neutrino mass problem, the dark matter problem, the hierarchy problem, and provides a mechanism for establishing the observed baryon asymmetry of the Universe. When we include quantum corrections to the Higgs potential of the model, we find that Radiative $B-L$ symmetry breaking occurs through the interplay between large Majorana...
Radiative Symmetry Breaking on D-branes at Non-supersymmetric Singularities
Kitazawa, N
2006-01-01
The possibility of radiative gauge symmetry breaking on D3-branes at non-supersymmetric orbifold singularities is examined. As an example, a simple model of D3-branes at non-supersymmetric C^3/Z_6 singularity with some D7-branes for the cancellations of R-R tadpoles in twisted sectors is analyzed in detail. We find that there are no tachyon modes in twisted sectors, and NS-NS tadpoles in twisted sectors are canceled out, though uncanceled tadpoles and tachyon modes exist in untwisted sectors. This means that this singularity background is a stable solution of string theory at tree level, though some specific compactification of six-dimensional space should be considered for a consistent untwisted sector. On D3-brane three massless "Higgs doublet fields" and three family "up-type quarks" are realized at tree level. Other fermion fields, "down-type quarks" and "leptons", can be realized as massless modes of the open strings stretching between D3-branes and D7-branes. The Higgs doublet fields have Yukawa couplin...
LHC 750 GeV Diphoton excess in a radiative seesaw model
Kanemura, Shinya; Okada, Hiroshi; Orikasa, Yuta; Park, Seong Chan; Watanabe, Ryoutaro
2015-01-01
We investigate a possibility for explaining the recently announced 750 GeV diphoton excess by the ATLAS and the CMS experiments at the CERN LHC in a model with multiple doubly-charged particles, which was originally suggested for explaining tiny neutrino masses through a three-loop effect in a natural way. The enhanced radiatively generated effective coupling of a new singlet scalar $S$ with diphoton, with multiple charged particles in the loop, enlarges the production rate of $S$ in $pp \\to S+X$ via photon fusion process and also the decay width $\\Gamma(S \\to \\gamma\\gamma)$ even without assuming a tree level production mechanism. Very interestingly, we find that the branching ratio $\\mathcal{B}(S \\to \\gamma\\gamma)$ is $\\simeq 60\\%$ fixed by quantum numbers and the model is consistent with all the constraints from $8\\,\\text{TeV}$ LHC data.
LHC 750 GeV diphoton excess in a radiative seesaw model
Kanemura, Shinya; Nishiwaki, Kenji; Okada, Hiroshi; Orikasa, Yuta; Chan Park, Seong; Watanabe, Ryoutaro
2016-12-01
We investigate a possibility for explaining the recently announced 750 GeV diphoton excess by the ATLAS and CMS experiments at the CERN LHC in a model with multiple doubly charged particles, that was originally suggested for explaining tiny neutrino masses through a three-loop effect in a natural way. The enhanced radiatively generated effective coupling of a new singlet scalar S with diphoton with multiple charged particles in the loop enlarges the production rate of S in pp→S+X via a photon fusion process and also the decay width Γ(S→γγ) even without assuming a tree-level production mechanism. We provide detailed analysis on the cases with or without allowing mixing between S and the standard model Higgs doublet.
Energy Technology Data Exchange (ETDEWEB)
King, Stephen F. [Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom)
2016-02-12
We propose the Littlest Seesaw (LS) model consisting of just two right-handed neutrinos, where one of them, dominantly responsible for the atmospheric neutrino mass, has couplings to (ν{sub e},ν{sub μ},ν{sub τ}) proportional to (0,1,1), while the subdominant right-handed neutrino, mainly responsible for the solar neutrino mass, has couplings to (ν{sub e},ν{sub μ},ν{sub τ}) proportional to (1,n,n−2). This constrained sequential dominance (CSD) model preserves the first column of the tri-bimaximal (TB) mixing matrix (TM1) and has a reactor angle θ{sub 13}∼(n−1)((√2)/3)((m{sub 2})/(m{sub 3})). This is a generalisation of CSD (n=1) which led to TB mixing and arises almost as easily if n≥1 is a real number. We derive exact analytic formulas for the neutrino masses, lepton mixing angles and CP phases in terms of the four input parameters and discuss exact sum rules. We show how CSD (n=3) may arise from vacuum alignment due to residual symmetries of S{sub 4}. We propose a benchmark model based on S{sub 4}×Z{sub 3}×Z{sub 3}{sup ′}, which fixes n=3 and the leptogenesis phase η=2π/3, leaving only two inputs m{sub a} and m{sub b}=m{sub ee} describing Δm{sub 31}{sup 2}, Δm{sub 21}{sup 2} and U{sub PMNS}. The LS model predicts a normal mass hierarchy with a massless neutrino m{sub 1}=0 and TM1 atmospheric sum rules. The benchmark LS model additionally predicts: solar angle θ{sub 12}=34{sup ∘}, reactor angle θ{sub 13}=8.7{sup ∘}, atmospheric angle θ{sub 23}=46{sup ∘}, and Dirac phase δ{sub CP}=−87{sup ∘}.
Lopez-Pavon, J; Petcov, S T
2015-01-01
We perform a detailed analysis of the one-loop corrections to the light neutrino mass matrix within low scale type I seesaw extensions of the Standard Model and their implications in experimental searches for neutrinoless double beta decay. We show that a sizable contribution to the effective Majorana neutrino mass from the exchange of heavy Majorana neutrinos is always possible, provided one requires a fine-tuned cancellation between the tree-level and one-loop contribution to the light neutrino masses. We quantify the level of fine-tuning as a function of the seesaw parameters and introduce a generalisation of the Casas-Ibarra parametrization of the neutrino Yukawa matrix, which easily allows to include the one-loop corrections to the light neutrino masses.
Lepton Flavour Violating Higgs Decays in the (SUSY) Inverse Seesaw
Arganda, E; Marcano, X; Weiland, C
2016-01-01
The observation of charged lepton flavour violation would be a smoking gun for new physics and could help in pinpointing the mechanism at the origin of neutrino masses and mixing. We present here our recent studies of lepton flavour violating Higgs decays in the inverse seesaw and its supersymmetric embedding, two examples of low-scale seesaw mechanisms. We predict branching ratios as large as $10^{-5}$ for the decays $h\\rightarrow \\tau \\mu$ and $h \\rightarrow \\tau e$ in the inverse seesaw, which can be probed in future colliders. Supersymmetric contributions can enhance the branching ratio of $h\\rightarrow \\tau \\mu$ up to $1\\%$, making it large enough to explain the small excess observed by ATLAS and CMS.
TeV-scale Seesaw with Quintuplet Fermions
Kumericki, Kresimir; Radovcic, Branimir
2012-01-01
We propose a new seesaw model based on fermionic hypercharge zero weak quintuplet in conjunction with additional scalar quadruplet which attains an induced vev. The model provides both tree-level seesaw ~ v^6/M^5 and a loop-suppressed radiative ~ (1 / 16 \\pi^2) v^2/M contributions to active neutrino masses. The empirical masses m_\
A renormalizable supersymmetric SO(10) model
Chen, Ying-Kang
2015-01-01
A realistic grand unified model has never been constructed in the literature due to three major difficulties: the seesaw mechanism without spoiling gauge coupling unification, the doublet-triplet splitting and the proton decay suppression. We propose a renormalizable supersymmetric SO(10) model with all these difficulties solved naturally.
Lepton flavor violation in low-scale seesaw models: SUSY and non-SUSY contributions
Abada, A; Porod, W; Staub, F; Vicente, A; Weiland, C
2014-01-01
Taking the supersymmetric inverse seesaw mechanism as the explanation for neutrino oscillation data, we investigate charged lepton flavor violation in radiative and 3-body lepton decays as well as in neutrinoless $\\mu-e$ conversion in muonic atoms. In contrast to former studies, we take into account all possible contributions: supersymmetric as well as non-supersymmetric. We take CMSSM-like boundary conditions for the soft supersymmetry breaking parameters. We find several regions where cancellations between various contributions exist, reducing the lepton flavor violating rates by an order of magnitude compared to the case where only the dominant contribution is taken into account. This is in particular important for the correct interpretation of existing data as well as for estimating the reach of near future experiments where the sensitivity will be improved by one to two orders of magnitude. Moreover, we demonstrate that ratios like BR($\\tau\\to 3 \\mu$)/BR($\\tau\\to \\mu e^+ e^-$) can be used to determine wh...
Arbeláez, Carolina; Kovalenko, Sergey; Schmidt, Ivan
2016-01-01
We propose a predictive inert 2 Higgs doublet model, where the Standard Model (SM) symmetry is extended by $S_{4}\\otimes Z_{2}\\otimes Z_{12}$ and the field content is enlarged by extra scalar fields, charged exotic fermions and one heavy righthanded Majorana neutrino. Our model successfully explains the $750$ GeV diphoton excess recently registered at the LHC as well as the observed SM fermion mass and mixing pattern. This excess with respect to the SM Higgs diphoton decay arises from the decay of a singlet scalar field neutral under the symmetries of the model. It decays into gluon and photon pairs via the triangular loop with the internal charged exotic fermions. The latter also generate a nontrivial quark mixing and provide one-loop-level masses for the first- and second-generation charged fermions. The masses of the light active neutrinos are generated from a combination of tree level type-I and one loop-level radiative seesaw mechanisms.
$\\mu\\to e\\gamma$ in a supersymmetric radiative neutrino mass model
Hundi, Raghavendra Srikanth
2016-01-01
We have considered a supersymmetric version of the inert Higgs doublet model, whose motivation is to explain smallness of neutrino masses and existence of dark matter. In this supersymmetric model, due to the presence of discrete symmetries, neutrinos acquire masses at loop level. After computing these neutrino masses, in order to fit the neutrino oscillation data, we have shown that by tuning some supersymmetry breaking soft parameters of the model, neutrino Yukawa couplings can be unsuppressed. In the above mentioned parameter space, we have computed branching ratio of the decay $\\mu\\to e\\gamma$. To be consistent with the current experimental upper bound on $Br(\\mu\\to e\\gamma)$, we have obtained constraints on the right-handed neutrino mass of this model.
SuSeFLAV: A program for calculating supersymmetric spectra and lepton flavour violation
Indian Academy of Sciences (India)
Debtosh Chowdhury; Raghuveer Garani; Sudhir K Vempti
2012-10-01
The program $\\mathnormal{SuSeFLAV}$ is introduced for computing supersymmetric mass spectra with flavour violation in various supersymmetric breaking scenarios with/without see-saw mechanism. A short user guide summarizing the compilation, executables and the input files is provided.
Neutrino masses within the minimal supersymmetric Standard Model
Cvetic, M; Cvetic, Mirjam; Langacker, Paul
1992-01-01
We investigate the possibility of accommodating neutrino masses compatible with the MSW study of the Solar neutrino deficit within the minimal supersymmetric Standard Model. The ``gravity-induced'' seesaw mechanism based on an interplay of nonrenormalizable and renormalizable terms in the superpotential allows neutrino masses $m_\
CP Violation in the SUSY Seesaw Leptogenesis and Low Energy
Davidson, Sacha; Palorini, Federica; Rius, Nuria
2008-01-01
We suppose that the baryon asymmetry is produced by thermal leptogenesis (with flavour effects), at temperatures $\\sim 10^{9} - 10^{10}$ GeV, in the supersymmetric seesaw with universal and real soft terms. The parameter space is restricted by assuming that $l_\\alpha \\to l_\\beta \\gamma$ processes will be seen in upcoming experiments. We study the sensitivity of the baryon asymmetry to the phases of the lepton mixing matrix, and find that leptogenesis can work for any value of the phases. We also estimate the contribution to the electric dipole moment of the electron, arising from the seesaw, and find that it is (just) beyond the sensitivity of next generation experiments ($\\lsim 10^{-29} e$ cm). The fourteen dimensional parameter space is efficiently explored with a Monte Carlo Markov Chain, which concentrates on the regions of interest.
Energy Technology Data Exchange (ETDEWEB)
Kanemura, Shinya; Machida, Naoki [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Shindou, Tetsuo [Division of Liberal-Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Tokyo 163-8677 (Japan)
2014-11-10
We propose a simple model to explain neutrino mass, dark matter and baryogenesis based on the extended Higgs sector which appears in the low-energy effective theory of a supersymmetric gauge theory with confinement. We here consider the SU(2){sub H} gauge symmetry with three flavours of fundamental representations which are charged under the standard SU(3){sub C}×SU(2){sub L}×U(1){sub Y} symmetry and a new discrete Z{sub 2} symmetry. We also introduce a Z{sub 2}-odd right-handed neutrino superfield in addition to the standard model matter superfields. The low-energy effective theory below the confinement scale contains the Higgs sector with fifteen composite superfields, some of which are Z{sub 2}-odd. When the confinement scale is of the order of ten TeV, electroweak phase transition can be sufficiently of first order, which is required for successful electroweak baryogenesis. The lightest Z{sub 2}-odd particle can be a new candidate for dark matter, in addition to the lightest R-parity odd particle. Neutrino masses and mixings can be explained by the quantum effects of Z{sub 2}-odd fields via the one-loop and three-loop diagrams. We find a benchmark scenario of the model, where all the constraints from the current neutrino, dark matter, lepton flavour violation and LHC data are satisfied. Predictions of the model are shortly discussed.
Kanemura, Shinya; Shindou, Tetsuo
2014-01-01
We propose a simple model to explain neutrino mass, dark matter and baryogenesis based on the extended Higgs sector which appears in the low-energy effective theory of a supersymmetric gauge theory with confinement. We here consider the SU(2)$_H$ gauge symmetry with three flavours of fundamental representations which are charged under the standard SU(3)$_C\\times$ SU(2)$_L\\times$U(1)$_Y$ symmetry and a new discrete $Z_2$ symmetry. We also introduce $Z_2$-odd right-handed neutrino superfields in addition to the standard model matter superfields. The low-energy effective theory below the confinement scale contains the Higgs sector with fifteen composite superfields, some of which are $Z_2$-odd. When the confinement scale is of the order of ten TeV, electroweak phase transition can be sufficiently of first order, which is required for successful electroweak baryogenesis. The lightest $Z_2$-odd particle can be a new candidate for dark matter, in addition to the lightest $R$-parity odd particle. Neutrino masses and...
Supersymmetric classical cosmology
Escamilla-Rivera, Celia; Urena-Lopez, L Arturo
2010-01-01
In this work a supersymmetric cosmological model is analyzed in which we consider a general superfield action of a homogeneous scalar field supermultiplet interacting with the scale factor in a supersymmetric FRW model. There appear fermionic superpartners associated with both the scale factor and the scalar field, and classical equations of motion are obtained from the super-Wheeler-DeWitt equation through the usual WKB method. The resulting supersymmetric Einstein-Klein-Gordon equations contain extra radiation and stiff matter terms, and we study their solutions in flat space for different scalar field potentials. The solutions are compared to the standard case, in particular those corresponding to the exponential potential, and their implications for the dynamics of the early Universe are discussed in turn.
The Supersymmetric Particle Spectrum
Barger, V; Ohmann, P
1994-01-01
We examine the spectrum of supersymmetric particles predicted by grand unified theoretical (GUT) models where the electroweak symmetry breaking is accomplished radiatively. We evolve the soft supersymmetry breaking parameters according to the renormalization group equations (RGE). The minimization of the Higgs potential is conveniently described by means of tadpole diagrams. We present complete one-loop expressions for these minimization conditions, including contributions from the matter and the gauge sectors. We concentrate on the low $\\tan \\beta$ fixed point region (that provides a natural explanation of a large top quark mass) for which we find solutions to the RGE satisfying both experimental bounds and fine-tuning criteria. We also find that the constraint from the consideration of the lightest supersymmetric particle as the dark matter of the universe is accommodated in much of parameter space where the lightest neutralino is predominantly gaugino. The supersymmetric mass spectrum displays correlations...
Does the hierarchy problem set the seesaw scale?
Kuchimanchi, Ravi
2014-01-01
We find that minimizing the number of fine tuning relations in non-supersymmetric models can determine the scales at which gauge symmetries beyond the standard model must break. We show that B-L gauge symmetry of the minimal left-right symmetric model breaks at a scale 10^{15} GeV or higher, determined by the hierarchy problem and small quark mass ratios, provided parameters that break chiral or $\\mu-$symmetries are not fine-tuned. This provides the raison d'etre for the seesaw scale ~ 10^{15}GeV indicated by neutrino experiments.
Non-minimal supersymmetric models. LHC phenomenolgy and model discrimination
Energy Technology Data Exchange (ETDEWEB)
Krauss, Manuel Ernst
2015-12-18
It is generally agreed upon the fact that the Standard Model of particle physics can only be viewed as an effective theory that needs to be extended as it leaves some essential questions unanswered. The exact realization of the necessary extension is subject to discussion. Supersymmetry is among the most promising approaches to physics beyond the Standard Model as it can simultaneously solve the hierarchy problem and provide an explanation for the dark matter abundance in the universe. Despite further virtues like gauge coupling unification and radiative electroweak symmetry breaking, minimal supersymmetric models cannot be the ultimate answer to the open questions of the Standard Model as they still do not incorporate neutrino masses and are besides heavily constrained by LHC data. This does, however, not derogate the beauty of the concept of supersymmetry. It is therefore time to explore non-minimal supersymmetric models which are able to close these gaps, review their consistency, test them against experimental data and provide prospects for future experiments. The goal of this thesis is to contribute to this process by exploring an extraordinarily well motivated class of models which bases upon a left-right symmetric gauge group. While relaxing the tension with LHC data, those models automatically include the ingredients for neutrino masses. We start with a left-right supersymmetric model at the TeV scale in which scalar SU(2){sub R} triplets are responsible for the breaking of left-right symmetry as well as for the generation of neutrino masses. Although a tachyonic doubly-charged scalar is present at tree-level in this kind of models, we show by performing the first complete one-loop evaluation that it gains a real mass at the loop level. The constraints on the predicted additional charged gauge bosons are then evaluated using LHC data, and we find that we can explain small excesses in the data of which the current LHC run will reveal if they are actual new
The reheating era leptogenesis in models with seesaw mechanism
Hamada, Yuta; Yasuhara, Daiki
2016-01-01
Observed baryon asymmetry can be achieved not only by the decay of right-handed neutrinos but also by the scattering processes in the reheating era. In the latter scenario, new physics in high energy scale does not need to be specified, but only two types of the higher dimensional operator of the standard model particles are assumed in the previous work. In this paper, we examine the origin of the higher dimensional operators assuming models with a certain seesaw mechanism at the high energy scale. The seesaw mechanism seems to be a simple realization of the reheating era leptogenesis because the lepton number violating interaction is included. We show that the effective interaction giving CP violating phases is provided in the several types of models and also the reheating era leptogenesis actually works in such models. Additionally, we discuss a possibility for lowering the reheating temperature in the radiative seesaw models, where the large Yukawa coupling is naturally realized.
Observable $N-\\bar{N}$ oscillation, high-scale see-saw and origin of matter
Indian Academy of Sciences (India)
R N Mohapatra
2006-11-01
See-saw mechanism has been a dominant paradigm in the discussion of neutrino masses. We discuss how this idea can be tested via a baryon number violating process such as $N-\\bar{N}$ oscillation. Since the expected see-saw scale is high and the $N-\\bar{N}$ amplitude goes like $M_{R}^{-5}$, one might think that this process is not observable in realistic see-saw models for neutrino masses. In this talk I show that in supersymmetric models, the above conclusion is circumvented leading to an enhanced and observable rate for $N-\\bar{N}$ oscillation. I also discuss a new mechanism for baryogenesis in generic models for neutron-anti-neutron oscillation.
Supersymmetric unification at the millennium
Indian Academy of Sciences (India)
Charanjit S Aulakh
2000-07-01
We argue that the discovery of neutrino mass effects at super-Kamiokande implies a clear logical chain leading from the Standard Model, through the MSSM and the recently developed minimal left right supersymmetric models with a renormalizable see-saw mechanism for neutrino mass, to left right symmetric SUSY GUTS: in particular, SO(10) and SU(2)× SU(2) × SU(4). The progress in constructing such GUTS explicitly is reviewed and their testability/falsiﬁability by lepton ﬂavour violation and proton decay measurements emphasized. SUSY violations of the survival principle and the interplay between third generation Yukawa coupling uniﬁcation and the structurally stable IR attractive features of the RG ﬂow in SUSY GUTS are also discussed.
Sun, Siyuan
The ATLAS experiment at Large Hadron Collider (LHC) searches for experimental evidence of beyond the standard model physics at the TeV scale. As we collect more data at the LHC we continue to extend our sensitivity to these new phenomena, probing for the existence of increasingly massive particles. Despite this progress there are still regions of parameter space where constraints remain weak. One common region where we lack sensitivity is when the new BSM particle has a very small mass splitting between it and its decay products. The BSM particle then has little energy left over to give momenta to its decay products and the low momenta decay products are difficult to experimentally detect. These regions of small mass splitting are called compressed regions. We are able to gain sensitivity to these difficult regions by searching for new particles produced in conjunction with hard initial state radiation (ISR). The hard ISR boosts the new particle’s decay products and gives them momentum. This thesis covers t...
Khoury, Justin; Ovrut, Burt A
2011-01-01
Galileon theories are of considerable interest since they allow for stable violations of the null energy condition. Since such violations could have occurred during a high-energy regime in the history of our universe, we are motivated to study supersymmetric extensions of these theories. This is carried out in this paper, where we construct generic classes of N=1 supersymmetric Galileon Lagrangians. They are shown to admit non-equivalent stress-energy tensors and, hence, vacua manifesting differing conditions for violating the null energy condition. The temporal and spatial fluctuations of all component fields of the supermultiplet are analyzed and shown to be stable on a large number of such backgrounds. In the process, we uncover a surprising connection between conformal Galileon and ghost condensate theories, allowing for a deeper understanding of both types of theories.
Barranco, Alejandro
2012-01-01
We implement relativistic BCS superconductivity in N=1 supersymmetric field theories with a U(1)_R symmetry. The simplest model contains two chiral superfields with a Kahler potential modified by quartic terms. We study the phase diagram of the gap as a function of the temperature and the specific heat. The superconducting phase transition turns out to be first order, due to the scalar contribution to the one-loop potential. By virtue of supersymmetry, the critical curves depend logarithmically with the UV cutoff, rather than quadratically as in standard BCS theory. We comment on the difficulties in having fermion condensates when the chemical potential is instead coupled to a baryonic U(1)_B current. We also discuss supersymmetric models of BCS with canonical Kahler potential constructed by "integrating-in" chiral superfields.
Seesaw geometry and leptogenesis
Di Bari, P
2005-01-01
The representation of the seesaw orthogonal matrix in the complex plane establishes a graphical correspondence between neutrino mass models and geometrical configurations, particularly useful to study relevant aspects of leptogenesis. We first derive the CP asymmetry bound for hierarchical heavy neutrinos and then an expression for the effective leptogenesis phase, determining the conditions for maximal phase and placing a lower bound on the phase suppression for generic models. Reconsidering the lower bounds on the lightest right-handed (RH) neutrino mass M_1 and on the reheating temperature T_{reh}, we find that models where the lightest neutrino mass m_1 is dominated by one of the two heavier right-handed (RH) neutrinos, typically arising from connections with quark masses, undergo both phase suppression and strong wash-out such that M_1 (T_{reh})\\gtrsim 1.5\\times 10^{11} (2x10^{10}) GeV. The window 10^9 GeV \\lesssim M_1,T_{reh}\\lesssim 10^{10} GeV is accessible only for a class of models where m_1 is domi...
Lorentz violation in supersymmetric field theories.
Nibbelink, Stefan Groot; Pospelov, Maxim
2005-03-04
We construct supersymmetric Lorentz violating operators for matter and gauge fields. We show that in the supersymmetric standard model the lowest possible dimension for such operators is five, and therefore they are suppressed by at least one power of an ultraviolet energy scale, providing a possible explanation for the smallness of Lorentz violation and its stability against radiative corrections. Supersymmetric Lorentz noninvariant operators do not lead to modifications of dispersion relations at high energies thereby escaping constraints from astrophysical searches for Lorentz violation.
Bosonic seesaw mechanism in a classically conformal extension of the Standard Model
Haba, Naoyuki; Okada, Nobuchika; Yamaguchi, Yuya
2015-01-01
We suggest the so-called bosonic seesaw mechanism in the context of a classically conformal $U(1)_{B-L}$ extension of the Standard Model with two Higgs doublet fields. The $U(1)_{B-L}$ symmetry is radiatively broken via the Coleman-Weinberg mechanism, which also generates the mass terms for the two Higgs doublets through quartic Higgs couplings. Their masses are all positive but, nevertheless, the electroweak symmetry breaking is realized by the bosonic seesaw mechanism. Analyzing the renormalization group evolutions for all model couplings, we find that a large hierarchy among the quartic Higgs couplings, which is crucial for the bosonic seesaw mechanism to work, is dramatically reduced toward high energies. Therefore, the bosonic seesaw is naturally realized with only a mild hierarchy, if some fundamental theory, which provides the origin of the classically conformal invariance, completes our model at some high energy, for example, the Planck scale. We identify the regions of model parameters which satisfy ...
Haba, Naoyuki; Okada, Nobuchika; Yamaguchi, Yuya
2015-01-01
We suggest the so-called bosonic seesaw mechanism in the context of a classically conformal $U(1)_{B-L}$ extension of the Standard Model with two Higgs doublet fields. The $U(1)_{B-L}$ symmetry is radiatively broken via the Coleman-Weinberg mechanism, which also generates the mass terms for the two Higgs doublets through quartic Higgs couplings. Their masses are all positive but, nevertheless, the electroweak symmetry breaking is realized by the bosonic seesaw mechanism. We analyze the renormalization group evolutions for all model couplings, and find that a large hierarchy among the quartic Higgs couplings, which is crucial for the bosonic seesaw mechanism to work, is dramatically reduced toward high energies. Therefore, the bosonic seesaw is naturally realized with only a mild hierarchy, if some fundamental theory, which provides the origin of the classically conformal invariance, completes our model at some high energy, for example, the Planck scale. The requirements for the perturbativity of the running c...
Type I seesaw mechanism for quasi-degenerate neutrinos
Energy Technology Data Exchange (ETDEWEB)
Joshipura, Anjan S., E-mail: anjan@prl.res.i [Physical Research Laboratory, Navarangpura, Ahmedabad 380 009 (India); Patel, Ketan M., E-mail: kmpatel@prl.res.i [Physical Research Laboratory, Navarangpura, Ahmedabad 380 009 (India); Vempati, Sudhir K., E-mail: vempati@cts.iisc.ernet.i [Centre for High Energy Physics, Indian Inst. of Science, Bangalore 560 012 (India)
2010-06-21
We discuss symmetries and scenarios leading to quasi-degenerate neutrinos in type I seesaw models. The existence of degeneracy in the present approach is not linked to any specific structure for the Dirac neutrino Yukawa coupling matrix y{sub D} and holds in general. Basic input is the application of the minimal flavour violation principle to the leptonic sector. Generalizing this principle, we assume that the structure of the right-handed neutrino mass matrix is determined by y{sub D} and the charged lepton Yukawa coupling matrix y{sub l} in an effective theory invariant under specific groups G{sub F} contained in the full symmetry group of the kinetic energy terms. G{sub F} invariance also leads to specific structure for the departure from degeneracy. The neutrino mass matrix (with degenerate mass m{sub 0}) resulting after seesaw mechanism has a simple form M{sub {nu}{approx}m0}(I-py{sub l}y{sub l}{sup T}) in one particular scenario based on supersymmetry. This form is shown to lead to correct description of neutrino masses and mixing angles. The thermal leptogenesis after inclusion of flavour effects can account for the observed baryon asymmetry of the universe within the present scenario. Rates for lepton flavour violating processes can occur at observable levels in the supersymmetric version of the scenario.
Energy Technology Data Exchange (ETDEWEB)
Kang, Zhaofeng [Korea Institute for Advanced Study, School of Physics, Seoul (Korea, Republic of); Institute of Theoretical Physics, Chinese Academy of Sciences, Key Laboratory of Frontiers in Theoretical Physics, Beijing (China); Li, Jinmian [Institute of Theoretical Physics, Chinese Academy of Sciences, Key Laboratory of Frontiers in Theoretical Physics, Beijing (China); University of Adelaide, ARC Centre of Excellence for Particle Physics at the Terascale and CSSM, Department of Physics, Adelaide, SA (Australia); Li, Tianjun [Institute of Theoretical Physics, Chinese Academy of Sciences, Key Laboratory of Frontiers in Theoretical Physics, Beijing (China); University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Liu, Tao [University of Alberta, Department of Physics, Edmonton, Alberta (Canada); Yang, Jin Min [Institute of Theoretical Physics, Chinese Academy of Sciences, Key Laboratory of Frontiers in Theoretical Physics, Beijing (China)
2016-05-15
The maximal U(1){sub L} supersymmetric inverse seesaw mechanism (MLSIS) provides a natural way to relate asymmetric darkmatter (ADM)with neutrino physics. In this paper we point out that MLSIS is a natural outcome if one dynamically realizes the inverse seesaw mechanism in the next-to minimal supersymmetric standard model (NMSSM) via the dimension-five operator (N){sup 2}S{sup 2}/M{sub *}, with S the NMSSM singlet developing TeV scale VEV; it slightly violates lepton number due to the suppression by the fundamental scale M{sub *}, thus preserving U(1){sub L} maximally. The resulting sneutrino is a distinguishable ADM candidate, oscillating and favored to have weak scale mass. A fairly large annihilating cross section of such a heavy ADM is available due to the presence of singlet. (orig.)
Indian Academy of Sciences (India)
Ram Lal Awasthi
2016-02-01
The grand unification theories based on SO(10) gauge group have been at the centre of attraction to beyond Standard Model phenomenology. The SO(10) gauge symmetry may pass through several intermediate symmetries before breaking to Standard Model. Therefore some higher symmetries may occur at the experimentally reachable scales. This feature flourishes easily in non-supersymmetric models compared to supersymmetric ones. We find that certain breaking chains give tremendous predictions for the physics being explored at various particle physics experiments. Explanation to neutrino masses through TeV scale inverse see-saw is the driving theme of the models studied.
Ilinskii, K N; Melezhik, V S; Ilinski, K N; Kalinin, G V; Melezhik, V V
1994-01-01
We revise the sequences of SUSY for a cyclic adiabatic evolution governed by the supersymmetric quantum mechanical Hamiltonian. The condition (supersymmetric adiabatic evolution) under which the supersymmetric reductions of Berry (nondegenerated case) or Wilczek-Zee (degenerated case) phases of superpartners are taking place is pointed out. The analogue of Witten index (supersymmetric Berry index) is determined. As the examples of suggested concept of supersymmetric adiabatic evolution the Holomorphic quantum mechanics on complex plane and Meromorphic quantum mechanics on Riemann surface are considered. The supersymmetric Berry indexes for the models are calculated.
Astrophysical Constraints on the scale of Left-Right Symmetry in Inverse Seesaw Models
Borah, Debasish
2012-01-01
We revisit the recently studied supersymmetric gauged inverse seesaw model \\cite{An:2011uq} to incorporate astrophysical constraints on lightest supersymmetric particle (LSP) lifetime such that LSP constitutes the dark matter of the Universe. The authors in \\cite{An:2011uq} considered light sneutrino LSP that can play the role of inelastic dark matter (iDM) such that desired iDM mass splitting and tiny Majorana masses of neutrinos can have a common origin. Here we point out that due to spontaneous R-parity $(R_p = (-1)^{3(B-L)+2s})$ breaking in such generic supersymmetric gauged inverse seesaw models, LSP can not be perfectly stable but decays to standard model particles after non-renormalizable operators allowed by the gauge symmetry are introduced. We show that strong astrophysical constraints on LSP lifetime makes sneutrino dark matter more natural than standard neutralino dark matter. We also show that long-livedness of sneutrino dark matter constrains the left right symmetry breaking scale $M_R < 10^4...
Supersymmetric unification in the light of neutrino mass
Indian Academy of Sciences (India)
Charanjit S Aulakh
2000-04-01
We argue that with the discovery of neutrino mass effects at super-Kamiokande there is a clear logical chain leading from the standard model through the MSSM and the recently developed minimal left right supersymmetric models with a renormalizable see-saw mechanism for neutrino mass to left right symmetric SUSY GUTS: in particular, SO(10) and SU(2) × SU(2) × SU(4). The progress in constructing such GUTS explicitly is reviewed and their testability/falsiﬁability by proton decay measurements emphasized
Potential of a Linear Collider for Lepton Flavour Violation studies in the SUSY seesaw
Figueiredo, A J R; Romao, J C; Teixeira, A M
2013-01-01
We study the potential of an e+- e- Linear Collider for charged lepton flavour violation studies in a supersymmetric framework where neutrino masses and mixings are explained by a type-I seesaw. Focusing on e-mu flavour transitions, we evaluate the background from standard model and supersymmetric charged currents to the e mu + missing E_T signal. We study the energy dependence of both signal and background, and the effect of beam polarisation in increasing the signal over background significance. Finally, we consider the mu- mu- + missing E_T final state in e- e- collisions that, despite being signal suppressed by requiring two e-mu flavour transitions, is found to be a clear signature of charged lepton flavour violation due to a very reduced standard model background.
Babu, K S; 10.1103/PhysRevD.68.035004
2003-01-01
The extended supersymmetric standard model (ESSM), motivated on several grounds, introduces two vectorlike families (16+16) of SO(10) with masses of the order of one TeV. It is noted that the successful predictions of prior work on fermion masses and mixings, based on the MSSM embedded in SO(10), can be retained rather simply within the ESSM extension. These include an understanding of the smallness of V /sub cb/ approximately=0.04 and the largeness of the nu /sub mu /- nu /sub tau / oscillation angle, sin/sup 2/2 theta /sub nu ( mu ) nu ( tau )//sup osc/ approximately=1. We analyze the new contributions arising through the exchange of the vectorlike families of the ESSM to radiative processes including tau to mu gamma , mu to e gamma , b to s gamma , the EDM of the muon and the muon (g-2). We show that the ESSM makes significant contributions especially to the decays tau to mu gamma and mu to e gamma and simultaneously to muon (g-2). For a large and plausible range of relevant parameters, we obtain a/sub mu ...
Testable Baryogenesis in Seesaw Models
Hernández, P; López-Pavón, J; Racker, J; Salvado, J
2016-01-01
We revisit the production of baryon asymmetries in the minimal type I seesaw model with heavy Majorana singlets in the GeV range. In particular we include for the first time "washout" effects from scattering processes with gauge bosons and higgs decays and inverse decays, besides the dominant top scatterings. We show that in the minimal model with two singlets, and for an inverted light neutrino ordering, future measurements from SHiP and neutrinoless double beta decay could in principle provide sufficient information to predict the matter-antimatter asymmetry in the universe up to a sign. We also show that SHiP measurements could provide very valuable information on the PMNS CP phases.
Perturbativity in the seesaw mechanism
Directory of Open Access Journals (Sweden)
Takehiko Asaka
2016-02-01
Full Text Available We consider the Standard Model extended by right-handed neutrinos to explain massive neutrinos through the seesaw mechanism. The new fermion can be observed when it has a sufficiently small mass and large mixings to left-handed neutrinos. If such a particle is the lightest right-handed neutrino, its contribution to the mass matrix of active neutrinos needs to be canceled by that of a heavier one. Yukawa couplings of the heavier one are then larger than those of the lightest one. We show that the perturbativity condition gives a severe upper bound on the mixing of the lightest right-handed neutrino, depending on the masses of heavier ones. Models of high energy phenomena, such as leptogenesis, can be constrained by low energy experiments.
Seesaw Mechanism with Occam's Razor
Harigaya, Keisuke; Yanagida, Tsutomu T
2012-01-01
We discuss the seesaw mechanism which includes the minimum number of pa- rameters for successful leptogenesis and three neutrino oscillations in the spirit of Occam's razor. We show that models with two right-handed neutrinos with two texture zeros supported by Occam's razor cannot fit the observed neutrino param- eters consistently for the normal light neutrino mass hierarchy. For the inverted light neutrino mass hierarchy, on the other hand, we find that the models can fit the observed neutrino parameters consistently. Besides, we show that the model predicts the maximal Dirac CP-phase of the neutrino mixing matrix in the mea- surable range in the foreseeable future for the inverted neutrino mass hierarchy. We also show that the predicted effective Majorana neutrino mass responsible for the neutrinoless double beta decay is around 50 meV which is also within reach of future experiments.
Supersymmetric Displaced Number States
Directory of Open Access Journals (Sweden)
Fredy R. Zypman
2015-06-01
Full Text Available We introduce, generate and study a family of supersymmetric displaced number states (SDNS that can be considered generalized coherent states of the supersymmetric harmonic oscillator. The family is created from the seminal supersymmetric boson-fermion entangling annihilation operator introduced by Aragone and Zypman and later expanded by Kornbluth and Zypman. Using the momentum representation, the states are obtained analytically in compact form as displaced supersymmetric number states. We study their position-momentum uncertainties, and their bunchiness by classifying them according to their Mandel Q-parameter in phase space. We were also able to find closed form analytical representations in the space and number basis.
Supersymmetric Open Wilson Lines
Baker, Edward B
2011-01-01
In this paper we study Open Wilson Lines (OWL's) in the context of two Supersymmetric Yang Mills theories. First we consider four dimensional N=2 Supersymmetric Yang Mills Theory with hypermultiplets transforming in the fundamental representation of the gauge group, and find supersymmetric OWL's only in the superconformal versions of these theories. We then consider four dimensional N=4 SYM coupled to a three dimensional defect hypermultiplet. Here there is a semi-circular supersymmetric OWL, which is related to the ray by a conformal transformation. We perform a perturbative calculation of the operators in both theories, and discuss using localization to compute them non-perturbatively.
SUSY see-saw and NMSO(10)GUT inflation after BICEP2
Indian Academy of Sciences (India)
Ila Garg
2016-02-01
Supersymmetric see-saw slow roll inflection point inflation occurs along a MSSM -flat direction associated with gauge invariant combination of Higgs, slepton and right-handed sneutrino at a scale set by the right-handed neutrino mass c ∼ 106−1013 GeV. The tensor to scalar perturbation ratio ∼ 10−3 can be achieved in this scenario. However, this scenario faced difficulty in being embedded in the realistic new minimal supersymmetric SO(10) grand unified theory (NMSO(10)GUT). The recent discovery of B-mode polarization by BICEP2, changes the prospects of NMSO(10)GUT inflation. Inflection point models become strongly disfavoured, as the trilinear coupling of SUSY see-saw inflation potential gets suppressed relative to the mass parameter favoured by BICEP2. Large values of ≈ 0.2 can be achieved with super-Planck scale inflaton values and mass scales of inflaton ≥1013 GeV. In NMSO(10)GUT, this can be made possible with an admixture of heavy Higgs doublet fields, i.e., other than MSSM Higgs field, which are present and have masses of order GUT scale.
A minimum thermodynamic model for the bipolar seesaw
DEFF Research Database (Denmark)
Stocker, Thomas F.; Johnsen, Sigfus Johann
2003-01-01
Bipolar seesaw, synchronization of Antarctic and Greenland ice cores, Dansgaard-Oeschger events, north-south connection......Bipolar seesaw, synchronization of Antarctic and Greenland ice cores, Dansgaard-Oeschger events, north-south connection...
Supersymmetric non conservative systems
Martínez-Pérez, N E
2015-01-01
We give the generalization of a recent variational formulation for nonconservative classical mechanics, for fermionic and sypersymmetric systems. Both cases require slightly modified boundary conditions. The supersymmetric version is given in the superfield formalism. The corresponding Noether theorem is formulated. As expected, like the energy, the supersymmetric charges are not conserved. Examples are discussed.
Directory of Open Access Journals (Sweden)
Shivani Gupta
2015-04-01
Full Text Available We examine the renormalization group evolution (RGE for different mixing scenarios in the presence of seesaw threshold effects from high energy scale (GUT to the low electroweak (EW scale in the Standard Model (SM and Minimal Supersymmetric Standard Model (MSSM. We consider four mixing scenarios namely Tri–Bimaximal Mixing, Bimaximal Mixing, Hexagonal Mixing and Golden Ratio Mixing which come from different flavor symmetries at the GUT scale. We find that the Majorana phases play an important role in the RGE running of these mixing patterns along with the seesaw threshold corrections. We present a comparative study of the RGE of all these mixing scenarios both with and without Majorana CP phases when seesaw threshold corrections are taken into consideration. We find that in the absence of these Majorana phases both the RGE running and seesaw effects may lead to θ13<5° at low energies both in the SM and MSSM. However, if the Majorana phases are incorporated into the mixing matrix the running can be enhanced both in the SM and MSSM. Even by incorporating non-zero Majorana CP phases in the SM, we do not get θ13 in its present 3σ range. The current values of the two mass squared differences and mixing angles including θ13 can be produced in the MSSM case with tanβ=10 and non-zero Majorana CP phases at low energy. We also calculate the order of effective Majorana mass and Jarlskog Invariant for each scenario under consideration.
Energy Technology Data Exchange (ETDEWEB)
Fuks, B
2007-06-15
Cross sections for supersymmetric particles production at hadron colliders have been extensively studied in the past at leading order and also at next-to-leading order of perturbative QCD. The radiative corrections include large logarithms which have to be re-summed to all orders in the strong coupling constant in order to get reliable perturbative results. In this work, we perform a first and extensive study of the resummation effects for supersymmetric particle pair production at hadron colliders. We focus on Drell-Yan like slepton-pair and slepton-sneutrino associated production in minimal supergravity and gauge-mediated supersymmetry-breaking scenarios, and present accurate transverse-momentum and invariant-mass distributions, as well as total cross sections. In non-minimal supersymmetric models, novel effects of flavour violation may occur. In this case, the flavour structure in the squark sector cannot be directly deduced from the trilinear Yukawa couplings of the fermion and Higgs supermultiplets. We perform a precise numerical analysis of the experimentally allowed parameter space in the case of minimal supergravity scenarios with non-minimal flavour violation, looking for regions allowed by low-energy, electroweak precision, and cosmological data. Leading order cross sections for the production of squarks and gauginos at hadron colliders are implemented in a flexible computer program, allowing us to study in detail the dependence of these cross sections on flavour violation. (author)
Littlest Seesaw model from S 4 × U(1)
King, Stephen F.; Luhn, Christoph
2016-09-01
We show how a minimal (littlest) seesaw model involving two right-handed neutrinos and a very constrained Dirac mass matrix, with one texture zero and two independent Dirac masses, may arise from S 4 ×U(1) symmetry in a semi-direct supersymmetric model. The resulting CSD3 form of neutrino mass matrix only depends on two real mass parameters plus one undetermined phase. We show how the phase may be fixed to be one of the cube roots of unity by extending the S 4 × U(1) symmetry to include a product of Z 3 factors together with a CP symmetry, which is spontaneously broken leaving a single residual Z 3 in the charged lepton sector and a residual Z 2 in the neutrino sector, with suppressed higher order corrections. With the phase chosen from the cube roots of unity to be -2π /3, the model predicts a normal neutrino mass hierarchy with m 1 = 0, reactor angle θ 13 = 8 .7°, solar angle θ 12 = 34°, atmospheric angle θ 23 = 44°, and CP violating oscillation phase δ CP = -93°, depending on the fit of the model to the neutrino masses.
Bosonic-Seesaw Portal Dark Matter
Ishida, Hiroyuki; Yamaguchi, Yuya
2016-01-01
We propose a new type of Higgs-portal dark matter-production mechanism, called bosonic-seesaw portal scenario. Bosonic seesaw provides the dynamical origin of the electroweak symmetry breaking, triggered by mixing between the elementary Higgs and a composite Higgs generated by a new-color strong dynamics (hypercolor) which dynamically breaks the classical-scale invariance of the model. The composite hypercolor-baryonic matter can then be a dark matter candidate, which significantly couples to the standard-model Higgs via the bosonic seesaw, and can be produced from the thermal plasma below the decoupling temperature around the new strong coupling scale, to account for the observed relic abundance of the dark matter: the dark matter can closely be related to the mechanism of the electroweak symmetry breaking.
Institute of Scientific and Technical Information of China (English)
2016-01-01
面对星巴克的不断扩张,seesaw coffee该如何调整战略.本文通过pestle,swot分析对seesaw coffee成功的原因进行了内外部分析,并研究了seesaw的竞争者——星巴克,通过对其财务报表分析,得出星巴克目前的经营状况、整体的产业市场环境以及大致战略方向,基于此,seesaw coffee该如何调整现有的战略以适应当前的市场环境.
Supersymmetric invariant theories
Esipova, S R; Radchenko, O V
2013-01-01
We study field models for which a quantum action (i.e. the action appearing in the generating functional of Green functions) is invariant under supersymmetric transformations. We derive the Ward identity which is direct consequence of this invariance. We consider a change of variables in functional integral connected with supersymmetric transformations when its parameter is replaced by a nilpotent functional of fields. Exact form of the corresponding Jacobian is found. We find restrictions on generators of supersymmetric transformations when a consistent quantum description of given field theories exists.
Supersymmetric invariant theories
Esipova, S. R.; Lavrov, P. M.; Radchenko, O. V.
2014-04-01
We study field models for which a quantum action (i.e. the action appearing in the generating functional of Green functions) is invariant under supersymmetric transformations. We derive the Ward identity which is a direct consequence of this invariance. We consider a change of variables in functional integral connected with supersymmetric transformations when its parameter is replaced by a nilpotent functional of fields. Exact form of the corresponding Jacobian is found. We find restrictions on generators of supersymmetric transformations when a consistent quantum description of given field theories exists.
