WorldWideScience

Sample records for tev-scale bileptons see-saw

  1. 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...

  2. Quark see-saw, Higgs mass and vacuum stability

    Indian Academy of Sciences (India)

    2015-12-29

    Dec 29, 2015 ... 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 ...

  3. Quark see-saw, Higgs mass and vacuum stability

    Indian Academy of Sciences (India)

    Abstract. 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 (λ1,λ2) and two mass parameters. There are only two physical neutral. Higgs bosons (h, H ), the lighter one ...

  4. Bilepton signatures at the LHC

    Science.gov (United States)

    Corcella, Gennaro; Corianò, Claudio; Costantini, Antonio; Frampton, Paul H.

    2017-10-01

    We discuss the main signatures of the Bilepton Model at the Large Hadron Collider, focusing on its gauge boson sector. The model is characterised by five additional gauge bosons, four charged and one neutral, beyond those of the Standard Model, plus three exotic quarks. The latter turn into ordinary quarks with the emission of bilepton doublets (Y++ ,Y+) and (Y- ,Y-) of lepton number L = - 2 and L = + 2 respectively, with the doubly-charged bileptons decaying into same-sign lepton pairs. We perform a phenomenological analysis investigating processes with two doubly-charged bileptons and two jets at the LHC and find that, setting suitable cuts on pseudorapidities and transverse momenta of final-states jets and leptons, the model yields a visible signal and the main Standard Model backgrounds can be suppressed. Compared to previous studies, our investigation is based on a full Monte Carlo implementation of the model and accounts for parton showers, hadronization and an actual jet-clustering algorithm for both signal and Standard Model background, thus providing an optimal framework for an actual experimental search.

  5. The see-saw mechanism: Neutrino mixing, leptogenesis and lepton ...

    Indian Academy of Sciences (India)

    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 ...

  6. Predictions of the most minimal see-saw model

    CERN Document Server

    Raidal, Martti

    2003-01-01

    We derive the most minimal see-saw texture from an extra-dimensional dynamics. If LMA is the solution to the solar neutrino problem, it predicts $\\theta_{13} = 0.07\\pm0.02$ and $m_{ee} = 2.5\\pm0.7 \\meV.$ Assuming thermal leptogenesis, the sign of the CP-phase measurable in neutrino oscillations, together with the sign of baryon asymmetry, determines the order of heavy neutrino masses. Unless heavy neutrinos are almost degenerate, successful leptogenesis fixes the lightest mass. Depending on the sign of the neutrino CP-phase, the supersymmetric version of the model with universal soft terms at high scale predicts BR($\\mu\\to e \\gamma$) or BR($\\tau\\to \\mu \\gamma$), and gives a lower bound on the other process.

  7. Observable N–N oscillation, high-scale see-saw and origin of matter

    Indian Academy of Sciences (India)

    Since the expected see-saw scale is high and the N − 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 ...

  8. SUSY see-saw and NMSO(10)GUT inflation after BICEP2

    Indian Academy of Sciences (India)

    2016-01-13

    Jan 13, 2016 ... Abstract. Supersymmetric see-saw slow roll inflection point inflation occurs along a MSSM. D-flat direction associated with gauge invariant combination of Higgs, slepton and right-handed sneutrino at a scale set by the right-handed neutrino mass Mνc. ∼ 106−1013 GeV. The tensor to scalar perturbation ...

  9. Discriminating neutrino mass models using Type-II see-saw formula

    Indian Academy of Sciences (India)

    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 ...

  10. Radiative see-saw formula in nonsupersymmetric SO (10) with dark ...

    Indian Academy of Sciences (India)

    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 ...

  11. A see-saw scenario of an $A_4$ flavour symmetric standard model

    CERN Document Server

    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 ...

  12. The Income Volatility See-Saw: Implications for School Lunch. ERS Report Summary

    Science.gov (United States)

    Newman, Constance

    2006-01-01

    Income volatility challenges the functioning of the safety net provided by U.S. Department of Agriculture (USDA) food assistance programs for low-income families in time of need. Low-income families may be on a see-saw of income changes that make it difficult for program administrators to accurately target benefits and to define sensible…

  13. Is there a see-saw over an ice-free Arctic Ocean?

    Science.gov (United States)

    Stendel, Martin; Yang, Shuting; Langen, Peter; Rodehacke, Christian; Mottram, Ruth; Hesselbjerg Christensen, Jens

    2017-04-01

    The "see-saw" in winter temperatures between western Greenland and the Canadian Arctic on one side and northern Europe on the other has been described by Loewe already in 1937, but actually this behaviour was at least known since the Danish colonization of Greenland in the early 18th century. The see-saw is associated with pressure anomalies not only near the region of interest, but as remote as the Mediterranean and the North Pacific. Recent research has pointed out the role of sea ice in maintaining the see-saw in either its warm or its cold phase over extended periods, which strongly affects European winter temperatures. What would happen to the seesaw if Arctic sea ice were to disappear suddenly? In the framework of the FP7-funded project ice2ice, we try to answer this and related questions. We have conducted a very long global simulation with a global climate model interactively coupled to a Greenland ice sheet component, covering the period 1850-3250 at a horizontal resolution of approximately 125 km. Up to 2005, the forcing is from observed greenhouse gas concentrations, and from 2006 onward it follows the extended RCP8.5 scenario, in which greenhouse gas concentrations continue to increase and eventually level out around 2250. With such a strong forcing, all Arctic sea ice has completely disappeared by roughly the same time, and the surface mass balance of the Greenland Ice Sheet becomes strongly negative. We investigate how the see-saw behaves in such an ice-free world and which implications circulation changes have in the Arctic and over Europe. To further elucidate the role of sea ice distribution on the atmospheric flow and the role of surface fluxes in maintaining the Greenland-European see-saw, we intend at a later time to expand our analysis to include a contrasting simulation with both western Greenland and northern Europe covered by ice during the Last Glacier Maximum.

  14. Neutrino mass matrix suppression by Abelian charges with see-saw mechanism

    CERN Document Server

    Nielsen, Holger Bech

    2000-01-01

    We have investigated a neutrino mass matrix model without supersymmetry including three see-saw right-handed neutrinos around order $10^{12}$ GeV masses, aiming at a picture with all small numbers explained as being due to approximately conserved gauge charges. The prediction of the solar neutrino mixing angle is given by $\\sin^22\\theta_{\\odot}= 3 {+3\\atop -2}\\times10^{-2}$; in fact, the solar mixing angle is, apart from detailed order unity corrections, equal to the Cabibbo angle. Furthermore the ratio of the solar neutrino mass square difference to that for the atmospheric neutrino oscillation is predicted to $6 {+11\\atop -4}\\times10^{-4}$ and is given by the same Cabibbo angle related parameter $\\xi$ as $6 \\xi^4$.

  15. 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.)

  16. Transplanckian collisions in TeV scale gravity

    Indian Academy of Sciences (India)

    Collisions at transplanckian energies offer model independent tests of TeV scale gravity. One spectacular signal is given by black-hole production, though a full calculation of the corresponding cross-section is not yet available. Another signal is given by gravitational elastic scattering, which may be less spectacular but ...

  17. High precision fundamental constants at the TeV scale

    CERN Document Server

    Moch, S.; Alekhin, S.; Blumlein, J.; de la Cruz, L.; Dittmaier, S.; Dowling, M.; Erler, J.; Espinosa, J.R.; Fuster, J.; Garcia i Tormo, X.; Hoang, A.H.; Huss, A.; Kluth, S.; Mulders, M.; Papanastasiou, A.S.; Piclum, J.; Rabbertz, K.; Schwinn, C.; Schulze, M.; Shintani, E.; Uwer, P.; Zerf, N.

    2014-01-01

    This report summarizes the proceedings of the 2014 Mainz Institute for Theoretical Physics (MITP) scientific program on "High precision fundamental constants at the TeV scale". The two outstanding parameters in the Standard Model dealt with during the MITP scientific program are the strong coupling constant $\\alpha_s$ and the top-quark mass $m_t$. Lacking knowledge on the value of those fundamental constants is often the limiting factor in the accuracy of theoretical predictions. The current status on $\\alpha_s$ and $m_t$ has been reviewed and directions for future research have been identified.

  18. Hadron supercolliders: The 1-TeV scale and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, C.

    1990-08-10

    Greater understanding of the connection between the weak and electromagnetic interactions is central to progress in elementary-particle physics. A definitive exploration of the mechanism for electroweak symmetry breaking will require collisions between fundamental constituents at energies on the order of 1 TeV. This goal drives the design of high-energy, high-luminosity hadron colliders that will be commissioned during the next decade, but by no means completely defines their scientific potential. These three lectures are devoted to a review of the standard-model issues that motivated an experimental assault on the 1-TeV scale, an introduction to the machines and the experimental environment they will present, and a survey of possibilities for measurement and discovery with a multi-TeV hadron collider. 72 refs., 29 figs.

  19. An east-west climate see-saw in the Mediterranean during the last 2.6 ka: evidence and mechanisms

    Science.gov (United States)

    Roberts, C.; Moreno-Caballud, A.; Valero-Garces, B. L.; Luterbacher, J.; Xoplaki, E.; Allcock, S. L.

    2012-12-01

    Global precipitation anomalies during the Common Era show a spatial coherency that appears to be about an order of magnitude lower (i.e. smaller) than for temperature changes, as some areas became wetter while others experienced drought (Seager et al., 2007, Quat. Sci. Rev. 26, 2322-36). The Mediterranean basin (10°W-40°E; 30°-45°N) is influenced by some of the main mechanisms acting upon the global climate system and its regional water resources are sensitive to hydro-climatic variations. Reconstructing the timing, intensity, and patterns of hydrological variability in the Mediterranean is important for testing spatial-temporal coherency in palaeo-precipitation, and for understanding underlying climate forcing mechanisms. The region offers a broad spectrum of documentary information and natural archives which allow high-resolution climate reconstructions (Luterbacher et al., 2012, In: Lionello et al. (eds) The Mediterranean Climate: from past to future. Elsevier, pp. 87-185). During the period of instrumental records, the NAO has strongly influenced inter-annual precipitation variations in the western Mediterranean, while parts of the eastern basin have shown an anti-phase relationship in precipitation and atmospheric pressure. A wide array of proxy-climate data from Iberia and Morocco indicate overall drier conditions during the Medieval Climate Anomaly (MCA) and a generally wetter climate in the Little Ice Age (LIA)(Moreno et al., 2012, Quat. Sci. Rev. 43, 16-32). This pattern is consistent with strong NAO forcing of western Mediterranean climate over the last 1.1 ka (Trouet et al., 2009; Science 324, 78-80). High-resolution palaeolimnological evidence from central Anatolia exhibit an opposite pattern, implying that an east-west climate see-saw operated in the Mediterranean basin during the LIA and MCA (Roberts et al., 2012; Glob. Planet. Change 84-85, 23-34). However, the strongest evidence for higher (lower) winter season precipitation during the MCA (LIA

  20. Hunting for TeV Scale Strings at the LHC

    CERN Document Server

    Bars, Itzhak

    2010-01-01

    In this paper I review the possibility of TeV scale strings that may be detectable by the Large Hadron Collider (LHC). This possibility was investigated extensively in a series of phenomenological papers during 1984-1985 in connection with the Superconducting Super Collider (SSC). The work was mainly based on a model independent systematic parametrization of scattering amplitudes and cross sections, for Standard Model particles, quarks and leptons, that were assumed to behave like strings, while gluons, photons, $W^{\\pm},Z$ were taken as elementary. By using Veneziano type beta functions consistent with crossing symmetry, duality and Regge behavior, bosonic or fermionic resonances in each channel were included, while the low energy behavior was matched to effective field theory non-renormalizable interactions consistent with the Standard Model SU(3)xSU(2)xU(1) gauge symmetry as well as global flavor and family symmetries. The motivation for this approach at that time was the possible compositeness of quarks a...

  1. SEE SAW BASED REGENERATIVE POWER SYSTEM

    OpenAIRE

    Tribhuwan Singh; Shahzad Ali

    2016-01-01

    Research related to electrical vehicles is gaining importance due to the energy crisis. Using regenerative braking when braking, improves the efficiency of an electric vehicle as it recovers energy that could go to waste if mechanical brakes were used. A novel regenerative braking system for neighborhood electric vehicles was designed, prototyped and tested. The proposed system utilizes a seesaw system to capture energy whereas the conventional systems regenerate to the batteries. The user ha...

  2. SEE SAW CREATED RECREATING POWER SYSTEM

    OpenAIRE

    Sameer Singh*, Saha Ali

    2016-01-01

    Research related to electrical vehicles is gaining importance due to the energy crisis. Using regenerative braking when braking, improves the efficiency of an electric vehicle as it recovers energy that could go to waste if mechanical brakes were used. A novel regenerative braking system for neighborhood electric vehicles was designed, prototyped and tested. The proposed system utilizes a seesaw system to capture energy whereas the conventional systems regenerate to the batteries. The user ha...

  3. Cosmic Ray Observations at the TeV Scale with the HAWC Observatory

    Science.gov (United States)

    Hampel-Arias, Zigfried

    2017-08-01

    Over the past two decades, a more detailed understanding of TeV-scale cosmic rays has emerged which appears to deviate from the isotropic, single power law description of the cosmic ray flux. This may be the result of the distribution of sources within the Galaxy, changes in source spectra, effects from the propagation of cosmic rays from their sources to Earth, or a combination of the three. Supernova remnants are thought to be the most likely source of Galactic cosmic rays, providing a natural power law source spectrum with sufficient power to generate the observed cosmic ray energy density. Yet, recent results from balloon-borne experiments hint at a possible change in the spectral index between 20?50 TeV. These direct detection apparatuses provide the most precise measurements of the cosmic ray flux up to ˜30 TeV, beyond which they are limited by the combined effects of their physical dimensions, runtime durations, and a rapidly decreasing flux. Above ˜100 TeV, the spectrum has been measured by ground based air shower arrays, with typical systematic uncertainties of order 10%. Despite having the combined measurements from various experimental techniques, their different energy scales and systematics imply that identifying finer structure between 10 - 100 TeV requires a single experimental method to span the entire range. Furthermore, as the nearest potential source is hundreds of parsecs away and the Larmor radius of TeV scale charged cosmic rays in the Galaxy is of order 10?3 parsecs, the previously observed anisotropy in arrival directions of cosmic rays is unexpected. In order to attain the statistical power necessary to observe TeV cosmic ray anisotropy at the 10-3 level and below, the long data taking periods required are only attainable by air shower arrays. This thesis presents a measurement of the cosmic ray energy spectrum and the energy dependence of the anisotropy on small scales O(10°) using data from the High Altitude Water Cherenkov (HAWC) Observatory, an air-shower array located near Puebla, Mexico that is sensitive to gamma rays and cosmic rays at TeV energies. The analyses in this work comprise data taking periods of order 1 yr containing ˜1010 events. An analysis of the cosmic ray Moon shadow is first presented as a verification of the angular resolution and energy scale of the detector. Next, a measurement of the all-particle cosmic ray energy spectrum from 10 - 500 TeV is shown, with an indication of structure deviating from a single power law. The final results presented in this work show an improved spectral measurement of a particular region of cosmic ray excess at the 10?4 level, previously observed both in HAWC and in other experiments.

  4. A Search for New Physics at the TeV Scale Via a Precise Measurement of the Weak Mixing Angle in Moller Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Emam, W.

    2004-11-01

    This dissertation reports on a precise measurement of the parity-violating asymmetry in electron-electron (Moeller) scattering at a four-momentum transfer Q{sup 2} = 0.03 (GeV/c){sup 2}. The observed parity-violating asymmetry is A{sub PV} = -128 {+-} 14 (stat.) {+-} 12 (syst.) x 10{sup -9}. This is the most precise asymmetry ever measured in a parity-violating electron scattering. In the context of the Standard Model, the A{sub PV} result determines the weak mixing angle, which is one of the fundamental parameters of the model. The result is sin{sup 2} {theta}{sub W}{sup eff} = 0.2403 {+-} 0.0014, which is consistent with the Standard Model expectation at the current level of precision. The comparison between this measurement of the weak mixing angle at low Q{sup 2} and at the Z{sup 0} pole establishes the running of sin{sup 2} {theta}{sub W} with 6.5{sigma} significance. In addition, they report on the first observation of a transverse asymmetry in electron-electron scattering. The observed asymmetry is A{sub T}{sup Moeller} = 2.7 x 10{sup -6}, which is consistent with the theoretical predictions. They also provide a new measurement of the transverse asymmetry in ep scattering A{sub T}{sup ep} = 2 x 10{sup -6}. The consistency of the result with the theoretical prediction provides new limits on the TeV scale physics. A limit of 0.9 TeV was set on the mass of the extra Z' boson in the SO(10) Model. A limit of 14 TeV and 6 TeV was set on the compositeness scales {Lambda}{sub ee}{sup +} and {Lambda}{sub ee}{sup -}, respectively. Finally a limit of 0.2 TeV was set on ratio of the doubly-charged Higgs mass to the ee{Delta} coupling g{sub ee{Delta}}{sup 2}/m{sub {delta}}{sup 2}.

  5. Sterile neutrino in a minimal three-generation see-saw model

    Indian Academy of Sciences (India)

    3Department of Physics and Astronomy, University of Maryland, College Park, MD 20742, USA. 4Abdus Salam International Centre .... σ2. (1,0,0). (1,0). ·2. 1 σ0. (1,0,0). (1,0). 0. 1. Then we get the following neutrino mass texture in the original basis. Transforming back to original basis (ν. ¼ e,ν. ¼. µ) (νe. L,νµ. L ). M = ¼ νe. L.

  6. Interesting differences between CH4 and d18Oatm records of bipolar see-saw activity

    Science.gov (United States)

    Severinghaus, Jeffrey; Baggenstos, Daniel; Rhodes, Rachael; Brook, Edward

    2014-05-01

    Abrupt changes in atmospheric methane concentration have long been used to infer changes in low-latitude hydrology. A lesser-used tracer is the oxygen-18 content of atmospheric dioxygen (d18Oatm), which is produced by photosynthesis and records the O-18 content of chloroplast water among other variables. Observations from ice core trapped air records suggest that strong Asian monsoons produce dioxygen with a relatively negative d18Oatm, whereas periods of weak Asian monsoon rainfall and strong southern hemisphere monsoons are characterized by relatively positive d18Oatm (Severinghaus et al., 2009, Science). Generally, CH4 and d18Oatm are anticorrelated, with high CH4 and negative d18Oatm during times of northern hemisphere warmth, strong Asian monsoons, and the bipolar seesaw in its "warm north" mode. However, interesting exceptions to this pattern occur during Heinrich Stadials and during the initial phases of the last deglaciation. Here, ice core data suggest episodes in which CH4 rise is not associated with negative d18Oatm, but instead positive d18Oatm. It is suggested that these intervals can be explained as being times of strong southern hemisphere low-latitude rainfall, which creates the positive values in d18Oatm. We hypothesize that dioxygen produced in southern hemisphere locales generally has higher O-18 content, due to the higher O-18 content of chloroplast water and the prevailing precipitation O-18 in those regions. In summary, we hypothesize that d18O of photosynthetic O2 is a more monotonic function of latitude, compared with methane production, which can be bimodally produced in the low latitudes of both hemispheres.

  7. SUSY see-saw and NMSO (10) GUT inflation after BICEP2

    Indian Academy of Sciences (India)

    -saw slow roll inflection point inflation ... Author Affiliations. Ila Garg1 2. Department of Physics, Panjab University, Chandigarh 160 014, India; Physical Research Laboratory, Ahmedabad 380 009, India. Dates. Early published: 13 January 2016 ...

  8. Observable N–¯N oscillation, high-scale see-saw and origin of matter

    Indian Academy of Sciences (India)

    Introduction. There are various reasons to suspect that baryon number is not a good symmetry of nature. They are: (i) nonperturbative effects of the Standard Model lead to. ∆B = 0, while keeping ∆(B − L) = 0 [1]; (ii) an understanding of the origin of matter in the Universe requires ∆B = 0 interactions [2] and (iii) many theories.

  9. The see-saw a vertical-lift incubator designed for channel catfish egg masses

    Science.gov (United States)

    Channel catfish egg masses are typically incubated in baskets that are suspended in water that is agitated with rotating or oscillating paddles. We designed and tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish egg masses. Preliminary research in commercial hatcheries...

  10. Coherent tropical-subtropical Holocene see-saw moisture patterns in the Eastern Hemisphere monsoon systems

    Science.gov (United States)

    Wang, Yongbo; Bekeschus, Benjamin; Handorf, Dörthe; Liu, Xingqi; Dallmeyer, Anne; Herzschuh, Ulrike

    2017-08-01

    The concept of a Global Monsoon (GM) has been proposed based on modern precipitation observations, but its application over a wide range of temporal scales is still under debate. Here, we present a synthesis of 268 continental paleo-moisture records collected from monsoonal systems in the Eastern Hemisphere, including the East Asian Monsoon (EAsM), the Indian Monsoon (IM), the East African Monsoon (EAfM), and the Australian Monsoon (AuM) covering the last 18,000 years. The overall pattern of late Glacial to Holocene moisture change is consistent with those inferred from ice cores and marine records. With respect to the last 10,000 years (10 ka), i.e. a period that has high spatial coverage, a Fuzzy c-Means clustering analysis of the moisture index records together with ;Xie-Beni; index reveals four clusters of our data set. The paleoclimatic meaning of each cluster is interpreted considering the temporal evolution and spatial distribution patterns. The major trend in the tropical AuM, EAfM, and IM regions is a gradual decrease in moisture conditions since the early Holocene. Moisture changes in the EAsM regions show maximum index values between 8 and 6 ka. However, records located in nearby subtropical areas, i.e. in regions not influenced by the intertropical convergence zone, show an opposite trend compared to the tropical monsoon regions (AuM, EAfM and IM), i.e. a gradual increase. Analyses of modern meteorological data reveal the same spatial patterns as in the paleoclimate records such that, in times of overall monsoon strengthening, lower precipitation rates are observed in the nearby subtropical areas. We explain this pattern as the effect of a strong monsoon circulation suppressing air uplift in nearby subtropical areas, and hence hindering precipitation. By analogy to the modern system, this would mean that during the early Holocene strong monsoon period, the intensified ascending airflows within the monsoon domains led to relatively weaker ascending or even descending airflows in the adjacent subtropical regions, resulting in a precipitation deficit compared to the late Holocene. Our conceptual model therefore integrates regionally contrasting moisture changes into the Global Monsoon hypothesis.

  11. TALSPEAK CURVE: AN ILLUSTRATION OF A SEE-SAW EFFECT IN SEPARATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Peter Zalupski; Leigh Martin

    2010-11-01

    A superbly balanced thermodynamic struggle for metal ion coordination by aqueous aminopolycarboxylate reagent, DTPA, and non-aqueous organophosphorous phase transfer reagent, HDEHP, affords the separation of trivalent actinides from trivalent lanthanides under the umbrella of the Talspeak liquid-liquid distribution process. This thermodynamic relationship has been linked to an analogous “see-saw” behavior, where the balance is distorted when either of the key complexing players is subject to adverse conditions that interfere with their optimal operation. The thermodynamic balance is tipped in favour of HDEHP whenever increased acidity of the aqueous solution out-competes the metal ion complexation by aqueous complexing agent. Also enhanced steric crowding may switch-off efficient coordination of the metal ion. When HDEHP is depolymerised due to the presence of aliphatic alcohol in the organic phase its phase transferring power is diminished. Such complication paves way for DTPA to establish its dominance on the distribution of trivalent metal ions in the 2-phase system. The illustrated sensitivity of the thermodynamic balance between DTPA and HDEHP in Talspeak-type systems may serve as informative tool when studying less-predictable realms of Talspeak chemistry.

  12. Discriminating neutrino mass models using Type-II see-saw formula

    Indian Academy of Sciences (India)

    L Verde et al, Astrophys. J. Suppl. 148, 195 (2003). H V Peiris et al, Astrophys. J. Suppl. 148, 213 (2003). [12] S Hannestad, J. Cosmol. Astropart. Phys. 0305, 004 (2003). O Elgaroy and O Lahav, J. Cosmol. Astropart. Phys. 0304, 004 (2003). S Hannestad, Eur. Phys. J. C33, 5800 (2004), hep-ph/0310220. S Hannestad and ...

  13. The Income Volatility See-Saw: Implications for School Lunch. Economic Research Report Number 23

    Science.gov (United States)

    Newman, Constance

    2006-01-01

    Income volatility challenges the effectiveness of the safety net that USDA food assistance programs provide low-income families. This study examines income volatility among households with children and the implications of volatility for eligibility in the National School Lunch Program (NSLP). The results show that income volatility was higher for…

  14. Channel catfish hatchery production efficiency using a vertical-lift incubator the see-saw at various egg loading densities

    Science.gov (United States)

    Channel catfish spawns are typically incubated in ¼-in mesh baskets suspended in water that is agitated with paddles positioned between baskets. We tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish spawns. Previous research demonstrated that when loaded with spawns at...

  15. Substructure and strong interactions at the TeV scale

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1985-12-01

    A review is given of the current status of the three main theoretical ideas relevant to strong-interaction 1 TeV physics. These are composite vector bosons, Higgs bosons (''Technicolor''), and matter fermions. All involve the assumption that some object which is assumed to be fundamental in the standard model actually has dynamical internal structure. Complex, mechanistic models of the new physics are discussed. A brief digression is then made on how the weak interaction allows probing for this new structure. Direct manifestations of new 1 TeV strong interactions are discussed. 125 refs., 18 figs. (LEW)

  16. μ → eγ decay versus the μ → eee bound and lepton flavor violating processes in supernova

    Science.gov (United States)

    Lychkovskiy, O. V.; Vysotsky, M. I.

    2012-03-01

    Even tiny lepton flavor violation (LFV) due to some New Physics is able to alter the conditions inside a collapsing supernova core and probably to facilitate the explosion. LFV emerges naturally in a see-saw type-II model of neutrino mass generation. Experimentally, the LFV beyond the Standard Model is constrained by rare lepton decay searches. In particular, strong bounds are imposed on the μ → eee branching ratio and on the μ- e conversion in muonic gold. Currently, the μ→ eγ is under investigation in the MEG experiment that aims at a dramatic increase in sensitivity in the next three years. We seek a see-saw type-II LFV pattern that fits all the experimental constraints, leads to Br(μ → eγ) ≳ Br(μμ → eee), and ensures a rate of LFV processes in supernova high enough to modify the supernova physics. These requirements are sufficient to eliminate almost all freedom in the model. In particular, they lead to the prediction 0.4 × 10-12 ≲ Br(μ → eγ) ≲ 6 × 10-12, which will be testable by MEG in the nearest future. The considered scenario also constrains the neutrino mass-mixing pattern and provides lower and upper bounds on τ-lepton LFV decays. We also briefly discuss a model with a single bilepton in which the μ → eee decay is absent at the tree level.

  17. Jet physics at the LHC the strong force beyond the TeV scale

    CERN Document Server

    Rabbertz, Klaus

    2017-01-01

    This book reviews the latest experimental results on jet physics from proton-proton collisons at the LHC. Jets allow to determine the strong coupling constant over a wide range of energies up the highest ones possible so far, and to constrain the gluon parton distribution of the proton, both of which are important uncertainties on theory predictions in general and for the Higgs boson in particular. A novel approach in this book is to categorize the examined quantities according to the types of absolute, ratio, or shape measurements and to explain in detail the advantages and differences. Including numerous illustrations and tables the physics message and impact of each observable is clearly elaborated.