Electroweak breaking in supersymmetric models
Ibáñez, L E
1992-01-01
We discuss the mechanism for electroweak symmetry breaking in supersymmetric versions of the standard model. After briefly reviewing the possible sources of supersymmetry breaking, we show how the required pattern of symmetry breaking can automatically result from the structure of quantum corrections in the theory. We demonstrate that this radiative breaking mechanism works well for a heavy top quark and can be combined in unified versions of the theory with excellent predictions for the running couplings of the model. (To be published in ``Perspectives in Higgs Physics'', G. Kane editor.)
Neutrino Physics in the Seesaw Model
Broncano, A; Jenkins, E
2003-01-01
The seesaw model of heavy and light Majorana neutrinos and its low-energy effective theory are studied, when the number of heavy neutrinos is equal to or less than the number of light lepton generations. We establish a general relationship between the high-energy parameters and the low-energy observables involving only the light fields. It is shown how low-energy measurements of the properties of light neutrinos suffice a priori to determine all couplings of the unobserved heavy neutrinos. CP violation is present in low-energy processes if seesaw-model leptogenesis creates the matter-antimatter asymmetry of the universe.
Neutrino physics in the seesaw model
Energy Technology Data Exchange (ETDEWEB)
Broncano, A. E-mail: alicia.broncano@uam.es; Gavela, M.B. E-mail: gavela@delta.ft.uam.es; Jenkins, E. E-mail: ejenkins@ucsd.edu
2003-11-10
The seesaw model of heavy and light Majorana neutrinos and its low-energy effective theory are studied, when the number of heavy neutrinos is equal to or less than the number of light lepton generations. We establish a general relationship between the high-energy parameters and the low-energy observables involving only the light fields. It is shown how low-energy measurements of the properties of light neutrinos suffice a priori to determine all couplings of the unobserved heavy neutrinos. CP violation is present in low-energy processes if seesaw-model leptogenesis creates the matter-antimatter asymmetry of the universe.
Discrete flavor symmetry and minimal seesaw mechanism
Nam, K H; Siyeon, Kim
2011-01-01
This work proposes a neutrino mass model that is derived using the minimal seesaw mechanism which contains only two right-handed neutrinos, under the non-abelian discrete flavor symmetry $\\mathbb{S}_4\\otimes\\mathbb{Z}_2$. Two standard model doublets, $L_\\mu$ and $L_\\tau$, are assigned simultaneously to a $\\mathbf{2}$ representation of $\\mathbb{S}_4$. When the scalar fields introduced in this model, addition to the Standard Model Higgs, and the leptons are coupled within the symmetry, the seesaw mechanism results in the tri-bi-maximal neutrino mixing. This study examined the possible deviations from TBM mixing related to the experimental data.
Supersymmetric Color Superconductivity
Harnik, R; Murayama, H; Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi
2004-01-01
Recent interest in novel phases in high density QCD motivates the study of high density supersymmetric QCD (SQCD), where powerful exact results for supersymmetric gauge theories can be brought to bear in the strongly coupled regime. We begin by describing how a chemical potential can be incorporated into a supersymmetric theory as a spurion vector superfield. We then study supersymmetric SU(N_c) gauge theories with N_f flavors of quarks in the presence of a baryon chemical potential mu, and describe the global symmetry breaking patterns at low energy. Our analysis requires mu mu_c. We also give a qualitative description of the phases in the `conformal window', 3/2 N_c < N_f < 3N_c, at finite density.
Energy Technology Data Exchange (ETDEWEB)
Bagger, J.A.
1984-09-01
We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model.
Renormalization of supersymmetric theories
Energy Technology Data Exchange (ETDEWEB)
Pierce, D.M.
1998-06-01
The author reviews the renormalization of the electroweak sector of the standard model. The derivation also applies to the minimal supersymmetric standard model. He discusses regularization, and the relation between the threshold corrections and the renormalization group equations. He considers the corrections to many precision observables, including M{sub W} and sin{sup 2}{theta}{sup eff}. He shows that global fits to the data exclude regions of supersymmetric model parameter space and lead to lower bounds on superpartner masses.
Renormalizability of Supersymmetric Group Field Cosmology
Upadhyay, Sudhaker
2014-01-01
In this paper we consider the gauge invariant third quantized model of supersymmetric group field cosmology. The supersymmetric BRST invariance for such theory in non-linear gauge is also analysed. The path integral formulation to the case of a multiverse made up of homogeneous and isotropic spacetimes filled with a perfect fluid is presented. The renormalizability for the scattering of universes in multiverse are established with suitably constructed master equations for connected diagrams and proper vertices. The Slavnov-Taylor identities for this theory hold to all orders of radiative corrections.
Renormalizability of supersymmetric group field cosmology
Upadhyay, Sudhaker
2014-03-01
In this paper we consider the gauge invariant third quantized model of supersymmetric group field cosmology. The supersymmetric BRST invariance for such theory in non-linear gauge is also analysed. The path integral formulation to the case of a multiverse made up of homogeneous and isotropic spacetimes filled with a perfect fluid is presented. The renormalizability for the scattering of universes in multiverse are established with suitably constructed master equations for connected diagrams and proper vertices. The Slavnov-Taylor identities for this theory hold to all orders of radiative corrections.
Supersymmetric color superconductivity
Energy Technology Data Exchange (ETDEWEB)
Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi
2003-09-18
Recent interest in novel phases in high density QCD motivates the study of high density supersymmetric QCD (SQCD), where powerful exact results for supersymmetric gauge theories can be brought to bear in the strongly coupled regime. We begin by describing how a chemical potential can be incorporated into a supersymmetric theory as a spurion vector superfield. We then study supersymmetric SU(N{sub c}) gauge theories with N{sub f} flavors of quarks in the presence of a baryon chemical potential {mu}, and describe the global symmetry breaking patterns at low energy. Our analysis requires {mu} < {Lambda} and is thus complementary to the variational approach that has been successful for {mu} >> {Lambda}. We find that for N{sub F} < N{sub c} a modified U(1){sub B} symmetry is preserved, analogous to the non-supersymmetric 2SC phase, whereas for N{sub f} = N{sub c} there is a critical chemical potential above which the U(1){sub B} is broken, as it is in the non-supersymmetric CFL phase. We further analyze the cases with N{sub c} + 1 {le} N{sub f} < 3/2 N{sub c} and find that baryon number is broken dynamically for {mu} > {mu}{sub c}. We also give a qualitative description of the phases in the ''conformal window'', 3/2 N{sub c} < N{sub f} < 3N{sub c}, at finite density.
Novel seesaw mechanism with vectorlike TeV-scale 5-plet
Picek, Ivica
2009-01-01
We propose novel tree level seesaw mechanism from dimension-nine operator, mediated by vectorlike fermion 5-plet of hypercharge zero in conjunction with additional isospin 3/2 scalar multiplet. In contrast to Majorana seesaw mediators in type I and type III seesaw, here Dirac seesaw mediators produce Majorana masses of light neutrinos. Due to new seesaw formula m_\
Renormalization of seesaw neutrino masses in the standard model with two-Higgs doublets
Indian Academy of Sciences (India)
N Nimai Singh; S Biramani Singh
2000-02-01
Using the theoretical ambiguities inherent in the seesaw mechanism, we derive the new analytic expressions for both quadratic and linear seesaw formulae for neutrino masses at low energies, with either up-type quark masses or charged lepton masses. This is possible through full radiative corrections arising out of the renormalizations of the Yukawa couplings, the coefﬁcients of the neutrino-mass-operator in the standard model with two-Higgs doublets, and also the QCD–QED rescaling factors below the top-quark mass scale, at one-loop level. We also investigate numerically the uniﬁcation of top-- Yukawa couplings at the scale =0.59× 108GeV for a ﬁxed value of tan =58.77, and then evaluate the seesaw neutrino masses which are too large in magnitude to be compatible with the presently available solar and atmospheric neutrino oscillation data. However, if we consider a higher but arbitrary value of =0.59× 1011GeV, the predictions from linear seesaw formulae with charged lepton masses, can accommodate simultaneousely both solar atmospheric neutrino oscillation data.
Bosonic seesaw mechanism in a classically conformal extension of the Standard Model
Directory of Open Access Journals (Sweden)
Naoyuki Haba
2016-03-01
Full Text Available We suggest the so-called bosonic seesaw mechanism in the context of a classically conformal U(1B−L extension of the Standard Model with two Higgs doublet fields. The U(1B−L symmetry is radiatively broken via the Coleman–Weinberg mechanism, which also generates the mass terms for the two Higgs doublets through quartic Higgs couplings. Their masses are all positive but, nevertheless, the electroweak symmetry breaking is realized by the bosonic seesaw mechanism. Analyzing the renormalization group evolutions for all model couplings, we find that a large hierarchy among the quartic Higgs couplings, which is crucial for the bosonic seesaw mechanism to work, is dramatically reduced toward high energies. Therefore, the bosonic seesaw is naturally realized with only a mild hierarchy, if some fundamental theory, which provides the origin of the classically conformal invariance, completes our model at some high energy, for example, the Planck scale. We identify the regions of model parameters which satisfy the perturbativity of the running couplings and the electroweak vacuum stability as well as the naturalness of the electroweak scale.
Neutrino Mass Seesaw Version 3: Recent Developments
Ma, Ernest
2009-01-01
The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet (version 3) has gained some attention. This is a review of the basic idea involved, its U(1) gauge extension, and some recent developments.
Massive and massless neutrinos on unbalanced seesaws
Institute of Scientific and Technical Information of China (English)
XING Zhi-Zhong
2008-01-01
The observation of neutrino oscillations requires new physics beyond the standard model (SM).A SM-like gauge theory with p lepton families can be extended by introducing q heavy right-handed Majorana neutrinos but preserving its SU(2)L x U(1)y gauge symmetry.The overall neutrino mass matrix M turns out to be a symmetric (p+q) x (p+q) matrix.Given p＞q,the rank of M is in general equal to 2q,corresponding to 2q non-zero mass eigenvalues.The existence of (p-q) massless left-handed Majorana neutrinos is an exact consequence of the model,independent of the usual approximation made in deriving the Type-I seesaw relation between the effective p x p light Majorana neutrino mass matrix M,and the q x q heavy Majorana neutrino mass matrix MR.In other words,the numbers of massive left- and right-handed neutrinos are fairly matched.A good example to illustrate this "seesaw fair play rule"is the minimal seesaw model with p ＝ 3 and q ＝ 2,in which one masslese neutrino sits on the unbalanced seesaw.
Leptogenesis in minimal predictive seesaw models
Björkeroth, Fredrik; Varzielas, Ivo de Medeiros; King, Stephen F
2015-01-01
We estimate the Baryon Asymmetry of the Universe (BAU) arising from leptogenesis within a class of minimal predictive seesaw models involving two right-handed neutrinos and simple Yukawa structures with one texture zero. The two right-handed neutrinos are dominantly responsible for the "atmospheric" and "solar" neutrino masses with Yukawa couplings to $(\
The gravitino problem in supersymmetric warm inflation
Sanchez, Juan C Bueno; Berera, Arjun; Dimopoulos, Konstantinos; Kohri, Kazunori
2010-01-01
The warm inflation paradigm considers the continuous production of radiation during inflation due to dissipative effects. In its strong dissipation limit, warm inflation gives way to a radiation dominated Universe. High scale inflation then yields a high reheating temperature, which then poses a severe gravitino overproduction problem for the supersymmetric realisations of warm inflation. In this paper we show that in certain class of supersymmetric models the dissipative dynamics of the inflaton is such that the field can avoid its complete decay after inflation. In some cases, the residual energy density stored in the field oscillations may come to dominate over the radiation bath at a later epoch. If the inflaton field finally decays much later than the onset of the matter dominated phase, the entropy produced in its decay may be sufficient to counteract the excess of gravitinos produced during the last stages of warm inflation.
Neutrino Oscillations, SUSY See-Saw Mechanism and Charged Lepton Flavor Violation
Deppisch, F; Redelbach, A; Rückl, R; Shimizu, Y
2003-01-01
Neutrino oscillations give clear evidence for non-vanishing neutrino masses and lepton-flavor violation (LFV) in the neutrino sector. This provides strong motivation to search for signals of LFV also in the charged lepton sector, and to probe the SUSY see-saw mechanism. We compare the sensitivity of rare radiative decays on the right-handed Majorana mass scale M_R with the reach in slepton-pair production at a future linear collider.
Planarizable Supersymmetric Quantum Toboggans
Directory of Open Access Journals (Sweden)
Miloslav Znojil
2011-02-01
Full Text Available In supersymmetric quantum mechanics the emergence of a singularity may lead to the breakdown of isospectrality between partner potentials. One of the regularization recipes is based on a topologically nontrivial, multisheeted complex deformations of the line of coordinate x giving the so called quantum toboggan models (QTM. The consistent theoretical background of this recipe is briefly reviewed. Then, certain supersymmetric QTM pairs are shown exceptional and reducible to doublets of non-singular ordinary differential equations a.k.a. Sturm-Schrödinger equations containing a weighted energy E→EW(x and living in single complex plane.
Supersymmetric Optical Structures
Miri, Mohammad-Ali; El-Ganainy, Ramy; Christodoulides, Demetrios N
2013-01-01
We show that supersymmetry can provide a versatile platform in synthesizing a new class of optical structures with desired properties and functionalities. By exploiting the intimate relationship between superpatners, one can systematically construct index potentials capable of exhibiting the same scattering and guided wave characteristics. In particular, in the Helmholtz regime, we demonstrate that one-dimensional supersymmetric pairs display identical reflectivities and transmittivities for any angle of incidence. Optical SUSY is then extended to two-dimensional systems where a link between specific azimuthal mode subsets is established. Finally we explore supersymmetric photonic lattices where discreteness can be utilized to design lossless integrated mode filtering arrangements.
Koehn, Michael
2015-01-01
In supersymmetric theories, topological defects can have nontrivial behaviors determined purely by whether or not supersymmetry is restored in the defect core. A well-known example of this is that some supersymmetric cosmic strings are automatically superconducting, leading to important cosmological effects and constraints. We investigate the impact of nontrivial kinetic interactions, present in a number of particle physics models of interest in cosmology, on the relationship between supersymmetry and supercurrents on strings. We find that in some cases it is possible for superconductivity to be disrupted by the extra interactions.
A Simple Realization of the Inverse Seesaw Mechanism
Dias, A G; da Silva, P S Rodrigues; Sampieri, A
2012-01-01
Differently from the canonical seesaw mechanism, which is grounded in grand unified theories, the inverse seesaw mechanism lacks a special framework that realizes it naturally. In this work we advocate that the 3-3-1 model with right-handed neutrinos has such an appropriate framework to accommodate the inverse seesaw mechanism. We also provide an explanation for the smallness of the $\\mu$ parameter and estimate the branching ratio for the rare lepton flavor violation process $\\mu \\rightarrow e\\gamma$.
On the decoupling of heavy sneutrinos in low-scale seesaw models
Krauss, Manuel E; Staub, Florian; Abada, Asmaa; Vicente, Avelino; Weiland, Cédric
2013-01-01
There have been some recent claims in the literature about large right-handed sneutrinos contributions to lepton flavor violating observables like $\\mu \\to 3e$ or $\\mu - e$ conversion in nuclei in supersymmetric low-scale seesaw models. These large contributions originate from $Z$-penguin diagrams which show a much weaker dependence on the heavy masses than the photonic contributions. We have traced this to an error in the evaluation of the corresponding loop amplitudes which has propagated in the literature. We explicitly show that after correcting this mistake the $Z$-penguins show the expected decoupling behavior. Moreover, the reported dominance of the $Z$-penguin over the photonic contributions disappears as well.
Fair scans of the seesaw. Consequences for predictions on LFV processes
Casas, J Alberto; Rius, Nuria; de Austri, Roberto Ruiz; Zaldivar, Bryan
2010-01-01
Usual analyses based on scans of the seesaw parameter-space can be biassed since they do not cover in a fair way the complete parameter-space. More precisely, we show that in the common "R-parametrization", many acceptable R-matrices, compatible with the perturbativity of Yukawa couplings, are normally disregarded from the beginning, which produces biasses in the results. We give a straightforward procedure to scan the space of complex R-matrices in a complete way, giving a very simple rule to incorporate the perturbativity requirement as a condition for the entries of the R-matrix, something not considered before. As a relevant application of this, we show that the extended believe that BR(mu --> e, gamma) in supersymmetric seesaw models depends strongly on the value of theta_13 is an "optical effect" produced by such biassed scans, and does not hold after a careful analytical and numerical study. When the complete scan is done, BR(mu --> e, gamma) gets very insensitive to theta_13. Moreover, the values of t...
Extended SUSY SU(5) predicting type-III seesaw testable at LHC
Awasthi, Ram Lal
2013-01-01
We propose an extension of the SUSY SU(5) which predicts LHC testable type-III seesaw. The supersymmetric SU(5) GUT model is extended by adding a 24-plet matter superfield along with a pair of $10_H$-plet and $\\bar{10}_H$-plet Higgs superfields. The 24-plet carries a triplet and a singlet fermion multiplet of SU(2)$_L$, which leads to type I+III seesaw. The additional $10_H$ (and $\\bar{10}_H$) multiplets help in achieving gauge coupling unification while keeping the triplet fermion mass in the TeV range, making them accessible at LHC. We study the phenomenology of this model in detail. Large lepton flavor violation predicted in this model puts severe constraints on the Yukawa couplings of the triplet fermion. We show that this smothers the possibility of observing the contribution of the heavy fermions in neutrinoless double beta decay experiments. The presence of the additional $10_H$ and $\\bar{10}_H$ in this model not only gives gauge coupling unification, it also leads to very large lepton flavor violation...
On the gravitational seesaw and light bending
Accioly, Antonio; Shapiro, Ilya L
2016-01-01
Local gravitational theories with more than four derivatives are superrenormalizable, and also may be unitary in the Lee-Wick sense. It makes sense to study low-energy properties of these theories, e.g., identify observables which might be useful for experimental detection of higher derivatives. Using an analogy with neutrino Physics, we explore the possibility of a gravitational seesaw mechanism, in which several dimensional parameters of the same order of magnitude produce a hierarchy in the masses of propagating particles and make a relatively light degree of freedom detectable by frequency dependence in the gravitational light bending. It turns out that such a seesaw mechanism in the six- and more-derivative theories is unable to reduce the lightest mass more than in the simplest four-derivative model. Adding more derivatives can only make heavier masses even larger. This fact may be favorable for protecting the theory from instabilities, but makes experimental detection of higher derivatives more difficu...
Scalar dark matter with type II seesaw
Directory of Open Access Journals (Sweden)
Arnab Dasgupta
2014-12-01
Full Text Available We study the possibility of generating tiny neutrino mass through a combination of type I and type II seesaw mechanism within the framework of an abelian extension of standard model. The model also provides a naturally stable dark matter candidate in terms of the lightest neutral component of a scalar doublet. We compute the relic abundance of such a dark matter candidate and also point out how the strength of type II seesaw term can affect the relic abundance of dark matter. Such a model which connects neutrino mass and dark matter abundance has the potential of being verified or ruled out in the ongoing neutrino, dark matter, as well as accelerator experiments.
Dynamical seesaw mechanism for Dirac neutrinos
Directory of Open Access Journals (Sweden)
José W.F. Valle
2016-04-01
Full Text Available So far we have not been able to establish that, as theoretically expected, neutrinos are their own anti-particles. Here we propose a dynamical way to account for the Dirac nature of neutrinos and the smallness of their mass in terms of a new variant of the seesaw paradigm in which the energy scale of neutrino mass generation could be accessible to the current LHC experiments.
Awasthi, Ram Lal
2011-01-01
Recently realization of TeV scale inverse seesaw mechanism in supersymmetric SO(10) framework has led to a number of experimentally verifiable predictions including low-mass W_R and Z' gauge bosons and nonunitarity effects. Using nonsupersymmetric SO(10) grand unified theory, we show how a TeV scale inverse seesaw mechanism for neutrino masses is implemented with a low-mass Z' boson accessible to Large Hadron Collider. We derive renormalization group equations for fermion masses and mixings in the presence of the intermediate symmetries of the model and extract the Dirac neutrino mass matrix at the TeV scale from successful GUT-scale parameterization of fermion masses. We estimate leptonic nonunitarity effects measurable at neutrino factories and lepton flavor violating decays expected to be probed in near future. While our prediction on the nonunitarity matrix element $\\eta_{\\mu\\tau}$ for degenerate right-handed neutrinos is similar to the supersymmetric SO(10) case, we find new predictions with significantl...
Supersymmetric heterotic string backgrounds
Gran, U.; Papadopoulos, G.; Roest, D.; Cvetič, M.
2007-01-01
We present the main features of the solution of the gravitino and dilatino Killing spinor equations derived in hep-th/0510176 and hep-th/0703143 which have led to the classification of geometric types of all type I backgrounds. We then apply these results to the supersymmetric backgrounds of the het
Gudnason, Sven Bjarke; Sasaki, Shin
2015-01-01
Construction of a supersymmetric extension of the Skyrme term was a long-standing problem because of the auxiliary field problem; that is, the auxiliary field may propagate and cannot be eliminated, and the problem of having fourth-order time derivative terms. In this paper, we construct for the first time a supersymmetric extension of the Skyrme term in four spacetime dimensions, in the manifestly supersymmetric superfield formalism that does not suffer from the auxiliary field problem. Chiral symmetry breaking in supersymmetric theories results not only in Nambu-Goldstone (NG) bosons (pions) but also in the same number of quasi-NG bosons so that the low-energy theory is described by an SL(N,C)-valued matrix field instead of SU(N) for NG bosons. The solution of auxiliary fields is trivial on the canonical branch of the auxiliary field equation, in which case our model results in a fourth-order derivative term that is not the Skyrme term. For the case of SL(2,C), we find explicitly a nontrivial solution to th...
Low-energy lepton violation from supersymmetric flipped SU(5)
Brahm, David E.; Hall, Lawrence J.
1989-10-01
We construct a supersymmetric flipped SU(5)⊗U(1) model which violates R parity and electron number at low energies, through a superpotential term (1/2CijkLiLjEck. Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the Cijk coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting Z0 decays are predicted: e.g., Z0-->e-μ+e+μ- with invariant-mass peaks in the (e,μ) channels.
Lepton flavor violating process in a supersymmetric grand unified theory with right-handed neutrino
Baek, S; Okada, Y; Okumura, K; Baek, Seungwon; Goto, Toru; Okada, Yasuhiro; Okumura, Ken-ichi
2001-01-01
Motivated from the recent results of neutrino oscillation experiment, we investigated lepton flavor violating (LFV) processes in a SU(5) supersymmetric grand unified theory with right-handed neutrino. The current experimental upper bound for $\\mu \\to e\\gamma$ process gives already some constraint on the model. Correlation between $\\mu \\to e \\gamma$ and the SUSY contribution to the muon anomalous magnetic moment is also discussed. Future LFV experiments will give considerable impacts on this type of SUSY GUT models equipped with seesaw neutrino mass generation.
Lepton flavor-violating process in a supersymmetric grand unified theory with right-handed neutrinos
Energy Technology Data Exchange (ETDEWEB)
Baek, Seungwon; Goto, Toru; Okada, Yasuhiro; Okumura, Ken-ichi E-mail: okumurak@icrr.u-tokyo.ac.jp
2003-05-01
Motivated by the recent results of neutrino oscillation experiments, we investigated lepton flavor-violating (LFV) processes in a SU(5) supersymmetric grand unified theory with right-handed neutrinos. The current experimental upper bound for the {mu}{yields}e{gamma} process already gives some constraint on the model. The correlation between {mu}{yields}e{gamma} and the SUSY contribution to the muon anomalous magnetic moment is also discussed. Future LFV experiments will have considerable impacts on this type of SUSY GUT model equipped with seesaw neutrino mass generation.
Borah, Debasish; Pritimita, Prativa
2014-01-01
We discuss a class of left-right symmetric models where the light neutrino masses originate dominantly from type I seesaw mechanism along with a sub-dominant type II seesaw contribution. The dominant type I seesaw gives rise to tri-bimaximal type neutrino mixing whereas sub-dominant type II seesaw acts as a small perturbation giving rise to non-zero $\\theta_{13}$ in our model which also has TeV scale right-handed neutrinos and $Z^\\prime$ gauge boson thereby making the model verifiable at current accelerator experiments. Sub-dominant type II and dominant type I seesaw can be naturally accommodated by allowing spontaneous breaking of D-parity and $SU(2)_R$ gauge symmetry at high scale and allowing TeV scale breaking of $U(1)_{R} \\times U(1)_{B-L}$ into $U(1)_Y$. We also embed the left-right model in a non-supersymmetric $SO(10)$ grand unified theory (GUT) with verifiable TeV scale $Z^\\prime$ gauge boson. Drawing it to an end, we scrutinize in detail the evaluation of one-loop renormalization group evolution for...
A model realizing inverse seesaw and resonant leptogenesis
Aoki, Mayumi; Takahashi, Ryo
2015-01-01
We construct a model realizing the inverse seesaw mechanism. The model has two types of gauge singlet fermions in addition to right-handed neutrinos. A required Majorana mass scale (keV scale) for generating the light active neutrino mass in the conventional inverse seesaw can be naturally explained by a "seesaw" mechanism between the two singlet fermions in our model. We find that our model can decrease the magnitude of hierarchy among mass parameters by $\\mathcal{O}(10^4)$ from that in the conventional inverse seesaw model. We also show that a successful resonant leptogenesis occurs for generating the baryon asymmetry of the universe in our model. The desired mass degeneracy for the resonant leptogenesis can also be achieved by the "seesaw" between the two singlet fermions.
Nearly Supersymmetric Dark Atoms
Energy Technology Data Exchange (ETDEWEB)
Behbahani, Siavosh R.; Jankowiak, Martin; /SLAC /Stanford U., ITP; Rube, Tomas; /Stanford U., ITP; Wacker, Jay G.; /SLAC /Stanford U., ITP
2011-08-12
Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions with the Standard Model communicate supersymmetry breaking to the dark sector. In these models supersymmetry breaking can be treated as a perturbation on the spectrum of bound states. Using a general formalism, the spectrum with leading supersymmetry effects is computed without specifying the details of the binding dynamics. The interactions of the composite states with the Standard Model are computed and several benchmark models are described. General features of non-relativistic supersymmetric bound states are emphasized.
Gukov, S G
1997-01-01
The evidently supersymmetric four-dimensional Wess-Zumino model with quenched disorder is considered at the one-loop level. The infrared fixed points of a beta-function form the moduli space $M = RP^2$ where two types of phases were found: with and without replica symmetry. While the former phase possesses only a trivial fixed point, this point become unstable in the latter phase which may be interpreted as a spin glass phase.
Decoupling of supersymmetric particles
Dobado, A; Peñaranda, S
1999-01-01
The possibility of a heavy supersymmetric spectrum at the Minimal Supersymmetric Standard Model is considered and the decoupling from the low energy electroweak scale is analyzed in detail. The formal proof of decoupling of supersymmetric particles from low energy physics is stated in terms of the effective action for the particles of the Standard Model that results by integrating out all the sparticles in the limit where their masses are larger than the electroweak scale. The computation of the effective action for the standard electroweak gauge bosons W^{+-}, Z and \\gamma is performed by integrating out all the squarks, sleptons, charginos and neutralinos to one-loop. The Higgs sector is not considered in this paper. The large sparticle masses limit is also analyzed in detail. Explicit analytical formulae for the two-point functions of the electroweak gauge bosons to be valid in that limit are presented. Finally, the decoupling of sparticles in the S, T and U parameters is studied analitically. A discussion...
Testing the low scale seesaw and leptogenesis
Drewes, Marco; Garbrecht, Björn; Gueter, Dario; Klarić, Juraj
2017-08-01
Heavy neutrinos with masses below the electroweak scale can simultaneously generate the light neutrino masses via the seesaw mechanism and the baryon asymmetry of the universe via leptogenesis. The requirement to explain these phenomena imposes constraints on the mass spectrum of the heavy neutrinos, their flavour mixing pattern and their CP properties. We first combine bounds from different experiments in the past to map the viable parameter regions in which the minimal low scale seesaw model can explain the observed neutrino oscillations, while being consistent with the negative results of past searches for physics beyond the Standard Model. We then study which additional predictions for the properties of the heavy neutrinos can be made based on the requirement to explain the observed baryon asymmetry of the universe. Finally, we comment on the perspectives to find traces of heavy neutrinos in future experimental searches at the LHC, NA62, BELLE II, T2K, SHiP or a future high energy collider, such as ILC, CEPC or FCC-ee. If any heavy neutral leptons are discovered in the future, our results can be used to assess whether these particles are indeed the common origin of the light neutrino masses and the baryon asymmetry of the universe. If the magnitude of their couplings to all Standard Model flavours can be measured individually, and if the Dirac phase in the lepton mixing matrix is determined in neutrino oscillation experiments, then all model parameters can in principle be determined from this data. This makes the low scale seesaw a fully testable model of neutrino masses and baryogenesis.
The seesaw path to leptonic CP violation
Caputo, A.; Kekic, M.; López-Pavón, J.; Salvado, J.
2017-04-24
Future experiments such as SHiP and high-intensity $e^+ e^-$ colliders will have a superb sensitivity to heavy Majorana neutrinos with masses below $M_Z$. We show that the measurement of the mixing to electrons and muons of one such state could imply the discovery of leptonic CP violation in the context of seesaw models. We quantify in the minimal model the CP discovery potential of these future experiments, and demonstrate that a 5$\\sigma$ CL discovery of leptonic CP violation would be possible in a very significant fraction of parameter space.
The seesaw path to leptonic CP violation
Caputo, A.; Kekic, M.; López-Pavón, J.; Salvado, J.
2016-01-01
Future experiments such as SHiP and high-intensity $e^+ e^-$ colliders will have a superb sensitivity to heavy Majorana neutrinos with masses below $M_Z$. We show that the measurement of the mixing to electrons and muons of one such state could imply the discovery of leptonic CP violation in the context of seesaw models. We quantify in the minimal model the CP discovery potential of these future experiments, and demonstrate that a 5$\\sigma$ CL discovery of leptonic CP violation would be possible in a very significant fraction of parameter space.
The seesaw path to leptonic CP violation
Energy Technology Data Exchange (ETDEWEB)
Caputo, A.; Hernandez, P. [Universidad de Valencia and CSIC, Edificio Institutos Investigacion, Instituto de Fisica Corpuscular, Paterna (Spain); CERN, Theoretical Physics Department, Geneva (Switzerland); Kekic, M.; Salvado, J. [Universidad de Valencia and CSIC, Edificio Institutos Investigacion, Instituto de Fisica Corpuscular, Paterna (Spain); Lopez-Pavon, J. [CERN, Theoretical Physics Department, Geneva (Switzerland)
2017-04-15
Future experiments such as SHiP and high-intensity e{sup +}e{sup -} colliders will have a superb sensitivity to heavy Majorana neutrinos with masses below M{sub Z}. We show that the measurement of the mixing to electrons and muons of one such state could establish the existence of CP violating phases in the neutrino mixing matrix, in the context of low-scale seesaw models. We quantify in the minimal model the CP reach of these future experiments, and demonstrate that CP violating phases in the mixing matrix could be established at 5σ CL in a very significant fraction of parameter space. (orig.)
Testing the low scale seesaw and leptogenesis
Drewes, Marco; Gueter, Dario; Klaric, Juraj
2016-01-01
Heavy neutrinos with masses below the electroweak scale could simultaneously generate the light neutrino masses via the seesaw mechanism and the baryon asymmetry of the universe via leptogenesis. The requirement to explain both imposes constraints on the mass spectrum of the heavy neutrinos, their flavour mixing pattern and CP properties. If any heavy neutral leptons are discovered in the future, it will be possible to use a combination of different observables in order to assess whether these are indeed the common origin of the light neutrino masses and the baryon asymmetry of the universe.
A constrained supersymmetric left-right model
Hirsch, Martin; Opferkuch, Toby; Porod, Werner; Staub, Florian
2016-01-01
We present a supersymmetric left-right model which predicts gauge coupling unification close to the string scale and extra vector bosons at the TeV scale. The subtleties in constructing a model which is in agreement with the measured quark masses and mixing for such a low left-right breaking scale are discussed. It is shown that in the constrained version of this model radiative breaking of the gauge symmetries is possible and a SM-like Higgs is obtained. Additional CP-even scalars of a similar mass or even much lighter are possible. The expected mass hierarchies for the supersymmetric states differ clearly from those of the constrained MSSM. In particular, the lightest down-type squark, which is a mixture of the sbottom and extra vector-like states, is always lighter than the stop. We also comment on the model's capability to explain current anomalies observed at the LHC.
Soft leptogenesis in the inverse seesaw model
Garayoa, J; Rius, N
2007-01-01
We consider leptogenesis induced by soft supersymmetry breaking terms ("soft leptogenesis"), in the context of the inverse seesaw mechanism. In this model there are lepton number (L) conserving and L-violating soft supersymmetry-breaking B-terms involving the singlet sneutrinos which, together with the -- generically small-- L-violating parameter responsible of the neutrino mass, give a small mass splitting between the four singlet sneutrino states of a single generation. In combination with the trilinear soft supersymmetry breaking terms they also provide new CP violating phases needed to generate a lepton asymmetry in the singlet sneutrino decays. We obtain that in this scenario the lepton asymmetry is proportional to the L-conserving soft supersymmetry-breaking B-term, and it is not suppressed by the L-violating parameters. Consequently we find that, as in the standard see-saw case, this mechanism can lead to sucessful leptogenesis only for relatively small value of the relevant soft bilinear coupling. The...
Harnik, R
2004-01-01
Supersymmetric models have traditionally been assumed to be perturbative up to high scales due to the requirement of calculable unification. In this note I review the recently proposed `Fat Higgs' model which relaxes the requirement of perturbativity. In this framework, an NMSSM-like trilinear coupling becomes strong at some intermediate scale. The NMSSM Higgses are meson composites of an asymptotically-free gauge theory. This allows us to raise the mass of the Higgs, thus alleviating the MSSM of its fine tuning problem. Despite the strong coupling at an intermediate scale, the UV completion allows us to maintain gauge coupling unification.
Generalized Supersymmetric Perturbation Theory
Institute of Scientific and Technical Information of China (English)
B. G(o)n(ǖ)l
2004-01-01
@@ Using the basic ingredient of supersymmetry, a simple alternative approach is developed to perturbation theory in one-dimensional non-relativistic quantum mechanics. The formulae for the energy shifts and wavefunctions do not involve tedious calculations which appear in the available perturbation theories. The model applicable in the same form to both the ground state and excited bound states, unlike the recently introduced supersymmetric perturbation technique which, together with other approaches based on logarithmic perturbation theory, are involved within the more general framework of the present formalism.
Supersymmetric Electroweak Baryogenesis
Rius, N; Rius, Nuria; Sanz, Veronica
2000-01-01
We calculate the baryon asymmetry generated at the electroweak phase transition in the minimal supersymmetric standard model, using a new method to compute the CP-violating asymmetry in the Higgsino flux reflected into the unbroken phase. The method is based on a Higgs insertion expansion. We find that the CP asymmetry at leading order is proportional to the change in $\\tan next-to-leading order this suppression factor disappears. These results explain previous discrepancies among different calculations, and may enhance the final baryon asymmetry generated during the electroweak phase transition.
Prolongation structures for supersymmetric equations
Roelofs, G.H.M.; Hijligenberg, van den N.W.
1990-01-01
The well known prolongation technique of Wahlquist and Estabrook (1975) for nonlinear evolution equations is generalized for supersymmetric equations and applied to the supersymmetric extension of the KdV equation of Manin-Radul. Using the theory of Kac-Moody Lie superalgebras, the explicit form of
Neutrino mass and mixing in the seesaw playground
Energy Technology Data Exchange (ETDEWEB)
King, Stephen F., E-mail: king@soton.ac.uk
2016-07-15
We discuss neutrino mass and mixing in the framework of the classic seesaw mechanism, involving right-handed neutrinos with large Majorana masses, which provides an appealing way to understand the smallness of neutrino masses. However, with many input parameters, the seesaw mechanism is in general not predictive. We focus on natural implementations of the seesaw mechanism, in which large cancellations do not occur, where one of the right-handed neutrinos is dominantly responsible for the atmospheric neutrino mass, while a second right-handed neutrino accounts for the solar neutrino mass, leading to an effective two right-handed neutrino model. We discuss recent attempts to predict lepton mixing and CP violation within such natural frameworks, focusing on the Littlest Seesaw and its distinctive predictions.
Neutrino mass and mixing in the seesaw playground
King, Stephen F.
2016-07-01
We discuss neutrino mass and mixing in the framework of the classic seesaw mechanism, involving right-handed neutrinos with large Majorana masses, which provides an appealing way to understand the smallness of neutrino masses. However, with many input parameters, the seesaw mechanism is in general not predictive. We focus on natural implementations of the seesaw mechanism, in which large cancellations do not occur, where one of the right-handed neutrinos is dominantly responsible for the atmospheric neutrino mass, while a second right-handed neutrino accounts for the solar neutrino mass, leading to an effective two right-handed neutrino model. We discuss recent attempts to predict lepton mixing and CP violation within such natural frameworks, focusing on the Littlest Seesaw and its distinctive predictions.
How can we test the neutrino mass seesaw mechanism experimentally?
Buckley, Matthew R; Murayama, Hitoshi
2006-12-01
The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve data from the CERN Large Hadron Collider, International Linear Collider, cosmology, underground, and low-energy flavor experiments to establish the case.
Quark Seesaw Vectorlike Fermions and Diphoton Excess
Dev, P S Bhupal; Zhang, Yongchao
2015-01-01
We present a possible interpretation of the recent diphoton excess reported by the $\\sqrt s=13$ TeV LHC data in quark seesaw left-right models with vectorlike fermions proposed to solve the strong $CP$ problem without the axion. The gauge singlet real scalar field responsible for the mass of the vectorlike fermions has the right production cross section and diphoton branching ratio to be identifiable with the reported excess at around 750 GeV diphoton invariant mass. Various ways to test this hypothesis as more data accumulates at the LHC are proposed. In particular, we find that for our interpretation to work, there is an upper limit on the right-handed scale $v_R$, which depends on the Yukawa coupling of singlet Higgs field to the vectorlike fermions.
Pseudo dirac neutrinos in seesaw model
Dutta, G; Gautam Dutta; Anjan S Joshipura
1995-01-01
Specific class of textures for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. These textures can be obtained by imposing a horizontal U(1) symmetry. A specific model is discussed in which: (1) All three neutrino masses are similar in magnitude and could lie around eV providing hot component of the dark matter in the universe. (2) Two of these are highly degenerate and their {\\hbox{(mass)}}^2 difference could solve the solar neutrino problem through large angle MSW solution. (3) The electron neutrino mass may be observable through Kurie plot as well as through search of the neutrinoless double beta decay.
Pseudo Dirac neutrinos in the seesaw model
Energy Technology Data Exchange (ETDEWEB)
Dutta, G.; Joshipura, A.S. (Theory Group, Physical Research Laboratory, Navrangpura, Ahmedabad 380 009 (India))
1995-04-01
A specific class of textures for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. These textures can be obtained by imposing a horizontal U(1) symmetry. A specific model is discussed in which (1) all three neutrino masses are similar in magnitude and could lie around 1 eV providing the hot component of the dark matter in the Universe, (2) two of these are highly degenerate and their (mass)[sup 2] difference could solve the solar neutrino problem through the large angle MSW solution, and (3) the electron neutrino mass may be observable through a Kurie plot as well as through a search of the neutrinoless double [beta] decay.
Gauge Anomalies and Neutrino Seesaw Models
Neves Cebola, Luis Manuel
Despite the success of the Standard Model concerning theoretical predictions, there are several experimental results that cannot be explained and there are reasons to believe that there exists new physics beyond it. Neutrino oscillations, and hence their masses, are examples of this. Experimentally it is known that neutrinos masses are quite small, when compared to all Standard Model particle masses. Among the theoretical possibilities to explain these tiny masses, the seesaw mechanism is a simple and well-motivated framework. In its minimal version, heavy particles are introduced that decouple from the theory in the early universe. To build consistent theories, classical symmetries need to be preserved at quantum level, so that there are no anomalies. The cancellation of these anomalies leads to constraints in the parameters of the theory. One attractive solution is to realize the anomaly cancellation through the modication of the gauge symmetry. In this thesis we present a short review of some features of t...
Leptogenesis in minimal predictive seesaw models
Björkeroth, Fredrik; de Anda, Francisco J.; de Medeiros Varzielas, Ivo; King, Stephen F.
2015-10-01
We estimate the Baryon Asymmetry of the Universe (BAU) arising from leptogenesis within a class of minimal predictive seesaw models involving two right-handed neutrinos and simple Yukawa structures with one texture zero. The two right-handed neutrinos are dominantly responsible for the "atmospheric" and "solar" neutrino masses with Yukawa couplings to ( ν e , ν μ , ν τ ) proportional to (0, 1, 1) and (1, n, n - 2), respectively, where n is a positive integer. The neutrino Yukawa matrix is therefore characterised by two proportionality constants with their relative phase providing a leptogenesis-PMNS link, enabling the lightest right-handed neutrino mass to be determined from neutrino data and the observed BAU. We discuss an SU(5) SUSY GUT example, where A 4 vacuum alignment provides the required Yukawa structures with n = 3, while a {{Z}}_9 symmetry fixes the relatives phase to be a ninth root of unity.
$\\mu \\to e \\gamma$ and $\\tau \\to l \\gamma$ decays in the fermion triplet seesaw model
Abada, A; Bonnet, F; Gavela, M B; Hambye, T
2008-01-01
In the framework of the seesaw models with triplets of fermions, we evaluate the decay rates of $\\mu \\to e \\gamma$ and $\\tau \\to l \\gamma$ transitions. We show that although, due to neutrino mass constraints, those rates are in general expected to be well under the present experimental limits, this is not necessarily always the case. Interestingly enough, the observation of one of those decays in planned experiments would nevertheless contradict bounds stemming from present experimental limits on the $\\mu \\to eee$ and $\\tau \\to 3 l$ decay rates. Such detection of radiative decays would therefore imply that there exist sources of lepton flavour violation not associated to triplet fermions.
Inter-joint coordination of posture on a seesaw device.
Noé, Frédéric; García-Massó, Xavier; Paillard, Thierry
2017-06-01
Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechanisms associated with these coordination patterns. The results illustrated a multi-joint organization of posture on both stable ground and on the seesaw, with a higher variability among the individual postural responses observed when standing on the seesaw. These findings challenge the classical assumption of ankle mechanisms as dominating control on seesaw devices and confirm that inter-joint coordination in postural control is strongly modulated by stance conditions. When standing on the seesaw without vision, a decrease in intermuscular coherence was observed without any impact on the joint coordination patterns, likely due to an increase dependence on proprioceptive information. Copyright © 2017 Elsevier Ltd. All rights reserved.
The supersymmetric flavor problem
Dimopoulos, Savas K; Dimopoulos, Savas; Sutter, Dave
1995-01-01
The supersymmetric SU(3)\\times SU(2)\\times U(1) theory with minimal particle content and general soft supersymmetry breaking terms has 110 physical parameters in its flavor sector: 30 masses, 39 real mixing angles and 41 phases. The absence of an experimental indication for the plethora of new parameters places severe constraints on theories posessing Planck or GUT-mass particles and suggests that theories of flavor conflict with naturalness. We illustrate the problem by studying the processes \\mu \\rightarrow e + \\gamma and K^0 - \\bar{K}^0 mixing which are very sensitive probes of Planckian physics: a single Planck mass particle coupled to the electron or the muon with a Yukawa coupling comparable to the gauge coupling typically leads to a rate for \\mu \\rightarrow e + \\gamma exceeding the present experimental limits. A possible solution is that the messengers which transmit supersymmetry breaking to the ordinary particles are much lighter than M_{\\rm Planck}.
Supersymmetrizing Massive Gravity
Malaeb, Ola
2013-01-01
When four scalar fields with global Lorentz symmetry are coupled to gravity and take a vacuum expectation value breaking diffeomorphism invariance spontaneously, the graviton becomes massive. This model is supersymmetrized by considering four N=1 chiral superfields with global Lorentz symmetry. When the scalar components of the chiral multiplets z^A acquire a vacuum expectation value, both diffeomorphism invariance and local supersymmetry are broken spontaneously. The global Lorentz index A becomes identified with the space-time Lorentz index making the scalar fields z^A vectors and the chiral spinors \\psi^A spin-3/2 Rarita-Schwinger fields. The global supersymmetry is promoted to a local one using the rules of tensor calculus of coupling the N=1 supergravity Lagrangian to the four chiral multiplets. We show that the spectrum of the model in the broken phase consists of a massive spin-2 field, two massive spin-3/2 fields with different mass and a massive vector.
Supersymmetric mode converters
Heinrich, Matthias; Miri, Mohammad-Ali; Stützer, Simon; Nolte, Stefan; Szameit, Alexander; Christodoulides, Demetrios N.
2015-08-01
In recent years, the ever-increasing demand for high-capacity transmission systems has driven remarkable advances in technologies that encode information on an optical signal. Mode-division multiplexing makes use of individual modes supported by an optical waveguide as mutually orthogonal channels. The key requirement in this approach is the capability to selectively populate and extract specific modes. Optical supersymmetry (SUSY) has recently been proposed as a particularly elegant way to resolve this design challenge in a manner that is inherently scalable, and at the same time maintains compatibility with existing multiplexing strategies. Supersymmetric partners of multimode waveguides are characterized by the fact that they share all of their effective indices with the original waveguide. The crucial exception is the fundamental mode, which is absent from the spectrum of the partner waveguide. Here, we demonstrate experimentally how this global phase-matching property can be exploited for efficient mode conversion. Multimode structures and their superpartners are experimentally realized in coupled networks of femtosecond laser-written waveguides, and the corresponding light dynamics are directly observed by means of fluorescence microscopy. We show that SUSY transformations can readily facilitate the removal of the fundamental mode from multimode optical structures. In turn, hierarchical sequences of such SUSY partners naturally implement the conversion between modes of adjacent order. Our experiments illustrate just one of the many possibilities of how SUSY may serve as a building block for integrated mode-division multiplexing arrangements. Supersymmetric notions may enrich and expand integrated photonics by versatile optical components and desirable, yet previously unattainable, functionalities.