  18. Searching for hot new physics using ultracold neutrons: fundamental symmetries above the TeV scale.

    CERN Multimedia

    CERN. Geneva

    2015-01-01

        As it stands now, the Standard Model surely requires an extension to explain dark matter, baryon number asymmetry and unification with gravity. While assured near the Planck scale, the lower energy limit of these extensions have not yet been discovered ...

  19. The Right Side of Tev Scale Spontaneous R-Parity Violation

    OpenAIRE

    Everett, Lisa L.; Perez, Pavel Fileviez; Spinner, Sogee

    2009-01-01

    We study a simple extension of the minimal supersymmetric Standard Model in which the Abelian sector of the theory consists of B-L and right-handed isospin. In the minimal model this Abelian gauge structure is broken to the standard model hypercharge gauge group by non-vanishing vacuum expectation values of the right-handed sneutrinos, resulting in spontaneous R-parity violation. This theory can emerge as a low energy effective theory of a left-right symmetric theory realized at a high scale....

  20. The Charged Lepton Mass Matrix and Non-zero θ13 with TeV Scale New Physics.

    Science.gov (United States)

    Rashed, Ahmed; Datta, Alakabha

    2012-03-01

    We provide an explicit structure of the charged lepton mass matrix which is 2-3 symmetric except for a single breaking of this symmetry by the muon mass. We identify a flavor symmetric limit for the mass matrices where the first generation is decoupled from the other two in the charged lepton sector while in the neutrino sector the third generation is decoupled from the first two generations. The leptonic mixing in the symmetric limit can be, among other structures, the bi-maximal (BM) or the tri-bimaximal (TBM) mixing. Symmetry breaking effects are included both in the charged lepton and the neutrino sector to produce corrections to the leptonic mixing and explain the recent θ13 measurements. A model that extends the SM by three right handed neutrinos, an extra Higgs doublet, and two singlet scalars is introduced to generate the leptonic mixing.[4pt] This work was supported in part by the US-Egypt Joint Board on Scientific and Technological Co-operation award (Project ID: 1855) administered by the US Department of Agriculture, summer grant from the College of Liberal Arts, University of Mississippi and in part by the National Science Foundation under Grant No. 1068052 and 1066293 and the hospitality of the Aspen Center for Physics.

  1. lW{nu} production at CLIC: a window to TeV scale non-decoupled neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Aguila, Francisco del [Departamento de Fisica Teorica y del Cosmos and Centro Andaluz de Fisica de Particulas elementales (CAFPE), Universidad de Granada, E-18071 Granada (Spain); Aguilar-Saavedra, Juan Antonio [Departamento de Fisica and CFTP, Instituto Superior Tecnico, P-1049-001 Lisbon (Portugal)

    2005-05-01

    We discuss single heavy neutrino production e{sup +}e{sup -}{yields}N{nu}{yields}lW{nu}, l = e,{mu},{tau}, at a future high energy collider like CLIC, with a centre of mass energy of 3 TeV. This process could allow to detect heavy neutrinos with masses of 1-2 TeV if their coupling to the electron V{sub eN} is in the range 0.004-0.01. We study the dependence of the limits on the heavy neutrino mass and emphasise the crucial role of lepton flavour in the discovery of a positive signal at CLIC energy. We present strategies to determine heavy neutrino properties once they are discovered, namely their Dirac or Majorana character and the size and chirality of their charged current couplings. Conversely, if no signal is found, the bound V{sub eN} {<=} 0.002-0.006 would be set for masses of 1-2 TeV, improving the present limit up to a factor of 30. We also extend previous work examining in detail the flavour and mass dependence of the corresponding limits at ILC, as well as the determination of heavy neutrino properties if they are discovered at this collider.

  2. Vacuum stability in U(1-prime extensions of the Standard Model with TeV scale right handed neutrinos

    Directory of Open Access Journals (Sweden)

    Claudio Corianò

    2014-11-01

    Full Text Available We investigate a minimal U(1′ extension of the Standard Model with one extra complex scalar and generic gauge charge assignments. We use a type-I seesaw mechanism with three heavy right handed neutrinos to illustrate the constraints on the charges, on their mass and on the mixing angle of the two scalars, derived by requiring the vacuum stability of the scalar potential. We focus our study on a scenario which could be accessible at the LHC, by selecting a vacuum expectation value of the extra Higgs in the TeV range and determining the constraints that emerge in the parameter space. To illustrate the generality of the approach, specific gauge choices corresponding to U(1B−L, U(1R and U(1χ are separately analyzed. Our results are based on a modified expression of one of the β functions of the quartic couplings of the scalar potential compared to the previous literature. This is due to a change in the coefficient of the Yukawa term of the right handed neutrinos. Differently from previous analysis, we show that this coupling may destabilize the vacuum.

  3. Why PeV scale left-right symmetry is a good thing

    Science.gov (United States)

    Yajnik, Urjit A.

    2017-10-01

    Left-right symmetric gauge theory presents a minimal paradigm to accommodate massive neutrinos with all the known conserved symmetries duly gauged. The work presented here is based on the argument that the see-saw mechanism does not force the new right-handed symmetry scale to be very high, and as such some of the species from the spectrum of the new gauge and Higgs bosons can have masses within a few orders of magnitude of the TeV scale. The scale of the left-right parity breaking in turn can be sequestered from the Planck scale by supersymmetry. We have studied several formulations of such just beyond Standard Model (JBSM) theories for their consistency with cosmology. Specifically, the need to eliminate phenomenologically undesirable domain walls gives many useful clues. The possibility that the exact left-right symmetry breaks in conjunction with supersymmetry has been explored in the context of gauge mediation, placing restrictions on the available parameter space. Finally, we have also studied a left-right symmetric model in the context of metastable supersymmetric vacua and obtained constraints on the mass scale of right-handed symmetry. In all the cases studied, the mass scale of the right-handed neutrino M_R remains bounded from above, and in some of the cases the scale 10^9 GeV favourable for supersymmetric thermal leptogenesis is disallowed. On the other hand, PeV scale remains a viable option, and the results warrant a more detailed study of such models for their observability in collider and astroparticle experiments.

  4. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. Ila Garg. Articles written in Pramana – Journal of Physics. Volume 86 Issue 2 February 2016 pp 315-323 Special: Cosmology. SUSY see-saw and NMSO(10)GUT inflation after BICEP2 · Ila Garg · More Details Abstract Fulltext PDF. Supersymmetric see-saw slow roll inflection ...

  5. Minimal extended flavor groups, matter fields chiral representations, and the flavor question

    OpenAIRE

    Doff, A.; Pisano, F [UNESP

    2000-01-01

    We show the specific unusual features on chiral gauge anomalies cancellation in the minimal, necessarily 3-3-1, and the largest 3-4-1 weak isospin chiral gauge semisimple group leptoquark-bilepton extensions of the 3-2-1 conventional standard model of nuclear and electromagnetic interactions. In such models a natural explanation for the fundamental question of fermion generation replication arises from the self-consistency of a local gauge quantum field theory, which constrains the number of ...

  6. Why PeV scale left–right symmetry is a good thing

    Indian Academy of Sciences (India)

    2017-10-05

    Oct 5, 2017 ... Left–right symmetric gauge theory presents a minimal paradigm to accommodate massive neutrinos with all the known conserved symmetries duly gauged. The work presented here is based on the argument that the see-saw mechanism does not force the new right-handed symmetry scale to be very high, ...

  7. SuSeFLAV: A program for calculating supersymmetric spectra and ...

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Abstract. The program \\mathnormal S u S e F L A V 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.

  8. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 2. Prospects of experimentally reachable beyond Standard Model physics in inverse see-saw motivated SO(10) GUT. Ram Lal Awasthi. Special: Supersymmetric Unified Theories and Higgs Physics Volume 86 Issue 2 February 2016 pp 223- ...

  9. New minimal SO (10) GUT: A theory for all epochs

    Indian Academy of Sciences (India)

    2016-01-07

    Jan 7, 2016 ... Measurable or near measurable level of tensor perturbations – and thus large inflaton mass scale – may be accommodated within the NMSGUT by supersymmetric see-saw inflation based on an LHN flat direction inflaton if the Higgs component contains contributions from heavy Higgs components.

  10. Deviation from tri-bimaximal mixings through flavour twisters in ...

    Indian Academy of Sciences (India)

    19], whereas Type-IHA is more stable under the presence of left-handed Higgs triplet term in Type-II see-saw mechanism [20]. For our present analysis, we will not address the issue of stability of neutrino mass model. Instead, we explore the properties of these two types of inverted hierarchical mass matrices and their.

  11. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Volume 86 Issue 2 February 2016 pp 265-280 Special: Supersymmetric Unified Theories and Higgs Physics. Quark see-saw, Higgs mass and vacuum stability · R N Mohapatra Yongchao Zhangi · More Details Abstract Fulltext PDF. The issue of vacuum stability of standard model (SM) is discussed by embedding it within ...

  12. Results from PAMELA, ATIC and FERMI: Pulsars or dark matter?

    Indian Academy of Sciences (India)

    codes compute the effects of interactions and energy losses during cosmic ray propagation. Figure 1. Results ... DARKSUSY [99] compute cosmic ray propagation in the galaxies required for indirect searches of dark .... Models involv- ing Type II see-saw mechanism [126] have also been considered recently where neutrino.

  13. On the role of convective systems over the northwest Pacific and monsoon activity over the Indian subcontinent

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Babu, A.K.; Reason, C.

    been examined in relation to breaks in monsoon conditions over the Indian sub-continent during contrasting monsoon years. A see-saw nature of convection between the NWP and north Indian Ocean was found during the years with excess monsoon rainfall...

  14. Models of neutrino masses and baryogenesis

    Indian Academy of Sciences (India)

    Assuming that the baryon asymmetry of the universe is generated before the electroweak phase transition, it is possible to discriminate different classes of models of neutrino masses. While see-saw mechanism and the triplet Higgs mechanism are preferred, the Zee-type radiative models and theR-parity breaking models ...

  15. Supersymmetric unification in the light of neutrino mass

    Indian Academy of Sciences (India)

    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 ...

  16. SuSeFLAV: A program for calculating supersymmetric spectra and ...

    Indian Academy of Sciences (India)

    2012-10-03

    Oct 3, 2012 ... E-mail: rgarani@cts.iisc.ernet.in. Abstract. The program SuSeFLAV is introduced for computing supersymmetric mass spec- tra with flavour violation in various supersymmetric breaking scenarios with/without see-saw mechanism. A short user guide summarizing the compilation, executables and the input ...

  17. Biswajoy Brahmachari

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. Biswajoy Brahmachari. Articles written in Pramana – Journal of Physics. Volume 60 Issue 2 February 2003 pp 377-381. Sterile neutrino in a minimal three-generation see-saw model · Biswajoy Brahmachari Sandhya Choubey Rabindra N Mohapatra · More Details Abstract ...

  18. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. Rabindra N Mohapatra. Articles written in Pramana – Journal of Physics. Volume 60 Issue 2 February 2003 pp 377-381. Sterile neutrino in a minimal three-generation see-saw model · Biswajoy Brahmachari Sandhya Choubey Rabindra N Mohapatra · More Details Abstract ...

  19. Advanced Relay Design and Technology for Energy-Efficient Electronics

    Science.gov (United States)

    2011-07-07

    Rumaner, R. Schweinfurth, S. Sivakumar, M. Stettler, S. Thompson, B. Tufts, J. Xu, S. Yang, and M. Bohr , “A 130 nm Generation Logic Technology...electrically, due to very high contact resistance. A single structure operated in see-saw mode has also been investigated for radio -frequency (RF) [13], [14

  20. with dark matter

    Indian Academy of Sciences (India)

    2012-11-16

    Nov 16, 2012 ... to have a dramatic impact on neutrino physics, dark matter and all fermion masses and mixings. Keywords. Radiative see-saw; fermion masses; grand unification. PACS Nos 12.10.Dm; 12.60.Jv; 14.60.Pq. 1. Introduction. In SO(10) grand unified theory which contains all standard fermions of one generation.

  1. Is the Standard Model about to crater?

    CERN Multimedia

    Lane, Kenneth

    2015-01-01

    The Standard Model is coming under more and more pressure from experiments. New results from the analysis of LHC's Run 1 data show effects that, if confirmed, would be the signature of new interactions at the TeV scale.

  2. Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period

    DEFF Research Database (Denmark)

    Blunier, T; Brook, E J

    2001-01-01

    A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings....... This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales....

  3. Tests of the left-right electroweak model at linear collider

    OpenAIRE

    Huitu, K.; Maalampi, J.; Pandita, P. N.; Puolamaki, K.; Raidal, M.; Romanenko, N.

    1999-01-01

    The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2)_R . The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry. The quark-lepton symmetry in weak interactions is also maintained in this theory. The model has many predictions one can directly test at a TeV-scale linear collider. We will consi...

  4. The one loop corrections to the neutrino masses in BLMSSM

    Directory of Open Access Journals (Sweden)

    Shu-Min Zhao

    2016-09-01

    Full Text Available The neutrino masses and mixings are studied in the model which is the supersymmetric extension of the standard model with local gauged baryon and lepton numbers (BLMSSM. At tree level the neutrinos can obtain tiny masses through the See-Saw mechanism in the BLMSSM. The one-loop corrections to the neutrino masses and mixings are important, and they are studied in this work with the mass insertion approximation. We study the numerical results and discuss the allowed parameter space of BLMSSM. It can contribute to study the neutrino masses and to explore the new physics beyond the standard model (SM.

  5. Symmetries, Large Leptonic Mixing and a Fourth Generation

    CERN Document Server

    Silva-Marcos, Joaquim I

    2002-01-01

    We show that large leptonic mixing occurs most naturally in the framework of the Sandard Model just by adding a fourth generation. One can then construct a small $Z_4$ discrete symmetry, instead of the large $S_{4L}\\times S_{4R}$, which requires that the neutrino as well as the charged lepton mass matrices be proportional to a $4\\times 4$ democratic mass matrix, where all entries are equal to unity. Without considering the see-saw mechanism, or other more elaborate extensions of the SM, and contrary to the case with only 3 generations, large leptonic mixing is obtained when the symmetry is broken.

  6. A No-Scale Framework for Sub-Planckian Physics

    CERN Document Server

    Ellis, John; Olive, Keith A

    2014-01-01

    We propose a minimal model framework for physics below the Planck scale with the following features: (i) it is based on no-scale supergravity, as favoured in many string compactifications, (ii) it incorporates Starobinsky-like inflation, and hence is compatible with constraints from the Planck satellite, (iii) the inflaton may be identified with a singlet field in a see-saw model for neutrino masses, providing an efficient scenario for reheating and leptogenesis, (iv) supersymmetry breaking occurs with an arbitrary scale and a cosmological constant that vanishes before radiative corrections, (v) regions of the model parameter space are compatible with all LHC, Higgs and dark matter constraints.

  7. A simple motivated completion of the standard model below the Planck scale: Axions and right-handed neutrinos

    Directory of Open Access Journals (Sweden)

    Alberto Salvio

    2015-04-01

    Full Text Available We study a simple Standard Model (SM extension, which includes three families of right-handed neutrinos with generic non-trivial flavor structure and an economic implementation of the invisible axion idea. We find that in some regions of the parameter space this model accounts for all experimentally confirmed pieces of evidence for physics beyond the SM: it explains neutrino masses (via the type-I see-saw mechanism, dark matter, baryon asymmetry (through leptogenesis, solves the strong CP problem and has a stable electroweak vacuum. The last property may allow us to identify the Higgs field with the inflaton.

  8. 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...

  9. Understanding the performance of CMS calorimeter

    Indian Academy of Sciences (India)

    which are proposed to incorporate higher symmetries at TeV energy scale giving a more natural description of particles and their interactions. Hadron colliders are optimum choice to explore the physics at TeV scale. Motivated by these ... Relative calibration of HCal tiles is done using radioactive source. Each of the scin-.

  10. Constraining new coloured matter from the ratio of 3- to 2-jets cross sections at the LHC

    DEFF Research Database (Denmark)

    Becciolini, Diego; Gillioz, Marc; Sannino, Francesco

    2015-01-01

    The Large Hadron Collider experiments are probing the evolution of the strong coupling $\\alpha_s$ up to the TeV scale. We show how the ratio of 3- to 2-jets cross sections is affected by the presence of new physics and argue that it can be used to place a model-independent bound on new particles...

  11. New U(1) gauge extension of the supersymmetric standard model.

    Science.gov (United States)

    Ma, Ernest

    2002-07-22

    In extending the minimal standard model of quarks and leptons to include supersymmetry, the conservation of baryon and lepton numbers is no longer automatic. I show how the latter may be achieved with a new U(1) gauge symmetry and new supermultiplets at the TeV scale. Neutrino masses and a solution of the mu problem are essential features of this proposed extension.

  12. The B  -  L supersymmetric standard model with inverse seesaw at the large hadron collider.

    Science.gov (United States)

    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).

  13. Collider Tests of the Little Higgs Model

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Aaron T

    2002-12-16

    The little Higgs model provides an alternative to traditional candidates for new physics at the TeV scale. The new heavy gauge bosons predicted by this model should be observable at the Large Hadron Collider (LHC). We discuss how the LHC experiments could test the little Higgs model by studying the production and decay of these particles.

  14. Design Concept and Parameters of a 15 T $Nb_{3}Sn$ Dipole Demonstrator for a 100 TEV Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Zlobin, A. V. [Fermilab; Andreev, N. [Fermilab; Barzi, E. [Fermilab; Kashikhin, V. V. [Fermilab; Novitski, I. [Fermilab

    2015-06-01

    FNAL has started the development of a 15 T $Nb_{3}Sn$ dipole demonstrator for a 100 TeV scale hadron collider. This paper describes the design concept and parameters of the 15 T $Nb_{3}Sn$ dipole demonstrator. The dipole magnetic, mechanical and quench protection concept and parameters are presented and discussed.

  15. Searches for Exotic Physics with leptons with the ATLAS Detector

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    With the large sample of pp collisions recorded in the past year, ATLAS has taken full advantage of the opportunity to explore new territory at the TeV scale. In this seminar, an overview of searches for new exotic particles is presented, with a special emphasis on signatures with leptons.

  16. Higgs physics at LHC

    Indian Academy of Sciences (India)

    The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation results for the standard model and minimal super symmetric standard model Higgs boson searches and ...

  17. Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Department of Physics, University of Wisconsin, Madison, WI 53706, USA. Email: dasu@hep.wisc.edu. Abstract. The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation ...

  18. Large compact dimensions and high energy experiments

    Indian Academy of Sciences (India)

    Keywords. Extra dimensions; Kaluza–Klein; graviton. Abstract. Models of spacetime with extra compact dimensions and having the Standard Model fields confined to a narrow slice of 4-dimensional spacetime can have strong gravitational effects at the TeV scale as well as electroweak-strength interactions at present-day ...

  19. Signals of universal extra dimension at the international linear collider

    Indian Academy of Sciences (India)

    New Physics at TeV Scale and Electroweak Precision Test Volume 69 Issue 5 November 2007 pp 855-860 ... Department of Physics, Calcutta University, 92 A.P.C. Road, Kolkata 700 009, India ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science

  20. Probing space–time structure of new physics with polarized beams ...

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Home; Journals; Pramana – Journal of Physics; Volume 69; Issue 5. Probing space-time structure of new physics with polarized beams at the international linear collider. B Ananthanarayan. New Physics at TeV Scale and Electroweak Precision Test Volume 69 Issue 5 November 2007 pp 849-854 ...

  1. Little Higgs model effects in γγ→ γγ

    Indian Academy of Sciences (India)

    ... there are still several theoretical problems associated with the Higgs sector of the SM, where it is widely believed that some new physics will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (LH) model. In this work we have investigated the effects of the LH model on ...

  2. Radiative electroweak symmetry breaking in non-supersymmetric extensions of standard model

    Science.gov (United States)

    Khan, Saki

    2017-11-01

    In this talk, I discuss the possibility of radiative electroweak symmetry breaking where loop corrections to the mass parameter of the Higgs boson trigger the symmetry breaking in various non-supersymmetric extensions of the Standard Model (SM). Although the mechanism fails in the SM, it is shown to be quite successful in several extensions which share a common feature of having an additional scalar around the TeV scale. Due to the cross couplings between the scalars in the Higgs potential, the positive Higgs mass parameter at a high energy scale is turned negative in the renormalization group flow to lower energy. The type-II seesaw model, a two-loop radiative neutrino mass model, the inert doublet model, scalar singlet dark matter model, and a universal seesaw model with an additional U(1) broken at the TeV scale are studied and shown to exhibit successful radiative electroweak symmetry breaking when the additional scalars are at TeV scale. Large Hadron Collider (LHC) may be able to detect some of these TeV scale particles in near future.

  3. Radiative electroweak symmetry breaking in standard model extensions

    Science.gov (United States)

    Babu, K. S.; Gogoladze, Ilia; Khan, S.

    2017-05-01

    We study the possibility of radiative electroweak symmetry breaking where loop corrections to the mass parameter of the Higgs boson trigger the symmetry breaking in various extensions of the Standard Model (SM). Although the mechanism fails in the SM, it is shown to be quite successful in several extensions which share a common feature of having an additional scalar around the TeV scale. The positive Higgs mass parameter at a high energy scale is turned negative in the renormalization group flow to lower energy by the cross couplings between the scalars in the Higgs potential. The type-II seesaw model with a TeV scale weak scalar triplet, a two-loop radiative neutrino mass model with new scalars at the TeV scale, the inert doublet model, scalar singlet dark matter model, and a universal seesaw model with an additional U (1 ) broken at the TeV scale are studied and shown to exhibit successful radiative electroweak symmetry breaking.

  4. Visions: The coming revolutions in particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Chris Quigg

    2002-04-11

    Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop the understanding of the problem of identity and the dimensionality of spacetime.

  5. Unified picture for Dirac neutrinos, dark matter, dark energy and matter-antimatter asymmetry

    OpenAIRE

    Gu, Pei-Hong

    2007-01-01

    We propose a unified scenario to generate the masses of Dirac neutrinos and cold dark matter at the TeV scale, understand the origin of dark energy and explain the matter-antimatter asymmetry of the universe. This model can lead to significant impact on the Higgs searches at LHC.

  6. Neutrino Oscillations in Extended Anti-GUT Model

    CERN Document Server

    Froggatt, C.D.; Takanishi, Y.

    2000-01-01

    What we call the Anti-GUT model is extended a bit to include also right-handed neutrinos and thus make use of the see-saw mechanism for neutrino masses. This model consists in assigning gauge quantum numbers to the known Weyl fermions and the three see-saw right-handed neutrinos. Each family (generation) is given its own Standard Model gauge fields and a gauge field coupled to the $B-L$ quantum number for that family alone. Further we assign a rather limited number of Higgs fields, so as to break these gauge groups down to the Standard Model gauge group and to fit, w.r.t. order of magnitude, the spectra and mixing angles of the quarks and leptons. We find a rather good fit, which for neutrino oscillations favours the small mixing angle MSW solution, although the mixing angle predicted is closest to the upper side of the uncertainty range for the measured solar neutrino mixing angle. An idea for making a ``finetuning''-principle to ``explain'' the large ratios found empirically in physics, and answer such ques...

  7. Hierarchy problem, gauge coupling unification at the Planck scale, and vacuum stability

    Directory of Open Access Journals (Sweden)

    Naoyuki Haba

    2015-11-01

    Full Text Available From the point of view of the gauge hierarchy problem, introducing an intermediate scale in addition to TeV scale and the Planck scale (MPl=2.4×1018 GeV is unfavorable. In that way, a gauge coupling unification (GCU is expected to be realized at MPl. We explore possibilities of GCU at MPl by adding a few extra particles with TeV scale mass into the standard model (SM. When extra particles are fermions and scalars (only fermions with the same mass, the GCU at MPl can (not be realized. On the other hand, when extra fermions have different masses, the GCU can be realized around 8πMPl without extra scalars. This simple SM extension has two advantages that a vacuum becomes stable up to MPl (8πMPl and a proton lifetime becomes much longer than an experimental bound.

  8. Searches for SUSY signals at ATLAS

    CERN Document Server

    Meloni, Federico; The ATLAS collaboration

    2017-01-01

    The High Luminosity-Large Hadron Collider (HL-LHC) is expected to start in 2026 and to pro- vide an integrated luminosity of 3000 fb−1 in ten years, a factor 10 more than what will be collected by 2023. This high statistics will allow ATLAS to improve searches for new physics at the TeV scale. The search prospects for Supersymmetry are presented, with a programme spanning from strong to electroweak production of sparticles.

  9. A Search for universal extra dimensions in the multi-lepton channel from proton anti-proton collisions at √s = 1.8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun [Yale Univ., New Haven, CT (United States)

    2005-12-01

    In this thesis we present the results of a search for Universal Extra Dimensions (UED) with compactification radius near the TeV scale in the multi-lepton channel from proton-antiproton collisions at center-of-mass energy of 1.8 TeV at the Fermi National Accelerator Laboratory. This is the first UED search in the multi-lepton channel performed at the Tevatron.

  10. D-brane Standard Model

    CERN Document Server

    Antoniadis, Ignatios; Tomaras, T N

    2001-01-01

    The minimal embedding of the Standard Model in type I string theory is described. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The correct prediction of the weak angle is obtained for a string scale of 6-8 TeV. Two Higgs doublets are necessary and proton stability is guaranteed. It predicts two massive vector bosons with masses at the TeV scale, as well as a new superweak interaction.

  11. Rare Kaon and Pion Decays: Incisive Probes for New Physics Beyond the Standard Model

    Science.gov (United States)

    Bryman, Douglas; Marciano, William J.; Tschirhart, Robert; Yamanaka, Taku

    2011-11-01

    We review the current status and future prospects of rare kaon and pion decay research programs. Our emphasis is on experimental probes of New Physics beyond the Standard Model via the theoretically pristine [Formula: see text] decays and precision tests of electron-muon universality. These studies test the Standard Model at the level of its quantum-loop predictions and have the potential to uncover new interactions beyond the O(1,000 TeV) scale.

  12. Search for supersymmetry in final states with two same sign leptons or three leptons and jets with the ATLAS detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00421293

    The Standard Model of particle physics is the culmination of decades of experimental and theoretical advancements to successfully describe the elementary particles and their interactions at low energies, up to 100 GeV. Beyond this scale lies the realm of new physics needed to remedy problems that arise at higher energies, the TeV scale and above. Supersymmetry (SUSY) is the most favored extension of the Standard Model that solves many of its limitations, if predicted SUSY particles exist at the TeV scale. The Large Hadron Collider (LHC) at CERN has opened a new phase of exploration into new physics at the TeV scale after increasing the center-of-mass energy of the proton-proton collisions to 13 TeV. The ATLAS experiment has collected this collision data with over 90% efficiency due to the excellent performance of many of its systems, in particular the data acquisition system. The work realized and described in this dissertation ensures the efficient collection of ATLAS data as well as the analysis of this dat...

  13. Search for supersymmetry in final states with two same sign leptons or three leptons and jets with the ATLAS detector at the LHC arXiv

    CERN Document Server

    Rifki, Othmane

    The Standard Model of particle physics successfully describes the elementary particles and their interactions at low energies, up to 100 GeV. Beyond this scale lies the realm of new physics needed to remedy problems that arise at higher energies, the TeV scale and above. Supersymmetry (SUSY) is the most favored extension of the Standard Model that solves many of its limitations, if predicted SUSY particles exist at the TeV scale. The Large Hadron Collider (LHC) at CERN has opened a new phase of exploration into new physics at the TeV scale after increasing the center-of-mass energy of the proton-proton collisions to 13 TeV. The ATLAS experiment has collected this collision data with over 90% efficiency due to the excellent performance of many of its systems, in particular the data acquisition system. The work described in this dissertation ensures the efficient collection of ATLAS data as well as the analysis of this data to search for SUSY. The search for strongly produced supersymmetric particles decaying i...

  14. Inverse type II seesaw mechanism and its signature at the LHC and ILC

    Science.gov (United States)

    Freitas, F. F.; de S. Pires, C. A.; Rodrigues da Silva, P. S.

    2017-06-01

    The advent of the LHC, and the proposal of building future colliders as the ILC, both programmed to explore new physics at the TeV scale, justify the recent interest in collider phenomenology of seesaw mechanisms whose signatures lie on TeV scale or less. The most popular TeV scale seesaw mechanisms are the inverse seesaw ones. There are three types of inverse seesaw mechanisms, but only that one implemented in an arrangement involving six non-standard heavy neutrinos has received attention. In this paper we develop an inverse seesaw mechanism based on Higgs triplet model and simulate its collider phenomenology by producing doubly charged Higgses at the LHC and ILC and analyzing their subsequent decays in pair of leptons. We find that although the new scalars decouple from the standard ones, signals of these scalars may be detected in the current run of the LHC or in the future ILC. Our simulations probe the model in the region of parameter space that generates the correct neutrino masses and mixing for both normal and inverted hierarchy cases.

  15. Inverse type II seesaw mechanism and its signature at the LHC and ILC

    Directory of Open Access Journals (Sweden)

    F.F. Freitas

    2017-06-01

    Full Text Available The advent of the LHC, and the proposal of building future colliders as the ILC, both programmed to explore new physics at the TeV scale, justify the recent interest in collider phenomenology of seesaw mechanisms whose signatures lie on TeV scale or less. The most popular TeV scale seesaw mechanisms are the inverse seesaw ones. There are three types of inverse seesaw mechanisms, but only that one implemented in an arrangement involving six non-standard heavy neutrinos has received attention. In this paper we develop an inverse seesaw mechanism based on Higgs triplet model and simulate its collider phenomenology by producing doubly charged Higgses at the LHC and ILC and analyzing their subsequent decays in pair of leptons. We find that although the new scalars decouple from the standard ones, signals of these scalars may be detected in the current run of the LHC or in the future ILC. Our simulations probe the model in the region of parameter space that generates the correct neutrino masses and mixing for both normal and inverted hierarchy cases.

  16. Inverse type II seesaw mechanism and its signature at the LHC and ILC

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, F.F.; Pires, C.A. de S, E-mail: cpires@fisica.ufpb.br; Rodrigues da Silva, P.S.

    2017-06-10

    The advent of the LHC, and the proposal of building future colliders as the ILC, both programmed to explore new physics at the TeV scale, justify the recent interest in collider phenomenology of seesaw mechanisms whose signatures lie on TeV scale or less. The most popular TeV scale seesaw mechanisms are the inverse seesaw ones. There are three types of inverse seesaw mechanisms, but only that one implemented in an arrangement involving six non-standard heavy neutrinos has received attention. In this paper we develop an inverse seesaw mechanism based on Higgs triplet model and simulate its collider phenomenology by producing doubly charged Higgses at the LHC and ILC and analyzing their subsequent decays in pair of leptons. We find that although the new scalars decouple from the standard ones, signals of these scalars may be detected in the current run of the LHC or in the future ILC. Our simulations probe the model in the region of parameter space that generates the correct neutrino masses and mixing for both normal and inverted hierarchy cases.

  17. Supersymmetric interpretations of the neutrino anomalies

    CERN Document Server

    Valle, José W F

    2002-01-01

    Solar and atmospheric neutrino data strongly indicate the need for physics beyond the standard model. The neutrino oscillation interpretation of the atmospheric data is rather unambiguous, with more options still open for the solar data. After a brief summary of the latest global fits of neutrino data, I discuss theoretical neutrino mass models. This is done first from a top-bottom approach inspired by unification ideas involving a see-saw mechanism or high dimension operators. Then I consider bottom-up approaches, with especial emphasis on the idea that the origin of neutrino mass and mixing is intrinsically supersymmetric. Models involve effective bilinear breaking of R-parity. This allows for the possibility of probing the neutrino mixing also in the context of high-energy collider experiments such as the LHC. (41 refs).

  18. Heterotic Road to the MSSM with R parity

    CERN Document Server

    Lebedev, Oleg; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K S; Wingerter, Akin

    2008-01-01

    In a previous paper, referred to as a "Mini-Landscape" search, we explored a "fertile patch" of the heterotic landscape based on a Z6-II orbifold with SO(10) and E6 local GUT structures. In the present paper we extend this analysis. We find many models with the minimal supersymmetric standard model spectra and an exact R parity. In all of these models, the vector-like exotics decouple along D flat directions. We present two "benchmark" models which satisfy many of the constraints of a realistic supersymmetric model, including non-trivial Yukawa matrices for 3 families of quarks and leptons and Majorana neutrino masses for right-handed neutrinos with non-trivial See-Saw masses for the 3 light neutrinos. In an appendix we comment on the important issue of string selection rules and in particular the so-called "gamma-rule".

  19. Testing R-parity with geometry

    Energy Technology Data Exchange (ETDEWEB)

    He, Yang-Hui [Department of Mathematics, City University, London,Northampton Square, London EC1V 0HB (United Kingdom); School of Physics, NanKai University,94 Weijin Road, Tianjin, 300071 (China); Merton College, University of Oxford,Merton Street, OX1 4JD (United Kingdom); Jejjala, Vishnu [Mandelstam Institute for Theoretical Physics, NITheP, and School of Physics,University of the Witwatersrand,1 Jan Smuts Avenue, Johannesburg, WITS 2050 (South Africa); Matti, Cyril [Department of Mathematics, City University, London,Northampton Square, London EC1V 0HB (United Kingdom); Mandelstam Institute for Theoretical Physics, NITheP, and School of Physics,University of the Witwatersrand,1 Jan Smuts Avenue, Johannesburg, WITS 2050 (South Africa); Nelson, Brent D. [Department of Physics, Northeastern University,360 Huntington Avenue, Boston, MA 02115 (United States)

    2016-03-14

    We present a complete classification of the vacuum geometries of all renormalizable superpotentials built from the fields of the electroweak sector of the MSSM. In addition to the Severi and affine Calabi-Yau varieties previously found, new vacuum manifolds are identified; we thereby investigate the geometrical implication of theories which display a manifest matter parity (or R-parity) via the distinction between leptonic and Higgs doublets, and of the lepton number assignment of the right-handed neutrino fields. We find that the traditional R-parity assignments of the MSSM more readily accommodate the neutrino see-saw mechanism with non-trivial geometry than those superpotentials that violate R-parity. However there appears to be no geometrical preference for a fundamental Higgs bilinear in the superpotential, with operators that violate lepton number, such as νHH̄, generating vacuum moduli spaces equivalent to those with a fundamental bilinear.

  20. Successful type I Leptogenesis with SO(10)-inspired mass relations

    CERN Document Server

    Di Bari, Pasquale

    2009-01-01

    It is well-known that thermal leptogenesis through the decays of the lightest right-handed neutrinos encounters serious difficulties when SO(10)-inspired mass conditions are imposed on the Dirac neutrino mass matrix and light neutrino masses are generated through the type I see-saw mechanism. We show that these can be circumvented when the production from the next-to-lightest right-handed neutrinos and flavor effects are properly taken into account. Some conditions on the low energy parameters have to be satisfied in order for inverse processes involving the lightest right-handed neutrino not to wash-out the asymmetry. In particular we find m_1 \\gtrsim 0.001 eV, where m_1 is the mass of the lightest left-handed neutrino and that non-vanishing values of the mixing angle theta_13 are preferred in the case of a normal fully hierarchical spectrum of light neutrinos.

  1. Heavy neutrino threshold effects in low energy phenomenology

    CERN Document Server

    Leontaris, George K; Ross, Graham G

    1995-01-01

    Right handed neutrinos with mass of {\\cal O} \\; (10^{12}-10^{13}) GeV are required to implement the see-saw mechanism and generate neutrino masses capable of playing a role in structure formation. Moreover models of fermion masses often relate the Yukawa couplings involving these neutrinos to the up-quark Yukawa couplings. Here we study the effects of such couplings on the radiative corrections to quark masses. We find that b-\\tau equality at M_{GUT} may still give the correct m_b/m_{\\tau}-- ratio at low energies, but only if there is large \\mu-\\tau mixing in the charged leptonic sector. We propose specific mass matrix ``textures'' dictated by a U(1) family symmetry whose structure preserves m_b=m_{\\tau} at M_{GUT}. In these schemes, due to the large \

  2. Reconciling Neutrino Oscillations with roman>SOroman>(10) Leptogenesis

    Science.gov (United States)

    Nezri, Emmanuel; Orloff, Jean

    We study the link between neutrino oscillations and leptogenesis in the minimal framework assuming an roman>SOroman>(10) see-saw mechanism with 3 families. The solar and atmospheric data then generically induce a large mass-hierarchy and a small mixing between the lightest right-handed neutrinos, which fails to produce sufficient lepton asymmetry by 5 orders of magnitudes at least. This conclusion can only be evaded in the case of solar vacuum oscillations and for a very specific value of the mixing roman>sinroman>2 2θe3 = 0.1, which interestingly lies at the boundary of the CHOOZ exclusion region, but should be accessible to future long baseline experiments.

  3. Neutrino physics present and future

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Our understanding of neutrinos has been revolutionized by the discovery that they have nonzero masses and very large mixing. We will explain the phenomenology of massive neutrinos, including neutrino oscillation in vacuum and in matter, and the physics of neutrinos that are their own antiparticles. We will review the evidence for neutrino masses and mixing, and summarize what has been learned about the neutrinos so far. Identifying the very interesting open questions raised by the discovery of neutrino mass, we will discuss how these questions may be answered through future experiments. Finally, we will consider the possibility that CP violation by neutrinos is the key to understanding the matter-antimatter asymmetry of the universe, and discuss the see-saw theory of why neutrino masses are so tiny.

  4. CERN Academic Training Programme 2008/2009

    CERN Multimedia

    HR Department

    2009-01-01

    LECTURE SERIES 12, 13, 14 & 15 May 2009 11:00-12:00 - TH Auditorium, Bldg. 4-3-006 Neutrino Physics Prof. Carlo GIUNTI / Istituto Nazionale Fisica Nucleare, Torino, Italy The general theory of neutrino masses and mixing is introduced. The theory of neutrino oscillations in vacuum and in matter is reviewed, with discussion of the most important general phenomenological aspects. Topics: - Dirac Neutrino Masses Higgs Mechanism in the Standard Model Three-Generation Neutrino Masses and Mixing - Majorana Neutrino Masses Two-Component Theory of a Massless Neutrino Majorana Mass Mixing of Three Majorana Neutrinos - Dirac-Majorana Mass One Generation See-Saw Mechanism Three-Generation Mixing - Neutrino Oscillations in Vacuum General Theory Two-Neutrino Mixing and Oscillations - Neutrino Oscillations in Matte Effective Potentials in Matter MSW Effect (Resonant Transitions in Matter) Phenomenology of Solar Neutrinos

  5. Flavoured B - L local symmetry and anomalous rare B decays

    Science.gov (United States)

    Alonso, Rodrigo; Cox, Peter; Han, Chengcheng; Yanagida, Tsutomu T.

    2017-11-01

    We consider a flavoured B - L gauge symmetry under which only the third generation fermions are charged. Such a symmetry can survive at low energies (∼TeV) while still allowing for two superheavy right-handed neutrinos, consistent with neutrino masses via see-saw and leptogenesis. We describe a mechanism for generating Yukawa couplings in this model and also discuss the low-energy phenomenology. Interestingly, the new gauge boson could explain the recent hints of lepton universality violation at LHCb, with a gauge coupling that remains perturbative up to the Planck scale. Finally, we discuss more general U (1) symmetries and show that there exist only two classes of vectorial U (1) that are both consistent with leptogenesis and remain phenomenologically viable at low-energies.

  6. Leptoquark mechanism of neutrino masses within the grand unification framework

    Energy Technology Data Exchange (ETDEWEB)

    Dorsner, Ilja [University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split (FESB), Split (Croatia); Fajfer, Svjetlana; Kosnik, Nejc [University of Ljubljana, Department of Physics, Ljubljana (Slovenia); Jozef Stefan Institute, Jamova 39, P. O. Box 3000, Ljubljana (Slovenia)

    2017-06-15

    We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are S{sub 3}-R{sub 2} and S{sub 1,3}-R{sub 2}, respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the S{sub 1,3}-R{sub 2} scenarios when the LQ masses are roughly between 10{sup 12} and 5 x 10{sup 13} GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the S{sub 3}-R{sub 2} scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the S{sub 3}-R{sub 2} scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups. (orig.)

  7. Transformational change in the SA gambling and lotteries sector

    Directory of Open Access Journals (Sweden)

    D. Van Lill

    2007-12-01

    Full Text Available Purpose: This paper examines the transformation of the South African gaming and casino sub-sector after South Africa's democratic dispensation in 1994 and the National Gambling Act (33 of 1996. These developments introduced an adapt-or-die scenario to the gambling and lotteries sector leading to a total overhaul of strategy, structure, systems, processes, technology, work, culture, behaviour and mindset. More specifically, Sun International's gaming and casino division's response to transformational change was examined by tapping into, and reflecting on, the experiences of managers involved in day-to-day casino operations. Design: The conceptual framework of the research is based on transformation as a form of change where business principles and people management are highly integrated. Subsequently, a user-friendly tool called the "See-Saw model" was developed to measure transformational progress. The model was applied in six change management workshops for casino managers and, from this framework, transformational progress was interpreted. Findings: The results highlighted the magnitude of change in the gambling and lotteries sector. It appeared that this sector has evolved in 10 year cycles up to 2000, whereas the current level of competitiveness fuels the demand for innovation and change in less than two year cycles. The second significant finding revolved around employees' perception that Sun International's gaming and casinos division has performed well in terms of value innovation variables. Implications: The study confirmed that, in successful transformation, business innovation needs to be balanced by fairness principles. Moreover, that the threat-rigidity in leader and employee mindset has become a most challenging people management puzzle to position in securing sustainable competitive advantage. Originality: The value of the research lies in the development of a user-friendly, non-threatening strategic tool called the "see-saw model

  8. Hints on the high-energy seesaw mechanism from the low-energy neutrino spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Casas, J.A.; Jimenez-Alburquerque, F. [Univ. Autonoma de Madrid (Spain). IFT-UAM/CSIC, C-XVI; Ibarra, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-12-15

    It is an experimental fact that the mass ratio for the two heavier neutrinos, h=m{sub 3}/m{sub 2}see-saw mechanism, determining 1) How the present experimental data restrict the structure of the high-energy seesaw parameters and 2) Which choices, among the allowed ones, produce more naturally the observed pattern of neutrino masses. We have studied in particular if starting with hierarchical neutrino Yukawa couplings, as for the other fermions, one can naturally get the observed hsee-saw mechanism in terms of (high-energy) basis-independent quantities. Among the main results, we find that in most cases m{sub 3}/m{sub 2} >> m{sub 3}/m{sub 2}, so m{sub 1} should be extremely tiny. Also, the V{sub R} matrix associated to the neutrino Yukawa couplings has a far from random structure, naturally resembling V{sub CKM}. In fact we show that identifying V{sub R} and V{sub CKM}, as well as neutrino and u-quark Yukawa couplings can reproduce h{sup exp} in a highly non-trivial way, which is very suggestive. The physical implications of these results are also discussed. (orig.)

  9. Leptoquark mechanism of neutrino masses within the grand unification framework

    Science.gov (United States)

    Doršner, Ilja; Fajfer, Svjetlana; Košnik, Nejc

    2017-06-01

    We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are S_3-R_2 and S_{1, 3}-\\tilde{R}_2, respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the S_{1, 3}-\\tilde{R}_2 scenarios when the LQ masses are roughly between 10^{12} and 5 × 10^{13} GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the S_3-\\tilde{R}_2 scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the S_3-R_2 scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups.

  10. Flipped SU(5)×U(1 models from F-theory

    Science.gov (United States)

    Jiang, Jing; Li, Tianjun; Nanopoulos, Dimitri V.; Xie, Dan

    2010-05-01

    We systematically construct flipped SU(5)×U(1 models without and with bulk vector-like particles from F-theory. To realize the decoupling scenario, we introduce sets of vector-like particles in complete SU(5)×U(1) multiplets at the TeV scale, or at the intermediate scale, or at the TeV scale and high scale. To avoid the Landau pole problem for the gauge couplings, we can only introduce five sets of vector-like particles around the TeV scale. These vector-like particles can couple to the Standard Model singlet fields, and obtain suitable masses by Higgs mechanism. We study gauge coupling unification in detail. We show that the U(1 flux contributions to the gauge couplings preserve the SU(5)×U(1 gauge coupling unification. We calculate the SU(3×SU(2 unification scales, and the SU(5)×U(1 unification scales and unified couplings. In most of our models, the high-scale or bulk vector-like particles can be considered as string-scale threshold corrections since their masses are close to the string scale. Furthermore, we discuss the phenomenological consequences of our models. In particular, in the models with TeV-scale vector-like particles, the vector-like particles can be observed at the Large Hadron Collider, the proton decay is within the reach of the future Hyper-Kamiokande experiment, the lightest CP-even Higgs boson mass can be increased, the hybrid inflation can be naturally realized, and the correct cosmic primordial density fluctuations can be generated.

  11. Gravitino or axino dark matter with reheat temperature as high as 1016 GeV

    Science.gov (United States)

    Co, Raymond T.; D'Eramo, Francesco; Hall, Lawrence J.

    2017-03-01

    A new scheme for lightest supersymmetric particle (LSP) dark matter is introduced and studied in theories of TeV supersymmetry with a QCD axion, a, and a high reheat temperature after inflation, T R . A large overproduction of axinos ( ã) and gravitinos (\\tilde{G}) from scattering at T R , and from freeze-in at the TeV scale, is diluted by the late decay of a saxion condensate that arises from inflation. The two lightest superpartners are ã, with mass of order the TeV scale, and \\tilde{G} with mass m 3/2 anywhere between the keV and TeV scales, depending on the mediation scale of supersymmetry breaking. Dark matter contains both warm and cold components: for \\tilde{G} LSP the warm component arises from \\tilde{a}\\to \\tilde{G}a , while for ã LSP the warm component arises from \\tilde{G}\\to \\tilde{a}a . The free-streaming scale for the warm component is predicted to be of order 1 Mpc (and independent of m 3/2 in the case of \\tilde{G} LSP). T R can be as high as 1016 GeV, for any value of m 3/2, solving the gravitino problem. The PQ symmetry breaking scale V PQ depends on T R and m 3/2 and can be anywhere in the range (1010 - 1016) GeV. Detailed predictions are made for the lifetime of the neutralino LOSP decaying to ã+ h/Z and \\tilde{G}+h/Z/γ , which is in the range of (10-1 -106)m over much of parameter space. For an axion misalignment angle of order unity, the axion contribution to dark matter is sub-dominant, except when V PQ approaches 1016 GeV.

  12. Neutrino interactions in neutron matter

    Science.gov (United States)

    Cipollone, Andrea

    2012-12-01

    Neutrino flow is the dominant mechanism of energy transfer in the latest stages of supernovae explosions and in compact stars. The Standard Model of particle physics and accelerator data, provide a satisfactory description of neutrino physics in vacuum up to TeV scale. Nevertheless modeling the dynamics of neutrino interaction in the nuclear environment involves severe difficulties. This thesis in mainly aimed at obtaining the weak response of infinite matter, using both the Correlated Basis Function theory and Landau Theory of Fermi liquid to take into account properly nucleon-nucleon hard core potential and long range correlation (quasi-particle, collective modes, ecc.)

  13. Electroweak precision measurements in ATLAS

    CERN Document Server

    Soldatov, Evgeny; The ATLAS collaboration

    2017-01-01

    The ATLAS collaboration has performed detailed integrated and differential cross-section measurements of heavy bosons and di-boson pairs production in fully-leptonic and semi-leptonic final states at the centre-of-mass energies of 8 and 13 TeV for pp collisions provided by the LHC. These measurements represent stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for the new physics at the TeV scale. The results are compared to theory predictions at NLO (and NNLO) and provide constraints on the new physics, by setting limits on anomalous gauge couplings.

  14. On Black Hole Detection with the OWL/Airwatch Telescope

    CERN Document Server

    Dutta, S I; Sarcevic, I; Dutta, Sharada Iyer; Reno, Mary Hall; Sarcevic, Ina

    2002-01-01

    In scenarios with large extra dimensions and TeV scale gravity ultrahigh energy neutrinos produce black holes in their interactions with the nucleons. We show that ICECUBE and OWL may observe large number of black hole events and provide valuable information about the fundamental Planck scale and the number of extra dimensions. OWL is especially well suited to observe black hole events produced by neutrinos from the interactions of cosmic rays with the 3 K background radiation. Depending on the parameters of the scenario of large extra dimensions and on the flux model, as many as 28 events per year are expected for a Planck scale of 3 TeV.

  15. Geonic black holes and remnants in Eddington-inspired Born-Infeld gravity

    Energy Technology Data Exchange (ETDEWEB)

    Olmo, Gonzalo J. [Universidad de Valencia-CSIC, Universidad de Valencia, Departamento de Fisica Teorica y IFIC, Centro Mixto, Valencia (Spain); Rubiera-Garcia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Sanchis-Alepuz, Helios [Justus-Liebig University of Giessen, Institute of Theoretical Physics, Giessen (Germany)

    2014-03-15

    We show that electrically charged solutions within the Eddington-inspired Born-Infeld theory of gravity replace the central singularity by a wormhole supported by the electric field. As a result, the total energy associated with the electric field is finite and similar to that found in the Born-Infeld electromagnetic theory. When a certain charge-to-mass ratio is satisfied, in the lowest part of the mass and charge spectrum the event horizon disappears, yielding stable remnants. We argue that quantum effects in the matter sector can lower the mass of these remnants from the Planck scale down to the TeV scale. (orig.)

  16. Minimal Coleman-Weinberg theory explains the diphoton excess

    DEFF Research Database (Denmark)

    Antipin, Oleg; Mojaza, Matin; Sannino, Francesco

    2016-01-01

    the introduction of an extra singlet scalar further coupled to new fermions. In this constrained setup the Higgs mass was close to the observed value and the new scalar mass was below a TeV scale. Here we first extend the previous analysis by taking into account the important difference between running mass...... and pole mass of the scalar states. We then investigate whether these theories can account for the 750 GeV excess in diphotons observed by the LHC collaborations. New QCD-colored fermions in the TeV mass range coupled to the new scalar state are needed to describe the excess. We further show, by explicit...

  17. Searching for signatures of E6

    Science.gov (United States)

    Joglekar, Aniket; Rosner, Jonathan L.

    2017-07-01

    The grand unified group E6 is a predictive scheme for physics beyond the standard model (SM). It offers the possibility of extra Z bosons, new vectorlike fermions, sterile neutrinos, and neutral scalars in addition to the SM Higgs boson. Some previous discussions of these features are updated and extended. Their relevance to present searches at the CERN Large Hadron Collider and in patterns of neutrino masses is noted. Addition of a small set of scalar bosons at the TeV scale permits gauge unification near a scale of 1 016 GeV and leads to bounds on masses of particles beyond those in the standard model.

  18. Low-scale gravity black holes at LHC

    CERN Document Server

    Regos, E; Gamsizkan, H; Trocsanyi, Z

    2009-01-01

    We search for extra dimensions by looking for black holes at LHC. Theoretical investigations provide the basis for the collider experiments. We use black hole generators to simulate the experimental signatures (colour, charge, spectrum of emitted particles, missing transverse energy) of black holes at LHC in models with TeV scale quantum gravity, rotation, fermion splitting, brane tension and Hawking radiation. We implement the extra-dimensional simulations at the CMS data analysis and test further beyond standard models of black holes too.

  19. Calorimetry for Lepton Collider Experiments – CALICE results and activities

    CERN Document Server

    Adloff, C.; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Bilki, B.; Cundiff, T.; De Lurgio, P.; Drake, G.; Francis, K.; Haberichter, B.; Guarino, V.; Kreps, A.; Repond, J.; Schlereth, J.; Skrzecz, F.; Smith, J.; Underwood, D.; Wood, K.; Xia, L.; Zhang, Q.; Zhao, A.; Price, T.; Watson, N.K.; Marshall, J.S.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Arfaoui, S.; Benoit, M.; Dannheim, D.; Dotti, A.; Duarte Ramos, F.; Elsener, K.; Folger, G.; Gerwig, H.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; Lam, C.B.; Linssen, L.; Lucaci-Timoce, A.I.; Muennich, A.; Nardulli, J.; Poss, S.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Speckmayer, P.; Strube, J.; Uzhinskiy, V.; Gay, P.; Manen, S.; Royer, L.; Soumpholphakdy, X.; Cauwenbergh, S.; Tytgat, M.; Zaganidis, N.; Blazey, G.C.; Chakraborty, D.; Dyshkant, A.; Hedin, D.; Lima, J.G.R.; Salcido, R.; Zutshi, V.; Astakhov, V.; Babkin, V.A.; Bazylev, S.N.; Golovatyuk, S.; Golutvin, I.; Gorbunov, N.; Malakhov, A.; Slepnev, S.; Tyapkin, I.; Volgin, S.V.; Zanevski, Y.; Zintchenko, A.; Dzahini, D.; Gallin-Martel, L.; Giraud, J.; Grondin, D.; Hostachy, J.Y.; Menu, J.; Rarbi, F-E.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Gottlicher, P.; Gunter, C.; Hermberg, B.; Karstensen, S.; Krivan, F.; Kruger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Vargas-Trevino, A.; Feege, N.; Garutti, E.; Laurien, S.; Marchesini, I.; Ramilli, M.; Eckert, P.; Harion, T.; Shen, W.; Stamen, R.; Wilson, G.W.; Kawagoe, K.; Miyazaki, Y.; Oishi, K.; Sudo, Y.; Ueno, H.; Yoshioka, T.; Dauncey, P.D.; Postranecky, M.; Warren, M.; Wing, M.; Cortina Gil, E.; Mannai, S.; Bonnevaux, A.; Combaret, C.; Caponetto, L.; Grenier, G.; Han, R.; Ianigro, J.C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Steen, A.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Buscher, V.; Masetti, L.; Schafer, U.; Tapprogge, S.; Wanke, R.; Welker, A.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Andreev, V.; Kirikova, N.; Komar, A.; Kozlov, V.; Negodaev, M.; Smirnov, P.; Soloviev, Y.; Terkulov, A.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Smirnov, S.; Baranova, N.; Boos, E.; d; Gladilin, L.; Karmanov, D.; Korolev, M.; Merkin, M.; Savin, A.; Voronin, A.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Augustin, J-E.; David, J.; Ghislain, P.; Lacour, D.; Lavergne, L.; Amjad, M.S.; Bonis, J.; Bouquet, B.; Callier, S.; Conforti, S.; Cornebise, P.; Dulucq, F.; Faucci Giannelli, M.; Fleury, J.; Frisson, T.; Guilhem, G.; Li, H.; Martin-Chassard, G.; Richard, F.; Poeschl, R.; Raux, L.; Rouene, J.; Seguin-Moreau, N.; Wicek, F.; Zhang, Z.; Anduze, M.; Belkadhi, K.; Boudry, V.; Brient, J-C.; Cerutti, M.; Clerc, C.; Cornat, R.; Decotigny, D.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Jeans, D.; Magniette, F.; Matthieu, A.; Mora, P.; Musat, G.; Roche, N.; Ruan, M.; Tran, T.H.; Videau, H.; Bulanek, B.; Zacek, J.; Carna, M.; Gallus, P.; Lednicky, D.; Tomasek, L.; Tomasek, M.; Cvach, J.; Havranek, M.; Janata, M.; Kvasnicka, J.; Marcisovsky, M.; Polak, I.; Popule, J.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Gapienko, V.; Semak, A.; Ukhanov, M.; Belhorma, B.; Ghazlane, H.; Hamasaki, R.; Ide, H.; Inayoshi, S.; Itoh, S.; Kawakami, Y.; Kobayashi, A.; Kotera, K.; Nishiyama, M.; Obe, S.; Ono, H.; Ogawa, T.; Ohtsuka, N.; Sakuma, T.; Sato, H.; Takeshita, T.; Totsuka, S.; Tsubokawa, T.; Yanagida, K.; Yamaura, W.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Uozumi, S.; Yang, Y.; Fuchi, R.; Ukegawa, F.; Gotze, M.; Hartbrich, O.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2012-01-01

    The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calorimeter systems for particle physics detectors to be addressed.