Supersymmetric Quantum Mechanics and Topology
Directory of Open Access Journals (Sweden)
Muhammad Abdul Wasay
2016-01-01
Full Text Available Supersymmetric quantum mechanical models are computed by the path integral approach. In the β→0 limit, the integrals localize to the zero modes. This allows us to perform the index computations exactly because of supersymmetric localization, and we will show how the geometry of target space enters the physics of sigma models resulting in the relationship between the supersymmetric model and the geometry of the target space in the form of topological invariants. Explicit computation details are given for the Euler characteristics of the target manifold and the index of Dirac operator for the model on a spin manifold.
Quark-lepton unification and eight-fold ambiguity in the left-right symmetric seesaw mechanism
Energy Technology Data Exchange (ETDEWEB)
Hosteins, Pierre [Service de Physique Theorique, CEA-Saclay, F-91191 Gif-sur-Yvette cedex, Laboratoire de la Direction des Sciences de la Matiere du Commissariat a l' Energie Atomique et Unite de Recherche associee au CNRS (URA 2306) (France); Lavignac, Stephane [Service de Physique Theorique, CEA-Saclay, F-91191 Gif-sur-Yvette cedex, Laboratoire de la Direction des Sciences de la Matiere du Commissariat a l' Energie Atomique et Unite de Recherche associee au CNRS (URA 2306) (France)]. E-mail: lavignac@spht.saclay.cea.fr; Savoy, Carlos A. [Service de Physique Theorique, CEA-Saclay, F-91191 Gif-sur-Yvette cedex, Laboratoire de la Direction des Sciences de la Matiere du Commissariat a l' Energie Atomique et Unite de Recherche associee au CNRS (URA 2306) (France)
2006-10-30
In many extensions of the Standard Model, including a broad class of left-right symmetric and grand unified theories, the light neutrino mass matrix is given by the left-right symmetric seesaw formula M{sub {nu}}=fv{sub L}-v{sup 2}v{sub R}Y{sub {nu}}f{sup -1}Y{sub {nu}}, in which the right-handed neutrino mass matrix and the SU(2){sub L} triplet couplings are proportional to the same matrix f. We propose a systematic procedure for reconstructing the 2{sup n} solutions (in the n-family case) for the matrix f as a function of the Dirac neutrino couplings (Y{sub {nu}}){sub ij} and of the light neutrino mass parameters, which can be used in both analytical and numerical studies. We apply this procedure to a particular class of supersymmetric SO(10) models with two 10-dimensional and a pair of 126-bar 126-bar representations in the Higgs sector, and study the properties of the corresponding 8 right-handed neutrino spectra. Then, using the reconstructed right-handed neutrino and triplet parameters, we study leptogenesis and lepton flavour violation in these models, and comment on flavour effects in leptogenesis in the type I limit. We find that the mixed solutions where both the type I and the type II seesaw mechanisms give a significant contribution to neutrino masses provide new opportunities for successful leptogenesis in SO(10) GUTs.
Continuous media interpretation of supersymmetric Wess-Zumino type models
Energy Technology Data Exchange (ETDEWEB)
Letelier, P.S. [Universidade Estadual de Campinas (Brazil). Departamento de Matematica Aplicada; Zanchin, V.T. [Departamento de Fisica-CCNE, Universidade Federal de Santa Maria, 97119, Santa Maria, R.S. (Brazil)
1995-02-20
Supersymmetric Wess-Zumino type models are considered as classical material media that can be interpreted as fluids of ordered strings with heat flow along the strings, or a mixture of fluids of ordered strings with either a cloud of particles or a flux of directed radiation. ((orig.))
Supersymmetric quantum mechanics and paraquantization
Energy Technology Data Exchange (ETDEWEB)
Morchedi, O.; Mebarki, N. [Laboratoire de Physique Mathematique et Subatomique, Mentouri University, Constantine (Algeria)
2012-06-27
The paraquantum Hamiltonian of a free particle is shown to be supersymmetric. Depending on the space-time dimension, the corresponding N=1 and N=2 supercharges are constructed and the related Hamiltonians are derived.
Supersymmetric $U(1)_{Y^{\\prime}}\\otimes U(1)_{B-L}$ extension of the standard model
Montero, J C; Rodriguez, M C; Sánchez-Vega, B L
2016-01-01
We build a supersymmetric version of the model with $SU(3)_C\\otimes SU(2)_L\\otimes U(1)_{Y^\\prime}\\otimes U(1)_{B-L}$ gauge symmetry, where $Y^\\prime$ is a new charge and $B$ and $L$ are the usual baryonic and leptonic numbers. The model has three right-handed neutrinos with identical $B-L$ charges, and can accommodate all fermion masses at the tree level. In particular, the type-I seesaw mechanism is implemented for the generation of the active neutrino masses. We also obtain the mass spectra of all the scalar sectors and the flat directions allowed by the model.
Supersymmetric quantum mechanics with reflections
Energy Technology Data Exchange (ETDEWEB)
Post, Sarah; Vinet, Luc [Centre de Recherches Mathematiques, Universite de Montreal, Montreal CP6128 (QC) H3C 3J7 (Canada); Zhedanov, Alexei, E-mail: post@crm.umontreal.ca, E-mail: luc.vinet@umontreal.ca, E-mail: zhedanov@fti.dn.ua [Donetsk Institute for Physics and Technology, Donetsk 83114 (Ukraine)
2011-10-28
We consider a realization of supersymmetric quantum mechanics where supercharges are differential-difference operators with reflections. A supersymmetric system with an extended Scarf I potential is presented and analyzed. Its eigenfunctions are given in terms of little -1 Jacobi polynomials which obey an eigenvalue equation of Dunkl type and arise as a q {yields} -1 limit of the little q-Jacobi polynomials. Intertwining operators connecting the wavefunctions of extended Scarf I potentials with different parameters are presented. (paper)
Maximal zero textures in Linear and Inverse seesaw
Directory of Open Access Journals (Sweden)
Roopam Sinha
2016-08-01
Full Text Available We investigate Linear and Inverse seesaw mechanisms with maximal zero textures of the constituent matrices subjected to the assumption of non-zero eigenvalues for the neutrino mass matrix mν and charged lepton mass matrix me. If we restrict to the minimally parametrized non-singular ‘me’ (i.e., with maximum number of zeros it gives rise to only 6 possible textures of me. Non-zero determinant of mν dictates six possible textures of the constituent matrices. We ask in this minimalistic approach, what phenomenologically allowed maximum zero textures are possible. It turns out that Inverse seesaw leads to 7 allowed two-zero textures while the Linear seesaw leads to only one. In Inverse seesaw, we show that 2 is the maximum number of independent zeros that can be inserted into μS to obtain all 7 viable two-zero textures of mν. On the other hand, in Linear seesaw mechanism, the minimal scheme allows maximum 5 zeros to be accommodated in ‘m’ so as to obtain viable effective neutrino mass matrices (mν. Interestingly, we find that our minimalistic approach in Inverse seesaw leads to a realization of all the phenomenologically allowed two-zero textures whereas in Linear seesaw only one such texture is viable. Next, our numerical analysis shows that none of the two-zero textures give rise to enough CP violation or significant δCP. Therefore, if δCP=π/2 is established, our minimalistic scheme may still be viable provided we allow larger number of parameters in ‘me’.
A review of Higgs mass calculations in supersymmetric models
DEFF Research Database (Denmark)
Draper, P.; Rzehak, H.
2016-01-01
related to the electroweak hierarchy problem. Perhaps the most extensively studied examples are supersymmetric models, which, while capable of producing a 125 GeV Higgs boson with SM-like properties, do so in non-generic parts of their parameter spaces. We review the computation of the Higgs mass...... in the Minimal Supersymmetric Standard Model, in particular the large radiative corrections required to lift mh to 125 GeV and their calculation via Feynman-diagrammatic and effective field theory techniques. This review is intended as an entry point for readers new to the field, and as a summary of the current...
Early universe cosmology. In supersymmetric extensions of the standard model
Energy Technology Data Exchange (ETDEWEB)
Baumann, Jochen Peter
2012-03-19
In this thesis we investigate possible connections between cosmological inflation and leptogenesis on the one side and particle physics on the other side. We work in supersymmetric extensions of the Standard Model. A key role is played by the right-handed sneutrino, the superpartner of the right-handed neutrino involved in the type I seesaw mechanism. We study a combined model of inflation and non-thermal leptogenesis that is a simple extension of the Minimal Supersymmetric Standard Model (MSSM) with conserved R-parity, where we add three right-handed neutrino super fields. The inflaton direction is given by the imaginary components of the corresponding scalar component fields, which are protected from the supergravity (SUGRA) {eta}-problem by a shift symmetry in the Kaehler potential. We discuss the model first in a globally supersymmetric (SUSY) and then in a supergravity context and compute the inflationary predictions of the model. We also study reheating and non-thermal leptogenesis in this model. A numerical simulation shows that shortly after the waterfall phase transition that ends inflation, the universe is dominated by right-handed sneutrinos and their out-of-equilibrium decay can produce the desired matter-antimatter asymmetry. Using a simplified time-averaged description, we derive analytical expressions for the model predictions. Combining the results from inflation and leptogenesis allows us to constrain the allowed parameter space from two different directions, with implications for low energy neutrino physics. As a second thread of investigation, we discuss a generalisation of the inflationary model discussed above to include gauge non-singlet fields as inflatons. This is motivated by the fact that in left-right symmetric, supersymmetric Grand Unified Theories (SUSY GUTs), like SUSY Pati-Salam unification or SUSY SO(10) GUTs, the righthanded (s)neutrino is an indispensable ingredient and does not have to be put in by hand as in the MSSM. We discuss
The Supersymmetric Standard Model
Fayet, Pierre
2016-10-01
The Standard Model may be included within a supersymmetric theory, postulating new sparticles that differ by half-a-unit of spin from their standard model partners, and by a new quantum number called R-parity. The lightest one, usually a neutralino, is expected to be stable and a possible candidate for dark matter. The electroweak breaking requires two doublets, leading to several charged and neutral Brout-Englert-Higgs bosons. This also leads to gauge/Higgs unification by providing extra spin-0 partners for the spin-1 W± and Z. It offers the possibility to view, up to a mixing angle, the new 125 GeV boson as the spin-0 partner of the Z under two supersymmetry transformations, i.e. as a Z that would be deprived of its spin. Supersymmetry then relates two existing particles of different spins, in spite of their different gauge symmetry properties, through supersymmetry transformations acting on physical fields in a non-polynomial way. We also discuss how the compactification of extra dimensions, relying on R-parity and other discrete symmetries, may determine both the supersymmetrybreaking and grand-unification scales.
The Supersymmetric Standard Model
Fayet, Pierre
2016-01-01
The Standard Model may be included within a supersymmetric theory, postulating new sparticles that differ by half-a-unit of spin from their standard model partners, and by a new quantum number called R-parity. The lightest one, usually a neutralino, is expected to be stable and a possible candidate for dark matter. The electroweak breaking requires two doublets, leading to several charged and neutral Brout- Englert-Higgs bosons. This also leads to gauge/Higgs unification by providing extra spin-0 partners for the spin-1 W$^\\pm$ and Z. It offers the possibility to view, up to a mixing angle, the new 125 GeV boson as the spin-0 partner of the Z under two supersymmetry transformations, i.e. as a Z that would be deprived of its spin. Supersymmetry then relates two existing particles of different spins, in spite of their different gauge symmetry properties, through supersymmetry transformations acting on physical fields in a non-polynomial way. We also discuss how the compactification of extra dimensions, relying ...
Fu, Wenbo; Maldacena, Juan; Sachdev, Subir
2016-01-01
We discuss a supersymmetric generalization of the Sachdev-Ye-Kitaev model. These are quantum mechanical models involving $N$ Majorana fermions. The supercharge is given by a polynomial expression in terms of the Majorana fermions with random coefficients. The Hamiltonian is the square of the supercharge. The ${\\cal N}=1$ model with a single supercharge has unbroken supersymmetry at large $N$, but non-perturbatively spontaneously broken supersymmetry in the exact theory. We analyze the model by looking at the large $N$ equation, and also by performing numerical computations for small values of $N$. We also compute the large $N$ spectrum of "singlet" operators, where we find a structure qualitatively similar to the ordinary SYK model. We also discuss an ${\\cal N}=2$ version. In this case, the model preserves supersymmetry in the exact theory and we can compute a suitably weighted Witten index to count the number of ground states, which agrees with the large $N$ computation of the entropy. In both cases, we disc...
Testing New TeV-scale Seesaw Mediators at the LHC
Picek, Ivica
2011-01-01
We propose TeV-scale Dirac fermions producing Majorana masses of the known neutrinos via tree-level seesaw, different from standard type I and III seesaw. The employed weak five-plet with nonzero hypercharge leads to new seesaw formula m_\
Leptogenesis with a dynamical seesaw scale
Energy Technology Data Exchange (ETDEWEB)
Sierra, D. Aristizabal; Vicente, A. [IFPA, Department of Astrophysics, Geophysics and Oceanography, Universite de Liege, Bat B5, Sart Tilman B-4000 Liege 1 (Belgium); Tórtola, M.; Valle, J.W.F., E-mail: daristizabal@ulg.ac.be, E-mail: mariam@ific.uv.es, E-mail: valle@ific.uv.es, E-mail: Avelino.Vicente@ulg.ac.be [AHEP Group, Institut de Física Corpuscular -- C.S.I.C./Universitat de València, Parc Cientific de Paterna, C/Catedratico Jose Beltran, 2 E-46980 Paterna (València) (Spain)
2014-07-01
In the simplest type-I seesaw leptogenesis scenario right-handed neutrino annihilation processes are absent. However, in the presence of new interactions these processes are possible and can affect the resulting B-L asymmetry in an important way. A prominent example is provided by models with spontaneous lepton number violation, where the existence of new dynamical degrees of freedom can play a crucial role. In this context, we provide a model-independent discussion of the effects of right-handed neutrino annihilations. We show that in the weak washout regime, as long as the scattering processes remain slow compared with the Hubble expansion rate throughout the relevant temperature range, the efficiency can be largely enhanced, reaching in some cases maximal values. Moreover, the B-L asymmetry yield turns out to be independent upon initial conditions, in contrast to the ''standard'' case. On the other hand, when the annihilation processes are fast, the right-handed neutrino distribution tends to a thermal one down to low temperatures, implying a drastic suppression of the efficiency which in some cases can render the B-L generation mechanism inoperative.
Leptogenesis in minimal predictive seesaw models
Energy Technology Data Exchange (ETDEWEB)
Björkeroth, Fredrik [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Anda, Francisco J. de [Departamento de Física, CUCEI, Universidad de Guadalajara,Guadalajara (Mexico); Varzielas, Ivo de Medeiros; King, Stephen F. [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom)
2015-10-15
We estimate the Baryon Asymmetry of the Universe (BAU) arising from leptogenesis within a class of minimal predictive seesaw models involving two right-handed neutrinos and simple Yukawa structures with one texture zero. The two right-handed neutrinos are dominantly responsible for the “atmospheric” and “solar” neutrino masses with Yukawa couplings to (ν{sub e},ν{sub μ},ν{sub τ}) proportional to (0,1,1) and (1,n,n−2), respectively, where n is a positive integer. The neutrino Yukawa matrix is therefore characterised by two proportionality constants with their relative phase providing a leptogenesis-PMNS link, enabling the lightest right-handed neutrino mass to be determined from neutrino data and the observed BAU. We discuss an SU(5) SUSY GUT example, where A{sub 4} vacuum alignment provides the required Yukawa structures with n=3, while a ℤ{sub 9} symmetry fixes the relatives phase to be a ninth root of unity.
Leptogenesis with a dynamical seesaw scale
Sierra, D Aristizabal; Valle, J W F; Vicente, A
2014-01-01
In the simplest type-I seesaw leptogenesis scenario right-handed neutrino annihilation processes are absent. However, in the presence of new interactions these processes are possible and can affect the resulting $B-L$ asymmetry in an important way. A prominent example is provided by models with spontaneous lepton number violation, where the existence of new dynamical degrees of freedom can play a crucial role. In this context, we provide a model-independent discussion of the effects of right-handed neutrino annihilations. We show that in the weak washout regime, as long as the scattering processes remain slow compared with the Hubble expansion rate throughout the relevant temperature range, the efficiency can be largely enhanced, reaching in some cases maximal values. Moreover, the $B-L$ asymmetry yield turns out to be independent upon initial conditions, in contrast to the "standard" case. On the other hand, when the annihilation processes are fast, the right-handed neutrino distribution tends to a thermal o...
Naturalness in see-saw mechanism and Bogoliubov transformation
Fujikawa, Kazuo; Tureanu, Anca
2017-04-01
We present an alternative perspective on the see-saw mechanism for the neutrino mass, according to which the small neutrino mass is given as a difference of two large masses. This view emerges when an analogue of the Bogoliubov transformation is used to describe Majorana neutrinos in the Lagrangian of the see-saw mechanism, which is analogous to the BCS theory. The Bogoliubov transformation clarifies the natural appearance of Majorana fermions when C is strongly violated by the right-handed neutrino mass term with good CP in the single flavor model. Analyzing typical models with mR =104 to 1015 GeV, it is shown that a hitherto unrecognized fine tuning of the order mν /mR =10-15 to 10-26 is required to make the commonly perceived see-saw mechanism work in a natural setting, namely, when none of the dimensionless coupling constants are very small.
Naturalness in see-saw mechanism and Bogoliubov transformation
Fujikawa, Kazuo
2016-01-01
The see-saw mechanism is customarily regarded as the ratio of two masses leading to the tiny neutrino mass. We propose an alternative perspective on the see-saw, according to which the small neutrino mass is given as a difference of two large fermion masses of the order of the grand unification scale, and thus hitherto unrecognized fine tuning. This alternative view is motivated by the use of an analogue of Bogoliubov transformation to describe Majorana neutrinos in the Lagrangian defining the see-saw mechanism, which is analogous to the Lagrangian of the BCS theory. The naturalness issue of the neutrino mass thus becomes related to that of the Higgs mass in the Standard Model.
Supersymmetric vacua in random supergravity
Bachlechner, Thomas C.; Marsh, David; McAllister, Liam; Wrase, Timm
2013-01-01
We determine the spectrum of scalar masses in a supersymmetric vacuum of a general mathcal{N}=1 supergravity theory, with the Kähler potential and superpotential taken to be random functions of N complex scalar fields. We derive a random matrix model for the Hessian matrix and compute the eigenvalue spectrum. Tachyons consistent with the Breitenlohner-Freedman bound are generically present, and although these tachyons cannot destabilize the supersymmetric vacuum, they do influence the likelihood of the existence of an `uplift' to a metastable vacuum with positive cosmological constant. We show that the probability that a supersymmetric AdS vacuum has no tachyons is formally equivalent to the probability of a large fluctuation of the smallest eigenvalue of a certain real Wishart matrix. For normally-distributed matrix entries and any N, this probability is given exactly by P=exp left( {{{{-2{N^2}{{{left| W right|}}^2}}} left/ {{m_{susy}^2}} right.}} right) , with W denoting the superpotential and m susy the supersymmetric mass scale; for more general distributions of the entries, our result is accurate when N ≫ 1. We conclude that for left| W right|gtrsim {{{{m_{susy}}}} left/ {N} right.} , tachyonic instabilities are ubiquitous in configurations obtained by uplifting supersymmetric vacua.
Role of Higher Fermion Representations in TeV-scale Seesaw
Picek, Ivica
2010-01-01
We consider a scenario in which additional vectorlike TeV-scale fermions belonging to higher weak-isospin multiplets provide new seesaw mediators. If these fermions have non-zero hypercharge, their tree-level exchange produces novel seesaw mechanism different from type I and III seesaw. In order to produce Majorana masses for light neutrinos, new Dirac seesaw mediators are constrained by the SM gauge symmetry to belong to a weak triplet and a five-plet. The latter, in conjunction with two isospin 3/2 scalar multiplets, leads to new seesaw formula m_\
Light Higgs from Scalar See-Saw in Technicolor
DEFF Research Database (Denmark)
Foadi, Roshan; Frandsen, Mads Toudal
2012-01-01
We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models......We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models...
A remark on the mathematics of the seesaw mechanism
Besnard, Fabien
2016-01-01
To demonstrate that matrices of seesaw type lead to a hieararchy in the neutrino masses, i.e. that there is a large gap in the singular spectrum of these matrices, one generally uses an approximate block-diagonalization procedure. In this note we show that no approximation is required to prove this gap property if the Courant-Fisher-Weyl theorem is used instead. This simple observation might not be original, however it does not seem to show up in the literature. We also sketch the proof of additional inequalities for the singular values of matrices of seesaw type.
The Matrix Reloaded - on the Dark Energy Seesaw
Enqvist, K; Sloth, M S; Enqvist, Kari; Hannestad, Steen; Sloth, Martin S.
2007-01-01
We propose a novel mechanism for dark energy, based on an extended seesaw for scalar fields, which does not require any new physics at energies below the TeV scale. A very light quintessence mass is usually considered to be technically unnatural, unless it is protected by some symmetry broken at the new very light scale. We propose that one can use an extended seesaw mechanism to construct technically natural models for very light fields, protected by SUSY softly broken above a TeV.
Running Neutrino Mass Parameters in See-Saw Scenarios
Antusch, S; Lindner, Manfred; Ratz, M; Schmidt, M A; Antusch, Stefan; Kersten, Joern; Lindner, Manfred; Ratz, Michael; Schmidt, Michael Andreas
2005-01-01
We systematically analyze quantum corrections in see-saw scenarios, including effects from above the see-saw scales. We derive approximate renormalization group equations for neutrino masses, lepton mixings and CP phases, yielding an analytic understanding and a simple estimate of the size of the effects. Even for hierarchical masses, they often exceed the precision of future experiments. Furthermore, we provide a software package allowing for a convenient numerical renormalization group analysis, with heavy singlets being integrated out successively at their mass thresholds. We also discuss applications to model building and related topics.
A new supersymmetric classical Boussinesq equation
Institute of Scientific and Technical Information of China (English)
Zhang Meng-Xia; Liu Qing-Ping; Wang Juan; Wu Ke
2008-01-01
In this paper,we obtain a supersymmetric generalization for the classical Boussinesq equation.We show that the supersymmetric equation system passes the Painlevé test and we also calculate its one- and two-soliton solutions.
Supersymmetric q-deformed quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Traikia, M. H.; Mebarki, N. [Laboratoire de Physique Mathematique et Subatomique, Mentouri University, Constantine (Algeria)
2012-06-27
A supersymmetric q-deformed quantum mechanics is studied in the weak deformation approximation of the Weyl-Heisenberg algebra. The corresponding supersymmetric q-deformed hamiltonians and charges are constructed explicitly.
Low-energy lepton violation from supersymmetric flipped SU(5)
Energy Technology Data Exchange (ETDEWEB)
Brahm, D.E.; Hall, L.J. (Physics Department, University of California, Berkeley, California 94720 (US) Theoretical Physics Group, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720)
1989-10-01
We construct a supersymmetric flipped SU(5){direct product}U(1) model which violates {ital R} parity and electron number at low energies, through a superpotential term (1/2{ital C}{sup {ital ijk}}L{sub i}L{sub j}E{sub k}{sup c}). Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the {ital C}{sup {ital ijk}} coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting {ital Z}{sup 0} decays are predicted: e.g., {ital Z}{sup 0}{r arrow}e{sup {minus}}{mu}{sup +}e{sup +}{mu}{sup {minus}} with invariant-mass peaks in the ({ital e},{mu}) channels.
The holographic supersymmetric Casimir energy
Benetti Genolini, Pietro; Cassani, Davide; Martelli, Dario; Sparks, James
2017-01-01
We consider a general class of asymptotically locally AdS5 solutions of minimal gauged supergravity, which are dual to superconformal field theories on curved backgrounds S1×M3 preserving two supercharges. We demonstrate that standard holographic renormalization corresponds to a scheme that breaks supersymmetry. We propose new boundary terms that restore supersymmetry, and show that for smooth solutions with topology S1×R4 the improved on-shell action reproduces both the supersymmetric Casimir energy and the field theory supersymmetric relation between charges.
n = 4 supersymmetric FRW model
Energy Technology Data Exchange (ETDEWEB)
Rosales, J.J.; Pashnev, A. [Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, 141980 (Russian Federation); Tkach, V.I. [Instituto de Fisica, Universidad de Guanajuato, 05315-970 Leon, 66318 Guanajuato (Mexico)]. e-mail: juan@ifug3.ugto.mx, pashnev@thsun1.jinr.ru, vladimir@ifug3.ugto.mx
2003-07-01
In this work we have constructed the n = 4 extended local conformal time supersymmetry for the Friedmann-Robertson-Walker cosmological models. This is based on the superfield construction of the action, which is invariant under world line local n = 4 supersymmetry with SU(2){sub local} X SU(2){sub global} internal subgroup. It is shown that the supersymmetric action has the form of the localized (or superconformal) version of the action for n = 4 supersymmetric quantum mechanics. This superfield procedure provides a well defined scheme for including super matter. (Author)
Bilinear approach to the supersymmetric Gardner equation
Babalic, C. N.; Carstea, A. S.
2016-08-01
We study a supersymmetric version of the Gardner equation (both focusing and defocusing) using the superbilinear formalism. This equation is new and cannot be obtained from the supersymmetric modified Korteweg-de Vries equation with a nonzero boundary condition. We construct supersymmetric solitons and then by passing to the long-wave limit in the focusing case obtain rational nonsingular solutions. We also discuss the supersymmetric version of the defocusing equation and the dynamics of its solutions.
See-saw mechanism and four light neutrino state
Czakon, M.; Gluza, J.; Zralek, M.
2001-01-01
A formal proof is given that in a see-saw type neutrino mass matrix with only two neutrino mass scales ($m_D \\ll m_R$) and the maximal rank of $m_{R(D)}$, we can not get a fourth light sterile neutrino.
See-saw mechanism and four light neutrino state
Czakon, M.; Gluza, J.; Zralek, M.
2001-01-01
A formal proof is given that in a see-saw type neutrino mass matrix with only two neutrino mass scales ($m_D \\ll m_R$) and the maximal rank of $m_{R(D)}$, we can not get a fourth light sterile neutrino.
The Matrix Reloaded - on the Dark Energy Seesaw
DEFF Research Database (Denmark)
Enqvist, Kari; Hannestad, Steen; Sloth, Martin Snoager
2007-01-01
We propose a novel mechanism for dark energy, based on an extended seesaw for scalar fields, which does not require any new physics at energies below the TeV scale. A very light quintessence mass is usually considered to be technically unnatural, unless it is protected by some symmetry broken at ...
Phenomenological study of extended seesaw model for light sterile neutrino
Nath, Newton; Goswami, Srubabati; Gupta, Shivani
2016-01-01
We study the zero textures of the Yukawa matrices in the minimal extended type-I seesaw (MES) model which can give rise to $\\sim$ eV scale sterile neutrinos. In this model, three right handed neutrinos and one extra singlet $S$ are added to generate a light sterile neutrino. The light neutrino mass matrix for the active neutrinos, $ m_{\
Consistent supersymmetric decoupling in cosmology
Sousa Sánchez, Kepa
2012-01-01
The present work discusses several problems related to the stability of ground states with broken supersymmetry in supergravity, and to the existence and stability of cosmic strings in various supersymmetric models. In particular we study the necessary conditions to truncate consistently a sector o
Supersymmetric Vacua in Random Supergravity
Bachlechner, Thomas C; McAllister, Liam; Wrase, Timm
2012-01-01
We determine the spectrum of scalar masses in a supersymmetric vacuum of a general N=1 supergravity theory, with the Kahler potential and superpotential taken to be random functions of N complex scalar fields. We derive a random matrix model for the Hessian matrix and compute the eigenvalue spectrum. Tachyons consistent with the Breitenlohner-Freedman bound are generically present, and although these tachyons cannot destabilize the supersymmetric vacuum, they do influence the likelihood of the existence of an `uplift' to a metastable vacuum with positive cosmological constant. We show that the probability that a supersymmetric AdS vacuum has no tachyons is formally equivalent to the probability of a large fluctuation of the smallest eigenvalue of a certain real Wishart matrix. For normally-distributed matrix entries and any N, this probability is given exactly by P = exp(-2N^2|W|^2/m_{susy}^2), with W denoting the superpotential and m_{susy} the supersymmetric mass scale; for more general distributions of the...
Introduction to Supersymmetric Gauge Theories
Piguet, O
1997-01-01
In these lectures I present a basic introduction to supersymmetry, especially to N=1 supersymmetric gauge theories and their renormalization, in the Wess-Zumino gauge. I also discuss the various ways supersymmetry may be broken in order to account for the lack of exact supersymmetry in the actual world of elementary particles.
Supersymmetric classical mechanics: free case
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, R. de Lima [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]|[Paraiba Univ., Cajazeiras, PB (Brazil). Dept. de Ciencias Exatas e da Natureza]. E-mail: rafael@cfp.ufpb.br; Almeida, W. Pires de [Paraiba Univ., Cajazeiras, PB (Brazil). Dept. de Ciencias Exatas e da Natureza; Fonseca Neto, I. [Paraiba Univ., Campina Grande, PB (Brazil). Dept. de Fisica
2001-06-01
We present a review work on Supersymmetric Classical Mechanics in the context of a Lagrangian formalism, with N = 1-supersymmetry. We show that the N = 1 supersymmetry does not allow the introduction of a potencial energy term depending on a single commuting supercoordinate, {phi}(t;{theta}). (author)
Neutrino masses and b - $\\tau$ unification in the supersymmetric standard model
Vissani, F
1994-01-01
ABSTRACT: There are several indications that the Majorana masses of the right-handed neutrino components, M_R, are at the intermediate scale: M_R\\sim (10^{10}-10^{12}) GeV or even lighter. The renormalization effects due to large Yukawa couplings of neutrinos from region of momenta M_R \\ltap q \\ltap M_G are studied in the supersymmetric standard model. It is shown that neutrino renormalization effect can increase the m_b/m_\\tau ratio up to (10\\div 15)\\%. This strongly disfavours m_b-m_\\tau unification for low values of \\tan\\beta < 10 especially at large values of \\alpha_s. Lower bounds on M_R and \\tan\\beta from the b-\\tau unification condition were found. The implications of the results to the see-saw mechanism of the neutrino mass generation are discussed.
Study of baryon number and lepton flavour violation in the new minimal supersymmetric SO(10)GUT
Kaur, Charanjit
2015-01-01
We study the so-called new minimal supersymmetric SO(10) GUT(NMSGUT) where explicit spontaneous symmetry breaking allows determination of superheavy spectrum and thus threshold corrections to the effective MSSM couplings. This provides a generic mechanism to resolve the long standing super fast proton decay in Susy GUTs. We estimate lepton flavor violation associated with realistic charged fermion and (Type I seesaw) neutrino fit and show compatibility with baryon number and lepton flavour violation limits. We improve NMSGUT fits by including important loop corrections to sparticle spectra. Our fits use 5 GUT compatible soft supersymmetry breaking parameters of the Supergravity with Non-Universal Higgs Masses(SUGRY-NUHM) type. We calculate the full two loop NMSGUT gauge-Yukawa beta functions to study feasibility of the NUHM parameters via strong renormalization of SO(10) Higgs soft masses. Focus on MSSM Higgs allows formulation of a "Yukawonification" strategy for gauged flavour unification.
Tian, Kai; Liu, Q. P.
2012-07-01
A new N=1 supersymmetric Harry Dym equation is constructed by applying supersymmetric reciprocal transformation to a trivial supersymmetric Harry Dym equation, and its recursion operator and Lax formulation are also obtained. Within the framework of symmetry approach, a class of 3rd order supersymmetric equations of Harry Dym type are considered. In addition to five known integrable equations, a new supersymmetric equation, admitting 5th order generalized symmetry, is shown to be linearizable through supersymmetric reciprocal transformation. Furthermore, its Lax representation and recursion operator are given so that the integrability of this new equation is confirmed.
Quark-lepton unification and eight-fold ambiguity in the left-right symmetric seesaw mechanism
Energy Technology Data Exchange (ETDEWEB)
Hosteins, P.; Lavignac, St.; Savoy, C.A
2006-07-01
In many extensions of the Standard Model, including a broad class of left-right symmetric and Grand United theories, the light neutrino mass matrix is given by the left-right symmetric seesaw formula M{sub {nu}} = f*v{sub L} - v{sup 2}/v{sub R}*Y{sub {nu}}*f{sup -1}*Y{sub {nu}}, in which the right-handed neutrino mass matrix and the SU(2){sub L} triplet couplings are proportional to the same matrix f. We propose a systematic procedure for reconstructing the 2{sup n} solutions (in the n-family case) for the matrix f as a function of the Dirac neutrino couplings (Y{sub {nu}}){sub ij} and of the light neutrino mass parameters, which can be used in both analytical and numerical studies. We apply this procedure to a particular class of supersymmetric SO(10) models with two 10-dimensional and a pair of 126 + 126 representations in the Higgs sector, and study the properties of the corresponding 8 right-handed neutrino spectra. Then, using the reconstructed right-handed neutrino and triplet parameters, we study lepton-genesis and lepton flavour violation in these models, and comment on flavour effects in lepton-genesis in the type I limit. We find that the mixed solutions where both the type I and the type II seesaw mechanisms give a significant contribution to neutrino masses provide new opportunities for successful lepton-genesis in SO(10) Great Unified Theories. (authors)
Radiative Seesaw Model with Degenerate Majorana Dark Matter
Nomura, Takaaki; Orikasa, Yuta
2016-01-01
We study a three loop induced neutrino mass model with exotic vector-like isospin doublet leptons which contain a dark matter candidate. Then we explore lepton flavor violations, and dark matter physics in co-annihilation system. In this paper the nearly degenerate Majorana fermion dark matter can naturally be achieved at the two loop level, while the mass splitting can be larger than ${\\cal O}$(200) keV which is required from the constraint of the direct detection search with spin independent inelastic scattering through $Z$ boson portal. As a result a monochromatic photon excess, its threshold energy is greater than ${\\cal O}$(200) keV, is predicted in our model that could be measured through indirect detection experiments such as INTEGRAL.
Radiative Seesaw in Minimal 3-3-1 Model
Okada, Hiroshi; Orikasa, Yuta
2015-01-01
We study the neutrino sector in a minimal $SU(3)_L\\times U(1)_X$ model, in which its mass is generated at one-loop level with the charged lepton mass, and hence there exists a strong correlation between the charged-lepton mass and the neutrino mass. We identify the parameter region of this model to satisfy the current neutrino oscillation data as well as the constraints on lepton flavor violating processes. We also discuss a possibility to explain the muon anomalous magnetic moment.
Electrophobic Lorentz invariance violation for neutrinos and the see-saw mechanism
Energy Technology Data Exchange (ETDEWEB)
Choubey, Sandhya; King, S.F
2004-04-29
We show how Lorentz invariance violation (LIV) can occur for Majorana neutrinos, without inducing LIV in the charged leptons via radiative corrections. Such 'electrophobic' LIV is due to the Majorana nature of the LIV operator together with electric charge conservation. Being free from the strong constraints coming from the charged lepton sector, electrophobic LIV can in principle be as large as current neutrino experiments permit. On the other hand, electrophobic LIV could be naturally small if it originates from LIV in some singlet 'right-handed neutrino' sector, and is felt in the physical left-handed neutrinos via a see-saw mechanism. We develop the formalism appropriate to electrophobic LIV for Majorana neutrinos, and discuss experimental constraints at current and future neutrino experiments.
Electrophobic Lorentz invariance violation for neutrinos and the see-saw mechanism
Choubey, S; Choubey, Sandhya
2003-01-01
We show how Lorentz invariance violation (LIV) can occur for Majorana neutrinos, without inducing LIV in the charged leptons via radiative corrections. Such ``electrophobic'' LIV is due to the Majorana nature of the LIV operator together with electric charge conservation. Being free from the strong constraints coming from the charged lepton sector, electrophobic LIV can in principle be as large as current neutrino experiments permit. On the other hand electrophobic LIV could be naturally small if it originates from LIV in some singlet ``right-handed neutrino'' sector, and is felt in the physical left-handed neutrinos via a see-saw mechanism. We develop the formalism appropriate to electrophobic LIV for Majorana neutrinos, and discuss experimental constraints at current and future neutrino experiments.
Signals of Supersymmetric Dark Matter
Abbas, A
2000-01-01
The Lightest Supersymmetric Particle predicted in most of the supersymmetric scenarios is an ideal candidate for the dark matter of cosmology. Their detection is of extreme significance today. Recently there have been intriguing signals of a 59 Gev neutralino dark matter at DAMA in Gran Sasso. We look at other possible signatures of dark matter in astrophysical and geological frameworks. The passage of the earth through dense clumps of dark matter would produce large quantities of heat in the interior of this planet through the capture and subsequent annihilation of dark matter particles. This heat would lead to large-scale volcanism which could in turn have caused mass extinctions. The periodicity of such volcanic outbursts agrees with the frequency of palaeontological mass extinctions as well as the observed periodicity in the occurrence of the largest flood basalt provinces on the globe. Binary character of these extinctions is another unique aspect of this signature of dark matter. In addition dark matter...
Exploring the Supersymmetric $\\sigma$ Model
De Oliveira-Imbiriba, B C
1999-01-01
The purpose of this work is to present some basic concepts about the non-linear sigma model in a simple and direct way. We start with showing the bosonic model and the Wess-Zumino-Witten term, making some comments about its topological nature, and its association with the torsion. It is also shown that to cancel the quantum conformal anomaly the model should obey the Einstein equations. We provide a quick introduction about supersymmetry in chapter 2 to help the understanding the supersymmetric extension of the model. In the last chapter we present the supersymmetric model and its equations of motion. Finally we work-out the two-supersymmetry case, introducing the chiral as well as the twisted chiral fields, expliciting the very specific $SU(2)\\otimes U(1)$ case.
Supersymmetric Higgs Bosons and Beyond
Energy Technology Data Exchange (ETDEWEB)
Carena, Marcela; /Fermilab /Chicago U., EFI; Kong, Kyoungchul; /Fermilab /SLAC; Ponton, Eduardo; /Columbia U.; Zurita, Jose; /Fermilab /Buenos Aires U.
2010-08-26
We consider supersymmetric models that include particles beyond the Minimal Supersymmetric Standard Model (MSSM) with masses in the TeV range, and that couple significantly to the MSSM Higgs sector. We perform a model-independent analysis of the spectrum and couplings of the MSSM Higgs fields, based on an effective theory of the MSSM degrees of freedom. The tree-level mass of the lightest CP-even state can easily be above the LEP bound of 114 GeV, thus allowing for a relatively light spectrum of superpartners, restricted only by direct searches. The Higgs spectrum and couplings can be significantly modified compared to the MSSM ones, often allowing for interesting new decay modes. We also observe that the gluon fusion production cross section of the SM-like Higgs can be enhanced with respect to both the Standard Model and the MSSM.
Supersymmetric Spacetimes from Curved Superspace
Kuzenko, Sergei M
2015-01-01
We review the superspace technique to determine supersymmetric spacetimes in the framework of off-shell formulations for supergravity in diverse dimensions using the case of 3D N=2 supergravity theories as an illustrative example. This geometric formalism has several advantages over other approaches advocated in the last four years. Firstly, the infinitesimal isometry transformations of a given curved superspace form, by construction, a finite-dimensional Lie superalgebra, with its odd part corresponding to the rigid supersymmetry transformations. Secondly, the generalised Killing spinor equation, which must be obeyed by the supersymmetry parameters, is a consequence of the more fundamental superfield Killing equation. Thirdly, general rigid supersymmetric theories on a curved spacetime are readily constructed in superspace by making use of the known off-shell supergravity-matter couplings and restricting them to the background chosen. It is the superspace techniques which make it possible to generate arbitra...
Fun with supersymmetric quantum mechanics
Freedman, B.; Cooper, F.
1984-04-01
The Hamiltonian and path integral approaches to supersymmetric quantum mechanics were reviewed. The related path integrals for the Witten Index and for stochastic processes were discussed and shown to be indications for supersymmetry breakdown. A system where in the superpotential W(x) has assymetrical values at + or - infinity was considered. Nonperturbative strategies for studying supersymmetry breakdown were described. These strategies are based on introducing a lattice and studying the behavior of the ground state energy as the lattice cutoff is removed.
Fun with supersymmetric quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Freedman, B.; Cooper, F.
1984-04-01
One reason for studying supersymmetric quantum mechanics is that there are a class of superpotentials W(x) which behave at large x as x/sup ..cap alpha../ for which we know from general arguments whether SUSY is broken or unbroken. Thus one can use these superpotentials to test various ideas about how to see if supersymmetry is broken in an arbitrary model. Recently, Witten proposed a topological invariant, the Witten index ..delta.. which counts the number of bosons minus the number of fermions having ground state energy zero. Since if supersymmetry is broken, the ground state energy cannot be zero, one expects if ..delta.. is not zero, SUSY is preserved and the theory is not a good candidate for a realistic model. In this study we evaluate ..delta.. for several examples, and show some unexpected peculiarities of the Witten index for certain choice of superpotentials W(x). We also discuss two other nonperturbative methods of studying supersymmetry breakdown. One involves relating supersymmetric quantum mechanics to a stochastic classical problem and the other involves considering a discrete (but not supersymmetric) version of the theory and studying its behavior as one removes the lattice cuttoff. In this survey we review the Hamiltonian and path integral approaches to supersymmetric quantum mechanics. We then discuss the related path integrals for the Witten Index and for stochastic processes and show how they are indications for supersymmetry breakdown. We then discuss a system where the superpotential W(x) has assymetrical values at +-infinity. We finally discuss nonperturbative strategies for studying supersymmetry breakdown based on introducing a lattice and studying the behavior of the ground state energy as the lattice cutoff is removed. 17 references.
Quantum integrability and supersymmetric vacua
Nekrasov, Nikita A.; Shatashvili, Samson L.
2009-01-01
This is an announcement of some of the results of a longer paper where the supersymmetric vacua of two dimensional N=2 susy gauge theories with matter are shown to be in one-to-one correspondence with the eigenstates of integrable spin chain Hamiltonians. The correspondence between the Heisenberg spin chain and the two dimensional U(N) theory with fundamental hypermultiplets is reviewed in detail. We demonstrate the isomorphism of the equivariant quantum cohomology of the cotangent bundle to ...
Testing New TeV-scale Seesaw Mediators at the LHC
Energy Technology Data Exchange (ETDEWEB)
Picek, Ivica; Radovcic, Branimir [Department of Physics, Faculty of Science, University of Zagreb, P.O.B. 331, HR-10002 Zagreb (Croatia)
2010-07-01
We are presenting a further elaboration of our recent work on a novel seesaw model which at the tree level corresponds to an effective dim > 5 operator. This enables one to lower the seesaw scale on account of the TeV-scale new states testable at the LHC. vector-like non-zero hypercharge fermionic seesaw mediators at hand would have at the LHC an appearance which is different from their commonly discussed Type I and Type III counterparts. (author)
Nayak, Bidyut Prava
2013-01-01
Dominance of type-II seesaw mechanism for neutrino physics has attracted considerable attention because of a number of advantages. We show a novel approach to achieve this dominance through non-supersymmetric $SO(10)$ grand unification where a low mass $Z^{\\prime}$ boson and specific patterns of right handed neutrino masses are predicted within the accessible energy range of the Large Hadron Collider. In spite of the high value of the seesaw scale, $M_{\\Delta}\\simeq 10^9$ GeV, the model predicts new dominant contributions to neutrino-less double beta decay in the $W_L-W_L$ channel via exchanges of heavier singlet fermions used as essential ingredients of this model. We also derive an analytic formula for the half-life of the double beta decay as a function of the fermion masses and provide a new plot that gives the lightest of these masses to be $m_{S_1}\\ge 4\\pm 2$ GeV from the existing experimental data. The underlying non-unitarity effects lead to lepton flavor violating decay branching ratios within the re...
Parida, Mina K
2010-01-01
We explore the prospects of low-scale leptogenesis in a class of supersymmetric SO(10) models using singlet neutrinos and the Higgs representations $126_H \\oplus \\overline{126}_H$ as well as $16_H \\oplus \\overline{16}_H$. A singlet neutrino, which we show can be as light as 10^5-10^6 GeV, decays through its small mixings with right-handed (RH) neutrinos creating a lepton asymmetry which is explicitly shown to be flavor dependent. While the doublet vacuum expectation value (vev) in $\\overline{16}_H$ triggers the generation of desired mixings, it also induces a large RH triplet vev that breaks the left-right intermediate gauge symmetry and gives large right-handed neutrino masses. Manifest unification of gauge couplings and generation of heavy RH neutrino masses are achieved by purely renormalizable interactions. The canonical (Type-I) see-saw contributions to the light neutrino mass matrix cancel out while the Type-II see-saw contribution is negligible. Determining the parameters of the dominant inverse see-sa...
The Higgs seesaw induced neutrino masses and dark matter
Directory of Open Access Journals (Sweden)
Yi Cai
2015-10-01
Full Text Available In this paper we propose a possible explanation of the active neutrino Majorana masses with the TeV scale new physics which also provide a dark matter candidate. We extend the Standard Model (SM with a local U(1′ symmetry and introduce a seesaw relation for the vacuum expectation values (VEVs of the exotic scalar singlets, which break the U(1′ spontaneously. The larger VEV is responsible for generating the Dirac mass term of the heavy neutrinos, while the smaller for the Majorana mass term. As a result active neutrino masses are generated via the modified inverse seesaw mechanism. The lightest of the new fermion singlets, which are introduced to cancel the U(1′ anomalies, can be a stable particle with ultra flavor symmetry and thus a plausible dark matter candidate. We explore the parameter space with constraints from the dark matter relic abundance and dark matter direct detection.
The Friedberg-Lee symmetry and minimal seesaw model
Energy Technology Data Exchange (ETDEWEB)
He Xiaogang [Center for High Energy Physics, Peking University, Beijing (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China); Liao Wei, E-mail: liaow@ecust.edu.c [Center for High Energy Physics, Peking University, Beijing (China); Institute of Modern Physics, East China University of Science and Technology, Shanghai (China)
2009-11-02
The Friedberg-Lee (FL) symmetry is generated by a transformation of a fermionic field q to q+xiz. This symmetry puts very restrictive constraints on allowed terms in a Lagrangian. Applying this symmetry to N fermionic fields, we find that the number of independent fields is reduced to N-1 if the fields have gauge interaction or the transformation is a local one. Using this property, we find that a seesaw model originally with three generations of left- and right-handed neutrinos, with the left-handed neutrinos unaffected but the right-handed neutrinos transformed under the local FL translation, is reduced to an effective theory of minimal seesaw which has only two right-handed neutrinos. The symmetry predicts that one of the light neutrino masses must be zero.
The Friedberg-Lee symmetry and minimal seesaw model
He, Xiao-Gang; Liao, Wei
2009-11-01
The Friedberg-Lee (FL) symmetry is generated by a transformation of a fermionic field q to q + ξz. This symmetry puts very restrictive constraints on allowed terms in a Lagrangian. Applying this symmetry to N fermionic fields, we find that the number of independent fields is reduced to N - 1 if the fields have gauge interaction or the transformation is a local one. Using this property, we find that a seesaw model originally with three generations of left- and right-handed neutrinos, with the left-handed neutrinos unaffected but the right-handed neutrinos transformed under the local FL translation, is reduced to an effective theory of minimal seesaw which has only two right-handed neutrinos. The symmetry predicts that one of the light neutrino masses must be zero.
Looking for the minimal realisation of the inverse seesaw
Abada, Asmaa
2014-01-01
In this work we consider a simple extension of the Standard Model involving additional fermionic singlets and assume an underlying inverse seesaw mechanism for neutrino mass~generation. Our goal is to determine which is the minimal realisation that accounts for neutrino data while at the same time complying with all experimental requirements (electroweak precision tests and laboratory constraints). This study aims at identifying the minimal inverse seesaw realisation for the 3-flavour and for the 3 + more-mixing schemes, the latter giving an explanation for the reactor anomalies and/or providing a possible candidate for the dark matter of the Universe. Based on a perturbative approach, our generic study shows that in the class of models giving rise to a 3-flavour flavour mixing scheme, only two mass scales are relevant (the light neutrino mass scale, $m_\
The Friedberg-Lee Symmetry and Minimal Seesaw Model
He, Xiao-Gang
2009-01-01
The Friedberg-Lee (FL) symmetry is generated by a transformation of a fermionic field $q$ to $q + \\xi z$. This symmetry puts very restrictive constraints on allowed terms in a Lagrangian. Applying this symmetry to $N$ fermionic fields, we find that the number of independent fields is reduced to $N-1$ if the fields have gauge interaction or the transformation is a local one. Using this property, we find that a seesaw model originally with three generations of left- and right-handed neutrinos, with the left-handed neutrinos unaffected but the right-handed neutrinos transformed under the local FL translation, is reduced to an effective theory of minimal seesaw which has only two right-handed neutrinos. The symmetry predicts that one of the light neutrino mass must be zero.
Novel TeV-scale seesaw mechanism with Dirac mediators
Energy Technology Data Exchange (ETDEWEB)
Picek, Ivica, E-mail: picek@phy.h [Department of Physics, Faculty of Science, University of Zagreb, P.O.B. 331, HR-10002 Zagreb (Croatia); Radovcic, Branimir, E-mail: bradov@phy.h [Department of Physics, Faculty of Science, University of Zagreb, P.O.B. 331, HR-10002 Zagreb (Croatia)
2010-04-19
We propose novel tree level seesaw mechanism with TeV-scale vectorlike Dirac mediators that produce Majorana masses of the known neutrinos. The gauge quantum number assignment to the Dirac mediators allows them to belong to a weak triplet and a five-plet of non-zero hypercharge. The latter leads to new seesaw formula m{sub n}uapproxv{sup 6}/M{sup 5}, so that the empirical masses m{sub n}uapprox10{sup -1} eV can be achieved by MapproxTeV new states. There is a limited range of the parameter space with M<=a few100 GeV where the tree level contribution dominates over the respective loop contributions and the proposed mechanism is testable at the LHC. We discuss specific signatures for Dirac type heavy leptons produced by Drell-Yan fusion at the LHC.
Type I seesaw mechanism for quasi degenerate neutrinos
Joshipura, Anjan S; Vempati, Sudhir K
2009-01-01
We discuss symmetries and scenarios leading to quasi-degenerate neutrinos in type-I seesaw models. The existence of degeneracy in the present approach is not linked to any specific structure for the Dirac neutrino Yukawa coupling matrix $y_D$ and holds in general. Basic input is the application of the minimal flavour violation principle to the leptonic sector. Generalizing this principle, we assume that the structure of the right handed neutrino mass matrix is determined by $y_D$ and the charged lepton Yukawa coupling matrix $y_l$ in an effective theory invariant under specific groups ${\\cal G}_F$ contained in the full symmetry group of the kinetic energy terms. ${\\cal G}_F$ invariance also leads to specific structure for the departure from degeneracy. The neutrino mass matrix (with degenerate mass $m_0$) resulting after seesaw mechanism has a simple form ${\\cal M}_\
A minimal seesaw model with mu-tau symmetry
Jurciukonis, Darius; Juodagalvis, Andrius
2015-01-01
We analyse a flavour model for a lepton sector which is based on type I seesaw mechanism, a Z_2 symmetry for lepton flavours, a mu-tau interchange symmetry and a CP symmetry. This model fits well the data of neutrino mass squared differences and oscillation angles. The model predicts an overall neutrino mass scale for normal and inverted neutrino mass hierarchy and the effective mass m_beta, which is used in the neutrinoless double beta decay.
Electroweak Vacuum Stability and the Seesaw Mechanism Revisited
Ng, John
2015-01-01
We study the electroweak vacuum stability in Type I seesaw models for 3 generations of neutrinos in scenarios where the right-handed neutrinos have explicit bare mass terms in the Lagrangian and where these are dynamically generated through the mechanism of spontaneous symmetry breaking. We observe that for the first scenario, the scale at which the scalar potential becomes unstable is lower from that within the Standard Model. In addition the Yukawa couplings $\\mathbf{Y}_\
Supersymmetric theories on squashed five-sphere
Imamura, Yosuke
2012-01-01
We construct supersymmetric theories on the SU(3)xU(1) symmetric squashed five-sphere with 2, 4, 6, and 12 supercharges. We first determine the Killing equation by dimensional reduction from 6d, and use Noether procedure to construct actions. The supersymmetric Yang-Mills action is straightforwardly obtained from the supersymmetric Chern-Simons action by using a supersymmetry preserving constant vector multiplet.
An atmospheric origin of the multi-decadal bipolar seesaw.
Wang, Zhaomin; Zhang, Xiangdong; Guan, Zhaoyong; Sun, Bo; Yang, Xin; Liu, Chengyan
2015-03-10
A prominent feature of recent climatic change is the strong Arctic surface warming that is contemporaneous with broad cooling over much of Antarctica and the Southern Ocean. Longer global surface temperature observations suggest that this contrasting pole-to-pole change could be a manifestation of a multi-decadal interhemispheric or bipolar seesaw pattern, which is well correlated with the North Atlantic sea surface temperature variability, and thus generally hypothesized to originate from Atlantic meridional overturning circulation oscillations. Here, we show that there is an atmospheric origin for this seesaw pattern. The results indicate that the Southern Ocean surface cooling (warming) associated with the seesaw pattern is attributable to the strengthening (weakening) of the Southern Hemisphere westerlies, which can be traced to Northern Hemisphere and tropical tropospheric warming (cooling). Antarctic ozone depletion has been suggested to be an important driving force behind the recently observed increase in the Southern Hemisphere's summer westerly winds; our results imply that Northern Hemisphere and tropical warming may have played a triggering role at an stage earlier than the first detectable Antarctic ozone depletion, and enhanced Antarctic ozone depletion through decreasing the lower stratospheric temperature.
Instanton Corrected Non-Supersymmetric Attractors
Dominic, Pramod
2010-01-01
We discuss non-supersymmetric attractors with an instanton correction in Type IIA string theory compactified on a Calabi-Yau three-fold at large volume. For a stable non-supersymmetric black hole, the attractor point must minimize the effective black hole potential. We study the supersymmetric as well as non-supersymmetric attractors for the D0-D4 system with instanton corrections. We show that in simple models, like the STU model, the flat directions of the mass matrix can be lifted by a suitable choice of the instanton parameters.
Duality in supersymmetric Yang-Mills theory
Energy Technology Data Exchange (ETDEWEB)
Peskin, M.E.
1997-02-01
These lectures provide an introduction to the behavior of strongly-coupled supersymmetric gauge theories. After a discussion of the effective Lagrangian in nonsupersymmetric and supersymmetric field theories, the author analyzes the qualitative behavior of the simplest illustrative models. These include supersymmetric QCD for N{sub f} < N{sub c}, in which the superpotential is generated nonperturbatively, N = 2 SU(2) Yang-Mills theory (the Seiberg-Witten model), in which the nonperturbative behavior of the effect coupling is described geometrically, and supersymmetric QCD for N{sub f} large, in which the theory illustrates a non-Abelian generalization of electric-magnetic duality. 75 refs., 12 figs.
The Glueball Spectrum In Conventional And Supersymmetric Quantum Chromodynamics
Gabadadze, Gregory T
1998-01-01
In the Dissertation we study some nonperturbative aspects of conventional Quantum Chromodynamics and its minimal supersymmetric counterpart, supersymmetric gluodynamics. After the introduction, the discussion of the spectrum of lightest glueballs in Quantum Chromodynamics is given. It is shown that the pseudoscalar glueball mass in Quantum Chromodynamics is less than the mass obtained in quenched lattice calculations. The glueball mass and nonperturbative glueball matrix elements are calculated. The production rate for the pseudoscalar glueball in radiative decays is predicted. Then, we study the nonperturbative features of the Lagrangian of Quantum Chromodynamics which might be responsible for formation of the pseudoscalar glueball state. The issue of the screening of the topological charge is analyzed. A possible non-perturbative mechanism of formation of the pseudoscalar glueball state is proposed. The masses of lowest pseudoscalar glueballs are predicted within the framework of this approach. The second h...
Higher-order predictions for supersymmetric particle decays
Energy Technology Data Exchange (ETDEWEB)
Landwehr, Ananda Demian Patrick
2012-06-12
We analyze particle decays including radiative corrections at the next-to-leading order (NLO) within the Minimal Supersymmetric Standard Model (MSSM). If the MSSM is realized at the TeV scale, squark and gluino production and decays yield relevant rates at the LHC. Hence, in the first part of this thesis, we compute decay widths including QCD and electroweak NLO corrections to squark and gluino decays. Furthermore, the Higgs sector of the MSSM is enhanced compared to the one of the Standard Model. Thus, the additional Higgs bosons decay also into supersymmetric particles. These decays and the according NLO corrections are analyzed in the second part of this thesis. The calculations are performed within a common renormalization framework and numerically evaluated in specific benchmark scenarios.
Geloun, Joseph Ben; Scholtz, Frederik G
2009-01-01
The N=1 supersymmetric invariant Landau problem is constructed and solved. By considering Landau level projections remaining non trivial under N=1 supersymmetry transformations, the algebraic structures of the N=1 supersymmetric covariant non(anti)commutative superplane analogue of the ordinary N=0 noncommutative Moyal-Voros plane are identified.
Supersymmetric Adler Functions and Holography
Iwanaga, Masaya; Sakai, Tadakatsu
2016-01-01
We perform several tests on a recent proposal by Shifman and Stepanyantz for an exact expression for the current correlation functions in supersymmetric gauge theories. We clarify the meaning of the relation in superconformal theories. In particular we show that it automatically follows from known relations between the current correlation functions and anomalies. It therefore also automatically matches between different dual realizations of the same superconformal theory. We use holographic examples as well as calculations in free theories to show that the proposed relation fails in theories with mass terms.
Adding momentum to supersymmetric geometries
Energy Technology Data Exchange (ETDEWEB)
Lunin, Oleg, E-mail: olunin@albany.edu [Department of Physics, University at Albany (SUNY), Albany, NY 12222 (United States); Mathur, Samir D., E-mail: mathur.16@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Turton, David, E-mail: turton.7@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)
2013-03-11
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a traveling wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T{sup 4}. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
Adding momentum to supersymmetric geometries
Lunin, Oleg; Turton, David
2012-01-01
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a travelling-wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T^4. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
The holographic supersymmetric Casimir energy
Genolini, Pietro Benetti; Martelli, Dario; Sparks, James
2016-01-01
We consider a general class of asymptotically locally AdS_5 solutions of minimal gauged supergravity, that are dual to superconformal field theories on curved backgrounds S^1 x M_3 preserving two supercharges. We demonstrate that standard holographic renormalization corresponds to a scheme that breaks supersymmetry. We propose new boundary terms that restore supersymmetry, and show that for smooth solutions with topology S^1 x R^4 the improved on-shell action reproduces both the supersymmetric Casimir energy and the field theory BPS relation between charges.
Supersymmetric photonic signals at LEP
López, J; Zichichi, Antonino
1996-01-01
We explore and contrast the single-photon and diphoton signals expected at LEP 2, that arise from neutralino-gravitino (e^+ e^- -> chi + gravitino -> gamma + E_miss) and neutralino-neutralino (e^+ e^- -> chi + chi -> gamma + gamma + E_miss) production in supersymmetric models with a light gravitino. LEP 1 limits imply that one may observe either one, but not both, of these signals at LEP 2, depending on the values of the neutralino and gravitino masses: single-photons for m_chi > Mz and m_gravitino < 3 x 10^-5 eV; diphotons for m_chi < Mz and all allowed values of m_gravitino.
Supersymmetric R4-actions in ten dimensions
Roo, M. de; Suelmann, H.; Wiedemann, A.
1992-01-01
We construct supersymmetric R+R4-actions in ten dimensions. Two invariants, of which the bosonic parts are known from string amplitude and sigma model calculations, are obtained. One of these invariants can be generalized to an R+F2+F4-invariant for supersymmetric Yang-Mills theory coupled to superg
Supersymmetric features of Maxwell fisheye lens
Rosu, H C; Wolf, K B; Obregón, O; Rosu, Haret C; Reyes, M; Wolf, K B; Obregon, O
1995-01-01
Following L\\'evai, we apply a Natanzon-type supersymmetric analysis to the Maxwell fisheye wave problem at zero energy. Working in the so-called R_{0}=0 sector, we obtain the corresponding superpartner (fermionic) fisheye scattering potential within the standard one-dimensional (radial) supersymmetric procedure.
N=1 Supersymmetric Boundary Bootstrap
Toth, G Z
2004-01-01
We investigate the boundary bootstrap programme for finding exact reflection matrices of integrable boundary quantum field theories with N=1 boundary supersymmetry. The bulk S-matrix and the reflection matrix are assumed to take the form S=S_1S_0, R=R_1R_0, where S_0 and R_0 are the S-matrix and reflection matrix of some integrable non-supersymmetric boundary theory that is assumed to be known, and S_1 and R_1 describe the mixing of supersymmetric indices. Under the assumption that the bulk particles transform in the kink and boson/fermion representations and the ground state is a singlet we present rules by which the supersymmetry representations and reflection factors for excited boundary bound states can be determined. We apply these rules to the boundary sine-Gordon model, to the boundary a_2^(1) and a_4^(1) affine Toda field theories, to the boundary sinh-Gordon model and to the free particle.
A Maximally Supersymmetric Kondo Model
Energy Technology Data Exchange (ETDEWEB)
Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; /Stanford U., Phys. Dept. /SLAC
2012-02-17
We study the maximally supersymmetric Kondo model obtained by adding a fermionic impurity to N = 4 supersymmetric Yang-Mills theory. While the original Kondo problem describes a defect interacting with a free Fermi liquid of itinerant electrons, here the ambient theory is an interacting CFT, and this introduces qualitatively new features into the system. The model arises in string theory by considering the intersection of a stack of M D5-branes with a stack of N D3-branes, at a point in the D3 worldvolume. We analyze the theory holographically, and propose a dictionary between the Kondo problem and antisymmetric Wilson loops in N = 4 SYM. We perform an explicit calculation of the D5 fluctuations in the D3 geometry and determine the spectrum of defect operators. This establishes the stability of the Kondo fixed point together with its basic thermodynamic properties. Known supergravity solutions for Wilson loops allow us to go beyond the probe approximation: the D5s disappear and are replaced by three-form flux piercing a new topologically non-trivial S3 in the corrected geometry. This describes the Kondo model in terms of a geometric transition. A dual matrix model reflects the basic properties of the corrected gravity solution in its eigenvalue distribution.
Neutrino oscillations and the seesaw origin of neutrino mass
Energy Technology Data Exchange (ETDEWEB)
Miranda, O.G., E-mail: omr@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 Mexico, Distrito Federal (Mexico); Valle, J.W.F. [AHEP Group, Institut de Física Corpuscular – C.S.I.C./Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, E-46980 Paterna (València) (Spain)
2016-07-15
The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.
Neutrino oscillations, seesaw mechanism and the quest for new physics
Miranda, O G
2016-01-01
The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, have brought neutrino physics to the precision era. Apart from dedicated leptonic CP violation studies, upcoming experiments should probe the unitarity of the lepton mixing matrix. These will shed light on the scale of new physics, such as the seesaw scale, and thereby guide us towards what could be the next step in particle physics. Moreover these efforts may also bring the key to elucidate some of the current cosmological puzzles.
Leptogenesis in natural low-scale seesaw mechanisms
Lucente, Michele
2015-01-01
We explore the hypothesis of having an approximate lepton number conservation as a way to achieve a successful leptogenesis in low-scale seesaw mechanisms. The smallness of the active neutrino masses, as well as a strong degeneracy in the mass spectrum of the heavy sterile states, are both consequence of the assumed approximate symmetry. We propose a minimal extension of the Standard Model in order to implement the idea, and perform an analytical and numerical study to determine the viable solutions in the model and the testability of this leptogenesis scenario in future experiments.
Yukawa couplings and seesaw neutrino masses in noncommutative gauge theory
Energy Technology Data Exchange (ETDEWEB)
Horvat, Raul [Physics Division, Rudjer Boskovic Institute, Bijenicka 54, Zagreb (Croatia); Ilakovac, Amon [Faculty of Science, University of Zagreb, Bijenicka 32, Zagreb (Croatia); Schupp, Peter [Center for Mathematics, Modeling and Computing, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany); Trampetic, Josip [Physics Division, Rudjer Boskovic Institute, Bijenicka 54, Zagreb (Croatia); Max-Planck-Institut fuer Physik, Werner-Heisenberg-Institut, Foehringer Ring 6, D-80805 Muenchen (Germany); You, Jiangyang, E-mail: Jiangyang.You@irb.hr [Physics Division, Rudjer Boskovic Institute, Bijenicka 54, Zagreb (Croatia)
2012-09-10
We consider Yukawa couplings in a {theta}-exact approach to noncommutative gauge field theory and show that both Dirac and singlet Majorana neutrino mass terms can be consistently accommodated. This shows that in fact the whole neutrino-mass extended standard model on noncommutative spacetime can be formulated in the new nonperturbative (in {theta}) approach which eliminates the previous restriction of Seiberg-Witten map based theories to low-energy phenomena. Spacetime noncommutativity induced couplings between neutrinos and photons as well as Z-bosons appear quite naturally in the model. We derive relevant Feynman rules for the type I seesaw mechanism.
$\\ell_1 \\to \\ell_2 \\gamma$ in type III seesaw
Bonnet, F
2008-01-01
We study the decay rates of the $\\mu \\to e \\gamma$ and $\\tau \\to \\ell \\gamma$ transitions in the framework of the type III seesaw model, where fermionic triplets are exchanged to generate neutrino masses. We show that the observation of one of those decays in planned experiments would contradict bounds arising from present experimental limits on the $\\mu \\to eee$ and $\\tau \\to 3 l$ decay rates, and therefore imply that there exist other sources of lepton flavour violation than those associated to triplet of fermions.
Congenital Achiasma and See-Saw Nystagmus in VACTERL Syndrome
Prakash, Saurabh; Dumoulin, Serge; Fischbein, Nancy; Wandell, Brian A.; Liao, Yaping Joyce
2013-01-01
A 29-year-old man with vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal defects, and limb defects (VACTERL) presented with headache, photophobia, and worsening nystagmus. He had near-normal visual acuity and visual fields, absent stereopsis, and see-saw nystagmus. Brain MRI revealed a thin remnant of the optic chiasm but normal-sized optic nerves. Functional MRI during monocular visual stimulation demonstrated non-crossing of the visual evoked responses in the occipital cortex, confirming achiasma. These findings have not previously been reported in VACTERL. PMID:20182207
Neutrino oscillations and the seesaw origin of neutrino mass
Miranda, O. G.; Valle, J. W. F.
2016-07-01
The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.
A supersymmetric grand unified theory of flavour with PSL{sub 2}(7)xSO(10)
Energy Technology Data Exchange (ETDEWEB)
King, Stephen F., E-mail: king@soton.ac.u [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Luhn, Christoph, E-mail: christoph.luhn@soton.ac.u [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom)
2010-06-11
We construct a realistic Supersymmetric Grand Unified Theory of Flavour based on PSL{sub 2}(7)xSO(10), where the quarks and leptons in the 16 of SO(10) are assigned to the complex triplet representation of PSL{sub 2}(7), while the flavons are assigned to a combination of sextets and anti-triplets of PSL{sub 2}(7). Using a D-term vacuum alignment mechanism, we require the flavon sextets of PSL{sub 2}(7) to be aligned along the 3-3 direction leading to the third family Yukawa couplings, while the flavon anti-triplets describe the remaining Yukawa couplings. Other sextets are aligned along the neutrino flavour symmetry preserving directions leading to tri-bimaximal neutrino mixing via a type II see-saw mechanism, with predictions for neutrinoless double beta decay and cosmology.
Detection of supersymmetric dark matter.
Xinrui, Hou; Li, Xueqian; Xinhe, Meng; Zhijian, Tao
1997-10-01
A re-analysis of a heavy charged particle production event observed at the cloudy chamber of the Yunnan Cosmic Ray Station (YCRS) in 1972 indicates that the mysterious heavy particle may be identified as a supersymmetric (SUSY) particle produced by bombarding a neutral SUSY cosmic ray particle on a proton. Based on the assumption, following literature studies that the neutral SUSY particle which constitutes the main fraction of the cold dark matter is a scalar neutrino (sneutrino) or neutralino (photino), the authors evaluate the flux of such SUSY particles which gain sufficient energies via elastic scattering with charged cosmic particles on the way to an Earth detector and the capture rates in both the sneutrino and photino cases respectively. The errors appearing in the study are briefly discussed and this work may provide a basis of designing cosmic ray detectors to search for SUSY particles.
Non-Supersymmetric Stringy Attractors
Dominic, Pramod
2011-01-01
In this paper we examine the stability of non-supersymmetric attractors in type IIA supergravity compactified on a Calabi-Yau manifold, in the presence of sub-leading corrections to the N=$ pre-potential. We study black hole configurations carrying D0-D6 and D0-D4 charges. We consider the O(1) corrections to the pre-potential given by the Euler number of the Calabi-Yau manifold. We argue that such corrections in general can not lift the zero modes for the D0-D6 attractors. However, for the attractors carrying the D0-D4 charges, they affect the zero modes in the vector multiplet sector. We show that, in the presence of such O(1) corrections, the D0-D4 attractors can either be stable or unstable depending on the geometry of the underlying Calabi-Yau manifold, and on the specific values of the charges they carry.
Instability of supersymmetric microstate geometries
Eperon, Felicity C; Santos, Jorge E
2016-01-01
We investigate the classical stability of supersymmetric, asymptotically flat, microstate geometries with five non-compact dimensions. Such geometries admit an "evanescent ergosurface": a timelike hypersurface of infinite redshift. On such a surface, there are null geodesics with zero energy relative to infinity. These geodesics are stably trapped in the potential well near the ergosurface. We present a heuristic argument indicating that this feature is likely to lead to a nonlinear instability of these solutions. We argue that the precursor of such an instability can be seen in the behaviour of linear perturbations: nonlinear stability would require that all linear perturbations decay sufficiently rapidly but the stable trapping implies that some linear perturbation decay very slowly. We study this in detail for the most symmetric microstate geometries. By constructing quasinormal modes of these geometries we show that generic linear perturbations decay slower than any inverse power of time.
Supersymmetric Sneutrino-Higgs Inflation
Deen, Rehan; Purves, Austin
2016-01-01
It is shown that in the phenomenologically realistic supersymmetric $B-L$ MSSM theory, a linear combination of the neutral, up Higgs field with the third family left-and right-handed sneutrinos can play the role of the cosmological inflaton. Assuming that supersymmetry is softly broken at a mass scale of order $10^{13}~\\mathrm{GeV}$, the potential energy associated with this field allows for 60 e-foldings of inflation with the cosmological parameters being consistent with all Planck2015 data. The theory does not require any non-standard coupling to gravity and the physical fields are all sub-Planckian during the inflationary epoch. It will be shown that there is a "robust" set of initial conditions which, in addition to satisfying the Planck data, simultaneously are consistent with all present LHC phenomenological requirements.
Instability of supersymmetric microstate geometries
Energy Technology Data Exchange (ETDEWEB)
Eperon, Felicity C.; Reall, Harvey S.; Santos, Jorge E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2016-10-07
We investigate the classical stability of supersymmetric, asymptotically flat, microstate geometries with five non-compact dimensions. Such geometries admit an “evanescent ergosurface”: a timelike hypersurface of infinite redshift. On such a surface, there are null geodesics with zero energy relative to infinity. These geodesics are stably trapped in the potential well near the ergosurface. We present a heuristic argument indicating that this feature is likely to lead to a nonlinear instability of these solutions. We argue that the precursor of such an instability can be seen in the behaviour of linear perturbations: nonlinear stability would require that all linear perturbations decay sufficiently rapidly but the stable trapping implies that some linear perturbation decay very slowly. We study this in detail for the most symmetric microstate geometries. By constructing quasinormal modes of these geometries we show that generic linear perturbations decay slower than any inverse power of time.
Currents in supersymmetric field theories
Derendinger, Jean-Pierre
2016-01-01
A general formalism to construct and improve supercurrents and source or anomaly superfields in two-derivative N=1 supersymmetric theories is presented. It includes arbitrary gauge and chiral superfields and a linear superfield coupled to gauge fields. These families of supercurrent structures are characterized by their energy-momentum tensors and R currents and they display a specific relation to the dilatation current of the theory. The linear superfield is introduced in order to describe the gauge coupling as a background (or propagating) field. Supersymmetry does not constrain the dependence on this gauge coupling field of gauge kinetic terms and holomorphicity restrictions are absent. Applying these results to an effective (Wilson) description of super-Yang-Mills theory, matching or cancellation of anomalies leads to an algebraic derivation of the all-order NSVZ beta function.
Supersymmetric Sneutrino-Higgs inflation
Deen, Rehan; Ovrut, Burt A.; Purves, Austin
2016-11-01
It is shown that in the phenomenologically realistic supersymmetric B - L MSSM theory, a linear combination of the neutral, up Higgs field with the third family left- and right-handed sneutrinos can play the role of the cosmological inflaton. Assuming that supersymmetry is softly broken at a mass scale of order 1013 GeV, the potential energy associated with this field allows for 60 e-foldings of inflation with the cosmological parameters being consistent with all Planck2015 data. The theory does not require any non-standard coupling to gravity and the physical fields are all sub-Planckian during the inflationary epoch. It will be shown that there is a "robust" set of initial conditions which, in addition to satisfying the Planck data, simultaneously are consistent with all present LHC phenomenological requirements.
Supersymmetric counterterms from new minimal supergravity
Assel, Benjamin; Martelli, Dario
2014-01-01
We present a systematic classification of counterterms of four-dimensional supersymmetric field theories on curved space, obtained as the rigid limit of new minimal supergravity. These are supergravity invariants constructed using the field theory background fields. We demonstrate that if the background preserves two supercharges of opposite chirality, then all dimensionless counterterms vanish. This implies that a supersymmetric renormalisation scheme is free of ambiguities. When only one Euclidean supercharge is preserved, we describe the ambiguities that appear in supersymmetric observables, in particular in the dependence on marginal couplings.
Supersymmetric predictions for the inclusive b --> s$\\gamma$ decay
Bertolini, S; Stefano Bertolini; Francesco Vissani
1994-01-01
We study the penguin induced transition b\\to s\\ \\gamma in the minimal N=1 supersymmetric extension of the Standard Model with radiative breaking of the electroweak group. We include the effects of one-loop corrections to the Higgs potential and scalar masses. We show that the present upper and lower experimental limits on the inclusive decay sharply constrain the parameter space of the model in a wide range of \\tan\\beta values. The implications of the recently advocated relation |B|\\ge 2 for the bilinear SUSY soft breaking parameter in grand unified theories are also analyzed.
Vacuum stability and radiative electroweak symmetry breaking in an SO(10) dark matter model
Mambrini, Yann; Nagata, Natsumi; Olive, Keith A.; Zheng, Jiaming
2016-06-01
Vacuum stability in the Standard Model is problematic as the Higgs quartic self-coupling runs negative at a renormalization scale of about 1010 GeV . We consider a nonsupersymmetric SO(10) grand unification model for which gauge coupling unification is made possible through an intermediate scale gauge group, Gint=SU (3 )C⊗SU (2 )L⊗SU (2 )R⊗U (1 )B -L . Gint is broken by the vacuum expectation value of a 126 of SO(10) which not only provides for neutrino masses through the seesaw mechanism but also preserves a discrete Z2 that can account for the stability of a dark matter candidate, here taken to be the Standard Model singlet component of a bosonic 16 . We show that in addition to these features the model insures the positivity of the Higgs quartic coupling through its interactions to the dark matter multiplet and 126 . We also show that the Higgs mass squared runs negative, triggering electroweak symmetry breaking. Thus, the vacuum stability is achieved along with radiative electroweak symmetry breaking and captures two more important elements of supersymmetric models without low-energy supersymmetry. The conditions for perturbativity of quartic couplings and for radiative electroweak symmetry breaking lead to tight upper and lower limits on the dark matter mass, respectively, and this dark matter mass region (1.35-2 TeV) can be probed in future direct detection experiments.
On the gravitational seesaw in higher-derivative gravity
Accioly, Antonio; Giacchini, Breno L.; Shapiro, Ilya L.
2017-08-01
Local gravitational theories with more than four derivatives are superrenormalizable. They also may be unitary in the Lee-Wick sense. Thus it is relevant to study the low-energy properties of these theories, especially to identify observables which might be useful for experimental detection of higher derivatives. Using an analogy with the neutrino physics, we explore the possibility of a gravitational seesaw mechanism in which several dimensional parameters of the same order of magnitude produce a hierarchy in the masses of propagating particles. Such a mechanism could make a relatively light degree of freedom detectable in low-energy laboratory and astrophysical observations, such as torsion-balance experiments and the bending of light. We demonstrate that such a seesaw mechanism in the six- and more-derivative theories is unable to reduce the lightest mass more than in the simplest four-derivative model. Adding more derivatives to the four-derivative action of gravity makes heavier masses even greater, while the lightest massive ghost is not strongly affected. This fact is favorable for protecting the theory from instabilities but makes the experimental detection of higher derivatives more difficult.
Inert Dark Matter in Type-II Seesaw
Chen, Chuan-Hung
2014-01-01
Weakly interacting massive particle (WIMP) as a dark matter (DM) candidate is further inspired by recent AMS-02 data, which confirm the excess of positron fraction observed earlier by PAMELA and Fermi-LAT experiments. Additionally, the excess of positron+electron flux is still significant in the measurement of Fermi-LAT. For solving the problem of massive neutrinos and observed excess of cosmic-ray by DM annihilation, we study the model with an inert Higgs doublet (IHD) in the framework of type-II seesaw mechanism by imposing a $Z_2$ symmetry on the IHD, where the lightest particle of IHD is the DM candidate while the neutrino masses origin from the Higgs triplet in type-II seesaw model. We calculate the cosmic-ray production in our model by using three kinds of neutrino mass spectra, classified as normal ordering, inverted ordering and quasi-degeneracy. We find that if leptonic triplet decays are dominant, the observed excess of positron/electron flux could be explained well in normal ordered neutrino mass s...
Invisible Axion-Like Dark Matter from Electroweak Bosonic Seesaw
Ishida, Hiroyuki; Yamaguchi, Yuya
2016-01-01
We explore a model based on the classically-scale invariant standard model (SM) with a strongly coupled vector-like dynamics, which is called hypercolor (HC). The scale symmetry is dynamically broken by the vector-like condensation at the TeV scale, so that the SM Higgs acquires the negative mass-squared by the bosonic seesaw mechanism to realize the electroweak symmetry breaking. An elementary pseudoscalar $S$ is introduced to give masses for the composite Nambu-Goldstone bosons (HC pions): the HC pions can thus be identified as the 750 GeV resonance in the LHC diphoton channel. As the consequence of the bosonic seesaw, the fluctuating mode of $S$, which we call $s$, develops tiny couplings to the SM particles and is predicted to be very light. The $s$ predominantly decays to diphoton and can behave as an invisible axion-like dark matter. The mass of the $s$-dark matter is constrained by currently available cosmological and astrophysical limits to be $10^{-4} {\\rm eV} \\lesssim m_s \\lesssim 1 \\,{\\rm eV}$. We ...
Invisible axionlike dark matter from the electroweak bosonic seesaw mechanism
Ishida, Hiroyuki; Matsuzaki, Shinya; Yamaguchi, Yuya
2016-11-01
We explore a model based on the classically scale-invariant standard model (SM) with a strongly coupled vectorlike dynamics, which is called hypercolor (HC). The scale symmetry is dynamically broken by the vectorlike condensation at the TeV scale, so that the SM Higgs acquires the negative mass squared by the bosonic seesaw mechanism to realize the electroweak symmetry breaking. An elementary pseudoscalar S is introduced to give masses for the composite Nambu-Goldstone bosons (HC pions): The HC pion can be a good target to explore through a diphoton channel at the LHC. As a consequence of the bosonic seesaw, the fluctuating mode of S , which we call s , develops tiny couplings to the SM particles and is predicted to be very light. The s predominantly decays to a diphoton and can behave as invisible axionlike dark matter. The mass of the s dark matter is constrained by currently available cosmological and astrophysical limits to be 10-4 eV ≲ms≲1 eV . We find that a sufficient amount of relic abundance for the s dark matter can be accumulated via the coherent oscillation. The detection potential in microwave cavity experiments is also addressed.
Minimal lepton flavor violating realizations of minimal seesaw models
Sierra, Diego Aristizabal; Kamenik, Jernej F
2012-01-01
We study the implications of the global U(1)R symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. In the context of minimal type I seesaw scenarios with a slightly broken U(1)R, we show that, depending on the R-charge assignments, two classes of generic models can be identified. Models where the right-handed neutrino masses and the lepton number breaking scale are decoupled, and models where the parameters that slightly break the U(1)R induce a suppression in the light neutrino mass matrix. We show that within the first class of models, contributions of right-handed neutrinos to charged lepton flavor violating processes are severely suppressed. Within the second class of models we study the charged lepton flavor violating phenomenology in detail, focusing on mu to e gamma, mu to 3e and mu to e conversion in nuclei. We show that sizable contributions to these processes are naturally obtained for right-handed neutrino masses at the TeV scale. We then ...
Fast neutrino decay in the minimal seesaw model
Joshipura, A S; Joshipura, Anjans S.; Rindani, Saurabh D.
1992-01-01
Neutrino decay in the minimal seesaw model containing three right handed neutrinos and a complex $SU(2)\\times U(1)$ singlet Higgs in addition to the standard model fields is considered. A global horizontal symmetry $U(1)_H$ is imposed, which on spontaneous breaking gives rise to a Goldstone boson. This symmetry is chosen in a way that makes a) the contribution of heavy ($\\leq$ MeV) majorana neutrinos to the neutrinoless double beta decay amplitude vanish and b) allows the heavy neutrino to decay to a lighter neutrino and the Goldstone boson. It is shown that this decay can occur at a rate much faster than in the original Majoron model even if one does not introduce any additional Higgs fields as is done in the literature. Possibility of describing the 17 keV neutrino in this minimal seesaw model is investigated. While most of the cosmological and astrophysical constraints on the 17 keV neutrino can be satisfied in this model, the laboratory limits coming from the neutrino oscillations cannot be easily met. An...
Electroweak vacuum stability and the seesaw mechanism revisited
Energy Technology Data Exchange (ETDEWEB)
Ng, J.N. [TRIUMF, Theory Department, Vancouver, BC (Canada); De la Puente, Alejandro [TRIUMF, Theory Department, Vancouver, BC (Canada); Carleton University, Department of Physics, Ottawa, ON (Canada)
2016-03-15
We study the electroweak vacuum stability in Type I seesaw models for three generations of neutrinos in scenarios where the right-handed neutrinos have explicit bare mass terms in the Lagrangian and where these are dynamically generated through the mechanism of spontaneous symmetry breaking. To best highlight the difference of the two cases we concentrate on the absolute stability of the scalar potential. We observe that for the first scenario, the scale at which the scalar potential becomes unstable is lower from that within the standard model. In addition the Yukawa couplings Y{sub ν} are constrained such that Tr[Y{sub ν}{sup †}Y{sub ν}]
New supersymmetric source of neutrino masses and mixings
Casas, J A; Navarro, I
2002-01-01
Conventionally, neutrino masses in a supersymmetric theory arise from non-renormalizable lepton-number (L)-violating operators in the superpotential. The alternative possibility of having such operators in the Kahler potential as the dominant source of neutrino masses has very interesting implications and differences with respect to the standard scenario: first, the scale of L-violation can be lowered dramatically and neutrino masses have a different tan beta-dependence; second, the renormalization of these operators has remarkable properties: in many cases it improves drastically the stability of neutrino textures against radiative corrections, while in others it makes possible to generate radiatively large mixing angles in a natural way. In particular, the mass splitting and mixing angle of solar neutrinos (LAMSW solution) can be explained as a purely radiative effect.
Invariant Regularization of Supersymmetric Chiral Gauge Theory
Hayashi, T; Okuyama, K; Suzuki, H; Hayashi, Takuya; Ohshima, Yoshihisa; Okuyama, Kiyoshi; Suzuki, Hiroshi
1998-01-01
We formulate a manifestly supersymmetric gauge-covariant regularization of supersymmetric chiral gauge theories. In our scheme, the effective action in the superfield background-field method above one-loop is always supersymmetric and gauge invariant. The gauge anomaly has the covariant form and can emerge only in one-loop diagrams with all the external lines are the background gauge superfield. We also present several illustrative applications in the one-loop approximation: The self-energy part of the chiral multiplet and the gauge multiplet; the super-chiral anomaly and the superconformal anomaly; as the corresponding anomalous commutators, the Konishi anomaly and the anomalous supersymmetric transformation law of the supercurrent (the ``central extension'' of N=1 supersymmetry algebra) and of the R-current.
The Minimal Supersymmetric Fat Higgs Model
Harnik, R; Larson, D T; Murayama, H; Harnik, Roni; Kribs, Graham D.; Larson, Daniel T.; Murayama, Hitoshi
2003-01-01
We present a calculable supersymmetric theory of a composite ``fat'' Higgs boson. Electroweak symmetry is broken dynamically through a new gauge interaction that becomes strong at an intermediate scale. The Higgs mass can easily be 200-450 GeV along with the superpartner masses, solving the supersymmetric little hierarchy problem. We explicitly verify that the model is consistent with precision electroweak data without fine-tuning. Gauge coupling unification can be maintained despite the inherently strong dynamics involved in electroweak symmetry breaking. Supersymmetrizing the Standard Model therefore does not imply a light Higgs mass, contrary to the lore in the literature. The Higgs sector of the minimal Fat Higgs model has a mass spectrum that is distinctly different from the Minimal Supersymmetric Standard Model.
Bosonization of supersymmetric KdV equation
Energy Technology Data Exchange (ETDEWEB)
Gao Xiaonan [Department of Physics, Shanghai Jiao Tong University, Shanghai, 200240 (China); Lou, S.Y., E-mail: sylou@sjtu.edu.cn [Department of Physics, Shanghai Jiao Tong University, Shanghai, 200240 (China); Faculty of Science, Ningbo University, Ningbo, 315211 (China); School of Mathematics, Fudan University, Shanghai, 200433 (China)
2012-01-16
Bosonization approach to the classical supersymmetric systems is presented. By introducing the multi-fermionic parameters in the expansions of the superfields, the N=1 supersymmetric KdV (sKdV) system is transformed to a system of coupled bosonic equations. The method can be applied to any fermionic systems. By solving the coupled bosonic equations, some novel types of exact solutions can be explicitly obtained. Especially, the richness of the localized excitations of the supersymmetric integrable system is discovered. The rich multi-soliton solutions obtained here have not yet been obtained by using other methods. However, the traditional known multi-soliton solutions can also not be obtained by the bosonization approach of this Letter. Some open problems on the bosonization of the supersymmetric integrable models are proposed in the both classical and quantum levels.
Proton Decay in Minimal Supersymmetric SU(5)
Bajc, Borut; Perez, Pavel Fileviez; Senjanovic, Goran
2002-01-01
We systematically study proton decay in the minimal supersymmetric SU(5) grand unified theory. We find that although the available parameter space of soft masses and mixings is quite constrained, the theory is still in accord with experiment.
Bubbles of Nothing and Supersymmetric Compactifications
Blanco-Pillado, Jose J; Sousa, Kepa; Urrestilla, Jon
2016-01-01
We investigate the non-perturbative stability of supersymmetric compactifications with respect to decay via a bubble of nothing. We show examples where this kind of instability is not prohibited by the spin structure, i.e., periodicity of fermions about the extra dimension. However, such "topologically unobstructed" cases do exhibit an extra-dimensional analog of the well-known Coleman-De Luccia suppression mechanism, which prohibits the decay of supersymmetric vacua. We demonstrate this explicitly in a four dimensional Abelian-Higgs toy model coupled to supergravity. The compactification of this model to $M_3 \\times S_1$ presents the possibility of vacua with different windings for the scalar field. Away from the supersymmetric limit, these states decay by the formation of a bubble of nothing, dressed with an Abelian-Higgs vortex. We show how, as one approaches the supersymmetric limit, the circumference of the topologically unobstructed bubble becomes infinite, thereby preventing the realization of this dec...
Patterns of flavor signals in supersymmetric models
Energy Technology Data Exchange (ETDEWEB)
Goto, T. [KEK National High Energy Physics, Tsukuba (Japan)]|[Kyoto Univ. (Japan). YITP; Okada, Y. [KEK National High Energy Physics, Tsukuba (Japan)]|[Graduate Univ. for Advanced Studies, Tsukuba (Japan). Dept. of Particle and Nucelar Physics; Shindou, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[International School for Advanced Studies, Trieste (Italy); Tanaka, M. [Osaka Univ., Toyonaka (Japan). Dept. of Physics
2007-11-15
Quark and lepton flavor signals are studied in four supersymmetric models, namely the minimal supergravity model, the minimal supersymmetric standard model with right-handed neutrinos, SU(5) supersymmetric grand unified theory with right-handed neutrinos and the minimal supersymmetric standard model with U(2) flavor symmetry. We calculate b{yields}s(d) transition observables in B{sub d} and B{sub s} decays, taking the constraint from the B{sub s}- anti B{sub s} mixing recently observed at Tevatron into account. We also calculate lepton flavor violating processes {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma} and {tau} {yields} e{gamma} for the models with right-handed neutrinos. We investigate possibilities to distinguish the flavor structure of the supersymmetry breaking sector with use of patterns of various flavor signals which are expected to be measured in experiments such as MEG, LHCb and a future Super B Factory. (orig.)
NEW EXACTLY SOLVABLE SUPERSYMMETRIC PERIODIC POTENTIALS
Institute of Scientific and Technical Information of China (English)
LIU KE-JIA; HE LI; ZHOU GUO-LI; WU YU-JIAO
2001-01-01
Using the formalism of supersymmetric quantum mechanics, we give an exact solution for a family of onedimensional periodic potentials, which are the supersymmetric partners of the potential proportional to the trigonometric function cos(2x) such that the Schrodinger equation for this potential is named the Mathieu equation mathematically.We show that the new potentials are distinctly different from their original ones. However, both have the same energy band structure. All the potentials obtained in this paper are free of singularities.
On the uniqueness of supersymmetric attractors
Directory of Open Access Journals (Sweden)
Taniya Mandal
2015-10-01
Full Text Available In this paper we discuss the uniqueness of supersymmetric attractors in four-dimensional N=2 supergravity theories coupled to n vector multiplets. We prove that for a given charge configuration the supersymmetry preserving axion free attractors are unique. We generalise the analysis to axionic attractors and state the conditions for uniqueness explicitly. We consider the example of a two-parameter model and find all solutions to the supersymmetric attractor equations and discuss their uniqueness.