  20. Oblique corrections in the Dine-Fischler-Srednicki axion model

    Directory of Open Access Journals (Sweden)

    Katanaeva Alisa

    2016-01-01

    We discuss the Dine-Fischler-Srednicki (DFS model, which extends the two-Higgs doublet model with an additional Peccei-Quinn symmetry and leads to a physically acceptable axion. The non-linear parametrization of the DFS model is exploited in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale. We compute the oblique corrections and use their values from the electroweak experimental fits to put constraints on the mass spectrum of the DFS model.

  1. Search for quantum black holes in the final state of one electron and one muon with CMS in 13 TeV data

    Energy Technology Data Exchange (ETDEWEB)

    Erdweg, Soeren; Gueth, Andreas; Hebbeker, Thomas; Keller, Henning; Meyer, Arnd; Mukherjee, Swagata [III. Physikalisches Institut A, RWTH Aachen (Germany)

    2016-07-01

    Many models of physics beyond the standard model predict charged lepton flavour violation. Low scale quantum gravity at the TeV scale could lead to the production of quantum black holes (QBH). They could decay into an electron and a muon and result in an excess of events at high invariant masses, thus leading to a striking signature with low standard model background. The analysis of the 2015 dataset of CMS corresponding to an integrated luminosity of 2.5 fb{sup -1} at a center of mass energy of 13 TeV is presented and interpreted in the context of quantum black holes.

  2. Strong CP Problem with $10^{32}$ Standard Model Copies

    CERN Document Server

    Dvali, Gia

    2008-01-01

    We show that a recently proposed solution to the Hierarchy Problem simultaneously solves the Strong CP Problem, without requiring an axion or any further new physics. Consistency of black hole physics implies a non-trivial relation between the number of particle species and particle masses, so that with ~10^{32} copies of the standard model, the TeV scale is naturally explained. At the same time, as shown here, this setup predicts a typical expected value of the strong-CP parameter in QCD of theta ~ 10^{-9}. This strongly motivates a more sensitive measurement of the neutron electric dipole moment.

  3. Two Higgs doublets to explain the excesses pp→γγ(750 GeV) and h→τ{sup ±}μ{sup ∓}

    Energy Technology Data Exchange (ETDEWEB)

    Bizot, Nicolas [Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier,Place Eugéne Bataillon, F-34095 Montpellier (France); Davidson, Sacha [IPNL, CNRS/IN2P3,4 rue E. Fermi, 69622 Villeurbanne cedex (France); Université Lyon 1,Villeurbanne F-69622, Lyon (France); Frigerio, Michele; Kneur, Jean-Loïc [Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier,Place Eugéne Bataillon, F-34095 Montpellier (France)

    2016-03-14

    The two Higgs doublet model emerges as a minimal scenario in which to address, at the same time, the γγ excess at 750 GeV and the lepton flavour violating decay into τ{sup ±}μ{sup ∓} of the 125 GeV Higgs boson. The price to pay is additional matter to enhance the γγ rate, and a peculiar pattern for the lepton Yukawa couplings. We add TeV scale vector-like fermions and find parameter space consistent with both excesses, as well as with Higgs and electroweak precision observables.

  4. Gravity stabilizes itself

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sumanta; SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2017-08-15

    We show that a possible resolution to the stabilization of an extra spatial dimension (radion) can be obtained solely in the context of gravitational dynamics itself without the necessity of introducing any external stabilizing field. In this scenario the stabilized value of the radion field gets determined in terms of the parameters appearing in the higher curvature gravitational action. Furthermore, the mass of the radion field and its coupling to the standard model fields are found to be in the weak scale implying possible signatures in the TeV scale colliders. Some resulting implications are also discussed. (orig.)

  5. Cosmological implications of low scale quark-lepton unification

    OpenAIRE

    T. L. Yoon; Foot, R.

    2002-01-01

    There is a unique $\\hbox{SU(4)}\\otimes\\hbox{SU(2)}_L \\otimes \\hbox{SU(2)}_R$ gauge model which allows quarks and leptons to be unified at the TeV scale -- thereby making the model testable and avoiding the gauge hierarchy problem. In its minimal form, this model could quite naturally accommodate simultaneous solutions to the solar and LSND neutrino oscillation data. The atmospheric neutrino anomaly can be easily accommodated by mirror-symmetrising the minimal model. The model also contains th...

  6. Special Colloquium for the CERN-Fermilab Hadron Collider Physics Summer School: Main Dilemmas in Particle Physics for the LHC

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    A review of the status of the most crucial issues in particle physics at the start of the LHC is presented. The main questions are related to electroweak symmetry breaking and the mystery of new physics at the TeV scale, that is reasonably expected to be nearby and yet must be very peculiar because it was not seen at LEP and in flavour physics experiments. The main current ideas on models will be discussed and their implications for LHC searches, dark matter etc.

  7. Di- and multiboson measurements in ATLAS

    CERN Document Server

    Yatsenko, Elena; The ATLAS collaboration

    2017-01-01

    Measurements of the di- and multiboson production cross sections at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has performed studies of $ZZ$, $WZ$, $WW$, $WW\\gamma$ and $WZ\\gamma$ productions in various decay modes at $\\sqrt{s}=8$ and 13~TeV, including total, fiducial and differential cross-section measurements. These results are compared to state-of-the art theory predictions and are used to provide constraints on new physics, by setting limits on anomalous gauge boson couplings.

  8. Phenomenology of the left-right twin Higgs model

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Hock-Seng; Goh, Hock-Seng; Su, Shufang

    2006-11-02

    The twin Higgs mechanism was proposed recently to solve the little hierarchy problem. We study the implementation of the twin Higgs mechanism in left-right models. At the TeV scale, heavy quark and gauge bosonsappear, with rich collider phenomenology. In addition, there are extra Higgs bosons, some of which couple to both the standard model fermion sector and the gauge sector, while others couple to the gauge bosons only. We present the particle spectrum and study the general features of the collider phenomenology of this class of model at the Large Hadron Collider.

  9. Physics Potential of CLIC Operation at 380 GeV

    CERN Document Server

    Winter, Alasdair

    2017-01-01

    The Compact Linear Collider (CLIC) is a multi-TeV linear electron positron collider proposed as a future project for CERN aiming to provide high precision measurements of the standard model and discovery potential for new physics at the TeV scale. We present the physics potential of the CLIC experiment in its 380 GeV stage, which focuses on measurement of the Higgs boson and the top quark. In particular, the precision with which the mass, width and couplings of each particle can be measured will be examined.

  10. Higgs bosons, electroweak symmetry breaking, and the physics of the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris; /Fermilab /CERN

    2007-02-01

    The Large Hadron Collider, a 7 {circle_plus} 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?

  11. Searches for direct pair production of third generation squarks with the ATLAS detector

    CERN Document Server

    Miano, Fabrizio; The ATLAS collaboration

    2017-01-01

    Supersymmetric theories offer an elegant solution to the naturalness problem of the Standard Model Higgs, constraining the mass of the superpartners of the third generation quarks, the stop and the sbottom, to be below the TeV scale. This talk presents the status of the ATLAS searches for direct pair production of third generation squarks. It presents an overview of the latest public analyses carried out during the Run 2 of the Large Hadron Collider (LHC) using statistics of 2015 and 2015+2016 proton-proton collisions at $\\sqrt{s} =$ 13 TeV collected by the ATLAS detector.

  12. Top pair and single top production in ATLAS

    CERN Document Server

    Fabbri, Federica; The ATLAS collaboration

    2017-01-01

    Measurements of inclusive and differential top-quark production cross sections in proton-proton collisions at a center of mass energy of 8 TeV and 13 TeV at the Large Hadron Collider using the ATLAS detector are presented. The inclusive measurements of top quark pair and single top quark production are compared to the best available theoretical calculations. Differential measurements of the kinematic properties of top quark events are also discussed. These measurements, including results using boosted top quarks, probe our understanding of top quark production up to the TeV scale.

  13. Searches for New Phenomena at the LHC

    CERN Document Server

    Sonnenschein, Lars

    2012-01-01

    Searches for physics beyond the Standard Model (SM) with the CMS and ATLAS experiments in pp collisions at a centre of mass energy of sqrt(s)=7 TeV at the LHC are presented. The discussed results are based on data taken in 2011, making use of integrated luminosities between L=1.1 and 4.9 inv. fb. Various important theories, encompassing TeV scale gravity, quark/lepton compositeness, contact interactions, new heavy vector bosons and other exotic signatures are probed.

  14. G-2 and CMS fast optical calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Winn, David R.

    2001-06-01

    The following projects are discussed: (A) Operation of the muon g-2 experiment at Brookhaven National Lab (Experiment E821), especially the pulsed laser calibration system, to test the standard model of forces, and to see if new forces may exist in the vacuum. (B) The second part of this project developed fast optical forward Cerenkov jet calorimetry used in the CMS experiment collaboration (US lead organization FermiLab) at CERN on the Large Hadron Collider, designed to detect new physics at the TeV scale, such as supersymmetry and the Higgs boson.

  15. Probing anomalous tt-barZ interactions with rare meson decays

    Energy Technology Data Exchange (ETDEWEB)

    Brod, Joachim [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States); Greljo, Admir [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Stamou, Emmanuel [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Uttayarat, Patipan [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States); Department of Physics, Srinakharinwirot University, Bangkok 10110 (Thailand)

    2015-02-23

    Anomalous couplings of the Z boson to top quarks are only marginally constrained by direct searches and are still sensitive to new particle dynamics at the TeV scale. Employing an effective field theory approach we consider the dimension-six operators which generate deviations from the standard-model vector and axial-vector interactions. We show that rare B and K meson decays together with electroweak precision observables provide strong constraints on these couplings. We also consider constraints from t-channel single-top production.

  16. A model of neutrino mass and dark matter with an accidental symmetry

    Directory of Open Access Journals (Sweden)

    Amine Ahriche

    2015-06-01

    Full Text Available We present a model of radiative neutrino mass that automatically contains an accidental Z2 symmetry and thus provides a stable dark matter candidate. This allows a common framework for the origin of neutrino mass and dark matter without invoking any symmetries beyond those of the Standard Model. The model can be probed by direct-detection experiments and μ→e+γ searches, and predicts a charged scalar that can appear at the TeV scale, within reach of collider experiments.

  17. Single production of excited leptons at theLHeC

    CERN Document Server

    SAUVAN, E

    2011-01-01

    Single production of excited electrons (e*) at the future Large Hadron-Electron Collider (LHeC) through both gauge (GM) and contact (CI) interactions is studied. Subsequent decays of excited electrons to ordinary electron and photon via gauge and contact interactions are considered. Expected sensitivity to e* production in electron-proton collisions at the LHeC at high centre of mass energies of TeV scale will be addressed and compared to the recent results obtained using the data accumulated from the three large colliders LEP, HERA and Tevatron, as well as to the expected sensitivities of the LHC and ILC.

  18. Microbunched electron cooling for high-energy hadron beams.

    Science.gov (United States)

    Ratner, D

    2013-08-23

    Electron and stochastic cooling are proven methods for cooling low-energy hadron beams, but at present there is no way of cooling hadrons as they near the TeV scale. In the 1980s, Derbenev suggested that electron instabilities, such as free-electron lasers, could create collective space charge fields strong enough to correct the hadron energies. This Letter presents a variation on Derbenev's electron cooling scheme using the microbunching instability as the amplifier. The large bandwidth of the instability allows for faster cooling of high-density beams. A simple analytical model illustrates the cooling mechanism, and simulations show cooling rates for realistic parameters of the Large Hadron Collider.

  19. The electroweak theory

    Energy Technology Data Exchange (ETDEWEB)

    Chris Quigg

    2001-08-10

    After a short essay on the current state of particle physics, the author reviews the antecedents of the modern picture of the weak and electromagnetic interactions and then undertakes a brief survey of the SU(2){sub L} {circle_times} U(1){sub Y} electroweak theory. The authors reviews the features of electroweak phenomenology at tree level and beyond, presents an introduction to the Higgs boson and the 1-TeV scale, and examines arguments for enlarging the electroweak theory. The author concludes with a brief look at low-scale gravity.

  20. Effective Higgs theories in supersymmetric grand unification

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Sibo [Chongqing University, Department of Physics, Chongqing (China)

    2017-09-15

    The effective Higgs theories at the TeV scale in supersymmetric SU(5) grand unification models are systematically derived. Restricted to extensions on 5{sub H} containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models. (orig.)

  1. Multifunctional optomechanical dynamics in integrated silicon photonics

    Science.gov (United States)

    Li, Huan

    Light can generate forces on matter. The nature of these forces is electromagnetic force, or Lorentz force. The emergence and rapid progress of nanotechnology provided an unprecedented platform where the very feeble optical forces began to play significant roles. The interactions between light and matter in nanoscale has been the focus of almost a decade of active theoretical and experimental investigations, which are still ongoing and constitute a whole new burgeoning branch of nanotechnology, nano-optomechanical systems (NOMS). In such context, the general goal of my research is to generate, enhance and control optical forces on silicon photonics platforms, with a focus on developing new functionalities and demonstrating novel effects, which will potentially lead to a new class of silicon photonic devices for a broad spectrum of applications. In this dissertation, the concept of optical force and the general background of the NOMS research area are first introduced. The general goal of the silicon photonics research area and the research presented in this dissertation is then described. Subsequently, the fundamental theory for optical force is summarized. The different methods to calculate optical forces are enumerated and briefly reviewed. Integrated hybrid plasmonic waveguide (HPWG) devices have been successfully fabricated and the enhanced optical forces experimentally measured for the first time. All-optical amplification of RF signals has been successfully demonstrated. The optical force generated by one laser is used to mechanically change the optical path and hence the output power of another laser. In addition, completely optically tunable mechanical nonlinear behavior has been demonstrated for the first time and systematically studied. Optomechanical photon shuttling between photonic cavities has been demonstrated with a "photon see-saw" device. This photon see-saw is a novel multicavity optomechanical device which consists of two photonic crystal

  2. FIMP realization of the scotogenic model

    Energy Technology Data Exchange (ETDEWEB)

    Molinaro, Emiliano; Zapata, Oscar [Physik-Department T30d, Technische Universität München, James-Franck-Straße, 85748 Garching (Germany); Yaguna, Carlos E., E-mail: emiliano.molinaro@tum.de, E-mail: carlos.yaguna@uni-muenster.de, E-mail: ozapata@fisica.udea.edu.co [Institut für Theoretische Physik, Universität Münster, Wilhelm-Klemm-Straße 9, D-48149 Münster (Germany)

    2014-07-01

    The scotogenic model is one of the simplest scenarios for physics beyond the Standard Model that can account for neutrino masses and dark matter at the TeV scale. It contains another scalar doublet and three additional singlet fermions (N{sub i}), all odd under a Z{sub 2} symmetry. In this paper, we examine the possibility that the dark matter candidate, N{sub 1}, does not reach thermal equilibrium in the early Universe so that it behaves as a Feebly Interacting Massive Particle (FIMP). In that case, it is found that the freeze-in production of dark matter is entirely dominated by the decays of the odd scalars. We compute the resulting dark matter abundance and study its dependence with the parameters of the model. The freeze-in mechanism is shown to be able to account for the observed relic density over a wide range of dark matter masses, from the keV to the TeV scale. In addition to freeze-in, the N{sub 1} relic density receives a further contribution from the late decay of the next-to-lightest odd particle, which we also analyze. Finally, we consider the possibility that the dark matter particle is a WIMP but receives an extra contribution to its relic density from the decay of the FIMP (N{sub 1}). In this case, important signals at direct and indirect detection experiments are generally expected.

  3. Topics in Beyond the Standard Model Physics and Cosmology

    Science.gov (United States)

    Stefanek, Ben A.

    In this thesis, we investigate possible extensions of the Standard Model (SM) in the context of particle physics and cosmology, in terms of what problems they can solve, constrain, or what experimental data they can explain. We first review the successes and shortcomings of the SM, as well as Big Bang cosmology and inflation. We then pivot toward extending the SM, placing a particular focus on the hierarchy problem, dark matter, and data driven approaches. In Chapter 2, we categorize a class of models which minimally extend the SM with new vector-like fermions at the TeV scale, interacting via new gauge forces. We analyze the rich phenomenology of a benchmark model in the context of discovery at the Large Hadron Collider (LHC). In Chapters 3 and 4, we investigate full or partial solutions to the hierarchy problem in the context of their experimental implications at the LHC and at short baseline neutrino oscillation experiments. In Chapter 5, we propose a model for inflation with concrete predictions for the production of primordial gravitational waves. Also in Chapter 5, we use data from observations of the Cosmic Microwave Background (CMB) to constrain the strength of long range scalar interactions between dark matter particles. With the CMB continuing to be measured and the LHC probing the TeV scale, we look forward to the insights future results will bring.

  4. Plateau inflation in R-parity violating MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty

    2016-12-01

    Full Text Available Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical Kähler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry after the end of the inflation. The proper choice of superpotential leads to strong stabilization of the Polonyi field, mZ2≫m3/22, which is required to solve the cosmological moduli problem. Also, the SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and trilinear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.

  5. 2:1 for Naturalness at the LHC?

    CERN Document Server

    Arkani-Hamed, Nima; D'Agnolo, Raffaele Tito; Fan, JiJi

    2013-01-01

    A large enhancement of a factor of 1.5 - 2 in Higgs production and decay in the diphoton channel, with little deviation in the ZZ channel, can only plausibly arise from a loop of new charged particles with large couplings to the Higgs. We show that, allowing only new fermions with marginal interactions at the weak scale, the required Yukawa couplings for a factor of 2 enhancement are so large that the Higgs quartic coupling is pushed to large negative values in the UV, triggering an unacceptable vacuum instability far beneath the 10 TeV scale. An enhancement by a factor of 1.5 can be accommodated if the charged fermions are lighter than 150 GeV, within reach of discovery in almost all cases in the 8 TeV run at the LHC, and in even the most difficult cases at 14 TeV. Thus if the diphoton enhancement survives further scrutiny, and no charged fermions beneath 150 GeV are found, there must be new bosons far beneath the 10 TeV scale. This would unambiguously rule out a large class of fine-tuned theories for physic...

  6. Renormalization group study of the minimal Majoronic dark radiation and dark matter model

    Energy Technology Data Exchange (ETDEWEB)

    Chang, We-Fu [Department of Physics, National Tsing Hua University,101, Sec. 2, KuangFu Rd., Hsinchu 300, Taiwan (China); Ng, John N. [Theory Group, TRIUMF,4004 Wesbrook Mall, Vancouver BC V6T 2A3 (Canada)

    2016-07-18

    We study the 1-loop renormalization group equation running in the simplest singlet Majoron model constructed by us earlier to accommodate the dark radiation and dark matter content in the universe. A comprehensive numerical study was performed to explore the whole model parameter space. A smaller effective number of neutrinos △N{sub eff}∼0.05, or a Majoron decoupling temperature higher than the charm quark mass, is preferred. We found that a heavy scalar dark matter, ρ, of mass 1.5–4 TeV is required by the stability of the scalar potential and an operational type-I see-saw mechanism for neutrino masses. A neutral scalar, S, of mass in the 10–100 GeV range and its mixing with the standard model Higgs as large as 0.1 is also predicted. The dominant decay modes are S into bb-bar and/or ωω. A sensitive search will come from rare Z decays via the chain Z→S+ff-bar, where f is a Standard Model fermion, followed by S into a pair of Majoron and/or b-quarks. The interesting consequences of dark matter bound state due to the sizable Sρρ-coupling are discussed as well. In particular, shower-like events with an apparent neutrino energy at M{sub ρ} could contribute to the observed effective neutrino flux in underground neutrino detectors such as IceCube.

  7. Academic Training: Neutrino Physics, Present and Future

    CERN Multimedia

    2006-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28, 29, 30 November, 1st December, from 11:00 to 12:00 - TH Auditorium, bldg 4 - 3 - 006 Neutrino Physics, Present and Future B. KAYSER / Fermilab, USA Our understanding of neutrinos has been revolutionized by the discovery that they have nonzero masses and very large mixing. We will explain the phenomenology of massive neutrinos, including neutrino oscillation in vacuum and in matter, and the physics of neutrinos that are their own antiparticles. We will review the evidence for neutrino masses and mixing, and summarize what has been learned about the neutrinos so far. Identifying the very interesting open questions raised by the discovery of neutrino mass, we will discuss how these questions may be answered through future experiments. Finally, we will consider the possibility that CP violation by neutrinos is the key to understanding the matter-antimatter asymmetry of the universe, and discuss the see-saw theory of why neutrino masses are so tiny....

  8. Academic Training: Neutrino Physics, Present and Future

    CERN Multimedia

    2006-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28, 29, 30 November, 1st December, from 11:00 to 12:00 - TH Auditorium, bldg 4 - 3 - 006 Neutrino Physics, Present and Future B. KAYSER, Fermilab, USA Our understanding of neutrinos has been revolutionized by the discovery that they have nonzero masses and very large mixing. We will explain the phenomenology of massive neutrinos, including neutrino oscillation in vacuum and in matter, and the physics of neutrinos that are their own antiparticles. We will review the evidence for neutrino masses and mixing, and summarize what has been learned about the neutrinos so far. Identifying the very interesting open questions raised by the discovery of neutrino mass, we will discuss how these questions may be answered through future experiments. Finally, we will consider the possibility that CP violation by neutrinos is the key to understanding the matter-antimatter asymmetry of the universe, and discuss the see-saw theory of why neutrino masses are so tiny....

  9. Search for heavy neutral leptons in the trilepton final state at CMS

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The smallness of neutrino masses provides a tantalizing allusion to physics beyond the standard model (SM). Heavy neutral leptons (HNL), such as hypothetical sterile neutrinos, provide a potential explanation of this observation through the see-saw mechanism. If they exist, HNL could also provide answers about the underlying nature of dark matter as well as the observed baryon asymmetry in the universe. A search for the production of HNL at the LHC, originating from leptonic W boson decays through the mixing of the HNL with SM neutrinos, is presented in this seminar. The search focuses on signatures with three prompt leptons (electrons or muons) in the final state, which allow to probe the production of the HNL with masses ranging from 1 GeV up to 1.2 TeV. Using 36/fb of proton-proton collision data collected by CMS in 2016, the analysis is optimized for finding HNL with masses above and below that of the W boson.

  10. Texture Zero Neutrino Models and Their Connection with Resonant Leptogenesis arXiv

    CERN Document Server

    Achelashvili, Avtandil

    Within the low scale resonant leptogenesis scenario, the cosmological CP asymmetry may arise by radiative corrections through the charged lepton Yukawa couplings. While in some cases, as one expects, decisive role is played by the $\\lambda_{\\tau }$ coupling, we show that in specific neutrino textures only by inclusion of the $\\lambda_{\\mu }$ the cosmological CP violation is generated at 1-loop level. With the purpose to relate the cosmological CP violation to the leptonic CP phase $\\delta $, we consider an extension of MSSM with two right handed neutrinos (RHN), which are degenerate in mass at high scales. Together with this, we first consider two texture zero 3x2 Dirac Yukawa matrices of neutrinos. These via see-saw generated neutrino mass matrices augmented by single $\\Delta L=2$ dimension five (d=5) operator give predictive neutrino sectors with calculable CP asymmetries. The latter is generated through $\\lambda_{\\mu , \\tau }$ coupling(s) at 1-loop level. Detailed analysis of the leptogenesis is performed....

  11. Late Holocene climate variability in the southwestern Mediterranean region: an integrated marine and terrestrial geochemical approach

    Directory of Open Access Journals (Sweden)

    C. Martín-Puertas

    2010-12-01

    Full Text Available A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G and terrestrial (Zoñar Lake, Andalucia, Spain geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP – synchronously to the global aridity crisis of the third-millennium BC – and during the Medieval Climate Anomaly (1.4–0.7 cal ka BP. Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean.

  12. Chiral Symmetry Restoration, Naturalness and the Absence of Fine-Tuning I: Global Theories

    CERN Document Server

    Lynn, Bryan W.

    2013-01-01

    The Standard Model (SM), and the scalar sector of its zero-gauge-coupling limit -- the chiral-symmetric limit of the Gell Mann-Levy Model (GML) -- have been shown not to suffer from a Higgs Fine-Tuning (FT) problem. All ultraviolet quadratic divergences (UVQD) are absorbed into the mass-squared of pseudo Nambu-Goldstone (pNGB) bosons, in GML. Since chiral SU(2)_{L-R} symmetry is restored as the pNGB mass-squared or as the Higgs vacuum expectation value (VEV) are taken to 0, small values of these quantities and of the Higgs mass are natural, and therefore not Fine-Tuned. In this letter, we extend our results on the absence of FT to a wide class of high-mass-scale (M_{Heavy}>>m_{Higgs}) extensions to a simplified SO(2) version of GML. We explicitly demonstrate naturalness and no-FT for two examples of heavy physics, both SO(2) singlets: a heavy (M_S >> m_{Higgs}) real scalar field (with or without a VEV); and a right-handed Type 1 See-Saw Majorana neutrino with M_R >> m_{Higgs}. We prove that for |q^2| <<...

  13. Higher-Dimensional Origin of Heavy Sneutrino Domination and Low-Scale Leptogenesis

    CERN Document Server

    Hebecker, A; Yanagida, T

    2003-01-01

    If the expectation value of the right-handed (rhd) sneutrino comes to dominate the universe, its decay naturally leads to successful leptogenesis, as well as significant dilution of dangerous inflationary relics, such as the gravitino. The resulting baryon asymmetry is independent of other cosmological initial conditions. This attractive variant of leptogenesis requires at least one of the rhd neutrinos to have small Yukawa coupling and to have mass ~ 10^6 GeV, much smaller than the grand unified (GUT) scale. We show that these features naturally arise in the context of independently motivated and successful 5d orbifold GUTs with inverse-GUT-scale-sized extra dimensions. Rhd neutrinos are realized as bulk fields N_i with 5d bulk masses, while Yukawa couplings and lepton-number-violating masses for the N_i are localized at the SM boundary. The exponential suppression of the would-be N_i zero-modes leads to the desired small 4d Yukawa couplings and small masses for the rhd neutrino states. The see-saw predictio...