Generalized Kahler Geometry from supersymmetric sigma models
Bredthauer, A; Persson, J; Zabzine, M; Bredthauer, Andreas; Lindstrom, Ulf; Persson, Jonas; Zabzine, Maxim
2006-01-01
We give a physical derivation of generalized Kahler geometry. Starting from a supersymmetric nonlinear sigma model, we rederive and explain the results of Gualtieri regarding the equivalence between generalized Kahler geometry and the bi-hermitean geometry of Gates-Hull-Rocek. When cast in the language of supersymmetric sigma models, this relation maps precisely to that between the Lagrangian and the Hamiltonian formalisms. We also discuss topological twist in this context.
(2+1)-dimensional supersymmetric integrable equations
Yan, Zhao-Wen; Tala; Chen, Fang; Liu, Tao-Ran; Han, Jing-Min
2017-09-01
By means of two different approaches, we construct the (2+1)-dimensional supersymmetric integrable equations based on the super Lie algebra osp(3/2). We relax the constraint condition of homogenous space of super Lie algebra osp(3/2) in the first approach. In another one, the technique of extending the dimension of the systems is used. Furthermore for the (2 + 1)-dimensional supersymmetric integrable equations, we also derive their Bäcklund transformations.
Neutral Supersymmetric Higgs Boson Searches
Energy Technology Data Exchange (ETDEWEB)
Robinson, Stephen Luke [Imperial College, London (United Kingdom)
2008-07-01
In some Supersymmetric extensions of the Standard Model, including the Minimal Supersymmetric Standard Model (MSSM), the coupling of Higgs bosons to b-quarks is enhanced. This enhancement makes the associated production of the Higgs with b-quarks an interesting search channel for the Higgs and Supersymmetry at D0. The identification of b-quarks, both online and offline, is essential to this search effort. This thesis describes the author's involvement in the development of both types of b-tagging and in the application of these techniques to the MSSM Higgs search. Work was carried out on the Level-3 trigger b-tagging algorithms. The impact parameter (IP) b-tagger was retuned and the effects of increased instantaneous luminosity on the tagger were studied. An extension of the IP-tagger to use the z-tracking information was developed. A new b-tagger using secondary vertices was developed and commissioned. A tool was developed to allow the use of large multi-run samples for trigger studies involving b-quarks. Offline, a neural network (NN) b-tagger was trained combining the existing offline lifetime based b-tagging tools. The efficiency and fake rate of the NN b-tagger were measured in data and MC. This b-tagger was internally reviewed and certified by the Collaboration and now provides the official b-tagging for all analyses using the Run IIa dataset at D0. A search was performed for neutral MSSM Higgs bosons decaying to a b{bar b} pair and produced in association with one or more b-quarks. Limits are set on the cross-section times the branching ratio for such a process. The limits were interpreted in various MSSM scenarios. This analysis uses the NN b-tagger and was the first to use this tool. The analysis also relies on triggers using the Level-3 IP b-tagging tool described previously. A likelihood discriminant was used to improve the analysis and a neural network was developed to cross-check this technique. The result of the analysis has been submitted to PRL
Parida, M. K.; Nayak, Bidyut Prava; Satpathy, Rajesh; Awasthi, Ram Lal
2017-04-01
We discuss gauge coupling unification of SU(3) C × SU(2) L × U(1) Y descending directly from non-supersymmetric SO(10) while providing solutions to the three out-standing problems of the standard model: neutrino masses, dark matter, and the baryon asymmetry of the universe. Conservation of matter parity as gauged discrete symmetry for the stability and identification of dark matter in the model calls for high-scale spontaneous symmetry breaking through 126 H Higgs representation. This naturally leads to the hybrid seesaw formula for neutrino masses mediated by heavy scalar triplet and right-handed neutrinos. Being quadratic in the Majorana coupling, the seesaw formula predicts two distinct patterns of right-handed neutrino masses, one hierarchical and another not so hierarchical (or compact), when fitted with the neutrino oscillation data. Predictions of the baryon asymmetry via leptogenesis are investigated through the decays of both the patterns of RH ν masses. A complete flavor analysis has been carried out to compute CP-asymmetries including washouts and solutions to Boltzmann equations have been utilised to predict the baryon asymmetry. The additional contribution to vertex correction mediated by the heavy left-handed triplet scalar is noted to contribute as dominantly as other Feynman diagrams. We have found successful predictions of the baryon asymmetry for both the patterns of right-handed neutrino masses. The SU(2) L triplet fermionic dark matter at the TeV scale carrying even matter parity is naturally embedded into the non-standard fermionic representation 45 F of SO(10). In addition to the triplet scalar and the triplet fermion, the model needs a nonstandard color octet fermion of mass ˜ 5 × 107 GeV to achieve precision gauge coupling unification at the GUT mass scale M U 0 = 1015.56 GeV. Threshold corrections due to superheavy components of 126H and other representations are estimated and found to be substantial. It is noted that the proton life
The Supersymmetric origin of matter
Energy Technology Data Exchange (ETDEWEB)
Balazs, C.; /Argonne; Carena, M.; /Fermilab; Menon, A.; Morrissey, D.E.; Wagner, C.E.M.; /Argonne /Chicago U., EFI
2004-12-01
The Minimal Supersymmetric extension of the Standard Model (MSSM) can provide the correct neutralino relic abundance and baryon number asymmetry of the universe. Both may be efficiently generated in the presence of CP violating phases, light charginos and neutralinos, and a light top squark. Due to the coannihilation of the neutralino with the light stop, we find a large region of parameter space in which the neutralino relic density is consistent with WMAP and SDSS data. We perform a detailed study of the additional constraints induced when CP violating phases, consistent with the ones required for baryogenesis, are included. We explore the possible tests of this scenario from present and future electron Electric Dipole Moment (EDM) measurements, direct neutralino detection experiments, collider searches and the b {yields} s{gamma} decay rate. We find that the EDM constraints are quite severe and that electron EDM experiments, together with stop searches at the Tevatron and Higgs searches at the LHC, will provide a definite test of our scenario of electroweak baryogenesis in the next few years.
Quantum Supersymmetric Bianchi IX Cosmology
Damour, Thibault
2014-01-01
We study the quantum dynamics of a supersymmetric squashed three-sphere by dimensionally reducing to one timelike dimension the action of D=4 simple supergravity for a Bianchi IX cosmological model. After imposition of the diffeomorphism constraints, the wave function of the Universe becomes a spinor of Spin(8,4) depending on the three squashing parameters, which satisfies Dirac, and Klein-Gordon-like, wave equations describing the propagation of a quantum spinning particle reflecting off spin-dependent potential walls. The algebra of the susy constraints and of the Hamiltonian one is found to close. One finds that the quantum Hamiltonian is built from operators that generate a 64-dimensional representation of the maximally compact sub-algebra of the rank-3 hyperbolic Kac-Moody algebra AE3. The (quartic-in-fermions) squared-mass term entering the Klein-Gordon-like equation has several remarkable properties: 1)it commutes with all the other (Kac-Moody-related) building blocks of the Hamiltonian; 2)it is a quad...
Quinto, A. G.; Ferrari, A. F.; Lehum, A. C.
2016-06-01
In this work, we investigate the consequences of the Renormalization Group Equation (RGE) in the determination of the effective superpotential and the study of Dynamical Symmetry Breaking (DSB) in an N = 1 supersymmetric theory including an Abelian Chern-Simons superfield coupled to N scalar superfields in (2 + 1) dimensional spacetime. The classical Lagrangian presents scale invariance, which is broken by radiative corrections to the effective superpotential. We calculate the effective superpotential up to two-loops by using the RGE and the beta functions and anomalous dimensions known in the literature. We then show how the RGE can be used to improve this calculation, by summing up properly defined series of leading logs (LL), next-to-leading logs (NLL) contributions, and so on... We conclude that even if the RGE improvement procedure can indeed be applied in a supersymmetric model, the effects of the consideration of the RGE are not so dramatic as it happens in the non-supersymmetric case.
Light composite scalar boson from a see-saw mechanism in two-scale TC models
National Research Council Canada - National Science Library
Doff, A; Natale, A.A
2015-01-01
We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models...
Vacuum stability and naturalness in type-II seesaw
Energy Technology Data Exchange (ETDEWEB)
Haba, Naoyuki; Ishida, Hiroyuki [Shimane University, Graduate School of Science and Engineering, Matsue (Japan); Okada, Nobuchika [University of Alabama, Department of Physics and Astronomy, Tuscaloosa, AL (United States); Yamaguchi, Yuya [Shimane University, Graduate School of Science and Engineering, Matsue (Japan); Hokkaido University, Department of Physics, Faculty of Science, Sapporo (Japan)
2016-06-15
We study the vacuum stability and perturbativity conditions in the minimal type-II seesaw model. These conditions give characteristic constraints to the model parameters. In the model, there is a SU(2){sub L} triplet scalar field, which could cause a large Higgs mass correction. From the naturalness point of view, heavy Higgs masses should be lower than 350 GeV, which may be testable by the LHC Run-II results. Due to the effects of the triplet scalar field, the branching ratios of the Higgs decay (h → γγ, Zγ) deviate from the standard model, and a large parameter region is excluded by the recent ATLAS and CMS combined analysis of h → γγ. Our result of the signal strength for h → γγ is R{sub γγ}
Disambiguating Seesaw Models using Invariant Mass Variables at Hadron Colliders
Dev, P S Bhupal; Mohapatra, Rabindra N
2015-01-01
We propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such models widely discussed in literature: (i) Standard Model extended by the addition of singlet neutrinos and (ii) Left-Right Symmetric Models. Relevant scenarios involving the same "smoking-gun" collider signature of dilepton plus dijet with no missing transverse energy differ from one another by their event topology, resulting in distinctive relationships among the kinematic endpoints to be used for discerning them at hadron colliders. These kinematic endpoints are readily translated to the mass parameters of the on-shell particles through simple analytic expressions which can be used for measuring the masses of the new particles. A Monte Carlo simulation with detector effects is conducted to test the viability of the proposed strategy in a realistic environment. Finally, we dis...
See-Saw Energy Scale and the LSND Anomaly
De Gouvêa, A
2005-01-01
The most general, renormalizable Lagrangian that includes massive neutrinos contains ``right-handed neutrino'' Majorana masses of order M. While there are prejudices in favor of M much larger than the weak scale, virtually nothing is known about the magnitude of M. I argue that the LSND anomaly provides, currently, the only experimental hint: M around 1 eV. If this is the case, the LSND mixing angles are functions of the active neutrino masses and mixing and, remarkably, adequate fits to all data can be naturally obtained. I also discuss consequences of this ``eV-seesaw'' for supernova neutrino oscillations, tritium beta-decay, neutrinoless double-beta decay, and cosmology.
The Seesaw Technique for Correction of Vertical Alar Discrepancy.
Hyun, Sang Min; Medikeri, Gaurav Shankar; Jung, Dong-Hak
2015-09-01
Alar vertical discrepancy including alar base has been viewed as one of the most challenging reconstructive problems in rhinoplasty. The authors have created a simple technique that consistently gives aesthetically acceptable results. The authors have designed the seesaw technique to correct alar discrepancy (type 1 to 3). Type 1 has been used in 14 patients, type 2 has been used in three patients, and type 3 has been used in seven patients. Alar discrepancy was corrected satisfactorily in all cases, with good cosmetic outcome. One case required scar revision and another case required revision for overcorrection; satisfactory results were ultimately achieved in both cases. This new technique is quite easy to design and is effective in the correction of alar discrepancy. It yields good postoperative results along with satisfactory aesthetic outcomes.
Axion Like Particles and the Inverse Seesaw Mechanism
Carvajal, C D R; Nishi, C C; Sánchez-Vega, B L
2015-01-01
Light pseudoscalars known as axion like particles (ALPs) may be behind physical phenomena like the Universe transparency to ultra-energetic photons, the soft $\\gamma$-ray excess from the Coma cluster, and the 3.5 keV line. We explore the connection of these particles with the inverse seesaw (ISS) mechanism for neutrino mass generation. We propose a very restrictive setting where the scalar field hosting the ALP is also responsible for generating the ISS mass scales through its vacuum expectation value on gravity induced nonrenormalizable operators. A discrete gauge symmetry protects the theory from the appearance of overly strong gravitational effects and discrete anomaly cancellation imposes strong constraints on the order of the group. The anomalous U$(1)$ symmetry leading to the ALP is an extended lepton number and the protective discrete symmetry can be always chosen as a subgroup of a combination of the lepton number and the baryon number.
A minimal three generation seesaw scenario for LSND
Brahmachari, B; Mohapatra, Rabindra N; Brahmachari, Biswajoy; Choubey, Sandhya; Mohapatra, Rabindra N.
2002-01-01
We show that in the minimal three generation seesaw models for neutrinos, the presence of leptonic $(L_e+L_{\\mu}-L_{\\tau})\\times S_2$ symmetry leads to one of the right handed neutrinos remaining massless. This state can then be identified with the sterile neutrino required for a simultaneous understanding of solar, atmospheric and LSND observations. We present a gauge model where the presence of higher dimensional operators originating from Planck scale physics lead to a realistic 2+2 mixed scenario that fits all oscillation data. The model predicts a range for the mixing angle $U_{e3}$ and an effective mass for neutrinos emitted in tritium decay, which can be used to test this model.
Democratic Seesaw Mass Matrix Model and New Physics
Koide, Y
1998-01-01
A seesaw mass matrix model is reviewed as a unification model of quark and lepton mass matrices. The model can understand why top-quark mass m_t is so singularly enhanced compared with other quark masses, especially, why m_t >> m_b in contrast to m_u = O(m_d), and why only top-quark mass is of the order of the electroweak scale Lambda_W, i.e., m_t = O(Lambda_W). The model predicts the fourth up-quark t' with a mass m_{t'}= O(m_{W_R}), and an abnormal structure of the right-handed up-quark mixing matrix U_R^u. Possible new physics is discussed.
Electron electric dipole moment in Inverse Seesaw models
Abada, Asmaa
2016-01-01
We consider the contribution of sterile neutrinos to the electric dipole moment of charged leptons in the most minimal realisation of the Inverse Seesaw mechanism, in which the Standard Model is extended by two right-handed neutrinos and two sterile fermion states. Our study shows that the two pairs of (heavy) pseudo-Dirac mass eigenstates can give significant contributions to the electron electric dipole moment, lying close to future experimental sensitivity if their masses are above the electroweak scale. The major contribution comes from two-loop diagrams with pseudo-Dirac neutrino states running in the loops. In our analysis we further discuss the possibility of having a successful leptogenesis in this framework, compatible with a large electron electric dipole moment.
See-saw masses for quarks and leptons
Rajpoot, S.
1987-09-01
An ambidextrous electroweak interaction model with SU(2)L×SU(2)R×U(1) gauge symmetry is described in which the conventional quarks and leptons are accompanied by a set of new fermions that transform as singlets of SU(2)L and SU(2)R. Only two doublets of Higgs scalars are introduced to break the gauge symmetry SU(2)L×SU(2)R×U(1) to U(1) of electromagnetism. The masses of all known quarks and leptons result from the Gell-Mann, Ramond, and Slansky ``see-saw mechanism'' between the conventional fermions and the new ``singlet'' fermions. The definition of the Fermi coupling constant and neutrino neutral-current interactions are identical to those of the standard SU(2)L×U(1) model. The singlet fermion masses lie in the 100-GeV to 1-TeV range to be probed by the oncoming accelerators of the 1990s.
Vacuum stability and naturalness in type-II seesaw
Haba, Naoyuki; Okada, Nobuchika; Yamaguchi, Yuya
2016-01-01
We study the vacuum stability and perturbativity conditions in the minimal type-II seesaw model. These conditions give characteristic constraints to model parameters. In the model, there is a $SU(2)_L$ triplet scalar field, which could cause a large Higgs mass correction. From the naturalness point of view, heavy Higgs masses should be lower than $350\\,{\\rm GeV}$, which can be testable by the LHC Run-II results. Due to effects of the triplet scalar field, branching ratios of the Higgs decay ($h\\to \\gamma \\gamma, Z\\gamma$) deviate from the standard model, and large parameter region is excluded by the recent ATLAS and CMS combined analysis of $h\\to \\gamma \\gamma$. Our result of the signal strength for $h\\to \\gamma \\gamma$ is $R_{\\gamma \\gamma} \\lesssim 1.1$, but its deviation is too small to observe at the LHC experiment.
Embedding cosmological inflation, axion dark matter and seesaw mechanism in a 3-3-1 gauge model
Ferreira, J. G.; de S. Pires, C. A.; Rodrigues, J. G.; Rodrigues da Silva, P. S.
2017-08-01
The Peccei-Quinn symmetry is an intrinsic global symmetry of the 3-3-1 gauge models. Its spontaneous breaking mechanism engendering an invisible KSVZ-like axion links the 3-3-1 models with new physics at ∼1010 GeV scale. The axion that results from this mechanism is an interesting candidate for the dark matter of the universe, while its real partner may drive inflation if radiative corrections are taken into account. This is obtained by connecting the type I seesaw mechanism with the spontaneous breaking of the Peccei-Quinn symmetry. In the end of the day we have a scenario providing a common answer to the strong-CP problem, inflation, dark matter and neutrino mass.
Embedding cosmological inflation, axion dark matter and seesaw mechanism in a 3-3-1 gauge model
Directory of Open Access Journals (Sweden)
J.G. Ferreira, Jr.
2017-08-01
Full Text Available The Peccei–Quinn symmetry is an intrinsic global symmetry of the 3-3-1 gauge models. Its spontaneous breaking mechanism engendering an invisible KSVZ-like axion links the 3-3-1 models with new physics at ∼1010 GeV scale. The axion that results from this mechanism is an interesting candidate for the dark matter of the universe, while its real partner may drive inflation if radiative corrections are taken into account. This is obtained by connecting the type I seesaw mechanism with the spontaneous breaking of the Peccei–Quinn symmetry. In the end of the day we have a scenario providing a common answer to the strong-CP problem, inflation, dark matter and neutrino mass.
Unifying Inflation with the Axion, Dark Matter, Baryogenesis, and the Seesaw Mechanism.
Ballesteros, Guillermo; Redondo, Javier; Ringwald, Andreas; Tamarit, Carlos
2017-02-17
A minimal extension of the standard model (SM) with a single new mass scale and providing a complete and consistent picture of particle physics and cosmology up to the Planck scale is presented. We add to the SM three right-handed SM-singlet neutrinos, a new vectorlike color triplet fermion, and a complex SM-singlet scalar σ that stabilizes the Higgs potential and whose vacuum expectation value at ∼10^{11} GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously. Primordial inflation is produced by a combination of σ (nonminimally coupled to the scalar curvature) and the SM Higgs boson. Baryogenesis proceeds via thermal leptogenesis. At low energies, the model reduces to the SM, augmented by seesaw-generated neutrino masses, plus the axion, which solves the strong CP problem and accounts for the dark matter in the Universe. The model predicts a minimum value of the tensor-to-scalar ratio r≃0.004, running of the scalar spectral index α≃-7×10^{-4}, the axion mass m_{A}∼100 μeV, and cosmic axion background radiation corresponding to an increase of the effective number of relativistic neutrinos of ∼0.03. It can be probed decisively by the next generation of cosmic microwave background and axion dark matter experiments.
Unifying Inflation with the Axion, Dark Matter, Baryogenesis, and the Seesaw Mechanism
Ballesteros, Guillermo; Redondo, Javier; Ringwald, Andreas; Tamarit, Carlos
2017-02-01
A minimal extension of the standard model (SM) with a single new mass scale and providing a complete and consistent picture of particle physics and cosmology up to the Planck scale is presented. We add to the SM three right-handed SM-singlet neutrinos, a new vectorlike color triplet fermion, and a complex SM-singlet scalar σ that stabilizes the Higgs potential and whose vacuum expectation value at ˜1 011 GeV breaks lepton number and a Peccei-Quinn symmetry simultaneously. Primordial inflation is produced by a combination of σ (nonminimally coupled to the scalar curvature) and the SM Higgs boson. Baryogenesis proceeds via thermal leptogenesis. At low energies, the model reduces to the SM, augmented by seesaw-generated neutrino masses, plus the axion, which solves the strong C P problem and accounts for the dark matter in the Universe. The model predicts a minimum value of the tensor-to-scalar ratio r ≃0.004 , running of the scalar spectral index α ≃-7 × 10-4, the axion mass mA˜100 μ eV , and cosmic axion background radiation corresponding to an increase of the effective number of relativistic neutrinos of ˜0.03 . It can be probed decisively by the next generation of cosmic microwave background and axion dark matter experiments.
A Supersymmetric Composite Model with Dynamical Supersymmetry Breaking
Kitazawa, N; Kitazawa, Noriaki; Okada, Nobuchika
1997-01-01
We present a supersymmetric composite model with dynamical supersymmetry breaking. The model is based on the gauge group $SU(2)_S \\times SU(2)_H \\times SU(3)_c \\times SU(2)_L \\times U(1)_Y$. Supersymmetry is dynamically broken by the non-perturbative effect of the $SU(2)_S$ `supercolor' interaction. The large top Yukawa coupling is naturally generated by the $SU(2)_H$ `hypercolor' interaction as recently proposed by Nelson and Strassler. The supersymmetry breaking is mediated to the standard model sector by a new mechanism. The electroweak symmetry breaking is caused by the radiative correction due to the large top Yukawa coupling with the supersymmetry breaking. This is the `radiative breaking scenario', which originates from the dynamics of the supercolor and hypercolor gauge interactions.
Hot-warm unstable supersymmetric dark matter and galaxy formation
Energy Technology Data Exchange (ETDEWEB)
Asselin, X.; Girardi, G.; Salati, P.; Blanchard, A.
1988-12-12
Recent observational results had lead to a revival of interest in neutrino-dominated universe. However, we recall that current constraints make the neutrino an unlikely candidate for the dark matter. In this paper, we show that a supersymmetric particle with a typical mass of a few tens of eV will be a much better candidate. Such a particle is radiatively unstable, and its lifetime is a few times larger than the age of the universe. This can drastically change the thermal history of the universe. We investigate in detail the heating of the intergalactic medium in the period z=100-z=10. In particular, we find that the universe can be fully reionized for lifetime less than or equal to 10/sup 24/. This, in turn, lowers the level of temperature fluctuations of the background radiation. We conclude that this model avoids the major problems of the neutrino picture.
The New Minimal Supersymmetric GUT: Spectra, RG analysis and fermion fits
Aulakh, Charanjit S.; Garg, Sumit K.
2012-04-01
The supersymmetric SO(10) GUT based on the 210⊕10⊕120⊕126⊕126¯ Higgs system provides a minimal framework for the emergence of the R-parity exact MSSM at low energies and a viable supersymmetric seesaw explanation for the observed neutrino masses and mixing angles. We present formulae for MSSM decomposition of the superpotential invariants, tree level light charged fermion effective Yukawa couplings, Weinberg neutrino mass generation operator, and the d=5, ΔB=ΔL≠0 effective superpotential in terms of GUT parameters. We use them to determine fits of the 18 available fermion mass-mixing data in terms of the superpotential parameters of the NMSGUT and SUGRY (NUHM) type soft supersymmetry breaking parameters ({m,m,A,MH,H¯2}) specified at the MSSM one-loop unification scale MX0=10 GeV. Our fits are compatible with electroweak symmetry breaking and Unification constraints and yield right-handed neutrino masses in the leptogenesis relevant range: 10-10 GeV. Matching the SM data requires lowering the strange and down quark Yukawas in the MSSM via large tanβ driven threshold corrections and characteristic soft Susy breaking spectra. The standard model Higgs mass emerges less than 130 GeV. The Susy spectra have light pure Bino LSP, heavy exotic Higgs(inos) and large μ, A, M parameters ˜100 TeV. Typically third generation sfermions are much heavier than the first two generations. The smuon is often the lightest charged sfermion thus offering a Bino-CDM co-annihilation channel. The parameter sets obtained are used to calculate B violation rates which are found to be generically much faster (˜10 yr) than the current experimental limits. Improvements which may allow acceptable B violation rates are identified.
Bubbles of nothing and supersymmetric compactifications
Energy Technology Data Exchange (ETDEWEB)
Blanco-Pillado, Jose J. [IKERBASQUE, Basque Foundation for Science, 48011, Bilbao (Spain); Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain); Shlaer, Benjamin [Department of Physics, University of Auckland,Private Bag 92019, Auckland (New Zealand); Institute of Cosmology, Department of Physics and Astronomy,Tufts University, Medford, MA 02155 (United States); Sousa, Kepa [Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain); Instituto de Fisica Teorica UAM-CSIC, Universidad Autonoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Urrestilla, Jon [Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain)
2016-10-03
We investigate the non-perturbative stability of supersymmetric compactifications with respect to decay via a bubble of nothing. We show examples where this kind of instability is not prohibited by the spin structure, i.e., periodicity of fermions about the extra dimension. However, such “topologically unobstructed” cases do exhibit an extra-dimensional analog of the well-known Coleman-De Luccia suppression mechanism, which prohibits the decay of supersymmetric vacua. We demonstrate this explicitly in a four dimensional Abelian-Higgs toy model coupled to supergravity. The compactification of this model to M{sub 3}×S{sub 1} presents the possibility of vacua with different windings for the scalar field. Away from the supersymmetric limit, these states decay by the formation of a bubble of nothing, dressed with an Abelian-Higgs vortex. We show how, as one approaches the supersymmetric limit, the circumference of the topologically unobstructed bubble becomes infinite, thereby preventing the realization of this decay. This demonstrates the dynamical origin of the decay suppression, as opposed to the more familiar argument based on the spin structure. We conjecture that this is a generic mechanism that enforces stability of any topologically unobstructed supersymmetric compactification.
Spectral properties in supersymmetric matrix models
Energy Technology Data Exchange (ETDEWEB)
Boulton, Lyonell, E-mail: L.Boulton@hw.ac.uk [Department of Mathematics and Maxwell Institute for Mathematical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Garcia del Moral, Maria Pilar, E-mail: garciamormaria@uniovi.es [Departamento de Fisica, Universidad de Oviedo, Avda Calvo Sotelo 18, 33007 Oviedo (Spain); Restuccia, Alvaro, E-mail: arestu@usb.ve [Departamento de Fisica, Universidad Simon Bolivar, Apartado 89000, Caracas (Venezuela, Bolivarian Republic of); Departamento de Fisica, Universidad de Oviedo, Avda Calvo Sotelo 18, 33007 Oviedo (Spain)
2012-03-21
We formulate a general sufficiency criterion for discreteness of the spectrum of both supersymmmetric and non-supersymmetric theories with a fermionic contribution. This criterion allows an analysis of Hamiltonians in complete form rather than just their semiclassical limits. In such a framework we examine spectral properties of various (1+0) matrix models. We consider the BMN model of M-theory compactified on a maximally supersymmetric pp-wave background, different regularizations of the supermembrane with central charges and a non-supersymmetric model comprising a bound state of N D2 with m D0. While the first two examples have a purely discrete spectrum, the latter has a continuous spectrum with a lower end given in terms of the monopole charge.
N=2 supersymmetric dynamics for pedestrians
Tachikawa, Yuji
2015-01-01
Understanding the dynamics of gauge theories is crucial, given the fact that all known interactions are based on the principle of local gauge symmetry. Beyond the perturbative regime, however, this is a notoriously difficult problem. Requiring invariance under supersymmetry turns out to be a suitable tool for analyzing supersymmetric gauge theories over a larger region of the space of parameters. Supersymmetric quantum field theories in four dimensions with extended N=2 supersymmetry are further constrained and have therefore been a fertile field of research in theoretical physics for quite some time. Moreover, there are far-reaching mathematical ramifications that have led to a successful dialogue with differential and algebraic geometry. These lecture notes aim to introduce students of modern theoretical physics to the fascinating developments in the understanding of N=2 supersymmetric gauge theories in a coherent fashion. Starting with a gentle introduction to electric-magnetic duality, the author guides r...
New dualities of supersymmetric gauge theories
2016-01-01
This book reviews a number of spectacular advances that have been made in the study of supersymmetric quantum field theories in the last few years. Highlights include exact calculations of Wilson loop expectation values, and highly nontrivial quantitative checks of the long-standing electric-magnetic duality conjectures. The book starts with an introductory article presenting a survey of recent advances, aimed at a wide audience with a background and interest in theoretical physics. The following articles are written for advanced students and researchers in quantum field theory, string theory and mathematical physics, our goal being to familiarize these readers with the forefront of current research. The topics covered include recent advances in the classification and vacuum structure of large families of N=2 supersymmetric field theories, followed by an extensive discussion of the localisation method, one of the most powerful tools for exact studies of supersymmetric field theories. The quantities that have ...
Superconformal Algebras and Supersymmetric Integrable Flows
Sachse, Christoph; Devchand, Chandrasekhar
2009-01-01
After a comprehensive review of superconformal algebras, super-diffeomorphisms and supervector fields on supercircles S^{1|n} we study various supersymmetric extensions of the KdV and Camassa-Holm equations. We describe their (super) Hamiltonian structures and their connection to bihamiltonian geometry. These are interpreted as geodesic flows on various superconformal groups. We also give an example of superintegrable systems of Ramond type. The one-parameter family of equations shown by Degasperis, Holm and Hone (DHH) to possess multi-peakon solutions is identified as a geodesic flow equation on a one-parameter deformation of the group of diffeomorphisms of the circle, with respect to a right-invariant Sobolev H^1--metric. A supersymmetrisation of the algebra of deformed vector fields on S^1 yields supersymmetric DHH equations (also known as b-field equations), which include the supersymmetric Camassa--Holm equation as a special case.
Supersymmetric defect models and mirror symmetry
Energy Technology Data Exchange (ETDEWEB)
Hook, Anson; Kachru, Shamit; Torroba, Gonzalo
2013-11-01
We study supersymmetric field theories in three space-time dimensions doped by various configurations of electric charges or magnetic fluxes. These are supersymmetric avatars of impurity models. In the presence of additional sources such configurations are shown to preserve half of the supersymmetries. Mirror symmetry relates the two sets of configurations. We discuss the implications for impurity models in 3d NN = 4 QED with a single charged hypermultiplet (and its mirror, the theory of a free hypermultiplet) as well as 3d NN = 2 QED with one flavor and its dual, a supersymmetric Wilson-Fisher fixed point. Mirror symmetry allows us to find backreacted solutions for arbitrary arrays of defects in the IR limit of NN = 4 QED. Our analysis, complemented with appropriate string theory brane constructions, sheds light on various aspects of mirror symmetry, the map between particles and vortices and the emergence of ground state entropy in QED at finite density.
Supersymmetric Defect Models and Mirror Symmetry
Hook, Anson; Torroba, Gonzalo
2013-01-01
We study supersymmetric field theories in three space-time dimensions doped by various configurations of electric charges or magnetic fluxes. These are supersymmetric avatars of impurity models. In the presence of additional sources such configurations are shown to preserve half of the supersymmetries. Mirror symmetry relates the two sets of configurations. We discuss the implications for impurity models in 3d N=4 QED with a single charged hypermultiplet (and its mirror, the theory of a free hypermultiplet) as well as 3d N=2 QED with one flavor and its dual, a supersymmetric Wilson-Fisher fixed point. Mirror symmetry allows us to find backreacted solutions for arbitrary arrays of defects in the IR limit of N=4 QED. Our analysis, complemented with appropriate string theory brane constructions, sheds light on various aspects of mirror symmetry, the map between particles and vortices and the emergence of ground state entropy in QED at finite density.
Gauging isometries in N=4 supersymmetric mechanics
Delduc, F
2008-01-01
This talk summarizes the study of superfield gaugings of isometries of extended supersymmetric mechanics in hep-th/0605211, hep-th/0611247 and arXiv:0706.0706. The gauging procedure provides a manifestly supersymmetric realization of d=1 automorphic dualities which interrelate various irreducible off-shell multiplets of d=1 extended supersymmetry featuring the same number of physical fermions but different divisions of bosonic fields into the physical and auxiliary subsets. We concentrate on the most interesting N=4 case and demonstrate that, with a suitable choice of the symmetry to be gauged, all such multiplets of N=4 supersymmetric mechanics and their generic superfield actions can be obtained from the "root" multiplet (4,4,0) and the appropriate gauged subclasses of the generic superfield action of the latter by a simple universal recipe.
Decoupling of Supersymmetric Particles in the MSSM
Dobado, A; Peñaranda, S
1998-01-01
A heavy supersymmetric spectrum at the Minimal Supersymmetric Standard Model is considered and the decoupling from the low energy electroweak scale is analyzed. A formal and partial proof of decoupling of supersymmetric particles in the limit where their masses are larger than the electroweak scale is performed by integrating out all the sparticles to one loop and by evaluating the effective action for the standard electroweak gauge bosons $W^{\\pm}, Z$ and two-point functions of the electroweak gauge bosons and the $S, T$ and $U$ parameters, to be valid in that limit, are also presented. A discussion on how the decoupling takes place in terms of both the physical sparticle masses and the non-physical mass parameters as the $\\mu$-parameter and the soft-breaking parameters is included.
Supersymmetric extension of the Snyder algebra
Energy Technology Data Exchange (ETDEWEB)
Gouba, L., E-mail: lgouba@ictp.it [Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34014 Trieste (Italy); Stern, A., E-mail: astern@bama.ua.edu [Dept. of Physics and Astronomy, Univ. of Alabama, Tuscaloosa, Al 35487 (United States)
2012-04-11
We obtain a minimal supersymmetric extension of the Snyder algebra and study its representations. The construction differs from the general approach given in Hatsuda and Siegel ( (arXiv:hep-th/0311002)) and does not utilize super-de Sitter groups. The spectra of the position operators are discrete, implying a lattice description of space, and the lattice is compatible with supersymmetry transformations. -- Highlights: Black-Right-Pointing-Pointer A new supersymmetric extension of the Snyder algebra is constructed. Black-Right-Pointing-Pointer The extension is minimal and the construction does not involve supersymmetric de Sitter algebras. Black-Right-Pointing-Pointer An involution is defined for the system and discrete representations are constructed. Black-Right-Pointing-Pointer The representations imply a spatial lattice and the lattice spacing is half that of the bosonic case. Black-Right-Pointing-Pointer A differential operator representation is given for fields on super-momentum space.
Quantum supersymmetric Bianchi IX cosmology
Damour, Thibault; Spindel, Philippe
2014-11-01
We study the quantum dynamics of a supersymmetric squashed three-sphere by dimensionally reducing (to one timelike dimension) the action of D =4 simple supergravity for a S U (2 ) -homogeneous (Bianchi IX) cosmological model. The quantization of the homogeneous gravitino field leads to a 64-dimensional fermionic Hilbert space. After imposition of the diffeomorphism constraints, the wave function of the Universe becomes a 64-component spinor of spin(8,4) depending on the three squashing parameters, which satisfies Dirac-like, and Klein-Gordon-like, wave equations describing the propagation of a "quantum spinning particle" reflecting off spin-dependent potential walls. The algebra of the supersymmetry constraints and of the Hamiltonian one is found to close. One finds that the quantum Hamiltonian is built from operators that generate a 64-dimensional representation of the (infinite-dimensional) maximally compact subalgebra of the rank-3 hyperbolic Kac-Moody algebra A E3 . The (quartic-in-fermions) squared-mass term μ^ 2 entering the Klein-Gordon-like equation has several remarkable properties: (i) it commutes with all the other (Kac-Moody-related) building blocks of the Hamiltonian; (ii) it is a quadratic function of the fermion number NF; and (iii) it is negative in most of the Hilbert space. The latter property leads to a possible quantum avoidance of the singularity ("cosmological bounce"), and suggests imposing the boundary condition that the wave function of the Universe vanish when the volume of space tends to zero (a type of boundary condition which looks like a final-state condition when considering the big crunch inside a black hole). The space of solutions is a mixture of "discrete-spectrum states" (parametrized by a few constant parameters, and known in explicit form) and of continuous-spectrum states (parametrized by arbitrary functions entering some initial-value problem). The predominantly negative values of the squared-mass term lead to a "bottle
Invariant Regularization of Supersymmetric Chiral Gauge Theory
Suzuki, H
1999-01-01
We present a regularization scheme which respects the supersymmetry and the maximal background gauge covariance in supersymmetric chiral gauge theories. When the anomaly cancellation condition is satisfied, the effective action in the superfield background field method automatically restores the gauge invariance without counterterms. The scheme also provides a background gauge covariant definition of composite operators that is especially useful in analyzing anomalies. We present several applications: The minimal consistent gauge anomaly; the super-chiral anomaly and the superconformal anomaly; as the corresponding anomalous commutators, the Konishi anomaly and an anomalous supersymmetric transformation law of the supercurrent (the ``central extension'' of N=1 supersymmetry algebra) and of the R-current.
Softly Broken Supersymmetric Gauge Theories through Compactifications
Takenaga, K
1998-01-01
Effects of boundary conditions of fields for compactified space directions on the supersymmetric gauge theories are discussed. For general and possible boundary conditions the supersymmetry is explicitly broken to yield universal soft supersymmetry breaking terms, and the gauge symmetry of the theory can also be broken through the dynamics of non-integrable phases, depending on number and the representation under the gauge group of matters. The 4-dimensional supersymmetric QCD is studied as a toy model when one of the space coordinates is compactified on $S^1$.
Just so oscillations in supersymmetric standard model
Joshipura, A S; Anjan S Joshipura; Marek Nowakowski
1995-01-01
We analyze the spectrum and mixing among neutrinos in the minimal supersymmetric standard model with explicit breaking of R parity. It is shown that ({\\em i}) the mixing among neutrinos is naturally large and ({\\em ii}) the non zero neutrino mass is constrained to be \\leq 10^{-5} eV from arguments based on baryogenesis. Thus vacuum oscillations of neutrinos in this model may offer a solution of the solar neutrino problem. The allowed space of the supersymmetric parameters consistent with this solution is determined.
Supersymmetric asymptotic safety is not guaranteed
DEFF Research Database (Denmark)
Intriligator, Kenneth; Sannino, Francesco
2015-01-01
It was recently shown that certain perturbatively accessible, non-supersymmetric gauge-Yukawa theories have UV asymptotic safety, without asymptotic freedom: the UV theory is an interacting RG fixed point, and the IR theory is free. We here investigate the possibility of asymptotic safety...... in supersymmetric theories, and use unitarity bounds, and the a-theorem, to rule it out in broad classes of theories. The arguments apply without assuming perturbation theory. Therefore, the UV completion of a non-asymptotically free susy theory must have additional, non-obvious degrees of freedom, such as those...
Supersymmetric asymptotic safety is not guaranteed
Intriligator, Kenneth
2015-01-01
It was recently shown that certain perturbatively accessible, non-supersymmetric gauge-Yukawa theories have UV asymptotic safety, without asymptotic freedom: the UV theory is an interacting RG fixed point, and the IR theory is free. We here investigate the possibility of asymptotic safety in supersymmetric theories, and use unitarity bounds, and the a-theorem, to rule it out in broad classes of theories. The arguments apply without assuming perturbation theory. Therefore, the UV completion of a non-asymptotically free susy theory must have additional, non-obvious degrees of freedom, such as those of an asymptotically free (perhaps magnetic dual) extension.
Supersymmetric axion grand unified theories and their predictions
Co, Raymond T.; D'Eramo, Francesco; Hall, Lawrence J.
2016-10-01
We introduce a class of unified supersymmetric axion theories with unified and Peccei-Quinn (PQ) symmetries broken by the same set of fields at a scale ˜2 ×1 016 GeV . A typical domain wall number of order 30 leads to an axion decay constant fa of order 1 015 GeV . Inflation generates a large saxion condensate, giving a reheat temperature TR below the QCD scale for supersymmetry breaking of order 1-10 TeV. Axion field oscillations commence in the saxion matter-dominated era near the QCD scale, and recent lattice computations of the temperature dependence of the axion mass in this era allow a controlled calculation of the axion dark matter abundance. The observed abundance can be successfully explained by an initial axion misalignment angle of order unity, θi˜1 . A highly correlated set of predictions is discussed for fa, TR, the supersymmetric Higgs mass parameter μ , the amount of dark radiation Δ Neff, the proton decay rate Γ (p →e+π0), isocurvature density perturbations and the B mode of the cosmic microwave background. The last two are particularly interesting when the energy scale of inflation is also of order 1 016 GeV .
Implications of a heavy top in supersymmetric theories
Leontaris, George K
1995-01-01
In the context of the radiative electroweak symmetry breaking scenario we investigate the implications of a heavy top quark mass, close to its infrared fixed point, on the low energy parameters of the minimal supersymmetric standard model. We use analytic expressions to calculate the Higgs masses as well as the supersymmetric masses of the third generation. We further assume bottom-tau unification at the GUT scale and examine the constraints put by this condition on the parameter space (\\tan\\beta,\\alpha_3), using the renormalization group procedure at the two-loop level. We find only a small fraction of the parameter space where the above conditions can be satisfied, namely 1\\le \\tan\\beta \\le 2, while 0.111\\le\\alpha_3(M_Z) \\le 0.118. We further analyse the case where all three Yukawa couplings reach the perturbative limit just after the unification scale. In this latter case, the situation turns out to be very strict demanding \\tan\\beta\\sim 63.
Angular Momentum of Supersymmetric Non-isotropic Traps
Institute of Scientific and Technical Information of China (English)
XU Qiang
2001-01-01
A simple way to explain quantum behavior of supersymmetric non-isotropic traps is proposed in the framework of sermiunitary formulation of supersymmetric quantum mechanics. Using semiunitary formulation we can simultaneously supersymmetrize the complete set of observables, especially including angular moment.
5D Maximally Supersymmetric Yang-Mills on the Lattice
Joseph, Anosh
2016-01-01
We provide details of the lattice construction of five-dimensional maximally supersymmetric Yang-Mills theory. The lattice theory is supersymmetric, gauge invariant and free from spectrum doublers. Such a supersymmetric lattice formulation is interesting as it can be used for non-perturbative explorations of the five-dimensional theory, which has a known gravitational dual.
Computing Maximally Supersymmetric Scattering Amplitudes
Stankowicz, James Michael, Jr.
This dissertation reviews work in computing N = 4 super-Yang--Mills (sYM) and N = 8 maximally supersymmetric gravity (mSUGRA) scattering amplitudes in D = 4 spacetime dimensions in novel ways. After a brief introduction and overview in Ch. 1, the various techniques used to construct amplitudes in the remainder of the dissertation are discussed in Ch. 2. This includes several new concepts such as d log and pure integrand bases, as well as how to construct the amplitude using exactly one kinematic point where it vanishes. Also included in this chapter is an outline of the Mathematica package on shell diagrams and numerics.m (osdn) that was developed for the computations herein. The rest of the dissertation is devoted to explicit examples. In Ch. 3, the starting point is tree-level sYM amplitudes that have integral representations with residues that obey amplitude relations. These residues are shown to have corresponding residue numerators that allow a double copy prescription that results in mSUGRA residues. In Ch. 4, the two-loop four-point sYM amplitude is constructed in several ways, showcasing many of the techniques of Ch. 2; this includes an example of how to use osdn. The two-loop five-point amplitude is also presented in a pure integrand representation with comments on how it was constructed from one homogeneous cut of the amplitude. On-going work on the two-loop n-point amplitude is presented at the end of Ch. 4. In Ch. 5, the three-loop four-point amplitude is presented in the d log representation and in the pure integrand representation. In Ch. 6, there are several examples of four- through seven-loop planar diagrams that illustrate how considerations of the singularity structure of the amplitude underpin dual-conformal invariance. Taken with the previous examples, this is additional evidence that the structure known to exist in the planar sector extends to the full theory. At the end of this chapter is a proof that all mSUGRA amplitudes have a pole at
Asymptotic iteration approach to supersymmetric bistable potentials
Institute of Scientific and Technical Information of China (English)
H. Ciftci; O. ozer; P. Roy
2012-01-01
We examine quasi exactly solvable bistable potentials and their supersymmetric partners within the framework of the asymptotic iteration method (AIM).It is shown that the AIM produces excellent approximate spectra and that sometimes it is found to be more useful to use the partner potential for computation. We also discuss the direct application of the AIM to the Fokker-Planck equation.
Photon structure function in supersymmetric QCD revisited
Energy Technology Data Exchange (ETDEWEB)
Sahara, Ryo, E-mail: sahara@scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Kyoto 606-8502 (Japan); Uematsu, Tsuneo, E-mail: uematsu@scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Kyoto 606-8502 (Japan); Kitadono, Yoshio, E-mail: kitadono@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei, Taiwan (China)
2012-02-07
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD and SQCD we evaluate the photon structure function and numerically study its behavior for the QCD and SQCD cases.
Photon Structure Function in Supersymmetric QCD Revisited
Sahara, Ryo; Kitadono, Yoshio
2011-01-01
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD and SQCD we evaluate the photon structure function and numerically study its behavior for the QCD and SQCD cases.
Neutrino masses and mixing in supersymmetric theories
Indian Academy of Sciences (India)
Sudhir K Vempati
2000-07-01
It has been known for sometime that supersymmetric theories with -parity violation provide a natural framework where small neutrino masses can be generated. We discuss neutrino masses and mixing in these theories in the presence of trilinear lepton number violating couplings. It will be shown that simultaneous solutions to solar and atmospheric neutrino problems can be realized in these models.
Spectral properties of supersymmetric shape invariant potentials
Indian Academy of Sciences (India)
Barnali Chakrabarti
2008-01-01
We present the spectral properties of supersymmetric shape invariant potentials (SIPs). Although the folded spectrum is completely random, unfolded spectrum shows that energy levels are highly correlated and absolutely rigid. All the SIPs exhibit harmonic oscillator-type spectral statistics in the unfolded spectrum. We conjecture that this is the reflection of shape invariant symmetry.
Partition functions for supersymmetric black holes
Manschot, J.
2008-01-01
This thesis presents a number of results on partition functions for four-dimensional supersymmetric black holes. These partition functions are important tools to explain the entropy of black holes from a microscopic point of view. Such a microscopic explanation was desired after the association of a
Supersymmetric integrable scattering theories with unstable particles
Fring, A
2005-01-01
We propose scattering matrices for N=1 supersymmetric integrable quantum field theories in 1+1 dimensions which involve unstable particles in their spectra. By means of the thermodynamic Bethe ansatz we analyze the ultraviolet behaviour of some of these theories and identify the effective Virasoro central charge of the underlying conformal field theories.
Geometry of all supersymmetric type I backgrounds
Gran, Ulf; Papadopoulos, George; Sloane, Peter; Roest, Diederik
2007-01-01
We find the geometry of all supersymmetric type I backgrounds by solving the gravitino and dilatino Killing spinor equations, using the spinorial geometry technique, in all cases. The solutions of the gravitino Killing spinor equation are characterized by their isotropy group in Spin(9, 1), while th
The spinorial method of classifying supersymmetric backgrounds
Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.
2006-01-01
We review how the classification of all supersymmetric backgrounds of IIB supergravity can be reduced to the evaluation of the Killing spinor equations and their integrability conditions, which contain the field equations, on five types of spinors. This is an extension of the work [hep-th/0503046] t
New supersymmetric localizations from topological gravity
Bae, Jinbeom; Imbimbo, Camillo; Rey, Soo-Jong; Rosa, Dario
2016-03-01
Supersymmetric field theories can be studied exactly on off-shell "localizing" supergravity backgrounds. We show that these supergravity configurations can be identified with BRST invariant configurations of background topological gravity coupled to background topological gauge multiplets. We apply this topological point of view to two-dimensional {N}=left(2,2right) supersymmetric matter theories to obtain, in a simple and straightforward way, a complete classification of localizing supersymmetric backgrounds in two dimensions. We recover all known localizing backgrounds and (infinitely) many more that have not been explored so far. The newly found localizing backgrounds are characterized by quantized fluxes for both graviphotons of the {N}=left(2,2right) supergravity multiplet. The BRST invariant topological backgrounds are parametrized by both Killing vectors and {{S}}^1 -equivariant cohomology of the two-dimensional spacetime. We completely reconstruct the supergravity backgrounds from the topological data: some of the supergravity fields are twisted versions of the topological backgrounds, but others are composite, in that they are nonlinear functionals of topological fields. Moreover, we show that the supersymmetric Ω-deformation is nothing but the background value of the ghost-for-ghost of topological gravity, a result which holds for higher dimensions too.
Effective action for supersymmetric chiral anomaly
Energy Technology Data Exchange (ETDEWEB)
Krivoshchekov, V.K.; Chekhov, L.O.
1987-05-01
It is shown that consistency conditions of the type of the Wess-Zumino conditions are necessary and sufficient conditions for local integrability of the supersymmetric chiral anomaly. It follows from the requirement of global integrability that the coefficient of the anomalous action is discrete. Explicit expressions are obtained for consistent anomalies and the corresponding functionals, which depend on superfields of various types.
Electric dipole moments in supersymmetric theories
Romanino, Andrea
1996-01-01
Intrinsic EDMs in microscopic systems at a level of sensitivity achievable in experiments under way or foreseen are predicted in supersymmetric unified theories. I describe this and other sources of measurable EDMs and I show how these sources can be distinguished through experiments in different systems.
Sterile Neutrinos, Dominant Seesaw Mechanisms, Double Beta Decay, and Other Predictions
Parida, M K
2016-01-01
In a recent review Mohapatra has discussed how type-I seesaw mechanism suppressed by fine tuning of Yukawa cpuplings, or specific textures of associated fermion mass matrices, can form the basis of neutrino masses in TeV scale $W_R$ boson models. In this paper we review recent works in another class of theories where the added presence of fermion singlets manifesting as sterile neutrinos render the type-I seesaw contribution vanishing but extended seesaw dominant where the light neutrino mass formula is same as the inverse seesaw but all massive neutrinos are Majorana fermions. We discuss how this cancellation criteria has led to a new mechanism of type-II seesaw dominance which also permits $U(1)_{B-L}$ breaking scale much smaller than the left-handed triplet mass and accessible to direct experimental tests. Out of a number of new observable predictions, the most visible one in both cases is the dominant contribution to double beta decay mediated by light sterile neutrinos in the $W_L-W_L$ channel. This sees...
Gravitational "seesaw" and light bending in higher-derivative gravity
Accioly, Antonio; Shapiro, Ilya L
2016-01-01
Local gravitational theories with more than four derivatives have remarkable quantum properties, e.g., they are super-renormalizable and may be unitary in the Lee-Wick sense. Therefore, it is important to explore also the IR limit of these theories and identify observable signatures of the higher derivatives. In the present work we study the scattering of a photon by a classical external gravitational field in the sixth-derivative model whose propagator contains only real, simple poles. Also, we discuss the possibility of a gravitational seesaw-like mechanism, which could allow the make up of a relatively small physical mass from the huge massive parameters of the action. If possible, this mechanism would be a way out of the Planck suppression, affecting the gravitational deflection of low energy photons. It turns out that the mechanism which actually occurs works only to shift heavier masses to the further UV region. This fact may be favourable for protecting the theory from instabilities, but makes experime...
Quark see-saw, Higgs mass and vacuum stability
Indian Academy of Sciences (India)
R N Mohapatra; Yongchao Zhangi
2016-02-01
The issue of vacuum stability of standard model (SM) is discussed by embedding it within the TeV scale left–right quark see-saw model. The Higgs potential in this case has only two coupling parameters (1, 2) and two mass parameters. There are only two physical neutral Higgs bosons (ℎ, ), the lighter one being identified with the 126 GeV Higgs boson. We explore the range of values for (1, 2) for which the vacuum is stable for all values of the Higgs fields till 1016 GeV. Combining with the further requirement that the scalar self-couplings remain perturbative till 1016 GeV, we findan upper and lower limit on the second Higgs () mass to be within the range: 0.4 ≤ (MH/vR) ≤ 0.7, where vR is the parity breaking scale andthe masses of heavy vector-like top, bottom and partner fermions (3, 3, 3) have an upper bound ≤vR. These predictions can be tested at LHC and future higher energy colliders.
Disambiguating seesaw models using invariant mass variables at hadron colliders
Energy Technology Data Exchange (ETDEWEB)
Dev, P.S. Bhupal [Consortium for Fundamental Physics, School of Physics and Astronomy,University of Manchester, Manchester M13 9PL (United Kingdom); Physik-Department T30d, Technische Univertität München,James-Franck-Straße 1, 85748 Garching (Germany); Kim, Doojin [Department of Physics, University of Florida,Gainesville, FL 32611 (United States); Mohapatra, Rabindra N. [Maryland Center for Fundamental Physics and Department of Physics,University of Maryland,College Park, Maryland 20742 (United States)
2016-01-19
We propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such models widely discussed in literature: (i) Standard Model extended by the addition of singlet neutrinos and (ii) Left-Right Symmetric Models. Relevant scenarios involving the same “smoking-gun” collider signature of dilepton plus dijet with no missing transverse energy differ from one another by their event topology, resulting in distinctive relationships among the kinematic endpoints to be used for discerning them at hadron colliders. These kinematic endpoints are readily translated to the mass parameters of the on-shell particles through simple analytic expressions which can be used for measuring the masses of the new particles. A Monte Carlo simulation with detector effects is conducted to test the viability of the proposed strategy in a realistic environment. Finally, we discuss the future prospects of testing these scenarios at the √s=14 and 100 TeV hadron colliders.
Neutrino Phenomenology of Very Low-Energy Seesaws
De Gouvêa, A; Vasudevan, N; Gouvea, Andre de; Jenkins, James; Vasudevan, Nirmala
2007-01-01
The Standard Model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this ``New Standard Model'' are right-handed neutrino Majorana masses M. Theoretical prejudice points to M much larger than the electroweak symmetry breaking scale, but it has recently been emphasized that all M values are technically natural and should be explored. Indeed, M around 1-10 eV can accommodate an elegant oscillation solution to the LSND anomaly, while other M values lead to several observable consequences. We consider the phenomenology of low energy seesaw scenarios with M less than and equal to approximately 1 keV. By exploring such a framework with three right-handed neutrinos, we can consistently fit all oscillation data -- including those from LSND -- while partially addressing several astrophysical puzzles, including anomalous pulsar kicks, heavy element nucleosynthesis in supernovae, and the existence of wa...
Higgs inflation, seesaw physics and fermion dark matter
Directory of Open Access Journals (Sweden)
Nobuchika Okada
2015-07-01
Full Text Available We present an inflationary model in which the Standard Model Higgs doublet field with non-minimal coupling to gravity drives inflation, and the effective Higgs potential is stabilized by new physics which includes a dark matter particle and right-handed neutrinos for the seesaw mechanism. All of the new particles are fermions, so that the Higgs doublet is the unique inflaton candidate. With central values for the masses of the top quark and the Higgs boson, the renormalization group improved Higgs potential is employed to yield the scalar spectral index ns≃0.968, the tensor-to-scalar ratio r≃0.003, and the running of the spectral index α=dns/dlnk≃−5.2×10−4 for the number of e-folds N0=60 (ns≃0.962, r≃0.004, and α≃−7.5×10−4 for N0=50. The fairly low value of r≃0.003 predicted in this class of models means that the ongoing space and land based experiments are not expected to observe gravity waves generated during inflation.
Higgs Inflation, Seesaw Physics and Fermion Dark Matter
Okada, Nobuchika
2015-01-01
We present an inflationary model in which the Standard Model Higgs doublet field with non-minimal coupling to gravity drives inflation, and the effective Higgs potential is stabilized by new physics which includes a dark matter particle and right-handed neutrinos for the seesaw mechanism. All of the new particles are fermions, so that the Higgs doublet is the unique inflaton candidate. With central values for the masses of the top quark and the Higgs boson, the renormalization group improved Higgs potential is employed to yield the scalar spectral index $n_s \\simeq 0.968$, the tensor-to-scalar ratio $r \\simeq 0.003$, and the running of the spectral index $\\alpha=dn_s/d \\ln k \\simeq -5.2 \\times 10^{-4}$ for the number of e-folds $N_0=60$ ($n_s \\simeq 0.962$, $r \\simeq 0.004$, and $\\alpha \\simeq -7.5 \\times 10^{-4}$ for $N_0=50$). The fairly low value of $r \\simeq 0.003$ predicted in this class of models means that the ongoing space and land based experiments are not expected to observe gravity waves generated ...
Spontaneous R-Parity Violating Type III Seesaw
Choubey, Sandhya
2009-01-01
We present a model where neutrino masses are generated by a combination of spontaneous R-parity violation and Type III seesaw. In addition to the usual MSSM particle content, our model consists of one extra triplet matter chiral superfield containing heavy SU(2) triplet fermions and its superpartners. R-parity is broken spontaneously when the sneutrinos associated with the one heavy neutrino as well as the three light neutrinos get vacuum expectation values, giving rise to the mixed $8\\times 8$ neutralino-neutrino mass matrix. We show that our model can comfortably explain all the existing neutrino oscillation data. Due to the presence of the triplet fermion, we have a pair of additional heavy charged leptons which mix with the standard model charged leptons and the charginos. This gives rise to a $6\\times 6$ chargino-charged lepton mass matrix, with 6 massive eigenstates. Finally we discuss about the different R-parity violating possible decay modes and the distinctive collider signatures which our model off...
Type-II Seesaw and Multilepton Signatures at Hadron Colliders
Mitra, Manimala; Spannowsky, Michael
2016-01-01
We investigate multilepton signatures, arising from the decays of doubly charged and singly charged Higgs bosons in the Type-II Seesaw model. Depending on the vacuum expectation value of the triplet $v_{\\Delta}$, the doubly and singly charged Higgs bosons can decay into a large variety of multi-lepton final states. We explore all possible decay modes corresponding to different regimes of $v_{\\Delta}$, that generate distinguishing four and five leptonic signatures. We focus on the 13 TeV Large Hadron Collider (LHC) and further extend the study to a very high energy proton-proton collider (VLHC) with a center-of-mass energy of 100 TeV. We find that a doubly charged Higgs boson of masses around 375 GeV can be discovered at immediate LHC runs. A heavier mass of 630 GeV can instead be discovered at the high-luminosity run of the LHC or at the VLHC with 30 $\\rm{fb}^{-1}$.
Littlest Seesaw model from S4 x U(1)
King, Stephen F
2016-01-01
We show how a minimal (littlest) seesaw model involving two right-handed neutrinos and a very constrained Dirac mass matrix, with one texture zero and two independent Dirac masses, may arise from $S_4\\times U(1)$ symmetry. The resulting CSD3 form of neutrino mass matrix only depends on two real mass parameters plus one undetermined phase. We show how the phase may be fixed to be one of the cube roots of unity by extending the $S_4\\times U(1)$ symmetry to include a product of $Z_3$ factors together with a CP symmetry, which is spontaneously broken leaving a single residual $Z_3$ in the charged lepton sector and a residual $Z_2$ in the neutrino sector, with suppressed higher order corrections. With the phase chosen from the cube roots of unity to be $-2\\pi/3$, the model predicts a normal neutrino mass hierarchy with $m_1=0$, reactor angle $\\theta_{13}=8.7^\\circ$, solar angle $\\theta_{12}=34^\\circ$, atmospheric angle $\\theta_{23}=44^\\circ$, and CP violating oscillation phase $\\delta_{\\rm CP}=-93^\\circ$, dependin...
Minimal supersymmetric hybrid inflation, flipped SU(5) and proton decay
Energy Technology Data Exchange (ETDEWEB)
Rehman, Mansoor Ur; Shafi, Qaisar [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Wickman, Joshua R., E-mail: jwickman@udel.ed [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)
2010-04-26
Minimal supersymmetric hybrid inflation utilizes a canonical Kaehler potential and a renormalizable superpotential which is uniquely determined by imposing a U(1) R-symmetry. In computing the scalar spectral index n{sub s} we take into account modifications of the tree level potential caused by radiative and supergravity corrections, as well as contributions from the soft supersymmetry breaking terms with a negative soft mass-squared term allowed for the inflaton. All of these contributions play a role in realizing n{sub s} values in the range 0.96-0.97 preferred by WMAP. The U(1) R-symmetry plays an important role in flipped SU(5) by eliminating the troublesome dimension five proton decay. The proton decays into e{sup +}pi{sup 0} via dimension six operators arising from the exchange of superheavy gauge bosons with a lifetime of order 10{sup 34}-10{sup 36} years.
Supersymmetric models with tan$\\beta$ close to unity
Ananthanarayan, B; Shafi, Qaisar
1994-01-01
Within the framework of supersymmetric grand unification, estimates of the $b$ quark mass based on the asymptotic relation $m_b \\simeq m_\\tau$ single out the region with $\\tan\\beta$ close to unity, particularly if $m_t(m_t) \\stackrel{_<}{_\\sim} 170\\ GeV$. We explore the radiative breaking of the electroweak symmetry and the associated sparticle and higgs spectroscopy in models with $1 < \\tan\\beta \\stackrel{_<}{_\\sim} 1.6$. The lightest scalar higgs is expected to have a mass below $100\\ GeV$, while the remaining four higgs masses exceed $300\\ GeV$. The lower bounds on some of the sparticle masses are within the range of LEP 200.
Top-color jungle gym: An alternative to the seesaw mechanism
Georgi, Howard; Grant, Aaron K.
2001-01-01
We discuss an alternative to the top-color seesaw mechanism. In our scheme, all the light quarks carry top-color, and there are many composite SU(2) doublets. This makes it possible to get the observed t quark mass and observed SU(2)×U(1) breaking in a way that is quite different from the classic seesaw mechanism. We discuss a model of this kind that arises naturally in the context of dynamically broken top-color. There are many composite scalars in a theory of this kind. This has important effects on the Pagels-Stokar relation and the Higgs boson mass. We find mHiggs<~330 GeV, lighter than in typical top-color models. We also show that the electroweak singlet quarks in such a model can be lighter than the corresponding quarks in a seesaw model.
Electroweak naturalness in three-flavour Type I see-saw and implications for leptogenesis
Clarke, Jackson D; Volkas, Raymond R
2015-01-01
In the Type I see-saw model, the naturalness requirement that corrections to the electroweak $\\mu$ parameter not exceed 1 TeV results in a rough bound on the lightest right-handed neutrino mass, $M_{N_1}\\lesssim 3\\times 10^7$ GeV. In this letter we derive generic bounds applicable in any three-flavour Type I see-saw model. We find $M_{N_1}\\lesssim 4\\times 10^7$ GeV and $M_{N_2}\\lesssim 7\\times 10^7$ GeV. In the limit of one massless neutrino, there is no naturalness bound on $M_{N_3}$ in the Poincare protected decoupling limit. Our results confirm that no Type I see-saw model can explain the observed neutrino masses and baryogenesis via hierarchical ($N_1$-, $N_2$-, or $N_3$-dominated) thermal leptogenesis whilst remaining completely natural.
Type I and $new$ seesaw in left-right symmetric theories
Chakrabortty, Joydeep
2010-01-01
We extend the Type I seesaw and suggest a $new$ seesaw mechanism to generate neutrino masses within the left-right symmetric theories where parity is spontaneously broken. We construct a next to minimal left-right symmetric model where neutrino masses are determined irrespective of the B-L breaking scale and call it the $new$ seesaw mechanism. In this scenario B-L scale can be very low. This makes B-L gauge boson and the quasi-Dirac $heavy$ leptons very light. These TeV scale particles could have large impact on lepton flavor and CP violating processes. We also shed light on the phenomenological aspects of the model within the reach of the LHC.
Friedberg-Lee symmetry and tribimaximal neutrino mixing in the inverse seesaw mechanism
Chan, Aik Hui; Low, Hwee Boon; Xing, Zhi-Zhong
2009-10-01
The inverse seesaw mechanism with three pairs of gauge-singlet neutrinos offers a natural interpretation of the tiny masses of three active neutrinos at the TeV scale. We combine this picture with the newly proposed Friedberg-Lee (FL) symmetry in order to understand the observed pattern of neutrino mixing. We show that the FL symmetry requires only two pairs of the gauge-singlet neutrinos to be massive, implying that one active neutrino must be massless. We propose a phenomenological ansatz with broken FL symmetry and exact μ-τ symmetry in the gauge-singlet neutrino sector, and obtain the tribimaximal neutrino mixing pattern by means of the inverse seesaw relation. We demonstrate that nonunitary corrections to this result can possibly reach the percent level, and a soft breaking of μ-τ symmetry can give rise to CP violation in such a TeV-scale seesaw scenario.
Multiple seesaw mechanisms of neutrino masses at the TeV scale
Xing, Zhi-zhong
2009-01-01
In pursuit of a balance between theoretical naturalness and experimental testability, we propose two classes of multiple seesaw mechanisms at the TeV scale to understand the origin of tiny neutrino masses. They are novel extensions of the canonical and double seesaw mechanisms, respectively, by introducing even and odd numbers of gauge-singlet fermions and scalars. It is thanks to a proper implementation of the global U(1)xZ_2N symmetry that the overall neutrino mass matrix in either class has a suggestive nearest-neighbor-interaction pattern. We briefly discuss possible consequences of these TeV-scale seesaw scenarios, which can hopefully be explored in the upcoming Large Hadron Collider and precision neutrino experiments, and present a simple but instructive example of model building.
Type II Seesaw Origin of Non-zero $\\theta_{13}, \\delta_{CP} $ and Leptogenesis
Borah, Debasish
2014-01-01
We discuss the possible origin of non-zero reactor mixing angle $\\theta_{13}$ and Dirac CP phase $\\delta_{CP}$ in the leptonic sector from a combination of type I and type II seesaw mechanisms. Type I seesaw contribution to neutrino mass matrix is of tri-bimaximal (TBM) type which gives rise to vanishing $\\theta_{13}$ leaving the Dirac CP phase undetermined. If the Dirac neutrino mass matrix is assumed to take the diagonal charged lepton type structure, such a TBM type neutrino mass matrix originating from type I seesaw corresponds to real values of Dirac Yukawa couplings in the terms $Y_{ij} \\bar{L_i} H N_j$. This makes the process of right handed heavy neutrino decay into a light neutrino and Higgs $(N \\rightarrow \
Friedberg-Lee symmetry and tri-bimaximal neutrino mixing in the inverse seesaw mechanism
Chan, Aik Hui; Xing, Zhi-zhong
2009-01-01
The inverse seesaw mechanism with three pairs of gauge-singlet neutrinos offers a natural interpretation of the tiny masses of three active neutrinos at the TeV scale. We combine this picture with the newly-proposed Friedberg-Lee (FL) symmetry in order to understand the observed pattern of neutrino mixing. We show that the FL symmetry requires only two pairs of the gauge-singlet neutrinos to be massive, implying that one active neutrino must be massless. We propose a phenomenological ansatz with broken FL symmetry and exact \\mu-\\tau symmetry in the gauge-singlet neutrino sector and obtain the tri-bimaximal neutrino mixing pattern by means of the inverse seesaw relation. We demonstrate that non-unitary corrections to this result are possible to reach the percent level and a soft breaking of \\mu-\\tau symmetry can give rise to CP violation in such a TeV-scale seesaw scenario.
Neutrinoless Double Beta Decay in LRSM with Natural Type-II seesaw Dominance
Pritimita, Prativa; Patra, Sudhanwa
2016-01-01
We present a detailed discussion on neutrinoless double beta decay within a class of left-right symmetric models where neutrino mass originates by natural type II seesaw dominance. The spontaneous symmetry breaking is implemented with doublets, triplets and bidoublet scalars. The fermion sector is extended with an extra sterile neutrino per generation that helps in implementing the seesaw mechanism. The presence of extra particles in the model exactly cancels type-I seesaw and allows large value for Dirac neutrino mass matrix $M_D$. The key feature of this work is that all the physical masses and mixing are expressed in terms of neutrino oscillation parameters and lightest neutrino mass thereby facilitating to constrain light neutrino masses from $0\
Small numbers in supersymmetric theories of nature
Energy Technology Data Exchange (ETDEWEB)
Graesser, Michael Lawrence [Univ. of California, Berkeley, CA (United States)
1999-05-01
The Standard Model of particle interactions is a successful theory for describing the interactions of quarks, leptons and gauge bosons at microscopic distance scales. Despite these successes, the theory contains many unsatisfactory features. The origin of particle masses is a central mystery that has eluded experimental elucidation. In the Standard Model the known particles obtain their mass from the condensate of the so-called Higgs particle. Quantum corrections to the Higgs mass require an unnatural fine tuning in the Higgs mass of one part in 10^{-32} to obtain the correct mass scale of electroweak physics. In addition, the origin of the vast hierarchy between the mass scales of the electroweak and quantum gravity physics is not explained in the current theory. Supersymmetric extensions to the Standard Model are not plagued by this fine tuning issue and may therefore be relevant in Nature. In the minimal supersymmetric Standard Model there is also a natural explanation for electroweak symmetry breaking. Supersymmetric Grand Unified Theories also correctly predict a parameter of the Standard Model. This provides non-trivial indirect evidence for these theories. The most general supersymmetric extension to the Standard Model however, is excluded by many physical processes, such as rare flavor changing processes, and the non-observation of the instability of the proton. These processes provide important information about the possible structure such a theory. In particular, certain parameters in this theory must be rather small. A physics explanation for why this is the case would be desirable. It is striking that the gauge couplings of the Standard Model unify if there is supersymmetry close to the weak scale. This suggests that at high energies Nature is described by a supersymmetric Grand Unified Theory. But the mass scale of unification must be introduced into the theory since it does not coincide with the probable mass scale of strong quantum gravity
Role of lepton flavor violating (LFV) muon decay in Seesaw model and LSND
Aslam, M J
2002-01-01
The aim of the work is to study LFV in a newly proposed Seesaw model of neutrino mass and to see whether it could explain LSND excess. The motivation of this Seesaw model was that there was no new physics beyond the TeV scale. By studying \\mu \\to 3e in this model, it is shown that the upper bound on the branching ratio requires Higgs mass m_{h} of a new scalar doublet with lepton number L=-1 needed in the model has to be about 9 TeV. The predicted branching ratio for \\mu \\to e\
TeV scale double seesaw in left-right symmetric theories
Chakrabortty, Joydeep
2010-01-01
We extend the Type I and Type III seesaw mechanisms to generate neutrino masses within the left-right symmetric theories where parity is spontaneously broken. We construct a next to minimal left-right symmetric model where neutrino masses are generated through a variant $double$ seesaw mechanism. In our model at least one of the triplet fermions and the right handed neutrinos are at TeV scale and others are heavy. The phenomenological aspects and testability of the TeV scale particles at collider experiments are discussed. The decays of heavy fermions leading to leptogenesis are pointed out.
Seesaw Scale and CP Phases in a Minimal Model of Leptogenesis
Kim, Siyeon
2016-01-01
The seesaw mechanism to derive the light masses of left-handed neutrinos using heavy masses of right-handed neutrinos gives rise to a connection between low-energy measurables and GUT-scale mechanism. We expresses the neutrino mixing angles in terms of a single variable $\\sin\\theta_{13}$, whose size was measured recently. The lepton asymmetry from heavy neutrinos via Yukawa coupling is described by CP phases in both Dirac and Majorana type. It is shown that the seesaw scale relevant to the lepton asymmetry can be constrained by CP phase in this minimal model.
Seesaw scale and CP phases in a minimal model of leptogenesis
Siyeon, Kim
2016-12-01
The seesaw mechanism to derive the light masses of left-handed neutrinos using heavy masses of right-handed neutrinos gives rise to a connection between low-energy measurables and Grand Unified Theory (GUT)-scale mechanism. We express the neutrino mixing angles in terms of a single variable sin θ 13, whose size was measured recently. The lepton asymmetry from the decays of heavy neutrinos via Yukawa coupling is described by CP phases in both Dirac and Majorana type. It is shown that the seesaw scale relevant to the lepton asymmetry can be constrained by CP phase in this minimal model.
The Effective Lagrangian for the Seesaw Model of Neutrino Mass and Leptogenesis
Broncano, A; Jenkins, E
2003-01-01
The effective Lagrangian for the seesaw model is derived including effects due to CP violation. Besides the usual dimension-5 operator responsible for light neutrino masses, a dimension-6 operator is obtained. For three or less heavy neutrino generations, the inclusion of both operators is necessary and sufficient for all independent physical parameters of the high-energy seesaw Lagrangian to appear in the low-energy effective theory, including the CP-odd phases relevant for leptogenesis. The dimension-6 operator implies exotic low-energy couplings for light neutrinos, providing a link between the high-energy physics and low-energy observables.
The effective Lagrangian for the seesaw model of neutrino mass and leptogenesis
Energy Technology Data Exchange (ETDEWEB)
Broncano, A.; Gavela, M.B.; Jenkins, E
2003-01-23
The effective Lagrangian for the seesaw model is derived including effects due to CP-violation. Besides the usual dimension-5 operator responsible for light neutrino masses, a dimension-6 operator is obtained. For three or less heavy neutrino generations, the inclusion of both operators is necessary and sufficient for all independent physical parameters of the high-energy seesaw Lagrangian to appear in the low-energy effective theory, including the CP-odd phases relevant for leptogenesis. The dimension-6 operator implies exotic low-energy couplings for light neutrinos, providing a link between the high-energy physics and low-energy observables.
Measuring And Explaining The Supersymmetric Lagrangian
Wang, L
2002-01-01
The issues of measuring the supersymmetric Lagrangian once data is available, and making the connections between the low energy effective Lagrangian and fundamental theory, are considered. After a brief introduction to the fundamentals of supersymmetry and overview of Minimal Supersymmetric Standard Model (MSSM), case studies in ways of measuring different parameters in the low energy MSSM Lagrangian are presented. They include: measuring CP violation phases and LSP masses in gluino decay; Higgs production and detection; flavor and CP violation in b → sγ processes; signature of cold dark matter in the cosmic rays. Potential ambiguities in the process of recovering the high energy effective Lagrangian from low energy data are discussed. A new basis, which is explicitly independent of unphysical parameters, is proposed to write the renormalization group equations. After a brief survey of some basic issues of string theory phenomenology, a string theory motivated Pati-Salam like model is const...
A supersymmetric consistent truncation for conifold solutions
Cassani, Davide
2010-01-01
We establish a supersymmetric consistent truncation of type IIB supergravity on the T^{1,1} coset space, based on extending the Papadopoulos-Tseytlin ansatz to the full set of SU(2)xSU(2) invariant Kaluza-Klein modes. The five-dimensional model is a gauged N=4 supergravity with three vector multiplets, which incorporates various conifold solutions and is suitable for the study of their dynamics. By analysing the scalar potential we find a family of new non-supersymmetric AdS_5 extrema interpolating between a solution obtained long ago by Romans and a solution employing an Einstein metric on T^{1,1} different from the standard one. Finally, we discuss some simple consistent subtruncations preserving N=2 supersymmetry. One of them is compatible with the inclusion of smeared D7-branes.
Bound States Of Supersymmetric Black Holes
Britto-Pacumio, R A
2002-01-01
The quantum mechanics of N slowly-moving supersymmetric black holes in five dimensions is considered. A divergent continuum of states describing arbitrarily closely bound black holes with arbitrarily small excitation energies is found. A superconformal structure appears at low energies and can be used to define a topological index counting the weighted number of supersymmetric bound states. It is shown that the index is determined from the dimensions of certain cohomology classes on the symmetric product of N copies of R4. This bound state index is computed exactly for two and three black holes. The required regulator for the infrared continuum of near-coincident black holes is chosen in accord with the enhanced superconformal symmetry.
Phenomenology of the Utilitarian Supersymmetric Standard Model
Fraser, Sean; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza
2016-01-01
We study the 2010 specific version of the 2002 proposed $U(1)_X$ extension of the supersymmetric standard model, which has no $\\mu$ term and conserves baryon number and lepton number separately and automatically. We consider in detail the scalar sector as well as the extra $Z_X$ gauge boson, and their interactions with the necessary extra color-triplet particles of this model, which behave as leptoquarks. We show how the diphoton excess at 750 GeV, recently observed at the LHC, may be explained within this context. We identify a new fermion dark-matter candidate and discuss its properties. An important byproduct of this study is the discovery of relaxed supersymmetric constraints on the Higgs boson's mass of 125 GeV.
Phenomenology of the utilitarian supersymmetric standard model
Fraser, Sean; Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza
2016-08-01
We study the 2010 specific version of the 2002 proposed U(1)X extension of the supersymmetric standard model, which has no μ term and conserves baryon number and lepton number separately and automatically. We consider in detail the scalar sector as well as the extra ZX gauge boson, and their interactions with the necessary extra color-triplet particles of this model, which behave as leptoquarks. We show how the diphoton excess at 750 GeV, recently observed at the LHC, may be explained within this context. We identify a new fermion dark-matter candidate and discuss its properties. An important byproduct of this study is the discovery of relaxed supersymmetric constraints on the Higgs boson's mass of 125 GeV.
Supersymmetric QCD: Exact Results and Strong Coupling
Dine, Michael; Pack, Lawrence; Park, Chang-Soon; Ubaldi, Lorenzo; Wu, Weitao
2011-01-01
We revisit two longstanding puzzles in supersymmetric gauge theories. The first concerns the question of the holomorphy of the coupling, and related to this the possible definition of an exact (NSVZ) beta function. The second concerns instantons in pure gluodynamics, which appear to give sensible, exact results for certain correlation functions, which nonetheless differ from those obtained using systematic weak coupling expansions. For the first question, we extend an earlier proposal of Arkani-Hamed and Murayama, showing that if their regulated action is written suitably, the holomorphy of the couplings is manifest, and it is easy to determine the renormalization scheme for which the NSVZ formula holds. This scheme, however, is seen to be one of an infinite class of schemes, each leading to an exact beta function; the NSVZ scheme, while simple, is not selected by any compelling physical consideration. For the second question, we explain why the instanton computation in the pure supersymmetric gauge theory is...
Selecting Supersymmetric String Scenarios From Sparticle Spectra
Allanach, Benjamin C; Quevedo, Fernando
2002-01-01
We approach the following question: if supersymmetry is discovered, how can we select among different supersymmetric extensions of the Standard Model? In particular, we perform an analysis of the sparticle spectrum in low-energy string effective theories, asking which observables best distinguish various scenarios. We examine scenarios differing by the fundamental string scale and concentrate on GUT and intermediate scale models. We scan over all parameters (two goldstino angles, tan beta and the gravitino mass) in each scenario, finding ratios of sparticle masses that provide the maximum discrimination between them. The necessary accuracy for discrimination is determined in each case. We find that the required accuracy on various sparticle mass ratios is at the few percent level, a precision that may be achieved in future linear colliders. We place phenomenological constraints on the parameter space and determine the supersymmetric contribution to the muon anomalous magnetic moment.
New Supersymmetric Localizations from Topological Gravity
Bae, Jinbeom; Rey, Soo-Jong; Rosa, Dario
2015-01-01
Supersymmetric field theories can be studied exactly on suitable off-shell supergravity backgrounds. We show that in two dimensions such backgrounds are identifiable with BRST invariant backgrounds of topological gravity coupled to an abelian topological gauge multiplet. This latter background is required for the consistent coupling of the topological `matter' YM theory to topological gravity. We make use of this topological point of view to obtain, in a simple and straightforward way, a complete classification of localizing supersymmetric backgrounds in two dimensions. The BRST invariant topological backgrounds are parametrized by both Killing vectors and $S^1$-equivariant cohomology of the 2-dimensional world-sheet. We reconstruct completely the supergravity backgrounds from the topological data: some of the supergravity fields are twisted versions of the topological backgrounds, but others are "composite", i.e. they are non-linear functionals of them. We recover all the known localizing 2-dimensional backg...
Galoisian Approach to Supersymmetric Quantum Mechanics
Acosta-Humanez, Primitivo B
2009-01-01
This thesis is concerning to the Differential Galois Theory point of view of the Supersymmetric Quantum Mechanics. The main object considered here is the non-relativistic stationary Schr\\"odinger equation, specially the integrable cases in the sense of the Picard-Vessiot theory and the main algorithmic tools used here are the Kovacic algorithm and the \\emph{algebrization method} to obtain linear differential equations with rational coefficients. We analyze the Darboux transformations, Crum iterations and supersymmetric quantum mechanics with their \\emph{algebrized} versions from a Galoisian approach. Applying the algebrization method and the Kovacic's algorithm we obtain the ground state, the set of eigenvalues, eigenfunctions, the differential Galois groups and eigenrings of some Schr\\"odinger equation with potentials such as exactly solvable and shape invariant potentials. Finally, we introduce one methodology to find exactly solvable potentials: to construct other potentials, we apply the algebrization alg...
Supersymmetric composite gauge fields with compensators
Nishino, Hitoshi; Rajpoot, Subhash
2016-06-01
We study supersymmetric composite gauge theory, supplemented with compensator mechanism. As our first example, we give the formulation of N = 1 supersymmetric non-Abelian composite gauge theory without the kinetic term of a non-Abelian gauge field. The important ingredient is the Proca-Stueckelberg-type compensator scalar field that makes the gauge-boson field equation non-singular, i.e., the field equation can be solved for the gauge field algebraically as a perturbative expansion. As our second example, we perform the gauging of chiral-symmetry for N = 1 supersymmetry in four dimensions by a composite gauge field. These results provide supporting evidence for the consistency of the mechanism that combines the composite gauge field formulations and compensator formulations, all unified under supersymmetry.
Flavor Mixing Phenomenology in Supersymmetric Models
Rehman, Muhammad
2016-01-01
This dissertation investigates the flavor mixing effects in supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays, lepton flavor violating charged lepton decays and lepton flavor violating Higgs decays. The flavor mixing effects are studied in model independent way i.e. by putting off-diagonal entries in the sfermion mass matrix by hand as well as in the minimal flavor violating constrained MSSM, where mixing can originate from CKM matrix in the case of squarks and from PMNS matrix in the case of sleptons. We found that flavor mixing can have large impact to some observables, enabling us to put new constraints on parameter space in supersymmetric models.
Topological solitons in the supersymmetric Skyrme model
Gudnason, Sven Bjarke; Sasaki, Shin
2016-01-01
A supersymmetric extension of the Skyrme model was obtained recently, which consists of only the Skyrme term in the Nambu-Goldstone (pion) sector complemented by the same number of quasi-Nambu-Goldstone bosons. Scherk-Schwarz dimensional reduction yields a kinetic term in three or lower dimensions and a potential term in two dimensions, preserving supersymmetry. Euclidean solitons (instantons) are constructed in the supersymmetric Skyrme model. In four dimensions, the soliton is an instanton first found by Speight. Scherk-Schwarz dimensional reduction is then performed once to get a 3-dimensional theory in which a 3d Skyrmion-instanton is found and then once more to get a 2d theory in which a 2d vortex-instanton is obtained. Although the last one is a global vortex it has finite action in contrast to conventional theory. All of them are non-BPS states breaking all supersymmetries.
Planar Gravitational Corrections For Supersymmetric Gauge Theories
Dijkgraaf, R; Ooguri, H; Vafa, C; Zanon, D
2004-01-01
In this paper we discuss the contribution of planar diagrams to gravitational F-terms for N=1 supersymmetric gauge theories admitting a large N description. We show how the planar diagrams lead to a universal contribution at the extremum of the glueball superpotential, leaving only the genus one contributions, as was previously conjectured. We also discuss the physical meaning of gravitational F-terms.
Approximate Flavor Symmetry in Supersymmetric Model
Tao, Zhijian
1998-01-01
We investigate the maximal approximate flavor symmetry in the framework of generic minimal supersymmetric standard model. We consider the low energy effective theory of the flavor physics with all the possible operators included. Spontaneous flavor symmetry breaking leads to the approximate flavor symmetry in Yukawa sector and the supersymmetry breaking sector. Fermion mass and mixing hierachies are the results of the hierachy of the flavor symmetry breaking. It is found that in this theory i...
Utilitarian Supersymmetric Gauge Model of Particle Interactions
Ma, Ernest
2010-01-01
A remarkable U(1) gauge extension of the supersymmetric standard model was proposed eight years ago. It is anomaly-free, has no mu term, and conserves baryon and lepton numbers automatically. The phenomenology of a specific version of this model is discussed. In particular, leptoquarks are predicted, with couplings to the heavy singlet neutrinos, the scalar partners of which may be components of dark matter. The Majorana neutrino mass matrix itself may have two zero subdeterminants.
Renormalizable supersymmetric gauge theory in six dimensions
Energy Technology Data Exchange (ETDEWEB)
Ivanov, E.A. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation)]. E-mail: eivanov@theor.jinr.ru; Smilga, A.V. [SUBATECH, Universite de Nantes, 4 rue Alfred Kastler, BP 20722, Nantes 44307 (France)]. E-mail: smilga@subatech.in2p3.fr; Zupnik, B.M. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation)]. E-mail: zupnik@theor.jinr.ru
2005-10-17
We construct and discuss a 6D supersymmetric gauge theory involving four derivatives in the action. The theory involves a dimensionless coupling constant and is renormalizable. At the tree level, it enjoys N=(1,0) superconformal symmetry, but the latter is broken by quantum anomaly. Our study should be considered as preparatory for seeking an extended version of this theory which would hopefully preserve conformal symmetry at the full quantum level and be ultraviolet-finite.
Supersymmetric solutions for non-relativistic holography
Energy Technology Data Exchange (ETDEWEB)
Donos, Aristomenis [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gauntlett, Jerome P. [Blackett Laboratory, Imperial College, London (United Kingdom)]|[Institute for Mathematical Sciences, Imperial College, London (United Kingdom)
2009-01-15
We construct families of supersymmetric solutions of type IIB and D=11 supergravity that are invariant under the non-relativistic conformal algebra for various values of dynamical exponent z{>=}4 and z{>=}3, respectively. The solutions are based on five- and seven-dimensional Sasaki-Einstein manifolds and generalise the known solutions with dynamical exponent z=4 for the type IIB case and z=3 for the D=11 case, respectively. (orig.)
Simple supersymmetric methods in neutron diffusion
1996-01-01
We present the supersymmetric Witten and double Darboux (strictly isospectral) constructions as applied to the diffusion of thermal neutrons from an infinitely long line source. While the Witten construction is just a mathematical scheme, the double Darboux method introduces a one-parameter family of diffusion solutions which are strictly isospectral to the stationary solution. They correspond to a Darboux-transformed diffusion length which is flux dependent
Supersymmetric branes on curved spaces and fluxes
Triendl, Hagen
2015-01-01
We discuss general supersymmetric brane configurations in flux backgrounds of string and M-theory and derive a necessary condition for the worldvolume theory to be supersymmetric on a given curved manifold. This condition resembles very much the conditions found from coupling a supersymmetric field theory to off-shell supergravity but can be derived in any dimension and for up to sixteen supercharges. Apart from the topological twist, all couplings appearing in the supersymmetry condition are linked to fluxes in the bulk. We explicitly derive the condition for D3-, M2- and M5-branes, in which case the results are also useful for constructing holographic duals to the corresponding field theories. In $N=1$ setups we compare the supersymmetry conditions to those that arise by coupling the field theory to off-shell supergravity. We find that the couplings of both old and new minimal supergravity are simultaneously realized, indicating that off-shell supergravity should be coupled via the S-multiplet of 16/16 supe...
Cosmological consequences of supersymmetric flat directions
Riva, Francesco; Sarkar, Subir; Giudice, Gian
In this work we analyze various implications of the presence of large field vacum expectation values (VEVs) along supersymmetric flat direct ions during the early universe. First, we discuss supersymmetric leptogenesis and the grav itino bound. Supersym- metric thermal leptogenesis with a hierarchical right-han ded neutrino mass spectrum normally requires the mass of the lightest right-handed neu trino to be heavier than about 10 9 GeV. This is in conflict with the upper bound on the reheating t empera- ture which is found by imposing that the gravitinos generate d during the reheating stage after inflation do not jeopardize successful nucleosy nthesis. We show that a solution to this tension is actually already incorporated i n the framework, because of the presence of flat directions in the supersymmetric scalar potential. Massive right- handed neutrinos are efficiently produced non-thermally and the observed baryon asymmetry can be explained even for a reheating temperature respecting the grav- itino bound...
Non-supersymmetric Orientifolds of Gepner Models
Gato-Rivera, B
2008-01-01
Starting from a previously collected set of tachyon-free closed strings, we search for N=2 minimal model orientifold spectra which contain the standard model and are free of tachyons and tadpoles at lowest order. For each class of tachyon-free closed strings -- bulk supersymmetry, automorphism invariants or Klein bottle projection -- we do indeed find non-supersymmetric and tachyon free chiral brane configurations that contain the standard model. However, a tadpole-cancelling hidden sector could only be found in the case of bulk supersymmetry. Although about half of the examples we have found make use of branes that break the bulk space-time supersymmetry, the resulting massless open string spectra are nevertheless supersymmetric in all cases. Dropping the requirement that the standard model be contained in the spectrum, we find chiral tachyon and tadpole-free solutions in all three cases, although in the case of bulk supersymmetry all massless spectra are supersymmetric. In the other two cases we find truly ...
Likelihood Analysis of Supersymmetric SU(5) GUTs
Energy Technology Data Exchange (ETDEWEB)
Bagnaschi, E. [DESY; Costa, J. C. [Imperial Coll., London; Sakurai, K. [Warsaw U.; Borsato, M. [Santiago de Compostela U.; Buchmueller, O. [Imperial Coll., London; Cavanaugh, R. [Illinois U., Chicago; Chobanova, V. [Santiago de Compostela U.; Citron, M. [Imperial Coll., London; De Roeck, A. [Antwerp U.; Dolan, M. J. [Melbourne U.; Ellis, J. R. [King' s Coll. London; Flächer, H. [Bristol U.; Heinemeyer, S. [Madrid, IFT; Isidori, G. [Zurich U.; Lucio, M. [Santiago de Compostela U.; Martínez Santos, D. [Santiago de Compostela U.; Olive, K. A. [Minnesota U., Theor. Phys. Inst.; Richards, A. [Imperial Coll., London; de Vries, K. J. [Imperial Coll., London; Weiglein, G. [DESY
2016-10-31
We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has 7 parameters: a universal gaugino mass $m_{1/2}$, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), $m_5$ and $m_{10}$, and for the $\\mathbf{5}$ and $\\mathbf{\\bar 5}$ Higgs representations $m_{H_u}$ and $m_{H_d}$, a universal trilinear soft SUSY-breaking parameter $A_0$, and the ratio of Higgs vevs $\\tan \\beta$. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + MET events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously-identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel ${\\tilde u_R}/{\\tilde c_R} - \\tilde{\\chi}^0_1$ coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of ${\\tilde \
Geometry and duality in Supersymmetric $\\sigma$-Models
Curtright, T L; Zachos, C K; Curtright, Thomas; Uematsu, Tsuneo; Zachos, Cosmas
1996-01-01
The Supersymmetric Dual Sigma Model (SDSM) is a local field theory introduced to be nonlocally equivalent to the Supersymmetric Chiral nonlinear sigma-Model (SCM), this dual equivalence being proven by explicit canonical transformation in tangent space. This model is here reconstructed in superspace and identified as a chiral-entwined supersymmetrization of the Dual Sigma Model (DSM). This analysis sheds light on the Boson-Fermion Symphysis of the dual transition, and on the new geometry of the DSM.
Bilinear approach to N=2 supersymmetric KdV equations
Institute of Scientific and Technical Information of China (English)
2009-01-01
The N=2 supersymmetric KdV equations are studied within the framework of Hirota bilinear method. For two such equations, namely N=2, a=4 and N=2, a=1 supersymmetric KdV equations, we obtain the corresponding bilinear formulations. Using them, we construct particular solutions for both cases. In particular, a bilinear Bcklund transformation is given for the N=2, a=1 supersymmetric KdV equation.