  14. L-functions and the oscillator representation

    CERN Document Server

    Rallis, Stephen

    1987-01-01

    These notes are concerned with showing the relation between L-functions of classical groups (*F1 in particular) and *F2 functions arising from the oscillator representation of the dual reductive pair *F1 *F3 O(Q). The problem of measuring the nonvanishing of a *F2 correspondence by computing the Petersson inner product of a *F2 lift from *F1 to O(Q) is considered. This product can be expressed as the special value of an L-function (associated to the standard representation of the L-group of *F1) times a finite number of local Euler factors (measuring whether a given local representation occurs in a given oscillator representation). The key ideas used in proving this are (i) new Rankin integral representations of standard L-functions, (ii) see-saw dual reductive pairs and (iii) Siegel-Weil formula. The book addresses readers who specialize in the theory of automorphic forms and L-functions and the representation theory of Lie groups. N

  15. Neutrino mass and mixing with discrete symmetry

    Science.gov (United States)

    King, Stephen F.; Luhn, Christoph

    2013-05-01

    This is a review paper about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally, we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A4, S4 and Δ(96).

  16. Recanalization strategy for chronic total occlusions with tapered and stiff-tip guidewire. The results of CTO new techniQUE for STandard procedure (CONQUEST) trial.

    Science.gov (United States)

    Mitsudo, Kazuaki; Yamashita, Takehiro; Asakura, Yasushi; Muramatsu, Toshiya; Doi, Osamu; Shibata, Yoshisato; Morino, Yoshihiro

    2008-11-01

    The success rate of percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO) lesions varies depending on the guidewire manipulation skills of the operator. The standardization of guidewire technique is very important. A new technique with a new tapered wire (Conquest, Confianza Pro) was tested to verify effectiveness for higher initial success rates and standardization of PCI for CTO. A prospective, multicenter registry was conducted at 6 investigational sites. In the CONQUEST trial, The CTO lesions were treated by using an intermediate guidewire to cross the lesion. If it did not cross, the guidewire was changed to the Conquest guidewire. If it did not cross, "seesaw-wiring" or the "parallel-wire technique" was performed. The primary endpoint was the initial procedural success rate. A total of 110 patients representing 116 CTO lesions were treated from July 2003 through March 2004. The procedural success rate was 86.2% on the first try, and 88.8% on the second try, respectively. The guidewire success rate on the second try was 90.5% during the hospital stay; no deaths, or acute myocardial infarctions were confirmed. Two patients deteriorated into tamponade, and surgical or percutaneous drainage was performed in each patient without any sequelae. A guidewire technique in PCI for CTOs that starts with the intermediate guidewire and moves to the Confianza Pro tapered guidewire, either alone or by performing a see-saw or parallel-wire technique, can achieve a high initial success rate with an acceptably low major complication rate.

  17. Leptogenesis from loop effects in curved spacetime

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Jamie I.; Shore, Graham M. [Department of Physics, Swansea University,Singleton Park, Swansea, SA2 8PP (United Kingdom)

    2016-04-05

    We describe a new mechanism — radiatively-induced gravitational leptogenesis — for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C and CP violating theories cause matter and antimatter to propagate differently in the presence of gravity, and prove this is forbidden in flat space by CPT and translation symmetry. This generates a curvature-dependent chemical potential for leptons, allowing a matter-antimatter asymmetry to be generated in thermal equilibrium in the early Universe. The time-dependent dynamics necessary for leptogenesis is provided by the interaction of the virtual self-energy cloud of the leptons with the expanding curved spacetime background, which violates the strong equivalence principle and allows a distinction between matter and antimatter. We show here how this mechanism is realised in a particular BSM theory, the see-saw model, where the quantum loops involve the heavy sterile neutrinos responsible for light neutrino masses. We demonstrate by explicit computation of the relevant two-loop Feynman diagrams how the size of the radiative corrections relevant for leptogenesis becomes enhanced by increasing the mass hierarchy of the sterile neutrinos, and show how the induced lepton asymmetry may be sufficiently large to play an important rôle in determining the baryon-to-photon ratio of the Universe.

  18. Tentorial mobility in centipedes (Chilopoda revisited: 3D reconstruction of the mandibulo-tentorial musculature of Geophilomorpha

    Directory of Open Access Journals (Sweden)

    Markus Koch

    2015-06-01

    Full Text Available Mandibular mechanisms in Geophilomorpha are revised based on three-dimensional reconstructions of the mandibulo-tentorial complex and its muscular equipment in Dicellophilus carniolensis (Placodesmata and Hydroschendyla submarina (Adesmata. Tentorial structure compares closely in the two species and homologies can be proposed for the 14/17 muscles that attach to the tentorium. Both species retain homologues of muscles that in other Pleurostigmophora are traditionally thought to cause swinging movements of the tentorium that complement the mobility of the mandibles. Although the original set of tentorial muscles is simplified in Geophilomorpha, the arrangement of the preserved homologues conforms to a system of six degrees of freedom of movement, as in non-geophilomorph Pleurostigmophora. A simplification of the mandibular muscles is confirmed for Geophilomorpha, but our results reject absence of muscles that in other Pleurostigmophora primarily support see-saw movements of the mandibles. In the construction of the tentorium, paralabial sclerites seem to be involved in neither Placodesmata nor Adesmata, and we propose their loss in Geophilomorpha as a whole. Current insights on the tentorial skeleton and its musculature permit two alternative conclusions on their transformation in Geophilomorpha: either tentorial mobility is primarily maintained in both Placodesmata and Adesmata (contrary to Manton’s arguments for immobility, or the traditional assumption of the tentorium as being mobile is a misinterpretation for Pleurostigmophora as a whole.

  19. Tri-bimaximal-Cabibbo mixing

    Energy Technology Data Exchange (ETDEWEB)

    King, S.F., E-mail: king@soton.ac.uk [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2012-11-15

    Recent measurements of the lepton mixing angle {theta}{sub 13} by the Daya Bay and RENO reactor experiments are consistent with the relationship {theta}{sub 13} Almost-Equal-To {theta}{sub C}/{radical}(2) where {theta}{sub C} is the Cabibbo angle. We propose Tri-Bimaximal-Cabibbo (TBC) mixing, in which sin{theta}{sub 13}=sin{theta}{sub C}/{radical}(2), sin{theta}{sub 23}=1/{radical}(2) and sin{theta}{sub 12}=1/{radical}(3). We show that TBC mixing may arise approximately from tri-bimaximal, bi-maximal or Golden Ratio neutrino mixing, together with Cabibbo-like charged lepton corrections arising from a Pati-Salam gauge group, leading to predictions for the CP-violating phase of {delta} Almost-Equal-To {+-}90 Degree-Sign ,{+-}180 Degree-Sign ,{+-}75 Degree-Sign , respectively. Alternatively, we show that TBC neutrino mixing may realised accurately using the type I see-saw mechanism with partially constrained sequential right-handed neutrino dominance, assuming a family symmetry which is broken by a flavon common to quarks and neutrinos.

  20. Atmospheric CO2 variations on millennial-scale during MIS 6

    Science.gov (United States)

    Shin, Jinhwa; Grilli, Roberto; Chappellaz, Jérôme; Teste, Grégory; Nehrbass-Ahles, Christoph; Schmidely, Loïc; Schmitt, Jochen; Stocker, Thomas; Fischer, Hubertus

    2017-04-01

    Understanding natural carbon cycle / climate feedbacks on various time scales is highly important for predicting future climate changes. Paleoclimate records of Antarctic temperatures, relative sea level and foraminiferal isotope and pollen records in sediment cores from the Portuguese margin have shown climate variations on millennial time scale over the Marine Isotope Stage 6 (MIS 6; from approximately 135 to 190 kyr BP). These proxy data suggested iceberg calving in the North Atlantic result in cooling in the Northern hemisphere and warming in Antarctica by changes in the Atlantic Meridional Overturning Circulation, which is explained by a bipolar see-saw trend in the ocean (Margari et al., 2010). Atmospheric CO2 reconstruction from Antarctic ice cores can provide key information on how atmospheric CO2 concentrations are linked to millennial-scale climate changes. However, existing CO2 records cannot be used to address this relationship because of the lack of suitable temporal resolution. In this work, we will present a new CO2 record with an improved time resolution, obtained from the Dome C ice core (75˚ 06'S, 123˚ 24'E) spanning the MIS 6 period, using dry extraction methods. We will examine millennial-scale features in atmospheric CO2, and their possible links with other proxies covering MIS 6. Margari, V., Skinner, L. C., Tzedakis, P. C., Ganopolski, A., Vautravers, M., and Shackleton, N. J.: The nature of millennial scale climate variability during the past two glacial periods, Nat.Geosci., 3, 127-131, 2010.

  1. Late Holocene climate variability in the southwestern Mediterranean region: an integrated marine and terrestrial geochemical approach

    Science.gov (United States)

    Martín-Puertas, C.; Jiménez-Espejo, F.; Martínez-Ruiz, F.; Nieto-Moreno, V.; Rodrigo, M.; Mata, M. P.; Valero-Garcés, B. L.

    2010-12-01

    A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G) and terrestrial (Zoñar Lake, Andalucia, Spain) geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP - synchronously to the global aridity crisis of the third-millennium BC - and during the Medieval Climate Anomaly (1.4-0.7 cal ka BP). Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean.

  2. Bipolar ice core records of millennial scale climate variability : an overview of recent findings (Invited)

    Science.gov (United States)

    Masson-Delmotte, V.; Landais, A.

    2013-12-01

    Greenland and Antarctic ice cores offer high resolution records of the imprints of millennial scale climate variability on polar climate, aerosol deposition, and atmospheric composition (Wolff et al, QSR, 2010). Improved chronologies and spatial coverage provide new data against which the mechanisms involved in millennial variability and simulated by climate models can be tested. We will first discuss the bipolar sequence of events based on the new AICC2012 chronology, during the last climatic cycle (Veres et al, Clim. Past, 2013; Bazin et al, Clim. Past, 2013). The matrix of ice cores allows to investigate regional differences in the cross-Greenland fingerprints of Dansgaard-Oeschger events (Guillevic et al, Clim. Past, 2013) and the circum-Antarctic signature of their Antarctic Isotopic Maxima counterpart (Buiron et al, QSR, 2012). While Heinrich events have long remained difficult to identify in ice core records, a step change in atmospheric CO2 concentrations has been identified during Heinrich 4 (Ahn et al, GRL, 2012), challenging the gradual CO2 emissions expected from the classical bipolar see-saw explanation. High resolution Antarctic data also reveal centennial to millennial variability during interglacial periods and glacial inceptions which bears similarities with glacial Antarctic Isotopic Maxima, questioning the source and amplifiers of glacial millennial variability. New investigations of the magnitude and recurrence of millennial variability based on multiple long Antarctic ice core records are expected to provide further hints on the interplay between mean climatic states and this millennial variability.

  3. Low Actuating Voltage Spring-Free RF MEMS SPDT Switch

    Directory of Open Access Journals (Sweden)

    Deepak Bansal

    2016-01-01

    Full Text Available RF MEMS devices are known to be superior to their solid state counterparts in terms of power consumption and electromagnetic response. Major limitations of MEMS devices are their low switching speed, high actuation voltage, larger size, and reliability. In the present paper, a see-saw single pole double throw (SPDT RF MEMS switch based on anchor-free mechanism is proposed which eliminates the above-mentioned disadvantages. The proposed switch has a switching time of 394 nsec with actuation voltage of 5 V. Size of the SPDT switch is reduced by utilizing a single series capacitive switch compared to conventional switches with capacitive and series combinations. Reliability of the switch is improved by adding floating metal and reducing stiction between the actuating bridge and transmission line. Insertion loss and isolation are better than −0.6 dB and −20 dB, respectively, for 1 GHz to 20 GHz applications.

  4. Simulation of Climatic Changes in the Arctic and North Atlantic During Recent Decades

    Science.gov (United States)

    Hakkinen, Sirpa; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    The interactions of the atmosphere and ice-ocean system in the Arctic will be studied using a coupled ice-ocean model which will also use ice drift derived from microwave observations as forcing. We especially search for linkages between the recent large climatic shifts in the Arctic Ocean and atmosphere for which period we also have microwave sea ice data. The coupled model area covers the whole N. Atlantic thus interactions between the lower latitudes are also investigated because we anticipate that the same large scale atmospheric patterns which dominate the midlatitudes extend their influence on the Arctic. The model hindcast for 1951-1993 shows clear decadal variability in the leading modes of ocean circulation. No specific low-freq modes are expected for the ice drift because its spectrum is white. However, the ice drift exhibits two see-saw patterns in response to the leading atmospheric circulation mode ('Arctic Oscillation'), one of them is the well-known out of phase relationship between Baffin Bay and Barents-Kara Seas, the other one is between Siberian shelf and Alaskan Coast (Hakkinen and Geiger, 2000).

  5. Leptogenesis from loop effects in curved spacetime

    Science.gov (United States)

    McDonald, Jamie I.; Shore, Graham M.

    2016-04-01

    We describe a new mechanism — radiatively-induced gravitational leptogenesis — for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C and CP violating theories cause matter and antimatter to propagate differently in the presence of gravity, and prove this is forbidden in flat space by CPT and translation symmetry. This generates a curvature-dependent chemical potential for leptons, allowing a matter-antimatter asymmetry to be generated in thermal equilibrium in the early Universe. The time-dependent dynamics necessary for leptogenesis is provided by the interaction of the virtual self-energy cloud of the leptons with the expanding curved spacetime background, which violates the strong equivalence principle and allows a distinction between matter and antimatter. We show here how this mechanism is realised in a particular BSM theory, the see-saw model, where the quantum loops involve the heavy sterile neutrinos responsible for light neutrino masses. We demonstrate by explicit computation of the relevant two-loop Feynman diagrams how the size of the radiative corrections relevant for leptogenesis becomes enhanced by increasing the mass hierarchy of the sterile neutrinos, and show how the induced lepton asymmetry may be sufficiently large to play an important rôle in determining the baryon-to-photon ratio of the Universe.

  6. Model of neutrino effective masses

    CERN Document Server

    Dinh Nguyen Dinh; Nguyen Thi Hong Van; Phi Quang Van

    2006-01-01

    It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3)L symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc.

  7. String completion of an SU(3)c ⊗ SU(3)L ⊗ U(1)X electroweak model

    Science.gov (United States)

    Addazi, Andrea; Valle, J. W. F.; Vaquera-Araujo, C. A.

    2016-08-01

    The extended electroweak SU(3)c ⊗ SU(3)L ⊗ U(1)X symmetry framework ;explaining; the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.

  8. E6SSM vs MSSM gluino phenomenology

    Directory of Open Access Journals (Sweden)

    Hall Jonathan

    2012-06-01

    Full Text Available The E6SSM is a promising model based on the group E6, assumed to be broken at the GUT scale, leading to the group SU(3×SU(2×U(1×U(1′ at the TeV scale. It gives a solution to the MSSM μ-problem without introducing massless axions, gauge anomalies or cosmological domain walls. The model contains three families of complete 27s of E6, giving a richer phenomenology than the MSSM. The E6SSM generically predicts gluino cascade decay chains which are about 2 steps longer than the MSSM’s due to the presence of several light neutralino states. This implies less missing (and more visible transverse momentum in collider experiments and kinematical distributions such as Meff are different. Scans of parameter space and MC analysis suggest that current SUSY search strategies and exclusion limits have to be reconsidered.

  9. E6SSM vs MSSM gluino phenomenology

    Science.gov (United States)

    Svantesson, Patrik; Belyaev, Alexander; Hall, Jonathan; King, Stephen F.

    2012-06-01

    The E6SSM is a promising model based on the group E6, assumed to be broken at the GUT scale, leading to the group SU(3)×SU(2)×U(1)×U(1)' at the TeV scale. It gives a solution to the MSSM μ-problem without introducing massless axions, gauge anomalies or cosmological domain walls. The model contains three families of complete 27s of E6, giving a richer phenomenology than the MSSM. The E6SSM generically predicts gluino cascade decay chains which are about 2 steps longer than the MSSM's due to the presence of several light neutralino states. This implies less missing (and more visible) transverse momentum in collider experiments and kinematical distributions such as Meff are different. Scans of parameter space and MC analysis suggest that current SUSY search strategies and exclusion limits have to be reconsidered.

  10. An optimization of jet reconstruction for the Matrix Element Method in semileptonic $ttH(bb)$ search using the ATLAS detector

    CERN Document Server

    Krupa, Jeffrey

    2016-01-01

    Run 2 of the LHC is probing physics at the TeV scale through pp collisions with centerof-mass energy $\\sqrt{s}$ = 13 TeV at unprecendented luminosities. One particular process that this promises to shed light on is the production of the Higgs boson in association with top quarks, $ttH(b\\bar{b})$. This report studies the reconstruction of jets from W boson decay in the $ttH(b\\bar{b})$ process. An algorithm to improve the reconstruction efficiency of the jets from W boson decay by recognizing their kinematic properties and applying specific requirements is introduced, implemented, and its effects are studied. The altered algorithm is shown to improve the separation between signal and background of the MEM calculations between 15% − 25%. The algorithm offers to potentially decrease the uncertainties in the calculated signal strength of the $ttH(b\\bar{b})$ process.

  11. Understanding flavour at the LHC

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Huge progress in flavour physics has been achieved by the two B-factories and the Tevatron experiments. This progress has, however, deepened the new physics flavour puzzle: If there is new physics at the TeV scale, why aren't flavour changing neutral current processes enhanced by orders of magnitude compared to the standard model predictions? The forthcoming ATLAS and CMS experiments can potentially solve this puzzle. Perhaps even more surprisingly, these experiments can potentially lead to progress in understanding the standard model flavour puzzle: Why is there smallness and hierarchy in the flavour parameters? Thus, a rich and informative flavour program is awaiting us not only in the flavour-dedicated LHCb experiment, but also in the high-pT ATLAS and CMS experiments.

  12. The flavour of natural SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, Felix [SISSA/ISAS, Trieste (Italy); Kraml, Sabine; Kulkarni, Suchita; Smith, Christopher [Universite Grenoble-Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble Cedex (France)

    2014-09-15

    An inverted mass hierarchy in the squark sector, as in so-called ''natural supersymmetry'', requires non-universal boundary conditions at the mediation scale of supersymmetry breaking. We propose a formalism to define such boundary conditions in a basis-independent manner and apply it to generic scenarios where the third-generation squarks are light, while the first two-generation squarks are heavy and near-degenerate. We show that not only is our formalism particularly well suited to study such hierarchical squark mass patterns, but in addition the resulting soft terms at the TeV scale are manifestly compatible with the principle of minimal flavour violation, and thus automatically obey constraints from flavour physics. (orig.)

  13. Landscape of Future Accelerators at the Energy and Intensity Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M. J. [Northern Illinois U.; Chattopadhyay, S. [Northern Illinois U.

    2016-11-21

    An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

  14. The Art and Science of Planning for the International Linear Collider

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    There is a consensus among the worldwide high energy physics community that a TeV scale linear electron positron collider is the highest priority long term goal for a new facility for the field. This new particle accelerator, together with the Large Hadron Collider (LHC) at CERN, will enable a comprehensive exploration of the TeV energy scale where many of the new phenomena we seek, like supersymmetry or possibly even extra dimensions could reveal themselves. The international community has chosen superconducting RF technology to be the basis of the ILC concept, and a global design effort has been created to guide the R&D and technical design toward construction. In this presentation, I will discuss the science motivation, the technology, recent progress and plans, and personally assess the prospects.

  15. Vector boson scattering, triple gauge-boson final states and limits on anomalous quartic gauge couplings with the ATLAS detector

    CERN Document Server

    Li, Bing; The ATLAS collaboration

    2018-01-01

    Measurements of the cross sections of the production of three electroweak gauge bosons and of vector-boson scattering processes at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has recently searched for the production of three W bosons or of a W boson and a photon together with a Z or W boson at a center of mass energy of 8 TeV. We also present searches for the electroweak production of a Z boson and a photon together with two jets. The results are compared to state-of-the art theory predictions and have been used to constrain anomalous quartic gauge couplings.

  16. Vector boson scattering, triple gauge-boson final states and limits on anomalous quartic gauge couplings with the ATLAS detector

    CERN Document Server

    Li, Bing; The ATLAS collaboration

    2017-01-01

    Measurements of the cross sections of the production of three electroweak gauge bosons and of vector-boson scattering processes at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has recently searched for the production of three $W$ bosons or of a $W$ boson and a photon together with a $Z$ or $W$ boson at a center of mass energy of 8 TeV. We also present searches for the electroweak production of a $Z$ boson and a photon together with two jets. The results are compared to state-of-the art theory predictions and have been used to constrain anomalous quartic gauge couplings.

  17. Vector boson scattering, triple gauge-boson final states and limits on anomalous quartic gauge couplings with the ATLAS detector

    CERN Document Server

    Li, Bing; The ATLAS collaboration

    2017-01-01

    Measurements of the cross sections of the production of three electroweak gauge bosons and of vector-boson scattering processes at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has recently searched for the production of three W bosons or of a W boson and a photon together with a Z or W boson at a center of mass energy of 8 TeV. We also present searches for the electroweak production of a Z boson and a photon together with two jets. The results are compared to state-of-the art theory predictions and have been used to constrain anomalous quartic gauge couplings.

  18. Precision Measurement of the Weak Mixing Angle in Moller Scattering

    CERN Document Server

    Anthony, P L; Arroyo, C; Bega, K; Biesiada, J; Bosted, P E; Bower, G; Cahoon, J; Carr, R; Cates, G D; Chen, J P; Chudakov, E; Cooke, M; Decowski, P; Deur, A; Emam, W; Erickson, R; Fieguth, T; Field, C; Gao, J; Gary, M; Gustafsson, K; Hicks, R S; Holmes, R; Hughes, E W; Humensky, T B; Jones, G M; Kaufman, L J; Keller, L; Kolomensky, Yu G; Kumar, K S; La Violette, P; Lhuillier, D; Lombard-Nelsen, R M; Marshall, Z; Mastromarino, P; McKeown, R D; Michaels, R; Niedziela, J; Olson, M; Paschke, K D; Peterson, G A; Pitthan, R; Relyea, D; Rock, S E; Saxton, O; Singh, J; Souder, P A; Szalata, Z M; Turner, J; Tweedie, B; Vacheret, A; Walz, D; Weber, T; Weisend, J; Woods, M; Younus, I

    2005-01-01

    We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -131 +/- 14 (stat.) +/- 10 (syst.) parts per billion, leading to the determination of the weak mixing angle \\sin^2\\theta_W^eff = 0.2397 +/- 0.0010 (stat.) +/- 0.0008 (syst.), evaluated at Q^2 = 0.026 GeV^2. Combining this result with the measurements of \\sin^2\\theta_W^eff at the Z^0 pole, the running of the weak mixing angle is observed with over 6 sigma significance. The measurement sets constraints on new physics effects at the TeV scale.

  19. Research and Development of Wires and Cables for High-Field Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Barzi, Emanuela; Zlobin, Alexander V.

    2016-04-01

    The latest strategic plans for High Energy Physics endorse steadfast superconducting magnet technology R&D for future Energy Frontier Facilities. This includes 10 to 16 T Nb3Sn accelerator magnets for the luminosity upgrades of the Large Hadron Collider and eventually for a future 100 TeV scale proton-proton (pp) collider. This paper describes the multi-decade R&D investment in the Nb3Sn superconductor technology, which was crucial to produce the first reproducible 10 to 12 T accelerator-quality dipoles and quadrupoles, as well as their scale-up. We also indicate prospective research areas in superconducting Nb3Sn wires and cables to achieve the next goals for superconducting accelerator magnets. Emphasis is on increasing performance and decreasing costs while pushing the Nb3Sn technology to its limits for future pp colliders.

  20. A 750 GeV graviton from holographic composite dark sectors

    CERN Document Server

    Carmona, Adrian

    2016-01-01

    We show that the 750 GeV di-photon excess can be interpreted as a spin-2 resonance arising from a strongly interacting dark sector featuring some departure from conformality. This spin-2 resonance has negligible couplings to the SM particles, with the exception of the SM gauge bosons which mediate the two sectors. We have explicitly studied the collider constraints as well as some theoretical bounds in a holographic five dimensional model with a warp factor that deviates from AdS$_5$. In particular, we have shown that it is not possible to decouple the vector resonances arising from the strong sector while explaining the di-photon anomaly and keeping the five dimensional gravity theory under perturbative control. However, due to the deformation of conformality, vector resonances with masses around the TeV scale can be present while all experimental constraints are met.

  1. Exotic diboson searches in the $\\ell\

    CERN Document Server

    Biesuz, Nicolo Vladi; The ATLAS collaboration

    2017-01-01

    Analyses searching for diboson resonances are very powerful tools to investigate many beyond the Standard Model scenarios such as extension of the Higgs sector, Heavy Vector triplets ($W^{'}$ and $Z^{'}$) or excited states of Gravitons. These searches exploit the many decay channels of the two bosons allowing to select topologies with varied signal to background ratios and statistics. Among these searches the one looking for $WW$/$WZ$ in the semileptonic final state finds a compromise between the high signal statistics allowed by the high branching ratio of the hadronic decay of the gauge boson while profiting of the good trigger and analysis signature of the lepton, decay product of the second gauge boson. The $WW$/$WZ$ search for TeV scale resonances in the $\\ell\

  2. NLO-QCD corrections to Higgs pair production in the MSSM

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, A.; Degrassi, G. [Dipartimento di Matematica e Fisica, Università di Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Gröber, R. [INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Slavich, P. [LPTHE, UPMC University Paris 06, Sorbonne Universités, 4 Place Jussieu, F-75252 Paris (France); LPTHE, CNRS, 4 Place Jussieu, F-75252 Paris (France)

    2016-04-18

    We take a step towards a complete NLO-QCD determination of the production of a pair of Higgs scalars in the MSSM. Exploiting a low-energy theorem that connects the Higgs-gluon interactions to the derivatives of the gluon self-energy, we obtain analytic results for the one- and two-loop squark contributions to Higgs pair production in the limit of vanishing external momenta. We find that the two-loop squark contributions can have non-negligible effects in MSSM scenarios with stop masses below the TeV scale. We also show how our results can be adapted to the case of Higgs pair production in the NMSSM.

  3. Z' portal to Chern-Simons Dark Matter

    Science.gov (United States)

    Arcadi, Giorgio; Ghosh, Pradipta; Mambrini, Yann; Pierre, Mathias; Queiroz, Farinaldo S.

    2017-11-01

    We study the phenomenological credibility of a vectorial dark matter, coupled to a Z' portal through Chern-Simons interaction. We scrutinize two possibilities of connecting a Z' with the Standard Model: (1) through kinetic mixing and (2) from a second Chern-Simons interaction. Both scenarios are characterized by suppressed nuclear recoil scatterings, rendering direct detection searches not promising. Indirect detection experiments, on the other hand, furnish complementary limits for TeV scale masses, specially with the CTA. Searches for mono-jet and dileptons signals at the LHC are important to partially probe the kinetic mixing setup. Finally we propose an UV completion of the Chern-Simons Dark Matter framework.