Vertex Operators for Irregular Conformal Blocks: Supersymmetric Case
Polyakov, Dimitri
2016-01-01
We construct supersymmetric irregular vertex operators of arbitrary rank, appearing in the colliding limit of primary fields. We find that the structure of the supersymmetric irregular vertices differs significantly from the bosonic case: upon supersymmetrization, the irregular operators are no longer the eigenstates of positive Virasoro and $W_N$ generators but block-diagonalize them. We relate the block-diagonal structure of the irregular vertices to contributions of the Ramond sector to the colliding limit.
On supersymmetric Chern-Simons-type theories in five dimensions
Kuzenko, Sergei M
2014-01-01
We present a closed-form expression for the supersymmetric non-Abelian Chern-Simons action in conventional five-dimensional N=1 superspace. Our construction makes use of the superform formalism to generate supersymmetric invariants. Similar ideas are applied to construct supersymmetric actions for off-shell supermultiplets with an intrinsic central charge. In particular, the large tensor multiplet is described in superspace for the first time.
Generational seesaw mechanism in [SU(6)][sup 3][times][ital Z][sub 3
Energy Technology Data Exchange (ETDEWEB)
Ponce, W.A. (Departamento de Fisica, Universidad de Antioquia A. A. 1226, Medellin (Colombia) Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Apartado Postal 14-740, 07000 Mexico Distrito Federal (Mexico)); Zepeda, A. (Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Apartado Postal 14-740, 07000 Mexico Distrito Federal (Mexico)); Lozano, R.G. (Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Apartado Postal 14-740, 07000 Mexico Distrito Federal (Mexico) Departamento de Fisica, Universidad Surcolombiana A. A. 385, Neiva (Colombia))
1994-05-01
For the gauge group [SU(6)[sup 3][times][ital Z][sub 3] which unifies nongravitational forces with flavors we analyze the generational seesaw mechanism. At the tree level we get [ital m][sub [nu][ital e
Fuzzy coordinator compensation for balancing control of cart-seesaw system
Lin, J.; Guo, S.-Y.; Chang, Julian
2011-12-01
In contrast with fully controllable systems, a super articulated mechanical system (SAMS) is a controlled underactuated mechanical system in which the dimensions of the configuration space exceed the dimensions of the control input space. The control of the cart-seesaw system is especially difficult since it is an underactuated mechanism (three degrees of freedom and only two inputs). This research develops a balancing approach for a novel SAMS model, called the cart-seesaw system, using fuzzy logic and fuzzy coordinator compensation to drive the sliding carts and keep the seesaw angle close to zero in the equilibrium state. Experimental results indicate that utilizing the proposed control methodology significantly enhances the performance. Moreover, the presentation of the fuzzy balancing controller is not considerably affected by changes in the environmental parameters, which demonstrates the effectiveness of the fuzzy controller in minimizing the seesaw tilt angle in the time domain, although the system is caused by unpredicted loading variation. Moreover, the experimental results indicate the usefulness and robustness of the proposed fuzzy control methodology. Furthermore, the proposed software/hardware platform can be beneficial for standardizing laboratory equipment and developing amusement apparatus.
Carvalho, R. L.; Almeida, G. L.
2009-01-01
Background: The purpose of this study was to investigate the kinematic and electromyography strategy used by individuals with intellectual disability to keep equilibrium during anterior-posterior balance on seesaws with different degrees of instability. Method: Six individuals with Down syndrome (DS) and six control group individuals (CG) balanced…
A neutrino mass model with S3 symmetry and see-saw interplay
Pramanick, Soumita
2016-01-01
We develop a see-saw model for neutrino masses and mixing with an S3\\times Z3 symmetry. It involves an interplay of Type-I and Type-II see-saw contributions of which the former is subdominant. The S3 \\times Z3 quantum numbers of the fermion and scalar fields are chosen such that the Type-II see-saw generates a mass matrix which incorporates the atmospheric mass splitting and sets \\theta_{23} = \\pi/4. The solar splitting and \\theta_{13} are absent, while the third mixing angle can achieve any value, \\theta_{12}^0. Specific choices of \\theta_{12}^0 are of interest, e.g., 35.3^\\circ (tribimaximal), 45.0^\\circ (bimaximal), 31.7^\\circ (golden ratio), and 0^\\circ (no solar mixing). The role of the Type-I see-saw is to nudge all quantities into the range indicated by the data. The model results in novel interrelationships between these quantities due to their common origin, making it readily falsifiable. For example, normal (inverted) ordering is associated with \\theta_{23} in the first (second) octant. CP-violation...
Seesaw-deflected Anomaly Mediation and the 125 GeV Higgs Boson
Tran, Hieu Minh; Okada, Nobuchika
2016-06-01
We investigate the phenomenology of a class of model that at the same time solves the tachyonic slepton problem of the pure anomaly mediated supersymmetry breaking (AMSB) model and generates neutrino masses. We introduce heavy fields in the seesaw mechanism that are the messengers in the deflected AMSB scenario. Various theoretical and phenomenological constraints have been taken into account, especially the Higgs mass limits. The viable parameter regions have been specified, and the properties of dark matter candidate have been studied. We point out that the type III seesaw with three generations of 24-messenger is excluded, while the type II seesaw and type III seesaw with two generations of 24-messenger are still allowed. The sparticle masses are heavy as in usual SUSY models. The spin-independent crosssection of the scattering between the lightest neutralino and proton show the possibility to see evidences of new physics from future dark matter search experiments. We find that the lepton flavor violation effects caused by the Yukawa mediation are suppressed due to the electroweak symmetry breaking condition.
Borah, Manikanta; Das, Mrinal Kumar; Patra, Sudhanwa
2014-01-01
We study the possibility of generating non-zero reactor mixing angle $\\theta_{13}$ by perturbing the $\\mu-\\tau$ symmetric neutrino mass matrix. The leading order $\\mu-\\tau$ symmetric neutrino mass matrix originates from type I seesaw mechanism whereas the perturbations to $\\mu-\\tau$ symmetry originate from type II seesaw term. We consider four different realizations of $\\mu-\\tau$ symmetry: Bimaximal Mixing(BM), Tri-bimaximal Mixing (TBM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM) all giving rise to $\\theta_{13} = 0, \\theta_{23} = \\frac{\\pi}{4}$ but different non-zero values of solar mixing angle $\\theta_{12}$. We assume a minimal $\\mu-\\tau$ symmetry breaking type II seesaw mass matrix as a perturbation and calculate the neutrino oscillation parameters as a function of type II seesaw strength. We then consider the origin of non-trivial leptonic CP phase in the charged lepton sector and calculate the lepton asymmetry arising from the lightest right handed neutrino decay by incorporating the presence o...
A see-saw scenario of an $A_4$ flavour symmetric standard model
Dinh, Dinh Nguyen; Văn, Phi Quang; Vân, Nguyen Thi Hông
2016-01-01
A see-saw scenario for an $A_4$ flavour symmetric standard model is presented. As before, the see-saw mechanism can be realized in several models of different types depending on different ways of neutrino mass generation corresponding to the introduction of new fields with different symmetry structures. In the present paper, a general desription of all these see-saw types is made with a more detailed investigation on type-I models. As within the original see-saw mechanism, the symmetry structure of the standard model fields decides the number and the symmetry structure of the new fields. In a model considered here, the scalar sector consists of three standard-model-Higgs-like iso-doublets ($SU_L(2)$-doublets) forming an $A_4$ triplet. The latter is a superposition of three mass-eigen states, one of which could be identified with the recently discovered Higgs boson. A possible relation to the still-deliberated 750 GeV diphoton resonance at the 13 TeV LHC collisions is also discussed. In the lepton sector, the ...
Non-renormalization theorems andN=2 supersymmetric backgrounds
Energy Technology Data Exchange (ETDEWEB)
Butter, Daniel [Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Wit, Bernard de [Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Institute for Theoretical Physics, Utrecht University,Leuvenlaan 4, 3584 CE Utrecht (Netherlands); Lodato, Ivano [Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands)
2014-03-28
The conditions for fully supersymmetric backgrounds of general N = 2 locally supersymmetric theories are derived based on the off-shell superconformal multiplet calculus. This enables the derivation of a non-renormalization theorem for a large class of supersymmetric invariants with higher-derivative couplings. The theorem implies that the invariant and its first order variation must vanish in a fully supersymmetric background. The conjectured relation of one particular higher-derivative invariant with a specific five-dimensional invariant containing the mixed gauge-gravitational Chern-Simons term is confirmed.
Non-renormalization theorems and N=2 supersymmetric backgrounds
Butter, Daniel; Lodato, Ivano
2014-01-01
The conditions for fully supersymmetric backgrounds of general N=2 locally supersymmetric theories are derived based on the off-shell superconformal multiplet calculus. This enables the derivation of a non-renormalization theorem for a large class of supersymmetric invariants with higher-derivative couplings. The theorem implies that the invariant and its first order variation must vanish in a fully supersymmetric background. The conjectured relation of one particular higher-derivative invariant with a specific five-dimensional invariant containing the mixed gauge-gravitational Chern-Simons term is confirmed.
One-loop adjoint masses for non-supersymmetric intersecting branes
Energy Technology Data Exchange (ETDEWEB)
Anastasopoulos, P. [Technische Univ., Vienna (Austria). 1. Inst. fuer Theoretische Physik; Antoniadis, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Benakli, K. [CNRS, UPMC Univ. Paris (France). Lab. de Physique Theorique et Haute Energies; Goodsell, M.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vichi, A. [Institute de Theorie des Phenomenes Physiques, EPFL, Lausanne (Switzerland)
2011-05-15
We consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane world-volumes. In the open string channel, the string two-point function receives contributions only from the infrared and the ultraviolet limits. The latter is due to tree-level closed string uncanceled NS-NS tadpoles, which we explicitly reproduce from the effective Born-Infeld action. On the other hand, the infrared region reproduces the one-loop mediation of supersymmetry breaking in the effective gauge theory, via messengers and their Kaluza-Klein excitations. In the toroidal set-up considered here, it receives contributions only from N {approx} 4 and N {approx} 2 supersymmetric configurations, and thus always leads at leading order to a tachyonic direction, in agreement with effective field theory expectations. (orig.)
Testing the Higgs Sector of the Minimal Supersymmetric Standard Model at Large Hadron Colliders
Kunszt, Zoltán
1992-01-01
We study the Higgs sector of the Minimal Supersymmetric Standard Model, in the context of proton-proton collisions at LHC and SSC energies. We assume a relatively heavy supersymmetric particle spectrum, and include recent results on one-loop radiative corrections to Higgs-boson masses and couplings. We begin by discussing present and future constraints from the LEP experiments. We then compute branching ratios and total widths for the neutral ($h,H,A$) and charged ($H^\\pm$) Higgs particles. We present total cross-sections and event rates for the important discovery channels at the LHC and SSC. Promising physics signatures are given by $h \\to \\gamma \\gamma$, $H \\to \\gamma \\gamma$ or $Z^* Z^*$ or $\\tau^+ \\tau^-$, $A \\to \\tau^+ \\tau^-$, and $t \\to b H^+$ followed by $H^+ \\to \\tau^+ \
Discriminating neutrino mass models using Type-II see-saw formula
Indian Academy of Sciences (India)
N Nimal Singh; Mahadev Patagiri; Mrinal Kumar Das
2006-02-01
An attempt has been made to discriminate theoretically the three possible patterns of neutrino mass models,viz., degenerate, inverted hierarchical and normal hierachical models, within the framework of Type-II see-saw formula. From detailed numerical analysis we are able to arrive at a conclusion that the inverted hierarchical model with the same CP phase (referred to as Type [IIA]), appears to be most favourable to survive in nature (and hence most stable), with the normal hierarchical model (Type [III]) and inverted hierarchical model with opposite CP phase (Type [IIB]), follow next. The degenerate models (Types [IA,IB,IC]) are found to be most unstable. The neutrino mass matrices which are obtained using the usual canonical see-saw formula (Type I), and which also give almost good predictions of neutrino masses and mixings consistent with the latest neutrino oscillation data, are re-examined in the presence of the left-handed Higgs triplet within the framework of non-canonical see-saw formula (Type II). We then estimate a parameter (the so-called discriminator) which may represent the minimum degree of suppression of the extra term arising from the presence of left-handed Higgs triplet, so as to restore the good predictions on neutrino masses and mixings already acquired in Type-I see-saw model. The neutrino mass model is said to be favourable and hence stable when its canonical see-saw term dominates over the non-canonical (perturbative) term, and this condition is used here as a criterion for discriminating neutrino mass models.
Likelihood analysis of supersymmetric SU(5) GUTs
Energy Technology Data Exchange (ETDEWEB)
Bagnaschi, E. [DESY, Hamburg (Germany); Costa, J.C. [Imperial College, London (United Kingdom). Blackett Lab.; Sakurai, K. [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomonology; Warsaw Univ. (Poland). Inst. of Theoretical Physics; Collaboration: MasterCode Collaboration; and others
2016-10-15
We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has 7 parameters: a universal gaugino mass m{sub 1/2}, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), m{sub 5} and m{sub 10}, and for the 5 and anti 5 Higgs representations m{sub H{sub u}} and m{sub H{sub d}}, a universal trilinear soft SUSY-breaking parameter A{sub 0}, and the ratio of Higgs vevs tan β. In addition to previous constraints from direct sparticle searches, low-energy and avour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets+E{sub T} events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously-identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel u{sub R}/c{sub R}-χ{sup 0}{sub 1} coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of ν{sub T} coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC.
Likelihood analysis of supersymmetric SU(5) GUTs
Energy Technology Data Exchange (ETDEWEB)
Bagnaschi, E.; Weiglein, G. [DESY, Hamburg (Germany); Costa, J.C.; Buchmueller, O.; Citron, M.; Richards, A.; De Vries, K.J. [Imperial College, High Energy Physics Group, Blackett Laboratory, London (United Kingdom); Sakurai, K. [University of Durham, Science Laboratories, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); University of Warsaw, Faculty of Physics, Institute of Theoretical Physics, Warsaw (Poland); Borsato, M.; Chobanova, V.; Lucio, M.; Martinez Santos, D. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Cavanaugh, R. [Fermi National Accelerator Laboratory, Batavia, IL (United States); University of Illinois at Chicago, Physics Department, Chicago, IL (United States); Roeck, A. de [CERN, Experimental Physics Department, Geneva (Switzerland); Antwerp University, Wilrijk (Belgium); Dolan, M.J. [University of Melbourne, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Parkville (Australia); Ellis, J.R. [King' s College London, Theoretical Particle Physics and Cosmology Group, Department of Physics, London (United Kingdom); Theoretical Physics Department, CERN, Geneva 23 (Switzerland); Flaecher, H. [University of Bristol, H.H. Wills Physics Laboratory, Bristol (United Kingdom); Heinemeyer, S. [Campus of International Excellence UAM+CSIC, Cantoblanco, Madrid (Spain); Instituto de Fisica Teorica UAM-CSIC, Madrid (Spain); Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Isidori, G. [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Olive, K.A. [University of Minnesota, William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, Minneapolis, MN (United States)
2017-02-15
We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has seven parameters: a universal gaugino mass m{sub 1/2}, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), m{sub 5} and m{sub 10}, and for the 5 and anti 5 Higgs representations m{sub H{sub u}} and m{sub H{sub d}}, a universal trilinear soft SUSY-breaking parameter A{sub 0}, and the ratio of Higgs vevs tan β. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + E{sub T} events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel u{sub R}/c{sub R} - χ{sup 0}{sub 1} coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of ν{sub τ} coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC. (orig.)
Counting Trees in Supersymmetric Quantum Mechanics
Cordova, Clay
2015-01-01
We study the supersymmetric ground states of the Kronecker model of quiver quantum mechanics. This is the simplest quiver with two gauge groups and bifundamental matter fields, and appears universally in four-dimensional N=2 systems. The ground state degeneracy may be written as a multi-dimensional contour integral, and the enumeration of poles can be simply phrased as counting bipartite trees. We solve this combinatorics problem, thereby obtaining exact formulas for the degeneracies of an infinite class of models. We also develop an algorithm to compute the angular momentum of the ground states, and present explicit expressions for the refined indices of theories where one rank is small.
Supersymmetric black holes in string theory
Energy Technology Data Exchange (ETDEWEB)
Mohaupt, T. [Theoretical Physics Division, Department of Mathematical Sciences, University of Liverpool, Peach Street, Liverpool L69 7ZL (United Kingdom)
2007-05-15
We review recent developments concerning supersymmetric black holes in string theory. After a general introduction to the laws of black hole mechanics and to black hole entropy in string theory, we discuss black hole solutions in N=2 supergravity, special geometry, the black hole attractor equations and the underlying variational principle. Special attention is payed to the crucial role of higher derivative corrections. Finally we discuss black hole partition functions and their relation with the topological string, mainly from the supergravity perspective. We summarize the state of art and discuss various open questions and problems. (Abstract Copyright [2007], Wiley Periodicals, Inc.)
BiHermitian supersymmetric quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Zucchini, Roberto [Dipartimento di Fisica, Universita degli Studi di Bologna, V Irnerio 46, I-40126 Bologna (Italy)
2007-04-21
BiHermitian geometry, discovered long ago by Gates, Hull and Rocek, is the most general sigma model target space geometry allowing for (2, 2) world sheet supersymmetry. In this paper, we work out supersymmetric quantum mechanics for a biHermitian target space. We display the full supersymmetry of the model and illustrate in detail its quantization procedure. Finally, we show that the quantized model reproduces the Hodge theory for compact twisted generalized Kaehler manifolds recently developed by Gualtieri. This allows us to recover and put in a broader context the results on the biHermitian topological sigma models obtained by Kapustin and Li.
BiHermitian Supersymmetric Quantum Mechanics
Zucchini, R
2006-01-01
BiHermitian geometry, discovered long ago by Gates, Hull and Rocek, is the most general sigma model target space geometry allowing for (2,2) world sheet supersymmetry. In this paper, we work out supersymmetric quantum mechanics for a biHermitian target space. We display the full supersymmetry of the model and illustrate in detail its quantization procedure. Finally, we show that the quantized model reproduces the Hodge theory for compact twisted generalized Kaehler manifolds recently developed by Gualtieri. This allows us to recover and put in a broader context the results on the biHermitian topological sigma models obtained by Kapustin and Li.
Supersymmetric structure of the induced $W$ gravities
Ader, J P; Noirot, Y; Ader, Jean-Pierre; Biet, Franck; Noirot, Yves
1999-01-01
We derive the supersymmetric structure present in W-gravities which has been already observed in various contexts as Yang-Mills theory, topological field theories, bosonic string and chiral W_{3}-gravity. This derivation which is made in the geometrical framework of Zucchini, necessitates the introduction of an appropriate new basis of variables which replace the canonical fields and their derivatives. This construction is used, in the W_{2}-case, to deduce from the Chern-Simons action the Wess-Zumino-Polyakov action.
BiHermitian supersymmetric quantum mechanics
Zucchini, Roberto
2007-04-01
BiHermitian geometry, discovered long ago by Gates, Hull and Rocek, is the most general sigma model target space geometry allowing for (2, 2) world sheet supersymmetry. In this paper, we work out supersymmetric quantum mechanics for a biHermitian target space. We display the full supersymmetry of the model and illustrate in detail its quantization procedure. Finally, we show that the quantized model reproduces the Hodge theory for compact twisted generalized Kähler manifolds recently developed by Gualtieri in [33]. This allows us to recover and put in a broader context the results on the biHermitian topological sigma models obtained by Kapustin and Li in [9].
Singularity Structure of Maximally Supersymmetric Scattering Amplitudes
DEFF Research Database (Denmark)
Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy
2014-01-01
We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....
Particle astrophysics of nonlinear supersymmetric general relativity
Energy Technology Data Exchange (ETDEWEB)
Shima, K.; Tsuda, M. [Laboratory of Physics, Saitama Institute of Technology, Fukaya, Saitama (Japan)
2009-05-15
An explanation of relations between the large scale structure of the universe and the tiny scale structure of the particle physics, e.g. the observed mysterious relation between the (dark) energy density and the dark matter of the universe and the neutrino mass and the SUSY breaking mass scale of the particle physics may be given by the nonlinear supersymmetric general relativity (NLSUSY GR). NLSUSY GR shows that considering the physics before/of the big bang (BB) of the universe may be significant and may give new insight to unsolved problems of the low energy particle physics, cosmology and their relations. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
Leptonic CP violation in supersymmetric standard model
Joshipura, A S
1995-01-01
We point out the possibility of spontaneous and hard CP-violation in the scalar potential of R-parity broken supersymmetric Standard Model. The existence of spontaneous CP-violation depends crucially on the R-parity breaking terms in the superpotential and, in addition, on the choice of the soft supersymmetry breaking terms. Unlike in theories with R-parity conservation, it is natural, in the context of the present model, for the sneutrinos to acquire (complex) vacuum expectation values. In the context of this model we examine here the global implications, like the strength of the CP-violating interactions and the neutrino masses.
Quark-Lepton Unification and Eight-Fold Ambiguity in the Left-Right Symmetric Seesaw Mechanism
Hosteins, P; Savoy, C A; Hosteins, Pierre; Lavignac, Stephane; Savoy, Carlos A.
2006-01-01
In many extensions of the Standard Model, including a broad class of left-right symmetric and Grand Unified theories, the light neutrino mass matrix is given by the left-right symmetric seesaw formula $M_\
Supersymmetric Chern-Simons terms in ten dimensions
Bergshoeff, E.; Roo, M. de
1989-01-01
We construct a supersymmetric extension of the Lorentz and Yang-Mills Chern-Simons terms in ten dimensions. In terms of dimensionful parameters Î± (Lorentz) and Î² (Yang-Mills), we obtain the complete O(Î±) supersymmetrization. Furthermore, we present the leading O(Î±2) and O(Î±Î²) corrections requi
Supersymmetric compactifications of heterotic strings with fluxes and condensates
Energy Technology Data Exchange (ETDEWEB)
Manousselis, Pantelis [Department of Engineering Sciences, University of Patras, GR-26110 Patras (Greece)]. E-mail: pantelis@upatras.gr; Prezas, Nikolaos [Institut de Physique, Universite de Neuchatel, CH-2000 Neuchatel (Switzerland)]. E-mail: nikolaos.prezas@unine.ch; Zoupanos, George [Physics Department, National Technical University of Athens, GR-15780 University Campus, Athens (Greece)]. E-mail: zoupanos@mail.cern.ch
2006-04-03
We discuss supersymmetric compactifications of heterotic strings in the presence of H-flux and general condensates using the formalism of G-structures and intrinsic torsion. We revisit the examples based on nearly-Kaehler coset spaces and show that supersymmetric solutions, where the Bianchi identity is satisfied, can be obtained when both gaugino and dilatino condensates are present.
On supermatrix models, Poisson geometry, and noncommutative supersymmetric gauge theories
Energy Technology Data Exchange (ETDEWEB)
Klimčík, Ctirad [Aix Marseille Université, CNRS, Centrale Marseille I2M, UMR 7373, 13453 Marseille (France)
2015-12-15
We construct a new supermatrix model which represents a manifestly supersymmetric noncommutative regularisation of the UOSp(2|1) supersymmetric Schwinger model on the supersphere. Our construction is much simpler than those already existing in the literature and it was found by using Poisson geometry in a substantial way.
Superconformal indices and partition functions for supersymmetric field theories
Energy Technology Data Exchange (ETDEWEB)
Gahramanov, I.B. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Vartanov, G.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-12-15
Recently there was a substantial progress in understanding of supersymmetric theories (in particular, their BPS spectrum) in space-times of different dimensions due to the exact computation of superconformal indices and partition functions using localization method. Here we discuss a connection of 4d superconformal indices and 3d partition functions using a particular example of supersymmetric theories with matter in antisymmetric representation.
Supersymmetric Wilson Loops and Super Non-Abelian Stokes Theorem
Karp, R L; Karp, Robert L.; Mansouri, Freydoon
2000-01-01
We generalize the standard product integral formalism to incorporateGrassmann valued matrices and show that the resulting supersymmetric productintegrals provide a natural framework for describing supersymmetric Wilsonlines and Wilson loops. We use this formalism to establish the supersymmetricversion of the non-Abelian Stokes Theorem.
Search for supersymmetric Higgs signatures at the LHC
Rompotis, Nikolaos; The ATLAS collaboration
2015-01-01
This talk reviews the searches for supersymmetric Higgs bosons signatures at the LHC after Run-I. Searches for the Higgs bosons of the minimal supersymmetric Standard Model (MSSM) have been spearheaded in ATLAS and CMS by $h/H/A\\to \\tau\\tau$ and $H^{\\pm}\\to \\tau\
Higher dimensional supersymmetric quantum mechanics and Dirac equation
Indian Academy of Sciences (India)
L P Singh; B Ram
2002-04-01
We exhibit the supersymmetric quantum mechanical structure of the full 3+1 dimensional Dirac equation considering `mass' as a function of coordinates. Its usefulness in solving potential problems is discussed with speciﬁc examples. We also discuss the `physical' signiﬁcance of the supersymmetric states in this formalism.
Chiral anomalies in N=1 supersymmetric Yang-Mills theories
Energy Technology Data Exchange (ETDEWEB)
Girardi, G.; Grimm, R.; Stora, R. (Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique des Particules)
1985-06-20
We establish a manifestly supersymmetric, compact, formula for the chiral anomalies of supersymmetric gauge theories. This result is obtained by combining superspace geometry with the usual algebra of anomalies. Except for a Wess-Zumino type term, we obtain an expression which is polynomial in the coefficients of the superconnection form.
What if the Higgsino is the lightest supersymmetric particles
Energy Technology Data Exchange (ETDEWEB)
Haber, H.E.
1985-11-01
A pedagogical introduction to the mixing of neutral gauginos and Higgsinos in supersymmetric models is given. The possibility that the Higgsino (rather than the photino) is the lightest supersymmetric particle is considered and implications for phenomenology are discussed with some emphasis on signatures of supersymmetry in Z decays. Some related aspects of Higgs boson detection in Z decays are mentioned.
All supersymmetric solutions of minimal supergravity in five dimensions
Energy Technology Data Exchange (ETDEWEB)
Gauntlett, Jerome P; Gutowski, Jan B; Hull, Christopher M; Pakis, Stathis; Reall, Harvey S [Department of Physics, Queen Mary, University of London, Mile End Rd, London E1 4NS (United Kingdom)
2003-11-07
All purely bosonic supersymmetric solutions of minimal supergravity in five dimensions are classified. The solutions preserve either one half or all of the supersymmetry. Explicit examples of new solutions are given, including a large family of plane-fronted waves and a maximally supersymmetric analogue of the Goedel universe which lifts to a solution of 11-dimensional supergravity that preserves 20 supersymmetries.
All supersymmetric solutions of minimal supergravity in five dimensions
Gauntlett, J P; Hull, C M; Pakis, S; Reall, H S; Gauntlett, Jerome P.; Gutowski, Jan B.; Hull, Christopher M.; Pakis, Stathis; Reall, Harvey S.
2003-01-01
All purely bosonic supersymmetric solutions of minimal supergravity in five dimensions are classified. The solutions preserve either one half or all of the supersymmetry. Explicit examples of new solutions are given, including a large family of plane-fronted waves and a maximally supersymmetric analogue of the G\\"odel universe which lifts to a solution of eleven dimensional supergravity that preserves 20 supersymmetries.
CP Violation in Supersymmetric U(1)' Models
Demir, D A
2004-01-01
The supersymmetric CP problem is studied within superstring-motivated extensions of the MSSM with an additional U(1)' gauge symmetry broken at the TeV scale. This class of models offers an attractive solution to the mu problem of the MSSM, in which U(1)' gauge invariance forbids the bare mu term, but an effective mu parameter is generated by the vacuum expectation value of a Standard Model singlet S which has superpotential coupling of the form SH_uH_d to the electroweak Higgs doublets. The effective mu parameter is thus dynamically determined as a function of the soft supersymmetry breaking parameters, and can be complex if the soft parameters have nontrivial CP-violating phases. We examine the phenomenological constraints on the reparameterization invariant phase combinations within this framework, and find that the supersymmetric CP problem can be greatly alleviated in models in which the phase of the SU(2) gaugino mass parameter is aligned with the soft trilinear scalar mass parameter associated with the ...
Supersymmetric quantum mechanics of the flux tube
Belitsky, A V
2016-01-01
The Operator Product Expansion approach to scattering amplitudes in maximally supersymmetric gauge theory operates in terms of pentagon transitions for excitations propagating on a color flux tube. These obey a set of axioms which allow to determine them to all orders in 't Hooft coupling and confront against explicit calculations. One of the simplifying features of the formalism is the factorizability of multiparticle transitions in terms of single-particle ones. In this paper we extend an earlier consideration of a sector populated by one kind of excitations to the case of a system with fermionic as well as bosonic degrees of freedom to address the origin of the factorization. While the purely bosonic case was analyzed within an integrable noncompact open-spin chain model, the current case is solved in the framework of a supersymmetric sl(2|1) magnet. We find the eigenfunctions for the multiparticle system making use of the R-matrix approach. Constructing resulting pentagon transitions, we prove their facto...
Supersymmetric quantum mechanics of the flux tube
Belitsky, A. V.
2016-12-01
The Operator Product Expansion approach to scattering amplitudes in maximally supersymmetric gauge theory operates in terms of pentagon transitions for excitations propagating on a color flux tube. These obey a set of axioms which allow one to determine them to all orders in 't Hooft coupling and confront against explicit calculations. One of the simplifying features of the formalism is the factorizability of multiparticle transitions in terms of single-particle ones. In this paper we extend an earlier consideration of a sector populated by one kind of excitations to the case of a system with fermionic as well as bosonic degrees of freedom to address the origin of the factorization. While the purely bosonic case was analyzed within an integrable noncompact open-spin chain model, the current case is solved in the framework of a supersymmetric sl (2 | 1) magnet. We find the eigenfunctions for the multiparticle system making use of the R-matrix approach. Constructing resulting pentagon transitions, we prove their factorized form. The discussion corresponds to leading order of perturbation theory.
Resummation predictions for supersymmetric electroweak particles
Energy Technology Data Exchange (ETDEWEB)
Fuks, Benjamin [Institut Pluridisciplinaire Hubert Curien/Departement Recherches Subatomiques, Universite de Strasbourg (France); Klasen, Michael; Lamprea, David R.; Rothering, Marcel [Institut fuer Theoretische Physik, Westfaelische Wilhelms-Universitaet Muenster (Germany)
2013-07-01
Since the discovery of a particle consistent with the properties of the Standard Model Higgs the experimentalists' effort of ATLAS and CMS at the LHC has been shifted towards the production of electroweak supersymmetric particles. In our work we have updated the resummation results for gauginos and sleptons with next-to-leading logarithmic accuracy matched to next-to-leading order computations for a center of mass energy of 8 TeV. We have used benchmark points for minimal supergravity breaking scenarios which are recently adopted by the experimental collaborations and motivated by the magnetic moment of the muon. Tables of total cross sections including scale and parton distribution function uncertainties are presented together with invariant mass and transverse momentum distributions. As expected, the resummation results reduce the scale dependence and ensure the convergence in the small transverse momentum region. The production of the lightest chargino with the next-to-lightest neutralino leads to the largest cross section of O(10 fb) for masses of a few hundred GeV. Due to the considered mixing in the third generation of sleptons the τ{sub 1} τ{sub 1}{sup *} production cross section can also reach the fb-region for the same benchmark point. The gauginos would give rise to the largest cross section and are probably soon accessible at the LHC being the first detected supersymmetric particles.
Toward precision holography with supersymmetric Wilson loops
Faraggi, Alberto; Pando Zayas, Leopoldo A.; Silva, Guillermo A.; Trancanelli, Diego
2016-04-01
We consider certain 1/4 BPS Wilson loop operators in SU( N) N=4 supersymmetric Yang-Mills theory, whose expectation value can be computed exactly via supersymmetric localization. Holographically, these operators are mapped to fundamental strings in AdS 5 × S 5. The string on-shell action reproduces the large N and large coupling limit of the gauge theory expectation value and, according to the AdS/CFT correspondence, there should also be a precise match between subleading corrections to these limits. We perform a test of such match at next-to-leading order in string theory, by deriving the spectrum of quantum fluctuations around the classical string solution and by computing the corresponding 1-loop effective action. We discuss in detail the supermultiplet structure of the fluctuations. To remove a possible source of ambiguity in the ghost zero mode measure, we compare the 1/4 BPS configuration with the 1/2 BPS one, dual to a circular Wilson loop. We find a discrepancy between the string theory result and the gauge theory prediction, confirming a previous result in the literature. We are able to track the modes from which this discrepancy originates, as well as the modes that by themselves would give the expected result.
Towards gauge unified, supersymmetric hidden strong dynamics
Chiang, Cheng-Wei; Ye, Fang
2016-01-01
We consider a class of models with extra complex scalars that are charged under both the Standard Model and a hidden strongly coupled $SU(N)_H$ gauge sector, and discuss the scenarios where the new scalars are identified as the messenger fields that mediate the spontaneously broken supersymmetries from the hidden sector to the visible sector. The new scalars are embedded into 5-plets and 10-plets of an $SU(5)_V$ gauge group that potentially unifies the Standard Model gauge groups. They also form a tower of bound states via hidden strong dynamics around the TeV scale. The Higgs bosons remain as elementary particles. Quadratically divergent contributions to the Higgs mass from the Standard Model fermions are canceled by the new scalar contributions to alleviate the fine-tuning problem. We also discuss a supersymmetrized version of this class of models, consisting of the minimal supersymmetric Standard Model plus extra chiral multiplets where the new scalars reside. Due to the hidden strong force, the new low-en...
Gravitational Quantum Foam and Supersymmetric Gauge Theories
Maeda, T; Noma, Y; Tamakoshi, T; Maeda, Takashi; Nakatsu, Toshio; Noma, Yui; Tamakoshi, Takeshi
2005-01-01
We study K\\"{a}hler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over \\mathbb{P}^1. With such a regularization prescription, the number of the gravitational quanta becomes finite and turns to be the perturbative prepotential for five-dimensional \\mathcal{N}=1 supersymmetric SU(N) Yang-Mills. These quanta are labelled by lattice points in a certain convex polyhedron on \\mathbb{R}^3. The polyhedron becomes obtainable from a plane partition which is the ground state of a statistical model of random plane partition that describes the exact partition function for the gauge theory. Each gravitational quantum of the local geometry is shown...
Quantum symmetries in supersymmetric Toda theories
Penati, S; Penati, Silvia; Zanon, Daniela
1992-01-01
: We consider two--dimensional supersymmetric Toda theories based on the Lie superalgebras $A(n,n)$, $D(n+1,n)$ and $B(n,n)$ which admit a fermionic set of simple roots and a fermionic untwisted affine extension. In particular, we concentrate on two simple examples, the $B(1,1)$ and $A(1,1)$ theories. Both in the conformal and massive case we address the issue of quantum integrability by constructing the first non trivial conserved currents and proving their conservation to all--loop orders. While the $D(n+1,n)$ and $B(n,n)$ systems are genuine $N=1$ supersymmetric theories, the $A(n,n)$ models possess a global $N=2$ supersymmetry. In the conformal case, we show that the $A(n,n)$ stress--energy tensor, uniquely determined by the holomorphicity condition, has vanishing central charge and it corresponds to the stress--energy tensor of the associated topological theory. (Invited talk at the International Workshop ``String theory, quantum gravity and the unification of the fundamental interactions'', Roma, Septem...
King, S F
2002-01-01
Recent SNO results strongly favour the large mixing angle (LMA) MSW solar solution. We argue that there are only two technically natural low energy neutrino mass matrix structures consistent with the LMA MSW solution, corresponding to either a hierarchy or an inverted hierarchy with pseudo-Dirac neutrinos. We first present a model-independent analysis in which we diagonalise each of these two mass matrix structures to leading order in $\\theta_{13}$ and extract the neutrino masses, mixing angles and phases. In this analysis we express the MNS matrix to leading order in the small angle $\\theta_{13}$ including the neutrino {\\em and} charged lepton mixing angles and phases, the latter playing a crucial r\\^{o}le for allowing the inverted hierarchy solution to be consistent with the LMA MSW solution. We then consider the see-saw mechanism with right-handed neutrino dominance and show how the successful neutrino mass matrix structures may be constructed with no tuning and with small radiative corrections, leading to...
Anomaly-free U(1) gauge symmetries in neutrino seesaw flavor models
Cebola, Luis M; Felipe, Ricardo Gonzalez
2013-01-01
Adding right-handed neutrino singlets and/or fermion triplets to the particle content of the Standard Model allows for the implementation of the seesaw mechanism to give mass to neutrinos and, simultaneously, for the construction of anomaly-free gauge group extensions of the theory. We consider Abelian extensions based on an extra U(1)_X gauge symmetry, where X is an arbitrary linear combination of the baryon number B and the individual lepton numbers L_{e,mu,tau}. By requiring cancellation of gauge anomalies, we perform a detailed analysis in order to identify the charge assignments under the new gauge symmetry that lead to neutrino phenomenology compatible with current experiments. In particular, we study how the new symmetry can constrain the flavor structure of the Majorana neutrino mass matrix, leading to two-zero textures with a minimal extra fermion and scalar content. The possibility of distinguishing different gauge symmetries and seesaw realizations at colliders is also briefly discussed.
Double seesaw mechanism in a left-right symmetric model with TeV neutrinos
Almeida, F M L de; Simões, J A Martins; Ramalho, A J; Pinto, L Ribeiro; Wulck, S; Vale, M A B do
2010-01-01
A left-right symmetric model is discussed with new mirror fermions and a Higgs sector with two doublets and neutral scalar singlets. The seesaw mechanism is generalized, including not only neutrino masses but also charged fermion masses. The spectrum of heavy neutrinos presents a second seesaw mass matrix and has neutrinos masses naturally in the TeV region. The model has very clear signatures for the new neutral vector gauge bosons. Two classes of models are discussed. New mirror neutrinos can be very light and a new $Z^{\\prime}$ can be discriminated from other models by a very high invisible branching fraction. The other possibility is that mirror neutrinos can have masses naturally in the TeV region and can be produced through $Z^{\\prime}$ decays into heavy neutrino pairs. Signatures and production processes for the model at the LHC energy are also presented.
On the importance of the 1-loop finite corrections to seesaw neutrino masses
Sierra, D Aristizabal
2011-01-01
In the standard seesaw mechanism, finite corrections to the neutrino mass matrix arise from 1-loop self-energy diagrams mediated by a heavy neutrino. We study in detail these corrections and demonstrate that they can be very significant, exceeding in several cases the tree-level result. We consider the normal and inverted hierarchy spectra for light neutrinos and compute the finite corrections to the different elements of the neutrino mass matrix. Special attention is paid to their dependence with the parameters of the seesaw model. Among the cases in which the corrections can be large, we identify the fine-tuned models considered previously in the literature, where a strong cancellation between the different parameters is required to achieve compatibility with the experimental data. As a particular example, we also analyze how these corrections modify the tribimaximal mixing pattern and find that the deviations may be sizable, in particular for $\\theta_{13}$. Finally, we emphasize that due to their large siz...
Renormalisation Group Corrections to the Littlest Seesaw Model and Maximal Atmospheric Mixing
King, Stephen F; Zhou, Shun
2016-01-01
The Littlest Seesaw (LS) model involves two right-handed neutrinos and a very constrained Dirac neutrino mass matrix, involving one texture zero and two independent Dirac masses, leading to a highly predictive scheme in which all neutrino masses and the entire PMNS matrix is successfully predicted in terms of just two real parameters. We calculate the renormalisation group (RG) corrections to the LS predictions, with and without supersymmetry, including also the threshold effects induced by the decoupling of heavy Majorana neutrinos both analytically and numerically. We find that the predictions for neutrino mixing angles and mass ratios are rather stable under RG corrections. For example we find that the LS model with RG corrections predicts close to maximal atmospheric mixing, $\\theta_{23}=45^\\circ \\pm 1^\\circ$, in most considered cases, in tension with the latest NOvA results. The techniques used here apply to other seesaw models with a strong normal mass hierarchy.
Renormalisation group corrections to the littlest seesaw model and maximal atmospheric mixing
Energy Technology Data Exchange (ETDEWEB)
King, Stephen F. [School of Physics and Astronomy, University of Southampton,SO17 1BJ Southampton (United Kingdom); Zhang, Jue [Center for High Energy Physics, Peking University,Beijing 100871 (China); Zhou, Shun [Center for High Energy Physics, Peking University,Beijing 100871 (China); Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China)
2016-12-06
The Littlest Seesaw (LS) model involves two right-handed neutrinos and a very constrained Dirac neutrino mass matrix, involving one texture zero and two independent Dirac masses, leading to a highly predictive scheme in which all neutrino masses and the entire PMNS matrix is successfully predicted in terms of just two real parameters. We calculate the renormalisation group (RG) corrections to the LS predictions, with and without supersymmetry, including also the threshold effects induced by the decoupling of heavy Majorana neutrinos both analytically and numerically. We find that the predictions for neutrino mixing angles and mass ratios are rather stable under RG corrections. For example we find that the LS model with RG corrections predicts close to maximal atmospheric mixing, θ{sub 23}=45{sup ∘}±1{sup ∘}, in most considered cases, in tension with the latest NOvA results. The techniques used here apply to other seesaw models with a strong normal mass hierarchy.
Enhancement of $h \\to \\gamma \\gamma$ by seesaw-motivated exotic scalars
Picek, Ivica
2012-01-01
We examine the role of seesaw motivated exotic scalars in loop-mediated Higgs decays. We consider a simple TeV-scale seesaw model built upon the fermionic quintuplet mediator in conjunction with the scalar quadruplet, where we examine portions of the model parameter space for which the contributions of charged components of the scalar quadruplet significantly increase the $h \\to \\gamma \\gamma$ decay rate. The most significant change in the diphoton width comes from a doubly charged scalar \\Phi^{--} which should be the lightest component in the scalar quadruplet. There is a mild suppression of the $h \\to Z \\gamma$ decay width by a factor 0.9 -- 0.7 in the part of the parameter space where the $h \\to \\gamma \\gamma$ decay width is enhanced by a factor 1.25 -- 2.
Enhancement of h→γγ by seesaw-motivated exotic scalars
Energy Technology Data Exchange (ETDEWEB)
Picek, Ivica, E-mail: picek@phy.hr [Department of Physics, Faculty of Science, University of Zagreb, P.O.B. 331, HR-10002 Zagreb (Croatia); Radovčić, Branimir [Department of Physics, Faculty of Science, University of Zagreb, P.O.B. 331, HR-10002 Zagreb (Croatia)
2013-02-26
We examine the role of seesaw-motivated exotic scalars in loop-mediated Higgs decays. We consider a simple TeV-scale seesaw model built upon the fermionic quintuplet mediator in conjunction with the scalar quadruplet, where we examine portions of the model parameter space for which the contributions of charged components of the scalar quadruplet significantly increase the h→γγ decay rate. The most significant change in the diphoton width comes from a doubly charged scalar Φ{sup −−} which should be the lightest component in the scalar quadruplet. In the part of the parameter space where the h→γγ decay width is enhanced by a factor 1.25–2 there is a mild suppression of the h→Zγ decay width by a factor 0.9–0.7.
Recent developments in thermal leptogenesis: the role of flavours in various seesaw realisations
Josse-Michaux, Francois-Xavier
2008-01-01
In this thesis, we study the role of flavours in leptogenesis. In a first time, we review the so-called one flavour picture, where only the lightest right-handed neutrino is taken into account, and where lepton flavours are neglected. After having showed why and how lepton flavours should be included in the computation of the lepton asymmetry, we study their effect in the type I seesaw model, as well as in the type I+II seesaw model, in a specific SO(10) unification realisation. In this model, besides flavours effects, we show that the inclusion of the second lightest right-handed neutrino, together with an accurate description of charged fermions masses, are necessary to make leptogenesis work.
Probing the Heavy Neutrinos of Inverse Seesaw Model at the LHeC
Mondal, Subhadeep
2016-01-01
We consider the production of a heavy neutrino and its possible signals at the Large Hadron-electron Collider (LHeC) in the context of an inverse-seesaw model for neutrino mass generation. The inverse seesaw model extends the Standard Model (SM) particle content by adding two neutral singlet fermions for each lepton generation. It is a well motivated model in the context of generating non-zero neutrino masses and mixings. The proposed future LHeC machine presents us with a particularly interesting possibility to probe such extensions of the SM with new leptons due to the presence of an electron beam in the initial state. We show that the LHeC will be able to probe an inverse scenario with much better efficacy compared to the LHC with very nominal integrated luminosities as well as exploit the advantage of having the electron beam polarized to enhance the heavy neutrino production rates.
Scaling in the Neutrino Mass Matrix, mu-tau Symmetry and the See-Saw Mechanism
Joshipura, Anjan S
2009-01-01
The scaling hypothesis postulates proportionality of two columns of the Majorana neutrino mass matrix in the flavor basis. This Ansatz was shown to lead to an inverted hierarchy and U_{e3} = 0. We discuss theoretical and phenomenological properties of this hypothesis. We show that (i) the neutrino mass matrix with scaling follows as a consequence of a generalized mu-tau symmetry imposed on the type-I see-saw model; (ii) there exists a unique texture for the Dirac mass matrix m_D which leads to scaling for arbitrary Majorana matrix M_R in the context of the type-I see-saw mechanism; (iii) unlike in the mu-tau symmetric case, a simple model with two right-handed neutrinos and scaling can lead to successful leptogenesis both with and without the inclusion of flavor effects.
Scaling in the neutrino mass matrix, {mu}-{tau} symmetry and the see-saw mechanism
Energy Technology Data Exchange (ETDEWEB)
Joshipura, Anjan S. [Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, Gujarat (India)], E-mail: anjan@prl.res.in; Rodejohann, Werner [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)], E-mail: werner.rodejohann@mpi-hd.mpg.de
2009-07-20
The scaling hypothesis postulates proportionality of two columns of the Majorana neutrino mass matrix in the flavor basis. This ansatz was shown to lead to an inverted hierarchy and U{sub e3}=0. We discuss theoretical and phenomenological properties of this hypothesis. We show that (i) the neutrino mass matrix with scaling follows as a consequence of a generalized {mu}-{tau} symmetry imposed on the type-I see-saw model; (ii) there exists a unique texture for the Dirac mass matrix m{sub D} which leads to scaling for arbitrary Majorana matrix M{sub R} in the context of the type-I see-saw mechanism; (iii) unlike in the {mu}-{tau} symmetric case, a simple model with two right-handed neutrinos and scaling can lead to successful leptogenesis both with and without the inclusion of flavor effects.
Running Effects on Lepton Mixing Angles in Flavour Models with Type I Seesaw
Lin, Y; Paris, A
2009-01-01
We study renormalization group running effects on neutrino mixing patterns when a (type I) seesaw model is implemented by suitable flavour symmetries. We are particularly interested in mass-independent mixing patterns to which the widely studied tribimaximal mixing pattern belongs. In this class of flavour models, the running contribution from neutrino Yukawa coupling, which is generally dominant at energies above the seesaw threshold, can be absorbed by a small shift on neutrino mass eigenvalues leaving mixing angles unchanged. Consequently, in the whole running energy range, the change in mixing angles is due to the contribution coming from charged lepton sector. Subsequently, we analyze in detail these effects in an explicit flavour model for tribimaximal neutrino mixing based on an A4 discrete symmetry group. We find that for normally ordered light neutrinos, the tribimaximal prediction is essentially stable under renormalization group evolution. On the other hand, in the case of inverted hierarchy, the d...
Radiative breaking of the minimal supersymmetric left–right model
Directory of Open Access Journals (Sweden)
Nobuchika Okada
2016-05-01
Full Text Available We study a variation to the SUSY Left–Right symmetric model based on the gauge group SU(3c×SU(2L×SU(2R×U(1BL. Beyond the quark and lepton superfields we only introduce a second Higgs bidoublet to produce realistic fermion mass matrices. This model does not include any SU(2R triplets. We calculate renormalization group evolutions of soft SUSY parameters at the one-loop level down to low energy. We find that an SU(2R slepton doublet acquires a negative mass squared at low energies, so that the breaking of SU(2R×U(1BL→U(1Y is realized by a non-zero vacuum expectation value of a right-handed sneutrino. Small neutrino masses are produced through neutrino mixings with gauginos. Mass limits on the SU(2R×U(1BL sector are obtained by direct search results at the LHC as well as lepton-gaugino mixing bounds from the LEP precision data.
Radiative Breaking of the Minimal Supersymmetric Left-Right Model
Okada, Nobuchika
2016-01-01
We propose a new variation to the SUSY Left-Right symmetric model based on the gauge group $SU(3)_c\\times SU(2)_L\\times SU(2)_R\\times U(1)_{BL}$. Beyond the quark and lepton superfields we only introduce a second Higgs bidoublet to produce realistic fermion mass matrices. This model does not include any $SU(2)_R$ triplets. We calculate renormalization group evolutions of soft SUSY parameters at the one-loop level down to low energy. We find that an $SU(2)_R$ slepton doublet acquires a negative mass squared at low energies, so that the breaking of $SU(2)_R\\times U(1)_{BL}\\rightarrow U(1)_Y$ is realized by a non-zero vacuum expectation value of a right-handed sneutrino. Small neutrino masses are produced through neutrino mixings with gauginos. Mass limits on the $SU(2)_R\\times U(1)_{BL}$ sector are obtained by direct search results at the LHC as well as lepton-gaugino mixing bounds from the LEP precision data.
Phenomenological analysis of properties of the RH Majorana neutrino in the seesaw mechanism
Pan, H; Pan, Haijun
2002-01-01
As an extension of our previous work in the seesaw mechanism, we analyze the influence of $U_{e3}$ on the properties (masses and mixing) of the RH Majorana neutrinos in three flavors. The quasidegenerate light neutrinos case is also considered. Assuming the hierarchical Dirac neutrino masses, we find the heavy Majorana neutrino mass spectrum is either hierarchical or partial degenerate if $\\theta_{23}^{\
The $\\mu$-Problem and Seesaw-type Mechanism in the Higgs Sector
Ito, M
2001-01-01
We explore a new solution to the $\\mu$-problem. In the scenario of SUSY breaking mediation via anti-generation fields, we point out that the $B\\mu$ term has its origin in seesaw-type mechanism as well as in loop diagram through gauge interactions. It is shown that the dominant contributions to the $B\\mu$ term are controlled by the flavor symmetry in the model.
Abbas, Mohammed; Khalil, Shaaban; Rashed, Ahmed; Sil, Arunansu
2016-01-01
We propose a scheme, based on Δ (27 ) flavor symmetry and supplemented by other discrete symmetries and the inverse seesaw mechanism, where both the light neutrino masses and the deviation from tribimaximal mixing matrix can be linked to the source of lepton number violation. The hierarchies of the charged leptons are explained. We find that the quark masses including their hierarchies and the mixing can also be constructed in a similar way.
Perturbative stability along the supersymmetric directions of the landscape
Energy Technology Data Exchange (ETDEWEB)
Sousa, Kepa [Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Ortiz, Pablo, E-mail: kepa.sousa@ehu.es, E-mail: ortiz@lorentz.leidenuniv.nl [Instituut-Lorentz for Theoretical Physics, Universiteit Leiden, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)
2015-02-01
We consider the perturbative stability of non-supersymmetric configurations in N=1 supergravity models with a spectator sector not involved in supersymmetry breaking. Motivated by the supergravity description of complex structure moduli in Large Volume Compactifications of type IIB-superstrings, we concentrate on models where the interactions are consistent with the supersymmetric truncation of the spectator fields, and we describe their couplings by a random ensemble of generic supergravity theories. We characterise the mass spectrum of the spectator fields in terms of the statistical parameters of the ensemble and the geometry of the scalar manifold. Our results show that the non-generic couplings between the spectator and the supersymmetry breaking sectors can stabilise all the tachyons which typically appear in the spectator sector before including the supersymmetry breaking effects, and we find large regions of the parameter space where the supersymmetric sector remains stable with probability close to one. We discuss these results about the stability of the supersymmetric sector in two physically relevant situations: non-supersymmetric Minkowski vacua, and slow-roll inflation driven by the supersymmetry breaking sector. For the class of models we consider, we have reproduced the regimes in which the KKLT and Large Volume Scenarios stabilise all supersymmetric moduli. We have also identified a new regime in which the supersymmetric sector is stabilised at a very robust type of dS minimum without invoking a large mass hierarchy.
Higher Derivative Corrections To Extended Supersymmetric Theories
Braun, G A
2004-01-01
We investigate higher-derivative terms in N = 2 supersymmetric effective actions. We systematically construct such terms in harmonic superspace despite the infinite redundancy in their description due to the infinite number of auxiliary fields. We write all 3- and 4-derivative terms on Higgs, Coulomb, and mixed branches, modulo the existence of superspace Chern-Simons-like terms. Among these terms are several with only holomorphic dependence on fields, and at least one satisfies a non-renormalization theorem. We then search for superspace Chern-Simons-like terms, which are those gauge-invariant terms which cannot be written solely in terms of field strength superfields and covariant derivatives, but in which gauge potential superfield appears explicitly. We find a class of four- derivative terms with N = 2 supersymmetry which, though locally on the Coulomb branch can be written solely in terms of field strengths, globally on the Coulomb branch are superspace Chern- Simons-like.
Supersymmetric inversion of effective-range expansions
Midya, Bikashkali; Abramowicz, Sylvain; Suárez, O L Ramírez; Sparenberg, Jean-Marc
2015-01-01
A complete and consistent inversion technique is proposed to derive an accurate interaction potential from an effective-range function for a given partial wave in the neutral case. First, the effective-range function is Taylor or Pad\\'e expanded, which allows high precision fitting of the experimental scattering phase shifts with a minimal number of parameters on a large energy range. Second, the corresponding poles of the scattering matrix are extracted in the complex wave-number plane. Third, the interaction potential is constructed with supersymmetric transformations of the radial Schr\\"odinger equation. As an illustration, the method is applied to the experimental phase shifts of the neutron-proton elastic scattering in the $^1S_0$ and $^1D_2$ channels on the $[0-350]$ MeV laboratory energy interval.
Towards a Non-Supersymmetric String Phenomenology
Abel, Steven; Mavroudi, Eirini
2015-01-01
Over the past three decades, considerable effort has been devoted to studying the rich and diverse phenomenologies of heterotic strings exhibiting spacetime supersymmetry. Unfortunately, during this same period, there has been relatively little work studying the phenomenologies associated with their non-supersymmetric counterparts. The primary reason for this relative lack of attention is the fact that strings without spacetime supersymmetry are generally unstable, exhibiting large one-loop dilaton tadpoles. In this paper, we demonstrate that this hurdle can be overcome in a class of tachyon-free four-dimensional string models realized through coordinate-dependent compactifications. Moreover, as we shall see, it is possible to construct models in this class whose low-lying states resemble the Standard Model (or even potential unified extensions thereof) --- all without any light superpartners, and indeed without supersymmetry at any energy scale. The existence of such models thus opens the door to general stu...
Simple supersymmetric strongly coupled preon model
Fajfer, S.; Tadić, D.
1988-08-01
This supersymmetric-SU(5) composite model is a natural generalization of the usual strong-coupling models. Preon superfields are in representations 5* and 10. The product representations 5*×10, 5×10, 5×5, and 5*×5 contain only those strongly hypercolor bound states which are needed in the standard electroweak theory. There are no superfluous quarklike states. The neutrino is massless. Only one strongly hypercolor bound singlet (10×10*) can exist as a free particle. At higher energies one should expect to see a plethora of new particles. Grand unification happens at the scale M~1014 GeV. Cabibbo mixing can be incorporated by using a transposed Kobayashi-Maskawa mixing matrix.
Supersymmetric quantum mechanics and Painleve equations
Bermudez, David
2013-01-01
In these lecture notes we shall study first the supersymmetric quantum mechanics (SUSY QM), specially when applied to the harmonic and radial oscillators. In addition, we will define the polynomial Heisenberg algebras (PHA), and we will study the general systems ruled by them: for zero and first order we obtain the harmonic and radial oscillators, respectively; for second and third order PHA the potential is determined by solutions to Painleve IV (PIV) and Painleve V (PV) equations. Taking advantage of this connection, later on we will find solutions to PIV and PV equations expressed in terms of confluent hypergeometric functions. Furthermore, we will classify them into several solution hierarchies, according to the specific special functions they are connected with.
A new perspective on supersymmetric inflation
Energy Technology Data Exchange (ETDEWEB)
Matsuda, Tomohiro, E-mail: matsuda@sit.ac.jp [Laboratory of Physics, Saitama Institute of Technology, Fusaiji, Okabe-machi, Saitama 369-0293 (Japan)
2009-11-01
We consider supersymmetric inflation with the hybrid-type potential. In the absence of the symmetry that forbids Hubble-induced mass terms, the inflaton mass will be as large as the Hubble scale during inflation. We consider gravitational decay of the trigger field as the least decay mode and find that the damping caused by the dissipation can dominate the friction of the inflaton when the heavy trigger field is coupled to the inflaton. The dissipative damping provides a solution to the traditional η problem without introducing additional symmetry and interactions. Considering the spatial inhomogeneities of the dissipative coefficient, we find that modulated inflation (modulation of the inflaton velocity) can create significant curvature perturbations.
Supersymmetric partition functions on Riemann surfaces
Benini, Francesco
2016-01-01
We present a compact formula for the supersymmetric partition function of 2d N=(2,2), 3d N=2 and 4d N=1 gauge theories on $\\Sigma_g \\times T^n$ with partial topological twist on $\\Sigma_g$, where $\\Sigma_g$ is a Riemann surface of arbitrary genus and $T^n$ is a torus with n=0,1,2, respectively. In 2d we also include certain local operator insertions, and in 3d we include Wilson line operator insertions along $S^1$. For genus g=1, the formula computes the Witten index. We present a few simple Abelian and non-Abelian examples, including new tests of non-perturbative dualities. We also show that the large N partition function of ABJM theory on $\\Sigma_g \\times S^1$ reproduces the Bekenstein-Hawking entropy of BPS black holes in AdS4 whose horizon has $\\Sigma_g$ topology.
Supersymmetric Microscopic Theory of the Standard Model
Ter-Kazarian, G T
2000-01-01
We promote the microscopic theory of standard model (MSM, hep-ph/0007077) into supersymmetric framework in order to solve its technical aspects of vacuum zero point energy and hierarchy problems, and attempt, further, to develop its realistic viable minimal SUSY extension. Among other things that - the MSM provides a natural unification of geometry and the field theory, has clarified the physical conditions in which the geometry and particles come into being, in microscopic sense enables an insight to key problems of particle phenomenology and answers to some of its nagging questions - a present approach also leads to quite a new realization of the SUSY yielding a physically realistic particle spectrum. It stems from the special subquark algebra, from which the nilpotent supercharge operators are derived. The resulting theory makes plausible following testable implications for the current experiments at LEP2, at the Tevatron and at LHC drastically different from those of the conventional MSSM models: 1. All t...
Supersymmetric leptogenesis and light hidden sectors
Weniger, Christoph
2010-01-01
Thermal leptogenesis and supergravity are attractive scenarios for physics beyond the standard model. However, it is well known that the super-weak interaction of the gravitino often leads to problems with primordial nucleosynthesis in the standard scenario of matter parity conserving MSSM + three right-handed neutrinos. We will present and compare two related solutions to these problems: 1) The conflict between BBN and leptogenesis can be avoided in presence of a hidden sector with light supersymmetric particles which open new decay channels for the dangerous long-lived particles. 2) If there is a condensate in the hidden sector, such additional decay channels can be alternatively opened by dynamical breaking of matter parity in the hidden sector.
Area law violations in a supersymmetric model
Huijse, Liza; Swingle, Brian
2013-01-01
We study the structure of entanglement in a supersymmetric lattice model of fermions on certain types of decorated graphs with quenched disorder. In particular, we construct models with controllable ground-state degeneracy protected by supersymmetry and the choice of Hilbert space. We show that in certain special limits, these degenerate ground states are associated with local impurities and that there exists a basis of the ground-state manifold in which every basis element satisfies a boundary law for entanglement entropy. On the other hand, by considering incoherent mixtures or coherent superpositions of these localized ground states, we can find regions that violate the boundary law for entanglement entropy over a wide range of length scales. More generally, we discuss various criteria for constructing violations of the boundary law for entanglement entropy and discuss possible relations of our work to recent holographic studies.
SU(2|2) supersymmetric mechanics
Ivanov, Evgeny; Sidorov, Stepan
2016-01-01
We introduce a new kind of non-relativistic ${\\cal N}{=}\\,8$ supersymmetric mechanics, associated with worldline realizations of the supergroup $SU(2|2)$ treated as a deformation of flat ${\\cal N}{=}\\,8$, $d{=}1$ supersymmetry. Various worldline $SU(2|2)$ superspaces are constructed as coset manifolds of this supergroup, and the corresponding superfield techniques are developed. For the off-shell $SU(2|2)$ multiplets $({\\bf 3,8,5})$, $({\\bf 4,8,4})$ and $({\\bf 5,8,3})$, we construct and analyze the most general superfield and component actions. Common features are mass oscillator-type terms proportional to the deformation parameter and a trigonometric realization of the superconformal group $OSp(4^*|4)$ in the conformal cases. For the simplest $({\\bf 5, 8, 3})$ model the quantization is performed.
Supersymmetric Wilson loops at two loops
Bassetto, Antonio; Pucci, Fabrizio; Seminara, Domenico
2008-01-01
We study the quantum properties of certain BPS Wilson loops in ${\\cal N}=4$ supersymmetric Yang-Mills theory. They belong to a general family, introduced recently, in which the addition of particular scalar couplings endows generic loops on $S^3$ with a fraction of supersymmetry. When restricted to $S^2$, their quantum average has been further conjectured to be exactly computed by the matrix model governing the zero-instanton sector of YM$_2$ on the sphere. We perform a complete two-loop analysis on a class of cusped Wilson loops lying on a two-dimensional sphere, finding perfect agreement with the conjecture. The perturbative computation reproduces the matrix-model expectation through a highly non-trivial interplay between ladder diagrams and self-energies/vertex contributions, suggesting the existence of a localization procedure.
Dynamics of Non-supersymmetric Flavours
Alam, M Sohaib; Kundu, Arnab; Kundu, Sandipan
2013-01-01
We continue investigating the effect of the back-reaction by non-supersymmetric probes in the Kuperstein-Sonnenschein model. In the limit when the back-reaction is small, we discuss physical properties of the back-reacted geometry. We further introduce additional probe flavours in this back-reacted geometry and study in detail the phase structure of this sector when a constant electromagnetic field or a chemical potential are present. We find that the Landau pole, which serves as the UV cut-off of the background geometry, also serves as an important scale in the corresponding thermodynamics of the additional flavour sector. We note that since this additional probe flavours are indistinguishable from the back-reacting flavours, the results we obtain point to a much richer phase structure of the system.
Supersymmetric backgrounds and generalised special holonomy
Coimbra, André; Strickland-Constable, Charles; Waldram, Daniel
2016-06-01
We define intrinsic torsion in generalised geometry and use it to introduce a new notion of generalised special holonomy. We then consider generic warped supersymmetric flux compactifications of M theory and Type II of the form {{{R}}}D-{1,1}× M. Using the language of {E}d(d)× {{{R}}}+ generalised geometry, we show that, for D≥slant 4, preserving minimal supersymmetry is equivalent to the manifold M having generalised special holonomy and list the relevant holonomy groups. We conjecture that this result extends to backgrounds preserving any number of supersymmetries. As a prime example, we consider { N }=1 in D = 4. The corresponding generalised special holonomy group is {SU}(7), giving the natural M theory extension to the notion of a G 2 manifold, and, for Type II backgrounds, reformulating the pure spinor {SU}(3)× {SU}(3) conditions as an integrable structure.
Supersymmetric Backgrounds and Generalised Special Holonomy
Coimbra, André; Waldram, Daniel
2014-01-01
We define intrinsic torsion in generalised geometry and use it to introduce a new notion of generalised special holonomy. We then consider generic warped supersymmetric flux compactifications of M theory and Type II of the form $\\mathbb{R}^{D-1,1}\\times M$. Using the language of $E_{d(d)}\\times\\mathbb{R}^+$ generalised geometry, we show that, for $D\\geq 4$, preserving minimal supersymmetry is equivalent to the manifold $M$ having generalised special holonomy and list the relevant holonomy groups. We conjecture that this result extends to backgrounds preserving any number of supersymmetries. As a prime example, we consider $\\mathcal{N}=1$ in $D=4$. The corresponding generalised special holonomy group is $SU(7)$, giving the natural M theory extension to the notion of a $G_2$ manifold, and, for Type II backgrounds, reformulating the pure spinor $SU(3)\\times SU(3)$ conditions as an integrable structure.
Gauge Unification from Split Supersymmetric String Models
Kokorelis, Christos
2016-01-01
We discuss the unification of gauge coupling constants in non-supersymmetric open string vacua that possess the properties of Split Supersymmetry, namely the Standard Model with Higgsinos at low energies and where the Standard model spectrum is always accompanied by right handed neutrinos. These vacua achieve partial unification of two out of three (namely SU(3)$_c$, SU(2), U(1)) running gauge couplings, possess massive gauginos and light Higgsinos at low energies and also satisfy $sin^2\\theta_w (M_s) = 3/8$. These vacua are based on four dimensional orbifold $Z_3 \\times Z_3$ compactifications of string IIA orientifolds with D6-branes intersecting at angles, where the (four dimensional) chiral fermions of the Standard Model appear as opens strings streching between the intersections of seven dimensional objects the so called D6-branes.
Effective Action of Softly Broken Supersymmetric Theories
Nibbelink, S G; Nibbelink, Stefan Groot; Nyawelo, Tino S.
2007-01-01
We study the renormalization of (softly) broken supersymmetric theories at the one loop level in detail. We perform this analysis in a superspace approach in which the supersymmetry breaking interactions are parameterized using spurion insertions. We comment on the uniqueness of this parameterization. We compute the one loop renormalization of such theories by calculating superspace vacuum graphs with multiple spurion insertions. To preform this computation efficiently we develop algebraic properties of spurion operators, that naturally arise because the spurions are often surrounded by superspace projection operators. Our results are general apart from the restrictions that higher super covariant derivative terms and some finite effects due to non-commutativity of superfield dependent mass matrices are ignored. One of the soft potentials induces renormalization of the Kaehler potential.
Phases of supersymmetric O(N) theories
Heilmann, Marianne; Synatschke-Czerwonka, Franziska; Wipf, Andreas
2012-01-01
We perform a global renormalization group study of O(N) symmetric Wess-Zumino theories and their phases in three euclidean dimensions. At infinite N the theory is solved exactly. The phases and phase transitions are worked out for finite and infinite short-distance cutoffs. A distinctive new feature arises at strong coupling, where the effective superfield potential becomes multi-valued, signalled by divergences in the fermion-boson interaction. Our findings resolve the long-standing puzzle about the occurrence of degenerate O(N) symmetric phases. At finite N, we find a strongly-coupled fixed point in the local potential approximation and explain its impact on the phase transition. We also examine the possibility for a supersymmetric Bardeen-Moshe-Bander phenomenon, and relate our findings with the spontaneous breaking of supersymmetry in other models.
SU(2|2) supersymmetric mechanics
Energy Technology Data Exchange (ETDEWEB)
Ivanov, Evgeny [Joint Institute for Nuclear Research,Dubna, Moscow Region, 141980 (Russian Federation); Lechtenfeld, Olaf [Institut für Theoretische Physik and Riemann Center for Geometry and Physics,Leibniz Universität Hannover,Appelstraße 2, 30167 Hannover (Germany); Sidorov, Stepan [Joint Institute for Nuclear Research,Dubna, Moscow Region, 141980 (Russian Federation)
2016-11-07
We introduce a new kind of non-relativistic N= 8 supersymmetric mechanics, associated with worldline realizations of the supergroup SU(2|2) treated as a deformation of flat N= 8, d=1 supersymmetry. Various worldline SU(2|2) superspaces are constructed as coset manifolds of this supergroup, and the corresponding superfield techniques are developed. For the off-shell SU(2|2) multiplets (3,8,5), (4,8,4) and (5,8,3), we construct and analyze the most general superfield and component actions. Common features are mass oscillator-type terms proportional to the deformation parameter and a trigonometric realization of the superconformal group OSp(4{sup ∗}|4) in the conformal cases. For the simplest (5,8,3) model the quantization is performed.
Supersymmetric One-family Model without Higgsinos
Mira, J M; Restrepo, D A; Sánchez, L A; Mira, Jesus M.; Ponce, William A.; Restrepo, Diego A.; Sanchez, Luis A.
2003-01-01
The Higgs potential and the mass spectrum of the N=1 supersymmetric extension of a recently proposed one-family model based on the local gauge group $SU(3)_c \\otimes SU(3)_L \\otimes U(1)_X$, which is a subgroup of the electroweak-strong unification group $E_6$, is analyzed. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons. We show how the $\\mu$ problem is successfully addressed in the context of this model which also predicts the existence of a light CP-odd scalar.
The Supersymmetric Effective Field Theory of Inflation
Delacretaz, Luca V; Senatore, Leonardo
2016-01-01
We construct the Supersymmetric Effective Field Theory of Inflation, that is the most general theory of inflationary fluctuations when time-translations and supersymmetry are spontaneously broken. The non-linear realization of these invariances allows us to define a complete SUGRA multiplet containing the graviton, the gravitino, the Goldstone of time translations and the Goldstino, with no auxiliary fields. Going to a unitary gauge where only the graviton and the gravitino are present, we write the most general Lagrangian built out of the fluctuations of these fields, invariant under time-dependent spatial diffeomorphisms, but softly-breaking time diffeomorphisms and gauged SUSY. With a suitable St\\"uckelberg transformation, we introduce the Goldstone boson of time translation and the Goldstino of SUSY. No additional dynamical light field is needed. In the high energy limit, larger than the inflationary Hubble scale for the Goldstino, these fields decouple from the graviton and the gravitino, greatly simplif...
On the stability of the electroweak vacuum in the presence of low-scale seesaw models
Rose, Luigi Delle; Urbano, Alfredo
2015-01-01
The scale of neutrino masses and the Planck scale are separated by more than twenty-seven order of magnitudes. However, they can be linked by imposing the stability of the electroweak (EW) vacuum. The crucial ingredient is provided by the generation of neutrino masses via a seesaw mechanism triggered by Yukawa interactions between the standard model (SM) Higgs and lepton doublets and additional heavy right-handed neutrinos. These neutrinos participate to the renormalization group (RG) running of the dimensionless SM couplings, affecting their high-energy behavior. The Higgs quartic coupling is dragged towards negative values, thus altering the stability of the EW vacuum. In the usual type-I seesaw model, this effect is too small to be a threat since, in order to comply with low-energy neutrino data, one is forced to consider either too small Yukawa couplings or too heavy right-handed neutrinos. In this paper we explore this general idea in the context of low-scale seesaw models. These models are characterized...
Active-passive vibration absorber of beam-cart-seesaw system with piezoelectric transducers
Lin, J.; Huang, C. J.; Chang, Julian; Wang, S.-W.
2010-09-01
In contrast with fully controllable systems, a super articulated mechanical system (SAMS) is a controlled underactuated mechanical system in which the dimensions of the configuration space exceed the dimensions of the control input space. The objectives of the research are to develop a novel SAMS model which is called beam-cart-seesaw system, and renovate a novel approach for achieving a high performance active-passive piezoelectric vibration absorber for such system. The system consists of two mobile carts, which are coupled via rack and pinion mechanics to two parallel tracks mounted on pneumatic rodless cylinders. One cart carries an elastic beam, and the other cart acts as a counterbalance. One adjustable counterweight mass is also installed underneath the seesaw to serve as a passive damping mechanism to absorb impact and shock energy. The motion and control of a Bernoulli-Euler beam subjected to the modified cart/seesaw system are analyzed first. Moreover, gray relational grade is utilized to investigate the sensitivity of tuning the active proportional-integral-derivative (PID) controller to achieve desired vibration suppression performance. Consequently, it is shown that the active-passive vibration absorber can not only provide passive damping, but can also enhance the active action authority. The proposed software/hardware platform can also be profitable for the standardization of laboratory equipment, as well as for the development of entertainment tools.
Naturalness and stability of the generalized Chaplygin gas in the {\\em seesaw cosmon} scenario
Bernardini, Alex E
2010-01-01
The {\\em seesaw} mechanism is conceived on the basis that a mass scale, $\\xi$, and a dimensionless scale, $s$, can be fine-tuned in order to control the dynamics of active and sterile neutrinos through {\\em cosmon}-type equations of motion: the {\\em seesaw cosmon} equations. This allows for sterile neutrinos to be a dark matter candidate. In this scenario, the dynamical masses and energy densities of active and sterile neutrinos can be consistently embedded into the generalized Chaplygin gas (GCG), the unified dark sector model. In addition, dark matter adiabatically coupled to dark energy allows for a natural decoupling of the (active) mass varying neutrino (MaVaN) component from the dark sector. Thus MaVaN's turn into a secondary effect. Through the scale parameters, $\\xi$ and $s$, the proposed scenario allows for a convergence among three distinct frameworks: the {\\em cosmon} scenario, the {\\em seesaw} mechanism for mass generation and the GCG model. It is found that the equation of state of the perturbati...
Neutrinoless double beta decay in LRSM with natural type-II seesaw dominance
Pritimita, Prativa; Dash, Nitali; Patra, Sudhanwa
2016-10-01
We present a detailed discussion on neutrinoless double beta decay within a class of left-right symmetric models where neutrino mass originates by natural type-II seesaw dominance. The spontaneous symmetry breaking is implemented with doublets, triplets and bidoublet scalars. The fermion sector is extended with an extra sterile neutrino per generation that helps in implementing the seesaw mechanism. The presence of extra particles in the model exactly cancels type-I seesaw and allows large value for Dirac neutrino mass matrix M D . The key feature of this work is that all the physical masses and mixing are expressed in terms of neutrino oscillation parameters and lightest neutrino mass thereby facilitating to constrain light neutrino masses from 0ν ββ decay. With this large value of M D new contributions arise due to; i) purely left-handed current via exchange of heavy right- handed neutrinos as well as sterile neutrinos, ii) the so called λ and η diagrams. New physics contributions also arise from right-handed currents with right-handed gauge boson W R mass around 3 TeV. From the numerical study, we find that the new contributions to 0 νββ decay not only saturate the current experimental bound but also give lower limit on absolute scale of lightest neutrino mass and favor NH pattern of light neutrino mass hierarchy.
Probing Seesaw in an Adjoint SUSY SU(5) Model at LHC
Awasthi, Ram Lal; Mitra, Manimala
2010-01-01
The SU(5) GUT model extended with fermions in the adjoint $24_F$ representation predicts triplet fermions in the 100 GeV mass range, opening up the possibility of testing seesaw at LHC. However, once the model is supersymmerized, the triplet fermion mass is constrained to be close to the GUT scale for the gauge couplings to unify. We propose an extension of the SUSY SU(5) model where type II seesaw can be tested at LHC. In this model we add a matter chiral field in the adjoint $\\hat{24}_F$ representation and Higgs chiral superfields in the symmetric $\\hat{15}_H$ and $\\hat{\\bar{15}}_H$ representations. We call this the symmetric adjoint SUSY SU(5) model. The triplet scalar and triplet fermion masses in this model are predicted to be in the 100 GeV and $10^{13}$ GeV range respectively, while the mass of the singlet fermion remains unconstrained. This gives a type I plus type II plus type III seesaw mass term for the neutrinos. The triplet scalars with masses $\\sim 100$ GeV range can be produced at the LHC. We b...
Dark Matter and the elusive $\\mathbf{Z'}$ in a dynamical Inverse Seesaw scenario
Energy Technology Data Exchange (ETDEWEB)
De Romeri, Valentina; Fernandez-Martinez, Enrique; Gehrlein, Julia; Machado, Pedro N.; Niro, Viviana
2017-07-26
The Inverse Seesaw naturally explains the smallness of neutrino masses via an approximate $B-L$ symmetry broken only by a correspondingly small parameter. In this work the possible dynamical generation of the Inverse Seesaw neutrino mass mechanism from the spontaneous breaking of a gauged $U(1)$ $B-L$ symmetry is investigated. Interestingly, the Inverse Seesaw pattern requires a chiral content such that anomaly cancellation predicts the existence of extra fermions belonging to a dark sector with large, non-trivial, charges under the $U(1)$ $B-L$. We investigate the phenomenology associated to these new states and find that one of them is a viable dark matter candidate with mass around the TeV scale, whose interaction with the Standard Model is mediated by the $Z'$ boson associated to the gauged $U(1)$ $B-L$ symmetry. Given the large charges required for anomaly cancellation in the dark sector, the $B-L$ $Z'$ interacts preferentially with this dark sector rather than with the Standard Model. This suppresses the rate at direct detection searches and thus alleviates the constraints on $Z'$-mediated dark matter relic abundance. The collider phenomenology of this elusive $Z'$ is also discussed.
Supersymmetric dark matter above the W mass
Griest, Kim; Kamionkowski, Marc; Turner, Michael S.
1989-01-01
The cosmological consequences are studied for the minimal supersymmetric extension of the standard model in the case that the neutralino is heavier than W. The cross section was calculated for annihilation of heavy neutralinos into final states containing gauge and Higgs bosons (XX yields WW, ZZ, HH, HW, HZ), where X is the lightest, nth neutralino and the results are compared with the results with those previously obtained for annihilation into fermions to find the relic cosmological abundance for the most general neutralino. The new channels are particularly important for the Higgsino-like and mixed-state neutralinos, but are sub-dominant (to the fermion-antifermion annihilation channels) in the case that the neutralino is mostly a gaugino. The effect of the top quark mass is also considered. Using these cross sections and the cosmological constraint omega(sub X)h squared is less than or approximately 1, the entire range of cosmologically acceptable supersymmetric parameter space is mapped and a very general bound on the neutralino mass is discovered. For a top quark mass of less than 180 GeV, neutralinos heavier than 3200 GeV are cosmologically inconsistent, and if the top quark mass is less than 120 GeV, the bound is lowered to 2600 GeV. Neutralino states that are mostly gaugino are constrained to be lighter than 550 GeV. It is found that a heavy neutralino that contributes omega(sub X) is approximately 1 arises for a very wide range of model parameters and makes, therefore, a very natural and attractive dark matter candidate.
The transformations between N = 2 supersymmetric Korteweg-de Vries and Harry Dym equations
Tian, Kai; Liu, Q. P.
2012-05-01
The N = 2 supercomformal transformations are employed to study supersymmetric integrable systems. It is proved that two known N = 2 supersymmetric Harry Dym equations are transformed into two N = 2 supersymmetric modified Korteweg-de Vries equations, thus are connected with two N = 2 supersymmetric Korteweg-de Vries equations.
Supersymmetric P(X,phi) and the Ghost Condensate
Khoury, Justin; Ovrut, Burt
2010-01-01
We show how to construct supersymmetric actions for higher-derivative scalar field theories of the form P(X,phi), within the context of d=4, N=1 supersymmetry. This construction is of general use, and is applied to write a supersymmetric version of the Dirac-Born-Infeld action. Our principal application of this formalism is to construct the supersymmetric extension of the ghost condensate. This allows us to study the interplay between supersymmetry, time-dependent backgrounds and violations of the null energy condition.
The geometry of supersymmetric coset models and superconformal algebras
Papadopoulos, G
1993-01-01
An on-shell formulation of (p,q), 2\\leq p \\leq 4, 0\\leq q\\leq 4, supersymmetric coset models with target space the group G and gauge group a subgroup H of G is given. It is shown that there is a correspondence between the number of supersymmetries of a coset model and the geometry of the coset space G/H. The algebras of currents of supersymmetric coset models are superconformal algebras. In particular, the algebras of currents of (2,2) and (4,0) supersymmetric coset models are related to the N=2 Kazama-Suzuki and N=4 Van Proeyen superconformal algebras correspondingly.
Ma, E
1994-01-01
In the minimal supersymmetric standard model, the Higgs sector has two unknown parameters, usually taken to be $\\tan \\beta \\equiv v_2/v_1$ and $m_A$, the mass of its one physical pseudoscalar particle. By minimizing the minimum of the Higgs potential along a certain direction in parameter space, it is shown that $m_A = M_Z$ + radiative correction, and if one further plausible assumption is made, $\\tan \\beta > \\sqrt 3$.
Honda, Meiji; Kushnir, Yochanan; Nakamura, Hisashi; Yamane, Shozo; Zebiak, Stephen E.
2005-05-01
The potential predictability associated with the remote influence of midlatitude tropospheric anomalies over the North Pacific or the North Atlantic, via a seesawlike interannual oscillation between the surface Aleutian and Icelandic lows (AL and IL, respectively) is investigated. Data from a 24-member ensemble of 50-yr atmospheric general circulation model simulation forced with observed sea surface temperature (SST) conditions are analyzed by separating the total simulated fluctuations into the external component forced by the prescribed SST and the internal component generated by atmospheric internal dynamics. The AL-IL seesaw can be identified in both the external and internal components of the variability. In the external variability, determined through the ensemble mean, the seesaw is gradually formed from December to March through the development of a Pacific-North American (PNA) pattern-like wave train, remotely forced by the El Niño-Southern Oscillation. The amplitudes of the externally forced North Atlantic anomalies are only about half as large as the North Pacific anomalies. The potential predictability of the Atlantic anomalies, defined as the ratio of the SST-forced variance to the total variance, does not exceed the 20% level. In the internal component of the variability, determined from the deviations of each ensemble member from the ensemble mean, the negative correlation between the AL and IL anomalies is modest but persistent through winter. It is confirmed that, regardless of the polarity of the AL-IL seesaw, the IL anomalies are formed through eastward wave activity propagation of the stationary Rossby wave train emanating from the AL region in the form of what may be called a “PNAA pattern,” the extension of the PNA-like wave train into the Atlantic. Thus, the midwinter development of North Pacific anomalies is found to be a necessary, though not sufficient, condition for the seesaw formation. The persistence of the North Pacific
Supersymmetric Descendants of Self-Adjointly Extended Quantum Mechanical Hamiltonians
Al-Hashimi, M H; Shalaby, A; Wiese, U -J
2013-01-01
We consider the descendants of self-adjointly extended Hamiltonians in supersymmetric quantum mechanics on a half-line, on an interval, and on a punctured line or interval. While there is a 4-parameter family of self-adjointly extended Hamiltonians on a punctured line, only a 3-parameter sub-family has supersymmetric descendants that are themselves self-adjoint. We also address the self-adjointness of an operator related to the supercharge, and point out that only a sub-class of its most general self-adjoint extensions is physical. Besides a general characterization of self-adjoint extensions and their supersymmetric descendants, we explicitly consider concrete examples, including a particle in a box with general boundary conditions, with and without an additional point interaction. We also discuss bulk-boundary resonances and their manifestation in the supersymmetric descendant.
Aspects of a supersymmetric Brans-Dicke theory
Energy Technology Data Exchange (ETDEWEB)
Catena, R.
2006-11-15
We consider a locally supersymmetric theory where the Planck mass is replaced by a dynamical superfield. This model can be thought of as the Minimal Supersymmetric extension of the Brans-Dicke theory (MSBD). The motivation that underlies this analysis is the research of possible connections between Dark Energy models based on Brans-Dicke-like theories and supersymmetric Dark Matter scenarios. We find that the phenomenology associated with the MSBD model is very different compared to the one of the original Brans-Dicke theory: the new scalar and fermionic degrees of freedom do not couple to matter in a universal metric way, i.e. they can not be removed from the matter sector by a Weyl rescaling of the metric. This feature could make the minimal supersymmetric extension of the BD idea phenomenologically inconsistent. (orig.)
LHC phenomenology of supersymmetric models beyond the MSSM
Porod, Werner
2010-01-01
We discuss various phenomenological aspects of supersymmetric models beyond the MSSM. A particular focus is on models which can correctly explain neutrino data and the possiblities of LHC to identify the underlying scenario.
N=2 supersymmetric extension of l-conformal Galilei algebra
Energy Technology Data Exchange (ETDEWEB)
Masterov, Ivan [Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634050 Tomsk, Lenin Ave. 30 (Russian Federation)
2012-07-15
N=2 supersymmetric extension of the l-conformal Galilei algebra is constructed. A relation between its representations in flat spacetime and in Newton-Hooke spacetime is discussed. An infinite-dimensional generalization of the superalgebra is given.
A supersymmetric composite model of quarks and leptons
Luty, Markus A.; Mohapatra, Rabindra N.
1997-02-01
We present a class of supersymmetric models with complete generations of composite quarks and leptons using recent non-perturbative results for the low energy dynamics of supersymmetric QCD. In these models, the quarks arise as composite ``mesons'' and the leptons emerge as composite ``baryons''. The quark and lepton flavor symmetries are linked at the preon level. Baryon number violation is automatically suppressed by accidental symmetries. We give some speculations on how this model might be made realistic.
Reduction of couplings and finiteness in realistic supersymmetric GUTs
Energy Technology Data Exchange (ETDEWEB)
Kubo, J. [Kanazawa Univ. (Japan). Dept. of Physics; Mondragon, M. [Instituto de Fisica, UNAM, Apdo. Postal 20-364, Mexico 01000 D.F. (Mexico); Zoupanos, G. [Physics Dept., Nat. Technical University, 157 80 Zografou, Athens (Greece)
1997-07-01
Reduction of couplings in supersymmetric GUTs is achieved by searching for renormalization group invariant (RGI) relations among couplings which hold beyond the unification scale. Finiteness is due to the fact that there exist RGI relations among couplings that guarantee the vanishing of the {beta}-functions of a N = 1 supersymmetric GUT even to all orders in perturbation theory. Of particular interest are the relations among gauge and Yukawa couplings which lead to very interesting predictions of the top quark mass. (orig.).
Neutralino annihilation into massive quarks with supersymmetric QCD corrections
Herrmann, Björn; Klasen, Michael; Kovařík, Karol
2009-03-01
We compute the full O(αs) supersymmetric (SUSY)-QCD corrections for neutralino annihilation into massive quarks through gauge or Higgs bosons and squarks in the minimal supersymmetric standard model, including the known resummation of logarithmically enhanced terms. The numerical impact of the corrections on the extraction of SUSY mass parameters from cosmological data is analyzed for gravity-mediated SUSY-breaking scenarios and shown to be sizable, so that these corrections must be included in common analysis tools.
Non-supersymmetric AdS and the Swampland
Ooguri, Hirosi
2016-01-01
We propose to sharpen the weak gravity conjecture by the statement that, except for BPS states in a supersymmetric theory, the gravitational force is strictly weaker than any electric force and provide a number of evidences for this statement. Our conjecture implies that any non-supersymmetric anti-de Sitter vacuum supported by fluxes must be unstable, as is the case for all known attempts at such holographic constructions.
Second Hopf map and supersymmetric mechanics with Yang monopole
Energy Technology Data Exchange (ETDEWEB)
Gonzales, M.; Toppan, F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Kuznetsova, Z. [Universidade Federal do ABC, Santo Andre, SP (Brazil); Nersessian, F. [Artsakh State University, Stepanakert (Armenia); Yeghikyan, V. [Yerevan State University (Armenia)
2009-07-01
We propose to use the second Hopf map for the reduction (via SU(2) group action) of the eight-dimensional supersymmetric mechanics to five-dimensional supersymmetric systems specified by the presence of an SU(2) Yang monopole. For our purpose we develop the relevant Lagrangian reduction procedure. The reduced system is characterized by its invariance under the N = 5 or N = 4 supersymmetry generators (with or without an additional conserved BRST charge operator) which commute with the su(2) generators. (author)
Supersymmetric Q-Lumps in the Grassmannian nonlinear sigma models
Bak, D; Lee, J; Oh, P; Bak, Dongsu; Hahn, Sang-Ok; Lee, Joohan; Oh, Phillial
2007-01-01
We construct the N=2 supersymmetric Grassmannian nonlinear sigma model for the massless case and extend it to massive N=2 model by adding an appropriate superpotential. We then study their BPS equations leading to supersymmetric Q-lumps carrying both topological and Noether charges. These solutions are shown to be always time dependent even sometimes involving multiple frequencies. Thus we illustrate explicitly that the time dependence is consistent with remaining supersymmetries of solitons.
Supersymmetric M5 brane theories on R × CP2
Kim, Hee-Cheol; Lee, Kimyeong
2013-07-01
We propose 4 and 12 supersymmetric conformal Yang-Mills-Chern-Simons theories on R × CP2 as multiple representations of the theory on M5 branes. These theories are obtained by twisted Zk modding and dimensional reduction of the 6d (2,0) superconformal field theory on R × S5 and have a discrete coupling constant 1/{g_{{YM}^2}}=k/{4{π^2}} with natural number k. Instantons in these theories are expected to represent the Kaluza-Klein modes. For the k = 1 , 2 cases, we argue that the number of supersymmetries in our theories should be enhanced to 32 and 16, respectively. For the k = 3 case, only the 4 supersymmetric theory gets the supersymmetric enhancement to 8. For the 4 supersymmetric case, the vacuum structure becomes more complicated as there are degenerate supersymmetric vacua characterized by fuzzy spheres. We calculate the perturbative part of the SU( N ) gauge group Euclidean path integral for the index function at the symmetric phase of the 4 supersymmetric case and confirm it with the known half-BPS index. From the similar twisted Z k modding of the AdS7 × S4 geometry, we speculate that the M region is for k ≲ N 1/3 and the type IIA region is N 1/3 ≲ k ≲ N. When nonperturbative corrections are included, our theories are expected to produce the full index of the 6d (2,0) theory.
A tool box for implementing supersymmetric models
Staub, Florian; Ohl, Thorsten; Porod, Werner; Speckner, Christian
2012-10-01
We present a framework for performing a comprehensive analysis of a large class of supersymmetric models, including spectrum calculation, dark matter studies and collider phenomenology. To this end, the respective model is defined in an easy and straightforward way using the Mathematica package SARAH. SARAH then generates model files for CalcHep which can be used with micrOMEGAs as well as model files for WHIZARD and O'Mega. In addition, Fortran source code for SPheno is created which facilitates the determination of the particle spectrum using two-loop renormalization group equations and one-loop corrections to the masses. As an additional feature, the generated SPheno code can write out input files suitable for use with HiggsBounds to apply bounds coming from the Higgs searches to the model. Combining all programs provides a closed chain from model building to phenomenology. Program summary Program title: SUSY Phenomenology toolbox. Catalog identifier: AEMN_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMN_v1_0.html. Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland. Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html. No. of lines in distributed program, including test data, etc.: 140206. No. of bytes in distributed program, including test data, etc.: 1319681. Distribution format: tar.gz. Programming language: Autoconf, Mathematica. Computer: PC running Linux, Mac. Operating system: Linux, Mac OS. Classification: 11.6. Nature of problem: Comprehensive studies of supersymmetric models beyond the MSSM is considerably complicated by the number of different tasks that have to be accomplished, including the calculation of the mass spectrum and the implementation of the model into tools for performing collider studies, calculating the dark matter density and checking the compatibility with existing collider bounds (in particular, from the Higgs searches). Solution method: The