  4. No-Scale Inflation

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V.; Olive, Keith A.

    2016-01-01

    Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string compactifications and yields a non-negative potential, and is therefore a plausible framework for constructing models of inflation. No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on $R + R^2$ gravity, with a tilted spectrum of scalar perturbations: $n_s \\sim 0.96$, and small values of the tensor-to-scalar perturbation ratio $r < 0.1$, as favoured by Planck and other data on the cosmic microwave background (CMB). Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics.

  5. Conference: Gearing up for LHC13

    CERN Document Server

    2015-01-01

    2015 will be an important year for the Large Hadron Collider. With the start of Run 2 at a centre of mass energy of 13 TeV, it will be possible to probe the existence of heavier states as expected in extensions of the Standard Model motivated by e.g. naturalness and dark matter. Preliminary results from Run 2 could either confirm the Standard Model with high accuracy or provide first hints of new structures at the TeV scale. In either case, the results from Run 2 will determine much of the future of the field for decades. During the conference we are planning to discuss the most recent LHC results and their implications for physics beyond the Standard Model.

  6. New ATLAS results in SUSY searches for 3rd generation squarks and electroweak production

    Directory of Open Access Journals (Sweden)

    David Claire

    2014-04-01

    Full Text Available Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses close to those of their Standard Model counterparts. Real and virtual production of third generation squarks via decay of a gluino can be significant if the mass of the gluino does not exceed the TeV scale. Top or bottom squarks with masses less than a few hundred GeV can also give rise to direct pair production rates at the LHC that can be observed in the 8 TeV data sample recorded by the ATLAS detector. Moreover, many supersymmetric models feature neutralinos, charginos and even sleptons with masses less than a few hundred GeV so that they can be observed in the available data sample. The talk presents recent ATLAS results from searches for direct stop and sbottom pair production as well as pair production of charginos, neutralinos and sleptons.

  7. Searches for pair production of third generation squarks with the ATLAS detector

    Directory of Open Access Journals (Sweden)

    Barber Thomas

    2013-05-01

    Full Text Available Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Production of third generation squarks via decay of a gluino can be significant if the mass of the gluino does not exceed the TeV scale. Scalar top or bottom squarks with masses less than a few hundred GeV can also give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents recent ATLAS results from searches for gluino mediated and direct stop and sbottom pair production.

  8. Solving the little hierarchy problem with a singlet and explicit μ terms.

    Science.gov (United States)

    Delgado, Antonio; Kolda, Christopher; Olson, J Pocahontas; de la Puente, Alejandro

    2010-08-27

    We present a generalization of the next-to-minimal supersymmetric standard model, with an explicit μ term and a supersymmetric mass for the singlet superfield, as a route to alleviating the little hierarchy problem of the minimal supersymmetric standard model (MSSM). Though this model does not address the μ problem of the MSSM, we are able to generate masses for the lightest neutral Higgs boson up to 140 GeV with top squarks below the TeV scale, all couplings perturbative to the gauge unification scale, and with no need to fine-tune parameters in the scalar potential. This model more closely resembles the MSSM phenomenologically than the canonical next-to-minimal supersymmetric standard model.

  9. Smoking-gun signatures of little Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Han Tao [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Institute of Theoretical Physics, Academia Sinica, Beijing 100080 (China); Logan, Heather E. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Wang, L.-T. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Jefferson Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2006-01-15

    Little Higgs models predict new gauge bosons, fermions and scalars at the TeV scale that stabilize the Higgs mass against quadratically divergent one-loop radiative corrections. We categorize the many little Higgs models into two classes based on the structure of the extended electroweak gauge group and examine the experimental signatures that identify the little Higgs mechanism in addition to those that identify the particular little Higgs model. We find that by examining the properties of the new heavy fermion(s) at the LHC, one can distinguish the structure of the top quark mass generation mechanism and test the little Higgs mechanism in the top sector. Similarly, by studying the couplings of the new gauge bosons to the light Higgs boson and to the Standard Model fermions, one can confirm the little Higgs mechanism and determine the structure of the extended electroweak gauge group.

  10. Physics at TeV e sup + e sup minus linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Chanowitz, M.S.

    1992-01-01

    A survey is presented of the physics opportunities at TeV e{sup +}e{sup {minus}} linear colliders. Examples are given of physics that might emerge in e{sup +}e{sup {minus}} collisions and in {gamma}{gamma} collisions using the back-scattered laser technique, including {gamma}{gamma} {yields} ZZ scattering as a probe of ultraheavy quanta. The second portion of the talk focuses on physics that must emerge at or below the TeV scale--the mechanism of electroweak symmetry breaking. In particular a very rough estimate is presented of the most challenging possible signal of symmetry breaking, strong WW scattering, as a function of collider energy. A subtheme, made explicit in the concluding section, is the continuing complementarity of e{sup +}e{sup {minus}} and pp colliders in the domain of TeV physics.

  11. Physics at TeV e{sup +}e{sup {minus}} linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Chanowitz, M.S.

    1992-01-01

    A survey is presented of the physics opportunities at TeV e{sup +}e{sup {minus}} linear colliders. Examples are given of physics that might emerge in e{sup +}e{sup {minus}} collisions and in {gamma}{gamma} collisions using the back-scattered laser technique, including {gamma}{gamma} {yields} ZZ scattering as a probe of ultraheavy quanta. The second portion of the talk focuses on physics that must emerge at or below the TeV scale--the mechanism of electroweak symmetry breaking. In particular a very rough estimate is presented of the most challenging possible signal of symmetry breaking, strong WW scattering, as a function of collider energy. A subtheme, made explicit in the concluding section, is the continuing complementarity of e{sup +}e{sup {minus}} and pp colliders in the domain of TeV physics.

  12. Searches for New Physics in boosted topologies at ATLAS

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The large increase in collision energy that the LHC reached in Run 2  provides an unprecedented opportunity to search for new physics beyond the Standard Model (SM). Various extensions of the SM predict heavy resonances at the TeV scale, which couple predominantly to the Higgs and electroweak gauge bosons and to top and bottom quarks. At resonance masses well above 1 TeV, these searches face specific challenges and  employ new identification techniques to disentangle the decay products of the boson in highly boosted configurations. This talk will review recent ATLAS Run-2 searches in various possible final states as well as  the dedicated techniques related to the specificity of such event topologies.

  13. Sakurai Prize: Why the Higgs Boson data implies an M-theory world

    Science.gov (United States)

    Kane, Gordon

    2017-01-01

    Compactifying 11D M-theory on a 7D G2 manifold automatically gives a supersymmetric 4D relativistic quantum field theory. The supersymmetry is softly broken by gluino condensation of the largest gauge group hidden sector, which runs fastest. The resulting gravitino mass is about 40 TeV, and the scalar masses and trilinears of the soft breaking Lagrangian have similar values. All solutions having electroweak symmetry breaking are in the two doublet decoupling region. The coefficient λ of the effective Higgs potential is calculable and determines Mh/MZ. Using the most recent match and run methods, and running down to the TeV scale gives Mh = 126 GeV, and decay BR within a few per cent of the SM Higgs. This was reported in summer 2011, before LHC data, though the result does not depend on any adjustable parameters so it would be unchanged whenever it was reported.

  14. B decay anomalies and dark matter from vectorlike confinement

    Science.gov (United States)

    Cline, James M.

    2018-01-01

    Lepton flavor universality violating B →K ℓℓ and K*ℓℓ decays tentatively observed by LHCb can be explained by leptoquark exchange. We explore a simple model for the B anomalies with a composite leptoquark from new strong dynamics at the TeV scale, a confining SU(NH C) hypercolor interaction. The new matter fields, fundamentals under SU (NH C) , are heavy vectorlike fermions Ψ , S , and an inert scalar doublet ϕ . Ψ is colored under QCD while S is neutral, and the hyperbaryon SN is an asymmetric dark matter candidate. The model is tightly constrained by meson-antimeson oscillations, lepton flavor violation, and LHC searches for resonant production of the exotic bound states. The dark matter may be detectable through its magnetic dipole moment. If mS is sufficiently small, composite leptoquarks and heavy lepton partners can be pair-produced at an observable level at LHC.

  15. arXiv Gauge leptoquark as the origin of B-physics anomalies

    CERN Document Server

    Di Luzio, Luca; Nardecchia, Marco

    2017-12-15

    The vector leptoquark representation, Uμ=(3,1,2/3), was recently identified as an exceptional single mediator model to address experimental hints on lepton flavor universality violation in semileptonic B-meson decays, both in neutral (b→sμμ) and charged (b→cτν) current processes. Nonetheless, it is well known that massive vectors crave an ultraviolet (UV) completion. We present the first full-fledged UV complete and calculable gauge model which incorporates this scenario while remaining in agreement with all other indirect flavor and electroweak precision measurements, as well as, direct searches at high-pT. The model is based on a new non-Abelian gauge group spontaneously broken at the TeV scale, and a specific flavor structure suppressing flavour violation in ΔF=2 processes while inducing sizeable semileptonic transitions.

  16. Identification of hadronically decaying W bosons and top quarks using multivariate techniques at ATLAS

    CERN Document Server

    Nitta, Tatsumi; The ATLAS collaboration

    2017-01-01

    By colliding protons and examining particles emitted from the collisions, the Large Hadron Collider aims to study the interactions of quarks and gluons at the highest energies accessible in a controlled experimental way. In such collisions, W bosons or top quarks which have TeV scale momentum can be accessible. Reconstructing such boosted jets are becoming important. In particular, the ability to identify original particle that decays to quarks against normal QCD jets plays a central role in various searches at high energy scale. This is typically done by the use of a single physically motivated observable constructed from the constituents of the jet. In this work, multiple complementary observables are combined using boosted decision trees and neural networks to increase the ability to distinguish W bosons and top quarks from light quark jets in the ATLAS experiment.

  17. 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.

  18. Confronting SUSY models with LHC data via electroweakino production

    Energy Technology Data Exchange (ETDEWEB)

    Arina, Chiara [Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium). Centre for Cosmology, Particle Physics and Phenomology (CP3); Chala, Mikael [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Martin-Lozano, Victor [Univ. Autonoma de Madrid UAM/CSIC (Spain). Dept. de Fisica Teorica y Inst. de Fisica Teorica; Bonn Univ. (Germany). Bethe Center for Theoretical Physics und Physikalisches Inst.; Nardini, Germano [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik

    2016-12-15

    We investigate multi-lepton signals produced by ElectroWeakino (EWino) decays in the MSSM and the TMSSM scenarios with sfermions, gluinos and non Standard Model Higgses at the TeV scale, being the Bino electroweak-scale dark matter. We recast the present LHC constraints on EWinos for these models and we find that wide MSSM and TMSSM parameter regions prove to be allowed. We forecast the number of events expected in the signal regions of the experimental multi-lepton analyses in the next LHC runs. The correlations among these numbers will help to determine whether future deviations in multi-lepton data are ascribable to the EWinos, as well as the supersymmetric model they originate from.

  19. On thermal corrections to near-threshold annihilation

    Science.gov (United States)

    Kim, Seyong; Laine, M.

    2017-01-01

    We consider non-relativistic ``dark'' particles interacting through gauge boson exchange. At finite temperature, gauge exchange is modified in many ways: virtual corrections lead to Debye screening; real corrections amount to frequent scatterings of the heavy particles on light plasma constituents; mixing angles change. In a certain temperature and energy range, these effects are of order unity. Taking them into account in a resummed form, we estimate the near-threshold spectrum of kinetically equilibrated annihilating TeV scale particles. Weakly bound states are shown to "melt" below freeze-out, whereas with attractive strong interactions, relevant e.g. for gluinos, bound states boost the annihilation rate by a factor 04... 8 with respect to the Sommerfeld estimate, thereby perhaps helping to avoid overclosure of the universe. Modestly non-degenerate dark sector masses and a way to combine the contributions of channels with different gauge and spin structures are also discussed.

  20. Mode Launcher Design for the Multi-moded DLDS

    CERN Document Server

    Li, Z

    2003-01-01

    The DLDS (Delay Line Distribution System) power delivery system proposed by KEK combines several klystrons to obtain the high peak power required to drive a TeV scale linear collider. In this system the combined klystron output is subdivided into shorter pulses by proper phasing of the sources, and each subpulse is delivered to various accelerator sections via separate waveguides. A cost-saving improvement suggested by SLAC is to use a single multimoded waveguide to deliver the power of all the subpulses. This scheme requires a mode launcher that can deliver each subpulse by way of a different waveguide mode through selective phasing of the sources when combining their power. We present a compact design for such a mode launcher that converts the power from four rectangular waveguide feeds to separate modes in a multi-moded circular guide through coupling slots. Such a design has been simulated and found to satisfy the requirements for high efficiency and low surface fields.

  1. Photoproduction of top and higgs particles at the LHC

    CERN Document Server

    Ovyn, Séverine

    Thanks to its high energy and luminosity, the Large Hadron Collider (LHC) at CERN can also be exploited as an high energy photon collider. In particular photoproduction offers interesting possibilities for the study of the electroweak sector up to TeV scale. After a brief presentation of cross sections for many photon-induced processes, prospects are discussed for the Higgs boson search as well as for the top quark physics. Although the studied final states possess striking characteristics, the separation of photon-induced processes from the overwhelming background of partonic interactions requires the use of advanced techniques. In this context, several tagging strategies are proposed, depending on the LHC luminosity. In order to realistically perform a simulation of the response of a multipurpose detector, a dedicated framework called DELPHES was designed. Using this fast simulation of a LHC-like detector, expected sensitivity on the tWb coupling measurement using several topologies resulting from the W ass...

  2. Very boosted Higgs in gluon fusion

    Energy Technology Data Exchange (ETDEWEB)

    Grojean, C. [Univ. Autonoma de Barcelona, Bellaterra (Spain). ICREA at IFAE; Salvioni, E. [California Univ., Davis, CA (United States). Dept. of Physics; European Organization for Nuclear Research (CERN), Geneva (Switzerland); Padova Univ. (Italy). Dipt. di Fisica e Astronomica; INFN, Sezione di Padova (Italy); Schlaffer, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Weiler, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-12-15

    The Higgs production and decay rates offer a new way to probe new physics beyond the Standard Model. While dynamics aiming at alleviating the hierarchy problem generically predict deviations in the Higgs rates, the current experimental analyses cannot resolve the long- and short-distance contributions to the gluon fusion process and thus cannot access directly the coupling between the Higgs and the top quark. We investigate the production of a boosted Higgs in association with a high-transverse momentum jet as an alternative to the t anti th channel to pin down this crucial coupling. Presented rst in the context of an effective field theory, our analysis is then applied to models of partial compositeness at the TeV scale and of natural supersymmetry.

  3. Physics Beyond the Standard Model

    CERN Document Server

    Ellis, John

    2009-01-01

    The Standard Model is in good shape, apart possibly from g_\\mu - 2 and some niggling doubts about the electroweak data. Something like a Higgs boson is required to provide particle masses, but theorists are actively considering alternatives. The problems of flavour, unification and quantum gravity will require physics beyond the Standard Model, and astrophysics and cosmology also provide reasons to expect physics beyond the Standard Model, in particular to provide the dark matter and explain the origin of the matter in the Universe. Personally, I find supersymmetry to be the most attractive option for new physics at the TeV scale. The LHC should establish the origin of particle masses has good prospects for discovering dark matter, and might also cast light on unification and even quantum gravity. Important roles may also be played by lower-energy experiments, astrophysics and cosmology in the searches for new physics beyond the Standard Model.

  4. Emergent Electroweak Symmetry Breaking with Composite W, Z Bosons

    CERN Document Server

    Cui, Yanou; Wells, James D

    2009-01-01

    We present a model of electroweak symmetry breaking in a warped extra dimension where electroweak symmetry is broken at the UV (or Planck) scale. An underlying conformal symmetry is broken at the IR (or TeV) scale generating masses for the electroweak gauge bosons without invoking a Higgs mechanism. By the AdS/CFT correspondence the W,Z bosons are identified as composite states of a strongly-coupled gauge theory, suggesting that electroweak symmetry breaking is an emergent phenomenon at the IR scale. The model satisfies electroweak precision tests with reasonable fits to the S and T parameter. In particular the T parameter is sufficiently suppressed since the model naturally admits a custodial SU(2) symmetry. The composite nature of the W,Z-bosons provide a novel possibility of unitarizing WW scattering via form factor suppression. Constraints from LEP and the Tevatron as well as discovery opportunities at the LHC are discussed for these composite electroweak gauge bosons.

  5. Geneva University: Searches for Exotic Physics with leptons with the ATLAS detector

    CERN Multimedia

    Université de Genève

    2011-01-01

    GENEVA UNIVERSITY Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 30 November  2011 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE at 17.00 hrs – Stückelberg Auditorium Searches for Exotic Physics with leptons with the ATLAS detector Dr Dominique Fortin, TRIUMF, Vancouver, Canada With the large 5 fb-1 sample of pp collisions recorded in 2011, ATLAS has taken full advantage of the opportunity to explore new territory at the TeV scale. In this seminar, an overview of searches for new exotic particles is presented, with a special emphasis on signatures with leptons. Information : http://dpnc.unige.ch/seminaire/annonce.html Organizer : Mrs Gabriella Pasztor

  6. Recent Multiboson measurements with the ATLAS experiment

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Measurements of the cross sections of the production of two electroweak gauge bosons constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. We present recent ATLAS measurements of inclusive and differential cross sections for WW, WZ, ZZ and Z + photon at centre of mass energies of 8 TeV and 13 TeV. Large next-to-next-to-leading order QCD corrections were recently calculated and are confronted with the measurements. We also present recent ATLAS measurements of inclusive cross sections for electroweak production of WZ + 2 jets and production of Z + di-photon at 8 TeV. Differential distributions sensitive to anomalous triple and quartic gauge couplings have been studied and limits on new physics have been derived.

  7. Superconductor Requirements and Characterization for High Field Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Barzi, E.; Zlobin, A. V.

    2015-05-01

    The 2014 Particle Physics Project Prioritization Panel (P5) strategic plan for U.S. High Energy Physics (HEP) endorses a continued world leadership role in superconducting magnet technology for future Energy Frontier Programs. This includes 10 to 15 T Nb3Sn accelerator magnets for LHC upgrades and a future 100 TeV scale pp collider, and as ultimate goal that of developing magnet technologies above 20 T based on both High Temperature Superconductors (HTS) and Low Temperature Superconductors (LTS) for accelerator magnets. To achieve these objectives, a sound conductor development and characterization program is needed and is herein described. This program is intended to be conducted in close collaboration with U.S. and International labs, Universities and Industry.

  8. Implementation of position and angle uncertainties in the muon reconstruction of the CMS experiment, and impact on the performance.

    CERN Document Server

    Abbiendi, Giovanni

    2016-01-01

    The alignment of muon chambers relative to each other and to the inner tracker is crucial to achieve the optimal performance of muon reconstruction at high momentum, in particular the best possible momentum measurement. With the energy and luminosity increase in LHC Run2, the high momentum muons have become more important for the searches of new particles with masses around the TeV scale. The muon reconstruction of the CMS experiment has been recently improved and made more robust with the introduction of alignment uncertainties on the positions and angles of the segments in the muon chambers. Not only does the momentum resolution improve at high energy, but, owing to the better quality of the muon track building and fit, also the trigger efficiency increases, especially in the initial phase of data-taking, after the opening and closure of the detector.

  9. String completion of an SU(3c⊗SU(3L⊗U(1X electroweak model

    Directory of Open Access Journals (Sweden)

    Andrea Addazi

    2016-08-01

    Full Text Available The extended electroweak SU(3c⊗SU(3L⊗U(1X symmetry framework “explaining” the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (unoriented open strings, on Calabi–Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron–antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.

  10. A constrained supersymmetric left-right model

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Martin [AHEP Group, Instituto de Física Corpuscular - C.S.I.C./Universitat de València, Edificio de Institutos de Paterna, Apartado 22085, E-46071 València (Spain); Krauss, Manuel E. [Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn, Nussallee 12, 53115 Bonn (Germany); Institut für Theoretische Physik und Astronomie, Universität Würzburg,Emil-Hilb-Weg 22, 97074 Wuerzburg (Germany); Opferkuch, Toby [Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn, Nussallee 12, 53115 Bonn (Germany); Porod, Werner [Institut für Theoretische Physik und Astronomie, Universität Würzburg,Emil-Hilb-Weg 22, 97074 Wuerzburg (Germany); Staub, Florian [Theory Division, CERN,1211 Geneva 23 (Switzerland)

    2016-03-02

    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.

  11. Limits on the effective quark radius from inclusive $ep$ scattering at HERA

    CERN Document Server

    Abramowicz, H; Adamczyk, L; Adamus, M; Antonelli, S; Aushev, V; Behnke, O; Behrens, U; Bertolin, A; Bloch, I; Boos, EG; Brock, I; Brook, NH; Brugnera, R; Bruni, A; Bussey, PJ; Caldwell, A; Capua, M; Catterall, CD; Chwastowski, J; Ciborowski, J; Ciesielski, R; Cooper-Sarkar, AM; Corradi, M; Dementiev, RK; Devenish, RCE; Dusini, S; Foster, B; Gach, G; Gallo, E; Garfagnini, A; Geiser, A; Gizhko, A; Gladilin, LK; Golubkov, Yu A; Grzelak, G; Guzik, M; Hain, W; Hochman, D; Hori, R; Ibrahim, ZA; Iga, Y; Ishitsuka, M; Januschek, F; Jomhari, NZ; Kadenko, I; Kananov, S; Karshon, U; Kaur, P; Kisielewska, D; Klanner, R; Klein, U; Korzhavina, IA; Kotański, A; Kötz, U; Kovalchuk, N; Kowalski, H; Krupa, B; Kuprash, O; Kuze, M; Levchenko, BB; Levy, A; Limentani, S; Lisovyi, M; Lobodzinska, E; Löhr, B; Lohrmann, E; Longhin, A; Lontkovskyi, D; Lukina, OYu; Makarenko, I; Malka, J; Mohamad Idris, F; Mohammad Nasir, N; Myronenko, V; Nagano, K; Nobe, T; Nowak, RJ; Onishchuk, Yu; Paul, E; Perlański, W; Pokrovskiy, NS; Przybycien, M; Roloff, P; Ruspa, M; Saxon, DH; Schioppa, M; Schneekloth, U; Schörner-Sadenius, T; Shcheglova, LM; Shevchenko, R; Shkola, O; Shyrma, Yu; Singh, I; Skillicorn, IO; Słomiński, W; Solano, A; Stanco, L; Stefaniuk, N; Stern, A; Stopa, P; Sztuk-Dambietz, J; Tassi, E; Tokushuku, K; Tomaszewska, J; Tsurugai, T; Turcato, M; Turkot, O; Tymieniecka, T; Verbytskyi, A; Wan Abdullah, WAT; Wichmann, K; Wing, M; Yamada, S; Yamazaki, Y; Zakharchuk, N; Żarnecki, AF; Zawiejski, L; Zenaiev, O; Zhautykov, BO; Zotkin, DS; Bhadra, S; Gwenlan, C; Hlushchenko, O; Polini, A; Mastroberardino, A; Sukhonos, D

    2016-01-01

    The high-precision HERA data allows searches up to TeV scales for Beyond the Standard Model contributions to electron-quark scattering. Combined measurements of the inclusive deep inelastic cross sections in neutral and charged current $ep$ scattering corresponding to a luminosity of around 1 fb$^{-1}$ have been used in this analysis. A new approach to the beyond the Standard Model analysis of the inclusive $ep$ data is presented; simultaneous fits of parton distribution functions together with contributions of "new physics" processes were performed. Results are presented considering a finite radius of quarks within the quark form-factor model. The resulting 95% C.L. upper limit on the effective quark radius is $0.43\\cdot 10^{-16}$ cm.

  12. A 750 GeV graviton from holographic composite dark sectors

    Directory of Open Access Journals (Sweden)

    Adrián Carmona

    2016-09-01

    Full Text Available We show that the 750 GeV di-photon excess can be interpreted as a spin-2 resonance arising from a strongly interacting dark sector featuring some departure from conformality. This spin-2 resonance has negligible couplings to the SM particles, with the exception of the SM gauge bosons which mediate between the two sectors. We have explicitly studied the collider constraints as well as some theoretical bounds in a holographic five dimensional model with a warp factor that deviates from AdS5. In particular, we have shown that it is not possible to decouple the vector resonances arising from the strong sector while explaining the di-photon anomaly and keeping the five dimensional gravity theory under perturbative control. However, vector resonances with masses around the TeV scale can be present while all experimental constraints are met.

  13. A Search for Heavy Resonances in the Dilepton Channel

    Directory of Open Access Journals (Sweden)

    Hayden Daniel

    2012-06-01

    Full Text Available There are many extensions to the Standard Model of particle physics which predict the addition of a U(1 symmetry, and/or extra spatial dimensions, which give rise to new high mass resonances such as the Z′ and Randall-Sundrum graviton. The LHC provides a unique opportunity to explore the TeV scale where these phenomena may become apparent, and can be searched for using the precision tracking and high energy resolution calorimetry of the ATLAS detector. This poster presents the search for high mass resonances in the dilepton channel, and was conducted with an integrated luminosity of 1.08/1.21 fb−1 in the dielectron/dimuon channel respectively, at a centre of mass energy √s = 7 TeV.

  14. Asymmetric dark matter and baryogenesis from S U (2 )ℓ

    Science.gov (United States)

    Fornal, Bartosz; Shirman, Yuri; Tait, Tim M. P.; West, Jennifer Rittenhouse

    2017-08-01

    We propose a theory in which the Standard Model gauge symmetry is extended by a new S U (2 )ℓgroup acting nontrivially on the lepton sector which is spontaneously broken at the TeV scale. Under this S U (2 )ℓtheordinaryleptons form doublets along with new lepton partner fields. This construction naturally contains a dark matter candidate, the partner of the right-handed neutrino, stabilized by a residual global U (1 )χ symmetry. We show that one can explain baryogenesis through an asymmetric dark matter scenario, in which generation of related asymmetries in the dark matter and baryon sectors is driven by the S U (2 )ℓ instantons during a first order phase transition in the early Universe.

  15. Natural supersymmetry and unification in five dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Abdalgabar, Ammar [National Institute for Theoretical Physics and School of Physics and Mandelstam Institute for Theoretical Physics, University of the Witwatersrand,Private Bag 3, Wits, 2050 (South Africa); Department of Physics, Sudan University of Science and Technology,Khartoum, 407 (Sudan); Cornell, Alan S. [National Institute for Theoretical Physics and School of Physics and Mandelstam Institute for Theoretical Physics, University of the Witwatersrand,Private Bag 3, Wits, 2050 (South Africa); Deandrea, Aldo [Université de Lyon,92, rue Pasteur, Lyon, F-69361 (France); IPNL, Université Lyon 1, CNRS/IN2P3,4 rue Fermi, Villeurbanne Cedex, F-69622 (France); Institut Universitaire de France,103 boulevard Saint-Michel, Paris, 75005 (France); McGarrie, Moritz [Faculty of Physics, University of Warsaw,Hoża 69, Warsaw, 00-681 (Poland)

    2016-01-14

    We explore unification and natural supersymmetry in a five dimensional extension of the standard model in which the extra dimension may be large, of the order of 1–10 TeV. Power law running generates a TeV scale A{sub t} term allowing for the observed 125 GeV Higgs and allowing for stop masses below 2 TeV, compatible with a natural SUSY spectrum. We supply the full one-loop RGEs for various models and use metastability to give a prediction that the gluino mass should be lighter than 3.5 TeV for A{sub t}≥−2.5 TeV, for such a compactification scale, with brane localised 3rd generation matter. We also discuss models in which only the 1st and 2nd generation of matter fields are located in the bulk. We also look at electroweak symmetry breaking in these models.

  16. Gauge coupling unification in a classically scale invariant model

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki; Ishida, Hiroyuki [Graduate School of Science and Engineering, Shimane University,Matsue 690-8504 (Japan); Takahashi, Ryo [Graduate School of Science, Tohoku University,Sendai, 980-8578 (Japan); Yamaguchi, Yuya [Graduate School of Science and Engineering, Shimane University,Matsue 690-8504 (Japan); Department of Physics, Faculty of Science, Hokkaido University,Sapporo 060-0810 (Japan)

    2016-02-08

    There are a lot of works within a class of classically scale invariant model, which is motivated by solving the gauge hierarchy problem. In this context, the Higgs mass vanishes at the UV scale due to the classically scale invariance, and is generated via the Coleman-Weinberg mechanism. Since the mass generation should occur not so far from the electroweak scale, we extend the standard model only around the TeV scale. We construct a model which can achieve the gauge coupling unification at the UV scale. In the same way, the model can realize the vacuum stability, smallness of active neutrino masses, baryon asymmetry of the universe, and dark matter relic abundance. The model predicts the existence vector-like fermions charged under SU(3){sub C} with masses lower than 1 TeV, and the SM singlet Majorana dark matter with mass lower than 2.6 TeV.

  17. 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.

  18. Basics of QCD for the LHC: pp → H + X as a case study

    CERN Document Server

    Maltoni, F

    2014-01-01

    Quantum Chromo Dynamics (QCD) provides the theoretical framework for any study of TeV scale physics at LHC. Being familiar with the basic concepts and techniques of QCD is therefore a must for any high-energy physicist. In these notes we consider Higgs production via gluon fusion as an example on how accurate and flexible predictions can be obtained in perturbative QCD. We start by illustrating how to calculate the total cross section at the leading order (yet one loop) in the strong coupling $\\alpha$S and go through the details of the next-to-leading order calculation eventually highlighting the limitations of fixed-order predictions at the parton level. Finally, we briefly discuss how more exclusive (and practical) predictions can be obtained through matching/merging fixed-order results with parton showers.

  19. Baryogenesis from strong CP violation and the QCD axion.

    Science.gov (United States)

    Servant, Géraldine

    2014-10-24

    We show that strong CP violation from the QCD axion can be responsible for the matter antimatter asymmetry of the Universe in the context of cold electroweak baryogenesis if the electroweak phase transition is delayed below the GeV scale. This can occur naturally if the Higgs couples to a O(100)  GeV dilaton, as expected in some models where the Higgs is a pseudo-Nambu-Goldstone boson of a new strongly interacting sector at the TeV scale. The existence of such a second scalar resonance with a mass and properties similar to the Higgs boson will soon be tested at the LHC. In this context, the QCD axion would not only solve the strong CP problem, but also the matter antimatter asymmetry and dark matter.

  20. Was the Universe actually radiation dominated prior to nucleosynthesis?

    Science.gov (United States)

    Giblin, John T.; Kane, Gordon; Nesbit, Eva; Watson, Scott; Zhao, Yue

    2017-08-01

    Maybe not. String theory approaches to both beyond the Standard Model and inflationary model building generically predict the existence of scalars (moduli) that are light compared to the scale of quantum gravity. These moduli become displaced from their low energy minima in the early Universe and lead to a prolonged matter-dominated epoch prior to big bang nucleosynthesis (BBN). In this paper, we examine whether nonperturbative effects such as parametric resonance or tachyonic instabilities can shorten, or even eliminate, the moduli condensate and matter-dominated epoch. Such effects depend crucially on the strength of the couplings, and we find that unless the moduli become strongly coupled, the matter-dominated epoch is unavoidable. In particular, we find that in string and M-theory compactifications where the lightest moduli are near the TeV scale, a matter-dominated epoch will persist until the time of big bang nucleosynthesis.

  1. Unity of elementary particles and forces for the third family

    Energy Technology Data Exchange (ETDEWEB)

    Chakdar, Shreyashi, E-mail: chakdar@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States); Li Tianjun, E-mail: tli@itp.ac.cn [State Key Laboratory of Theoretical Physics and Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Nandi, S., E-mail: s.nandi@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States); Rai, Santosh Kumar, E-mail: santosh.rai@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States)

    2012-11-15

    We propose a non-supersymmetric SU(5) model in which only the third family of fermions are unified. The model remedies the non-unification of the three Standard Model couplings in non-supersymmetric SU(5). It also provides a mechanism for baryon number violation which is needed for the baryon asymmetry of the Universe and is not present in the Standard Model. Current experimental constraints on the leptoquark gauge bosons, mediating such baryon and lepton violating interactions in our model, allow their masses to be at the TeV scale. These can be searched for as a (b{tau}) or (tt) resonance at the Large Hadron Collider as predicted in our model.

  2. Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation

    Directory of Open Access Journals (Sweden)

    C.A. de S. Pires

    2016-08-01

    Full Text Available 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 Sˆ. 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.

  3. 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.

  4. Higgs portal dark matter and neutrino mass and mixing with a doubly charged scalar

    Directory of Open Access Journals (Sweden)

    I.M. Hierro

    2017-06-01

    Full Text Available We consider an extension of the Standard Model involving two new scalar particles around the TeV scale: a singlet neutral scalar ϕ, to be eventually identified as the Dark Matter candidate, plus a doubly charged SU(2L singlet scalar, S++, that can be the source for the non-vanishing neutrino masses and mixings. Assuming an unbroken Z2 symmetry in the scalar sector, under which only the additional neutral scalar ϕ is odd, we write the most general (renormalizable scalar potential. The model may be regarded as a possible extension of the conventional Higgs portal Dark Matter scenario which also accounts for neutrino mass and mixing. This framework cannot completely explain the observed positron excess. However a softening of the discrepancy observed in conventional Higgs portal framework can be obtained, especially when the scale of new physics responsible for generating neutrino masses and lepton number violating processes is around 2 TeV.

  5. Parity-Violating Electron Scattering: New Results and Future Prospects

    Energy Technology Data Exchange (ETDEWEB)

    Krishna S. Kumar

    2006-11-01

    We discuss the status and prospects of an experimental program of parity-violating asymmetry measurements in the scattering of longitudinally polarized electrons off unpolarized fixed targets. One thrust is the measurements of nucleon neutral weak form factors at intermediate four-momentum transfer (0.1 < Q2 < 1) (GeV/c)2 which provide information about the role of virtual strange quarks on the charge and current distributions inside nucleons. A new topic is the elastic neutral weak amplitude from scattering off a heavy spinless nucleus, which is sensitive to the presence of a neutron skin. Finally, we discuss the neutral current elastic amplitude at very low Q2, which allows precision measurements of the weak mixing angle at low energy and is thus sensitive to new physics at the TeV scale. The physics implications of recent results, potential measurements from experiments under construction as well as new ideas at future facilities are discussed.

  6. Virtual signatures of dark sectors in Higgs couplings

    Science.gov (United States)

    Voigt, Alexander; Westhoff, Susanne

    2017-11-01

    Where collider searches for resonant invisible particles lose steam, dark sectors might leave their trace as virtual effects in precision observables. Here we explore this option in the framework of Higgs portal models, where a sector of dark fermions interacts with the standard model through a strong renormalizable coupling to the Higgs boson. We show that precise measurements of Higgs-gauge and triple Higgs interactions can probe dark fermions up to the TeV scale through virtual corrections. Observation prospects at the LHC and future lepton colliders are discussed for the so-called singlet-doublet model of Majorana fermions, a generalization of the bino-higgsino scenario in supersymmetry. We advocate a two-fold search strategy for dark sectors through direct and indirect observables.

  7. Searches for natural supersymmetry with the ATLAS detector

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks, Higgs and electroweak gauge bosons with masses not too far from those of their Standard Model counterparts. Under this paradigm, also the gluino mass would not exceed 1-2 TeV. Real and virtual production of third generation squarks via decay of a gluino can therefore be significant. Top and bottom squarks as well as charginos, neutralinos and sleptons with masses well below the TeV scale can also give rise to observable direct pair production rates at the LHC. The seminar will present results from searches for natural supersymmetry, many using the full data sample recorded during the 2012 run at 8 TeV centre-of-mass energy by the ATLAS detector.

  8. The No-Higgs Signal: Strong WW Scattering at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Michael S. Chanowitz

    2004-12-07

    Strong WW scattering at the LHC is discussed as a manifestation of electroweak symmetry breaking in the absence of a light Higgs bosom. The general framework of the Higgs mechanism--with or without a Higgs boson--is reviewed, and unitarity is shown to fix the scale of strong WW scattering. Strong WW scattering is also shown to be a possible outcome of five-dimensional models, which do not employ the usual Higgs mechanism at the TeV scale. Precision electroweak constraints are briefly discussed. Illustrative LHC signals are reviewed for models with QCD-like dynamics, stressing the complementarity of the W{sup {+-}}Z and like-charge W{sup +}W{sup +} + W{sup -}W{sup -} channels.

  9. Effective theory for electroweak doublet dark matter

    Science.gov (United States)

    Dedes, A.; Karamitros, D.; Spanos, V. C.

    2016-11-01

    We perform a detailed study of an effective field theory which includes the standard model particle content extended by a pair of Weyl fermionic SU(2) doublets with opposite hypercharges. A discrete symmetry guarantees that a linear combination of the doublet components is stable and can act as a candidate particle for dark matter. The dark sector fermions interact with the Higgs and gauge bosons through renormalizable d =4 operators, and nonrenormalizable d =5 operators that appear after integrating out extra degrees of freedom above the TeV scale. We study collider, cosmological and astrophysical probes for this effective theory of dark matter. We find that a weakly interacting dark matter particle with a mass nearby the electroweak scale, and thus observable at the LHC, is consistent with collider and astrophysical data only when fairly large magnetic dipole moment transition operators with the gauge bosons exist, together with moderate Yukawa interactions.

  10. Higgs Sector of Non-minimal Supersymmetric Models at Future Hadron Colliders

    CERN Document Server

    Hugonie, Cyril

    2001-01-01

    We investigate the potential of current and planned hadron colliders operating at the TeV scale in disentangling the structure of the Higgs sector of non-minimal Supersymmetric extensions of the Standard Model with an extra gauge singlet. We assume universality of the soft Supersymmetry breaking terms at the GUT scale as well as a CP-even Higgs boson with mass around 115 GeV, as suggested by LEP. We find that mixing angles between the doublet and singlet Higgs states are always small. However, concrete prospects exist at both the Tevatron (Run II) and the Large Hadron Collider of detecting at least one neutral Higgs state with a dominant singlet component, in addition to those available from a doublet Higgs sector which is similar to the one of the Minimal Supersymmetric Standard Model.

  11. Electroweak sphaleron with dimension-six operators

    Science.gov (United States)

    Gan, Xucheng; Long, Andrew J.; Wang, Lian-Tao

    2017-12-01

    New physics at the TeV scale can affect the dynamics of the electroweak phase transition in many ways. In this paper, we evaluate its impact on the rate of baryon-number violation via sphaleron transitions. We parametrize the effect of new physics with dimension-six operators, and we use the Newton-Kantorovich method to numerically solve the resulting equations of motion. Depending on the sign of the coefficient of the dimension-six operators, their presence can either increase or decrease the sphaleron energy at the level of a few percent, parametrically of order mW2/Λ2 where Λ is the scale suppressing the dimension-six operator. The baryon-number washout condition, typically written as vc/Tc>1 , is directly proportional to the sphaleron energy, and we discuss how the presence of dimension-six operators can affect electroweak baryogenesis.

  12. Gauge Trimming of Neutrino Masses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mu-Chun; /Fermilab /UC, Irvine; de Gouvea, Andre; /Northwestern U. /Fermilab; Dobrescu, Bogdan A.; /Fermilab

    2006-12-01

    We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This ''Leptocratic'' Model predicts the existence of light quasi-sterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

  13. Global effective-field-theory analysis of new-physics effects in (semi)leptonic kaon decays

    Energy Technology Data Exchange (ETDEWEB)

    González-Alonso, Martín [IPN de Lyon/CNRS, Universite Lyon 1,Villeurbanne (France); Camalich, Jorge Martin [CERN, Theoretical Physics Department,Geneva (Switzerland)

    2016-12-14

    We analyze the decays K→πℓν and P→ℓν (P=K,π, ℓ=e, μ) using a low-energy Effective-Field-Theory approach to parametrize New Physics and study the complementarity with baryon β decays. We then provide a road map for a global analysis of the experimental data, with all the Wilson coefficients simultaneously, and perform a fit leading to numerical bounds for them and for V{sub us}. A prominent result of our analysis is a reinterpretation of the well-known V{sub ud}−V{sub us} diagram as a strong constraint on new physics. Finally, we reinterpret our bounds in terms of the SU(2){sub L}× U(1){sub Y}-invariant operators, provide bounds to the corresponding Wilson coefficients at the TeV scale and compare our results with collider searches at the LHC.

  14. Low Scale Gravity Signatures in ATLAS

    CERN Document Server

    Karagoz-Unel, M

    2008-01-01

    The ATLAS detector may reveal in the LHC collisions signatures of extra dimensional models which predict quantum gravity at the TeV scale. One of the most dramatic consequences of such models is the copious production of micro blackholes. Micro blackholes can yield distinct signatures with large multiplicity and large energy release in the ATLAS detector. Extra dimensional models also predict the existence of Kaluza-Klein partners of SM gauge bosons, such as the excited graviton and gluon. These particles can be searched for in their two-body decays. The emerging final state particles are highly energetic, thus requiring novel reconstruction techniques, in particular in the heavy quark (t, b) channels. I will summarize the current status of the low scale gravity studies in ATLAS with example signatures.

  15. Search for Low Scale Gravity Signatures in ATLAS

    CERN Document Server

    Karagöz Ünel, M

    2009-01-01

    The ATLAS detector may reveal in the LHC collisions signatures of extra dimensional models which predict quantum gravity at the TeV scale. One of the most dramatic consequences of such models is the copious production of micro blackholes. Micro blackholes can yield distinct signatures with large multiplicity and large energy release in the ATLAS detector. Extra dimensional models also predict the existence of Kaluza-Klein partners of SM gauge bosons, such as the excited graviton and gluon. These particles can be searched for in their two-body decays. The emerging final state particles are highly energetic, thus requiring novel reconstruction techniques, in particular in the heavy quark (t, b) channels. I will summarize the current status of the low scale gravity studies in ATLAS with example signatures.

  16. Is an axizilla possible for di-photon resonance?

    Directory of Open Access Journals (Sweden)

    Jihn E. Kim

    2016-04-01

    Full Text Available Heavy axion-like particles, called axizillas, are simple extensions of the standard model (SM. An axizilla is required not to couple to the quarks, leptons, and Brout–Englert–Higgs doublets of the SM, but couple to the gauge anomalies of the W±, Z and photon. It is possible to have its branching ratios (BRs to two photons greater than 10 % and to two Z's less than 10 %. To have a (production cross section ⋅ (BR to di-photons at a 10−38 cm2 level, a TeV scale heavy quark Q is required for the gluon–quark fusion process. The decay of Q to axizilla plus quark, and the subsequent decay of the axizilla to two photons can be fitted at the required level of 10−38 cm2.

  17. Dark matter phenomenology of SM and enlarged Higgs sectors extended with vector-like leptons

    Energy Technology Data Exchange (ETDEWEB)

    Angelescu, Andrei [Universite Paris-Saclay, CNRS, Laboratoire de Physique Theorique, Orsay (France); Arcadi, Giorgio [Max Planck Institut fuer Kernphysik, Heidelberg (Germany)

    2017-07-15

    We will investigate the scenario in which the Standard Model (SM) Higgs sector and its two-doublet extension (called the Two Higgs Doublet Model or 2HDM) are the ''portal'' for the interactions between the Standard Model and a fermionic Dark Matter (DM) candidate. The latter is the lightest stable neutral particle of a family of vector-like leptons (VLLs). We will provide an extensive overview of this scenario combining the constraints coming purely from DM phenomenology with more general constraints like Electroweak Precision Test (EWPT) as well as with collider searches. In the case that the new fermionic sector interacts with the SM Higgs sector, constraints from DM phenomenology force the new states to lie above the TeV scale. This requirement is relaxed in the case of 2HDM. Nevertheless, strong constraints coming from EWPTs and the Renormalization Group Equations (RGEs) limit the impact of VLFs on collider phenomenology. (orig.)

  18. Dark matter phenomenology of SM and enlarged Higgs sectors extended with vector-like leptons.

    Science.gov (United States)

    Angelescu, Andrei; Arcadi, Giorgio

    2017-01-01

    We will investigate the scenario in which the Standard Model (SM) Higgs sector and its two-doublet extension (called the Two Higgs Doublet Model or 2HDM) are the "portal" for the interactions between the Standard Model and a fermionic Dark Matter (DM) candidate. The latter is the lightest stable neutral particle of a family of vector-like leptons (VLLs). We will provide an extensive overview of this scenario combining the constraints coming purely from DM phenomenology with more general constraints like Electroweak Precision Test (EWPT) as well as with collider searches. In the case that the new fermionic sector interacts with the SM Higgs sector, constraints from DM phenomenology force the new states to lie above the TeV scale. This requirement is relaxed in the case of 2HDM. Nevertheless, strong constraints coming from EWPTs and the Renormalization Group Equations (RGEs) limit the impact of VLFs on collider phenomenology.

  19. Limits on the effective quark radius from inclusive ep scattering at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, H. [Tel Aviv Univ. (Israel). School of Physics; Max Planck Institute for Physics, Munich (Germany); Abt, I. [Max Planck Institute for Physics, Munich (Germany); Adamczyk, L. [AGH-Univ. of Science and Technology, Krakow (Poland). Faculty of Physics and Applied Computer Sciences; Collaboration: ZEUS Collaboration; and others

    2016-04-15

    The high-precision HERA data allows searches up to TeV scales for Beyond the Standard Model contributions to electron-quark scattering. Combined measurements of the inclusive deep inelastic cross sections in neutral and charged current ep scattering corresponding to a luminosity of around 1 fb{sup -1} have been used in this analysis. A new approach to the beyond the Standard Model analysis of the inclusive ep data is presented; simultaneous fits of parton distribution functions together with contributions of ''new physics'' processes were performed. Results are presented considering a finite radius of quarks within the quark form-factor model. The resulting 95% C.L. upper limit on the effective quark radius is 0.43.10{sup -16} cm.

  20. Limit on the quark-charge effective radius from inclusive ep scattering at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Turkot, Oleksii; Wichmann, Katarzyna [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Zarnecki, Aleksander Filip [Faculty of Physics, University of Warsaw, Warsaw (Poland)

    2016-07-01

    The H1 and ZEUS experiments at HERA have recently presented the combined measurement of inclusive deep inelastic cross sections in neutral and charged current ep scattering corresponding to a luminosity of about 1 fb{sup -1}. The high precision of the data makes searches for new contributions to electron-quark scattering possible up to TeV scales. A new approach to beyond the Standard Model (BSM) analysis of inclusive ep data is outlined, taking into account possible contributions to the QCD fit of parton distributions coming from ''new physics'' processes. Results are presented considering a finite radius of quarks within the quark form factor model. The resulting 95% C.L. upper limit for the radius of the electroweak charge of quarks is 0.43 . 10{sup -16} cm.

  1. Physics potential of ATLAS upgrades at HL-LHC

    CERN Document Server

    Testa, Marianna; The ATLAS collaboration

    2017-01-01

    The High Luminosity-Large Hadron Collider (HL-LHC) is expected to start in 2026 and to provide an integrated luminosity of 3000 fb-1 in ten year, a factor 10 more than what will be collected by 2021. This high statistics will allow to perform precise measurements in the Higgs sector and improve searches of new physics at the TeV scale. The luminosity needed is L ~7.5 1034 cm-2 s-1, correspondent to ~200 additional proton-proton pile-up interactions. To face such harsh environment some sub-detectors of the ATLAS experiment will be upgraded or completely substituted. In this poster, the performances of the new or upgraded ATLAS sub-detectors will be described, focusing in particular on the new inner tracker and a proposed high granularity time device. The poster will also show the impact of those upgrades on crucial physics measurements for HL-LHC program

  2. Physics potential of ATLAS upgrades at HL-LHC

    CERN Document Server

    Testa, Marianna; The ATLAS collaboration

    2017-01-01

    The High Luminosity-Large Hadron Collider (HL-LHC) is expected to start in 2026 and to pro- vide an integrated luminosity of 3000 fb−1 in ten years, a factor 10 more than what will be collected by 2023. This high statistics will allow ATLAS to perform precise measurements in the Higgs sector and improve searches for new physics at the TeV scale. The luminosity needed is L ∼ 7.51034 cm−2 s−1, corresponding to ∼200 additional proton-proton pile- up interactions. To face such harsh environment some sub-detectors of the ATLAS experiment will be upgraded or completely substituted. The performances of the new or upgraded ATLAS sub-detectors are presented, focusing in particular on the new inner tracker and a proposed high granularity time device. The impact of those upgrades on crucial physics measurements for HL-LHC program is also shown.

  3. Hypercharged dark matter and direct detection as a probe of reheating.

    Science.gov (United States)

    Feldstein, Brian; Ibe, Masahiro; Yanagida, Tsutomu T

    2014-03-14

    The lack of new physics at the LHC so far weakens the argument for TeV scale thermal dark matter. On the other hand, heavier, nonthermal dark matter is generally difficult to test experimentally. Here we consider the interesting and generic case of hypercharged dark matter, which can allow for heavy dark matter masses without spoiling testability. Planned direct detection experiments will be able to see a signal for masses up to an incredible 1010  GeV, and this can further serve to probe the reheating temperature up to about 109  GeV, as determined by the nonthermal dark matter relic abundance. The Z-mediated nature of the dark matter scattering may be determined in principle by comparing scattering rates on different detector nuclei, which in turn can reveal the dark matter mass. We will discuss the extent to which future experiments may be able to make such a determination.

  4. Optimisation of the Hadronic Tau Identification Based on the Classification of Tau Decay Modes with the ATLAS Detector

    CERN Document Server

    Hanisch, Stefanie; Siegert, Frank

    Hadronically decaying tau leptons play an essential role in the LHC physics program. Final states involving tau leptons are important to verify processes of the Standard Model of particle physics at the TeV scale, but are also of high interest for Higgs physics and beyond Standard Model studies, like Higgs CP measurements and $A\\to Zh$ searches. Due to the high production cross section of QCD jets which are the dominant background, efficient reconstruction and identification techniques are crucial to guarantee an excellent selection of interesting physics events. Therefore, sophisticated multivariate algorithms are used. This thesis presents an advanced concept exploiting the information of reconstructed neutral and charged pions in the ATLAS detector, to access the tau decay substructure, and thus enhance the applicability of the tau identification to a broader field of physics analyses. First, several updates of the general algorithms used within the tau identification are implemented in order to provide...

  5. Symmetry breaking: The standard model and superstrings

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K.

    1988-08-31

    The outstanding unresolved issue of the highly successful standard model is the origin of electroweak symmetry breaking and of the mechanism that determines its scale, namely the vacuum expectation value (vev)v that is fixed by experiment at the value v = 4m//sub w//sup 2///g/sup 2/ = (..sqrt..2G/sub F/)/sup /minus/1/ approx. = 1/4 TeV. In this talk I will discuss aspects of two approaches to this problem. One approach is straightforward and down to earth: the search for experimental signatures, as discussed previously by Pierre Darriulat. This approach covers the energy scales accessible to future and present laboratory experiments: roughly (10/sup /minus/9/ /minus/ 10/sup 3/)GeV. The second approach involves theoretical speculations, such as technicolor and supersymmetry, that attempt to explain the TeV scale. 23 refs., 5 figs.

  6. Reheating for closed string inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mazumdar, Anupam [Lancaster Univ. (United Kingdom). Physics Dept.; Copenhagen Univ. (Denmark). Niels Bohr Institute

    2010-05-15

    We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N=1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation. (orig.)

  7. A Singlet Extension of the Minimal Supersymmetric Standard Model: Towards a More Natural Solution to the Little Hierarchy Problem

    Energy Technology Data Exchange (ETDEWEB)

    de la Puente, Alejandro [Univ. of Notre Dame, IN (United States)

    2012-05-01

    In this work, I present a generalization of the Next-to-Minimal Supersymmetric Standard Model (NMSSM), with an explicit μ-term and a supersymmetric mass for the singlet superfield, as a route to alleviating the little hierarchy problem of the Minimal Supersymmetric Standard Model (MSSM). I analyze two limiting cases of the model, characterized by the size of the supersymmetric mass for the singlet superfield. The small and large limits of this mass parameter are studied, and I find that I can generate masses for the lightest neutral Higgs boson up to 140 GeV with top squarks below the TeV scale, all couplings perturbative up to the gauge unification scale, and with no need to fine tune parameters in the scalar potential. This model, which I call the S-MSSM is also embedded in a gauge-mediated supersymmetry breaking scheme. I find that even with a minimal embedding of the S-MSSM into a gauge mediated scheme, the mass for the lightest Higgs boson can easily be above 114 GeV, while keeping the top squarks below the TeV scale. Furthermore, I also study the forward-backward asymmetry in the t¯t system within the framework of the S-MSSM. For this purpose, non-renormalizable couplings between the first and third generation of quarks to scalars are introduced. The two limiting cases of the S-MSSM, characterized by the size of the supersymmetric mass for the singlet superfield is analyzed, and I find that in the region of small singlet supersymmetric mass a large asymmetry can be obtained while being consistent with constraints arising from flavor physics, quark masses and top quark decays.

  8. Eastern and Central Pacific ENSO and their relationships to the recharge/discharge oscillator paradigm

    Science.gov (United States)

    Singh, A.; Delcroix, T.

    2012-12-01

    Four major theories have been proposed to explain the oscillatory nature of the El Niño Southern Oscillation (ENSO), the largest signal on interannual timescales in the tropical Pacific Ocean. These theories, however, were proposed more than a decade ago, before the recent enhanced attention given to a 'new' flavor of El Niño referred to here as central Pacific (CP) El Niño. Different structures between eastern Pacific (EP) and CP events have been found and documented by looking at the location of anomalous patterns in usual climate and biological variables (e.g., sea surface temperature and salinity, wind stress, precipitation, surface zonal currents and chlorophyll). The contrasted EP and CP ENSO features were, however, very poorly documented in terms of dynamics. Consequently, this study aims to test the applicability of one of the leading ENSO theories, the recharge/discharge (RD) oscillator paradigm, to explain the EP and CP ENSO features. In brief, the RD paradigm emphasizes that there is an inward flux of warm waters entering the equatorial band (recharge) at the onset and an outward flux (discharge) during an El Niño event. Accordingly, a key element of the RD paradigm, as well as a notable ENSO precursor, is warm water volume (WWV) and a good proxy for this is sea level anomaly (SLA). We first show the existence of the different flavors of ENSO in the tropical Pacific using monthly 1993-2010 SLA obtained from altimetry, and a validated 1958-2007 DRAKKAR model simulation. An Agglomerative Hierarchical Clustering (AHC) technique performed on the observed and modeled WWV, together with the corresponding sea surface temperature, shows the existence of four distinct clusters, which are reminiscent of the conventional EP El Niño and La Niña, and CP El Niño and La Niña. The patterns of EP El Niño and La Niña clusters are almost symmetrical and show a zonal see-saw pattern pivoted near the eastern edge of the western Pacific warm pool (at around 180

  9. Contemporary treatment of patients with chronic total occlusion: critical appraisal of different state-of-the-art techniques and devices.

    Science.gov (United States)

    García-García, Héctor M; Kukreja, Neville; Daemen, Joost; Tanimoto, Shuzou; van Mieghem, Carlos; Gonzalo, Nieves; van Weenen, Sander; van der Ent, Martin; Sianos, Georgios; de Feyter, Pim; Serruys, Patrick W

    2007-08-01

    To describe the contemporary approach of chronic total occlusion (CTO) treatment of patients at the Thoraxcenter, Rotterdam, The Netherlands. Additionally, to make a critical appraisal of the performance of state-of-the-art CTO dedicated guidewires and devices in a prospective registry of patients. During 20 months, a total of 160 consecutive patients (165 CTOs) were enrolled. The mean age was 61.5+/-11.1 years and 83.6% were male. In 91.5% of the patients this was the first attempt to open the CTO and 93.8% were de novo. The overall success rate was 60.6%. A median of 1 guiding catheter was used per case (Range: 1 to 9) and a median of 4 guidewires (Range: 1 to 11; 13 different types). 74.5% patients required more than one guidewire/device for the treatment of the CTO. The guidewires that most frequently crossed the CTO were the following: PT Graphix intermediate 33.0%, Miracle 3 g 27.4% and Crosswire NT 25.5%. The only device tested as a first option for the treatment of the CTOs was the CROSSER. Overall, the CROSSER system was used in 23 (13.9%) patients with a success rate of 60.9%. The Point 9(R) X-80 Laser catheter was used in 10 (6.1%) patients with a success rate of 60%. Another 3 patients were treated with the Point 7(R) laser catheter. Both were used either to facilitate the crossing of the balloon, or to treat primarily in-stent restenosis occlusions. The SafeCross(R) System was used in 15 (9.1%) patients and the success rate in these patients was 46.7%. The most common strategy used in this registry was the use of an over-the-wire balloon in 81.5% of the cases. The parallel wire technique was used in 27.3% of the cases and in 12.7% was converted into a "see-saw" technique. When a large false lumen was created, re-entry into the true lumen was attempted in 21.2% of the cases, by means of IVUS guided approach and/or the use of stiffer guidewires, such as a Confianza guidewire. Retrograde recanalisation was attempted in 10 cases (6.1%), in three cases a

  10. Landfill gas distribution at the base of passive methane oxidation biosystems: Transient state analysis of several configurations.

    Science.gov (United States)

    Ahoughalandari, Bahar; Cabral, Alexandre R

    2017-11-01

    The design process of passive methane oxidation biosystems needs to include design criteria that account for the effect of unsaturated hydraulic behavior on landfill gas migration, in particular, restrictions to landfill gas flow due to the capillary barrier effect, which can greatly affect methane oxidation rates. This paper reports the results of numerical simulations performed to assess the landfill gas flow behavior of several passive methane oxidation biosystems. The concepts of these biosystems were inspired by selected configurations found in the technical literature. We adopted the length of unrestricted gas migration (LUGM) as the main design criterion in this assessment. LUGM is defined as the length along the interface between the methane oxidation and gas distribution layers, where the pores of the methane oxidation layer material can be considered blocked for all practical purposes. High values of LUGM indicate that landfill gas can flow easily across this interface. Low values of LUGM indicate greater chances of having preferential upward flow and, consequently, finding hotspots on the surface. Deficient designs may result in the occurrence of hotspots. One of the designs evaluated included an alternative to a concept recently proposed where the interface between the methane oxidation and gas distribution layers was jagged (in the form of a see-saw). The idea behind this ingenious concept is to prevent blockage of air-filled pores in the upper areas of the jagged segments. The results of the simulations revealed the extent of the capability of the different scenarios to provide unrestricted and conveniently distributed upward landfill gas flow. They also stress the importance of incorporating an appropriate design criterion in the selection of the methane oxidation layer materials and the geometrical form of passive biosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Contribution to the study of thermal-hydraulic problems in nuclear reactors; Contribution a l`etude de problemes de thermohydraulique dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cognet, G

    1998-07-07

    In nuclear reactors, whatever the type considered, Pressurized Water Water Reactors (PWRs), Fast Breeder reactors (FBRs)..., thermal-hydraulics, the science of fluid mechanics and thermal behaviour, plays an essential role, both in nominal operating and accidental conditions. Fluid can either be the primary fluid (liquid or gas) or a very specific fluid called corium, which, in case of severe accident, could result from core and environning structure melting. The work reported here represents a 20-year contribution to thermal-hydraulic issues which could occur in FBRs and PWRs. Working on these two types of reactors, both in nominal and severe accident situations, has allowed me to compare the problems and to realize the importance of communication between research teams. The evolution in the complexity of studied problems, unavoidable in order to reduce costs and significantly improve safety, has led me from numerical modelling of single-phase flow turbulence to high temperature real melt experiments. The difficulties encountered in understanding the observed phenomena and in increasing experimental databases for computer code qualification have often entailed my participation in specific measurement device developments or adaptations, in particular non-intrusive devices generally based on optical techniques. Being concerned about the end-use of this research work, I actively participated in `in-situ` thermalhydraulic experiments in the FBRs: Phenix and Super-Phenix, of which I appreciated their undeniable scientific contribution. In my opinion, the thermal-hydraulic questions related to severe accidents are the most complex as they are at the cross-roads of several scientific specialities. Consequently, they require a multi-disciplinary approach and a continuous see-saw motion between experimentalists and modelling teams. After a brief description of the various problems encountered, the main ones are reported. Finally, the importance for research teams to

  12. Experimentally testing the standard cosmological model

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Chicago Univ., IL (USA) Fermi National Accelerator Lab., Batavia, IL (USA))

    1990-11-01

    The standard model of cosmology, the big bang, is now being tested and confirmed to remarkable accuracy. Recent high precision measurements relate to the microwave background; and big bang nucleosynthesis. This paper focuses on the latter since that relates more directly to high energy experiments. In particular, the recent LEP (and SLC) results on the number of neutrinos are discussed as a positive laboratory test of the standard cosmology scenario. Discussion is presented on the improved light element observational data as well as the improved neutron lifetime data. alternate nucleosynthesis scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density, {Omega}{sub b}, remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the standard model conclusion that {Omega}{sub b} {approximately} 0.06. This latter point is the deriving force behind the need for non-baryonic dark matter (assuming {Omega}{sub total} = 1) and the need for dark baryonic matter, since {Omega}{sub visible} < {Omega}{sub b}. Recent accelerator constraints on non-baryonic matter are discussed, showing that any massive cold dark matter candidate must now have a mass M{sub x} {approx gt} 20 GeV and an interaction weaker than the Z{sup 0} coupling to a neutrino. It is also noted that recent hints regarding the solar neutrino experiments coupled with the see-saw model for {nu}-masses may imply that the {nu}{sub {tau}} is a good hot dark matter candidate. 73 refs., 5 figs.

  13. The annual cycle in lower stratospheric temperatures revisited

    Directory of Open Access Journals (Sweden)

    S. Fueglistaler

    2011-04-01

    Full Text Available Observed lower stratospheric temperatures show a prominent annual cycle. The cycles in the tropics and Northern Hemisphere are in phase and the cycle in the Southern Hemisphere has the opposite phase. In an elegant and influential paper, Yulaeva, Holton and Wallace (1994 explained the observed pattern as a direct consequence of hemispheric asymmetries in the dynamical forcing of the stratospheric circulation. They showed that in Microwave Sounding Unit channel 4 (weighting centered in the lower stratosphere data the combined extratropical and the tropical temperature cycle nearly compensate and interpreted the out-of-phase temperature variations between tropics and extratropics as the temperature response to an annual cycle in the wave driven residual circulation. We show that the near-compensation of temperature variations observed by Yulaeva et al. (1994 is artefact of the weighting function of the MSU-4 channel and does not hold on individual pressure levels. We discuss in detail the conditions required that temperature variations compensate, and what insights can be obtained from analysis of tropical, extratropical and global mean temperature variations. Dynamically induced seasonal variations of lower stratospheric ozone lead to an amplification of the seasonal temperature cycle particularly in the tropics. The latitudinal structure of static stability also induces a significant deviation from compensation of tropical and combined extratropical temperature variations. In line with Yulaeva et al. (1994 we affirm that the see-saw pattern in the annual cycles of tropical and combined extratropical temperatures provides an important pointer to mechanistic models for interannual variability and trends, but additionally conclude that the feedback of dynamically induced ozone variations on temperatures and the latitudinal structure of static stability should be included as leading order processes in such models.

  14. Floral synomone of a wild orchid, Bulbophyllum cheiri, lures Bactrocera fruit flies for pollination.

    Science.gov (United States)

    Tan, Keng-Hong; Nishida, Ritsuo; Toong, Yock-Chai

    2002-06-01

    The major fruit fly attractant component in the floral fragrance of Bulbophyllum cheiri (fruit fly orchid) is methyl eugenol (ME). In the lowland rain forest of Malaysia, the solitary and nonresupinate flowers of the fruit fly orchid attract only males of the ME-sensitive fruit fly species (Bactrocera carambolae, B. papayae. and B. umbrosa. During the morning, the fruit fly orchid flower is visited by many fruit flies, which can sometimes cover the whole flower. The number of visitors dwindles in the afternoon. Headspace analysis of the flower shows a high ME peak in the morning, a small one between 12:00 and 14:00 hr, and no detectable ME peak after 14:00 hr. The process of pollination in the wild is initiated by attraction of fruit flies to floral ME. The flower, with the aid of its specialized hinged see-saw lip (labellum), temporarily traps (feed on the floral attractant found on surfaces of petals, sepals, and lip. The pollinaria borne by two wild B. papayae males (caught on and near the fruit fly orchid flower) are identical in morphology and structure with those obtained from the flower. Many of the B. papayae males (17 of 22 analyzed) attracted to the fruit fly orchid already possessed both ME metabolites, trans-coniferyl alcohol and 2-allyl-4,5-dimethoxyphenol, in their rectal glands. indicating that they had previously consumed ME. In this orchid-fruit fly association, both organisms gain direct reproductive benefits: the orchid flower gets pollinated without having to offer nectar, while the fruit fly boosts its pheromone and defense system, as well as its sexual competitiveness by feeding on the ME produced by the flower.

  15. ENSO nonlinearity in a warming climate

    Energy Technology Data Exchange (ETDEWEB)

    Boucharel, J. [Universite de Toulouse; UPS (OMP-PCA), LEGOS, Toulouse (France); University of Hawai' i at Manoa, School of Ocean and Earth Science and Technology, Department of Meteorology, Honolulu, HI (United States); Dewitte, B.; Penhoat, Y. du [Universite de Toulouse; UPS (OMP-PCA), LEGOS, Toulouse (France); IRD, LEGOS, Toulouse (France); Garel, B. [Universite de Toulouse, INP-ENSEEIHT, Institut de Mathematiques de Toulouse (UPS), Toulouse (France); Yeh, S.W. [Hanyang University, Department of Environmental Marine Science, Ansan (Korea, Republic of); Kug, J.S. [Korea Ocean Research and Development Institute, Ansan (Korea, Republic of)

    2011-11-15

    The El Nino Southern Oscillation (ENSO) is known as the strongest natural inter-annual climate signal, having widespread consequences on the global weather, climate, ecology and even on societies. Understanding ENSO variations in a changing climate is therefore of primordial interest to both the climate community and policy makers. In this study, we focus on the change in ENSO nonlinearity due to climate change. We first analysed high statistical moments of observed Sea Surface Temperatures (SST) timeseries of the tropical Pacific based on the measurement of the tails of their Probability Density Function (PDF). This allows defining relevant metrics for the change in nonlinearity observed over the last century. Based on these metrics, a zonal ''see-saw'' (oscillation) in nonlinearity patterns is highlighted that is associated with the change in El Nino characteristics observed in recent years. Taking advantage of the IPCC database and the different projection scenarios, it is showed that changes in El Nino statistics (or ''flavour'') from a present-day climate to a warmer climate are associated with a significant change in nonlinearity patterns. In particular, in the twentieth century climate, the ''conventional'' eastern Pacific El Nino relates more to changes in nonlinearity than to changes in mean state whereas the central Pacific El Nino (or Modoki El Nino) is more sensitive to changes in mean state than to changes in nonlinearity. An opposite behaviour is found in a warmer climate, namely the decreasing nonlinearity in the eastern Pacific tends to make El Nino less frequent but more sensitive to mean state, whereas the increasing nonlinearity in the west tends to trigger Central Pacific El Nino more frequently. This suggests that the change in ENSO statistics due to climate change might result from changes in the zonal contrast of nonlinearity characteristics across the tropical Pacific. (orig.)

  16. Constraining neutrino masses, the cosmological constant and BSM physics from the weak gravity conjecture

    Science.gov (United States)

    Ibáñez, Luis E.; Martín-Lozano, Víctor; Valenzuela, Irene

    2017-11-01

    It is known that there are AdS vacua obtained from compactifying the SM to 2 or 3 dimensions. The existence of such vacua depends on the value of neutrino masses through the Casimir effect. Using the Weak Gravity Conjecture, it has been recently argued by Ooguri and Vafa that such vacua are incompatible with the SM embedding into a consistent theory of quantum gravity. We study the limits obtained for both the cosmological constant Λ4 and neutrino masses from the absence of such dangerous 3D and 2D SM AdS vacua. One interesting implication is that Λ4 is bounded to be larger than a scale of order m ν 4 , as observed experimentally. Interestingly, this is the first argument implying a non-vanishing Λ4 only on the basis of particle physics, with no cosmological input. Conversely, the observed Λ4 implies strong constraints on neutrino masses in the SM and also for some BSM extensions including extra Weyl or Dirac spinors, gravitinos and axions. The upper bounds obtained for neutrino masses imply (for fixed neutrino Yukawa and Λ4) the existence of upper bounds on the EW scale. In the case of massive Majorana neutrinos with a see-saw mechanism associated to a large scale M ≃ 1010 - 14 GeV and Y ν1 ≃ 10-3, one obtains that the EW scale cannot exceed M EW ≲ 102 - 104 GeV. From this point of view, the delicate fine-tuning required to get a small EW scale would be a mirage, since parameters yielding higher EW scales would be in the swampland and would not count as possible consistent theories. This would bring a new perspective into the issue of the EW hierarchy.

  17. Chirp-aided power fading mitigation for upstream 100 km full-range long reach PON with DBR DML

    Science.gov (United States)

    Zhang, Kuo; He, Hao; Xin, Haiyun; Hu, Weisheng; Liang, Song; Lu, Dan; Zhao, Lingjuan

    2018-01-01

    The DML is a promising option for cost-sensitive ONUs in optical access networks, but suffers from severe power fading due to dispersion and chirp. In this work, we investigate to mitigate the power fading by optimizing the chirp. Theoretical analysis indicates, a see-saw effect, influenced by the bias, exists between the adiabatic notch-induced fading (A-fading) and the transient notch-induced fading (T-fading). High bias can mitigate T-fading, but causes large A-fading. Low bias can avoid A-fading, but cannot completely mitigate T-fading. For each transmission distance, balance should be achieved to favor transmission. The ∼20 km short distance requires high bias to obtain large adiabatic chirp to counteract the T-fading, while the ∼100 km long distance requires relatively low bias to avoid the A-fading. With this power fading mitigation technique, we conduct upstream transmission experiment of LR-PON. Experiments show that, although signal contamination is inevitable, clear ;1; and ;0; are obtained with this power fading mitigation scheme for any 0 ∼100 km distance with 10 Gb/s OOK signal and DBR DML. The optical power budget penalty induced by 0 ∼100 km fiber is limited within only 2.2 dB, with optimum bias for each distance. More than 10 and 15 dB improvement is achieved when BER is 10-3 and 10-6. A method is also proposed to automatically obtain optimum bias from the ranging procedure of PON protocol.

  18. Experimental Smoke and Electromagnetic Analog Study of Induced Flow Field About a Model Rotor in Steady Flight Within Ground Effect

    Science.gov (United States)

    Gray, Robin B.

    1960-01-01

    Hovering and steady low-speed forward-flight tests were run on a 4-foot-diameter rotor at a ground height of 1 rotor radius. The two blades had a 2 to 1 taper ratio and were mounted in a see-saw hub. The solidity ratio was 0.05. Measurements were made of the rotor rpm, collective pitch, and forward-flight velocity. Smoke was introduced into the tip vortex and the resulting vortex pattern was photographed from two positions. Using the data obtained from these photographs, wire models of the tip vortex configurations were constructed and the distribution of the normal component of induced velocity at the blade feathering axis that is associated with these tip vortex configurations was experimentally determined at 450 increments in azimuth position from this electromagnetic analog. Three steady-state conditions were analyzed. The first was hovering flight; the second, a flight velocity just under the wake "tuck under" speed; and the third, a flight velocity just above this speed. These corresponded to advance ratios of 0, 0.022, and 0.030 (or ratios of forward velocity to calculated hovering induced velocity of approximately 0, 0.48, and 0.65), respectively, for the model test rotor. Cross sections of the wake at 450 intervals in azimuth angle as determined from the path of the tip vortex are presented graphically for all three cases. The nondimensional normal component of the induced velocity that is associated with the tip vortex as determined by an electromagnetic analog at 450 increments in azimuth position and at the blade feathering axis is presented graphically. It is shown that the mean value of this component of the induced velocity is appreciably less after tuck-under than before. It is concluded that this method yields results of engineering accuracy and is a very useful means of studying vortex fields.

  19. Lepton flavour violating heavy Higgs decays within the {nu}MSSM and their detection at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Cruz, J.L. [C.A. de Particulas, Campos y Relatividad, FCFM-BUAP, Puebla, Pue., 72570 (Mexico); DUAL CP Institute of High Energy Physics, Puebla, Pue., 72570 (Mexico)], E-mail: ldiaz@sirio.ifuap.buap.mx; Ghosh, Dilip Kumar [Theoretical Physics Division, Physical Research Laboratory, Navrangpura, Ahmedabad-380 009 (India); Moretti, S. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

    2009-08-31

    Within the {nu}MSSM, a Minimal Supersymmetric neutrino See-saw Model, Lepton Flavour Violating Higgs couplings are strongly enhanced at large tan{beta} ({>=}30), which can lead to BR(H{sup 0}/A{sup 0}{yields}{tau}{mu}){approx_equal}O(10{sup -4}), for M{sub H{sup 0}/A{sup 0}}{>=}160 GeV. Enhancements on the production of Higgs bosons, through the gluon fusion mechanism, gg{yields}H{sup 0}/A{sup 0}, and the associated production channel gg,qq-bar {yields}bb-bar H{sup 0}/A{sup 0}, whose rates grow with tan{beta}, as well as the mass degeneracy that occurs between the H{sup 0} and A{sup 0} states in this regime, also contribute to further the possibilities to detect a heavy Higgs signal into {tau}{mu} pairs. We show that the separation of {tau}{mu} Higgs events from the background at the upcoming CERN Large Hadron Collider could be done for Higgs masses up to about 600 GeV for 300 fb{sup -1} of luminosity, for large tan{beta} values. However, even with as little as 10 fb{sup -1} one can probe H{sup 0}/A{sup 0} masses up to 400 GeV or so, if tan{beta}=60. Altogether, these processes then provide a new Higgs discovery mode as well as an independent test of flavour physics.

  20. Theoretical & Experimental Research in Weak, Electromagnetic & Strong Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, Satyanarayan [Oklahoma State Univ., Stillwater, OK (United States); Babu, Kaladi [Oklahoma State Univ., Stillwater, OK (United States); Rizatdinova, Flera [Oklahoma State Univ., Stillwater, OK (United States); Khanov, Alexander [Oklahoma State Univ., Stillwater, OK (United States); Haley, Joseph [Oklahoma State Univ., Stillwater, OK (United States)

    2015-09-17

    The conducted research spans a wide range of topics in the theoretical, experimental and phenomenological aspects of elementary particle interactions. Theory projects involve topics in both the energy frontier and the intensity frontier. The experimental research involves energy frontier with the ATLAS Collaboration at the Large Hadron Collider (LHC). In theoretical research, novel ideas going beyond the Standard Model with strong theoretical motivations were proposed, and their experimental tests at the LHC and forthcoming neutrino facilities were outlined. These efforts fall into the following broad categories: (i) TeV scale new physics models for LHC Run 2, including left-right symmetry and trinification symmetry, (ii) unification of elementary particles and forces, including the unification of gauge and Yukawa interactions, (iii) supersummetry and mechanisms of supersymmetry breaking, (iv) superworld without supersymmetry, (v) general models of extra dimensions, (vi) comparing signals of extra dimensions with those of supersymmetry, (vii) models with mirror quarks and mirror leptons at the TeV scale, (viii) models with singlet quarks and singlet Higgs and their implications for Higgs physics at the LHC, (ix) new models for the dark matter of the universe, (x) lepton flavor violation in Higgs decays, (xi) leptogenesis in radiative models of neutrino masses, (xii) light mediator models of non-standard neutrino interactions, (xiii) anomalous muon decay and short baseline neutrino anomalies, (xiv) baryogenesis linked to nucleon decay, and (xv) a new model for recently observed diboson resonance at the LHC and its other phenomenological implications. The experimental High Energy Physics group has been, and continues to be, a successful and productive contributor to the ATLAS experiment at the LHC. Members of the group performed search for gluinos decaying to stop and top quarks, new heavy gauge bosons decaying to top and bottom quarks, and vector-like quarks produced in pairs and decaying to light quarks. Members of the OSU group played a leading role in the detailed optimization studies for the future ATLAS Inner Tracker (ITk), which will be installed during the Phase-II upgrade, replacing the current tracking system. The proposed studies aim to enhance the ATLAS discovery potential in the high-luminosity LHC era. The group members have contributed to the calibration of algorithms for identifying boosted vector bosons and b-jets, which will help expand the ATLAS reach in many searches for new physics.

  1. Anisotropic modulus stabilisation. Strings at LHC scales with micron-sized extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Burgess, C.P. [McMaster Univ., Hamilton (Canada). Dept. of Physics and Astronomy; Perimeter Institute for Theoretical Physics, Waterloo (Canada); Quevedo, F. [Cambridge Univ. (United Kingdom). DAMTP/CMS; Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

    2011-04-15

    We construct flux-stabilised Type IIB string compactifications whose extra dimensions have very different sizes, and use these to describe several types of vacua with a TeV string scale. Because we can access regimes where two dimensions are hierarchically larger than the other four, we find examples where two dimensions are micron-sized while the other four are at the weak scale in addition to more standard examples with all six extra dimensions equally large. Besides providing ultraviolet completeness, the phenomenology of these models is richer than vanilla large-dimensional models in several generic ways: (i) they are supersymmetric, with supersymmetry broken at sub-eV scales in the bulk but only nonlinearly realised in the Standard Model sector, leading to no MSSM superpartners for ordinary particles and many more bulk missing-energy channels, as in supersymmetric large extra dimensions (SLED); (ii) small cycles in the more complicated extra-dimensional geometry allow some KK states to reside at TeV scales even if all six extra dimensions are nominally much larger; (iii) a rich spectrum of string and KK states at TeV scales; and (iv) an equally rich spectrum of very light moduli exist having unusually small (but technically natural) masses, with potentially interesting implications for cosmology and astrophysics that nonetheless evade new-force constraints. The hierarchy problem is solved in these models because the extra-dimensional volume is naturally stabilised at exponentially large values: the extra dimensions are Calabi-Yau geometries with a 4D K3-fibration over a 2D base, with moduli stabilised within the well-established LARGE-Volume scenario. The new technical step is the use of poly-instanton corrections to the superpotential (which, unlike for simpler models, are present on K3-fibered Calabi-Yau compactifications) to obtain a large hierarchy between the sizes of different dimensions. For several scenarios we identify the low-energy spectrum and briefly discuss some of their astrophysical, cosmological and phenomenological implications. (orig.)

  2. The large-scale ENSO event, the El Niño and other important regional features

    Directory of Open Access Journals (Sweden)

    1993-01-01

    pertenecen a las categorías de intensidad fuerte y muy fuerte. A veces, el inicio de estos desarrollos de gran escala se nota en el lado occidental del «sube-y-baja» antes que en el lado oriental. No hay mejor ejemplo de esto que el desarrollo del ENSO muy fuerte de 1982-1983. Una meta última de toda la investigación sobre los ENSO de gran escala, el Niño y otros rasgos climáticos regionales asociados es la de eventualmente desarrollar la capacidad de proveer razonablemente perspectivas de largo plazo y fiables como el tiempo de inicio, extensión areal, duración e intensidad de estas fluctuaciones climáticas oceano-atmosféricas recurrentes asociadas a la SO. Aquí, se presentan y discuten algunas informaciones de base, datos y registros obtenidos en el pasado histórico. Information has been and is continuing to be gathered, coordinated and improved on this activity. However, the rather tenuous year-to-year data on the Southern Oscillation (SO-related climatic changes are primarily limited to the period AD 622 to the present. The recurring large-scale ocean-atmosphere fluctuation, the El Niño/Southern Oscillation (ENSO, which is noted over the lower latitudes from East Africa eastward to the Americas manifests itself roughly as a «see-saw» in ocean-atmosphere conditions between the area in and surrounding the tropical Indian Ocean and the area in and surrounding most of the tropical Pacific Ocean. The ENSO relates to a low index phase of the SO and is associated on the west side of the «see-saw» with an eastern and northern Australian drought, an east monsoon drought over Indonesia, deficient summer monsoon rainfall over India, and deficient summer monsoon rainfall over the highlands of Ethiopia (resulting in a weak contribution to the Nile River system. In contrast, on the east side of the «see-saw» it relates to an El Niño, anomalously high sea surface temperatures (SSTs and above normal rainfall over the central and eastern equatorial Pacific, and

  3. Cell structure, stiffness and permeability of freeze-dried collagen scaffolds in dry and hydrated states.

    Science.gov (United States)

    Varley, M C; Neelakantan, S; Clyne, T W; Dean, J; Brooks, R A; Markaki, A E

    2016-03-01

    Scaffolds for tissue engineering applications should be highly permeable to support mass transfer requirements while providing a 3-D template for the encapsulated biological cells. High porosity and cell interconnectivity result in highly compliant scaffolds. Overstraining occurs easily with such compliant materials and can produce misleading results. In this paper, the cell structure of freeze-dried collagen scaffolds, in both dry and hydrated states, was characterised using X-ray tomography and 2-photon confocal microscopy respectively. Measurements have been made of the scaffold's Young's modulus using conventional mechanical testing and a customised see-saw testing configuration. Specific permeability was measured under constant pressure gradient and compared with predictions. The collagen scaffolds investigated here have a coarse cell size (∼100-150 μm) and extensive connectivity between adjacent cells (∼10-30 μm) in both dry and hydrated states. The Young's modulus is very low, of the order of 10 kPa when dry and 1 kPa when hydrated. There is only a single previous study concerning the specific permeability of (hydrated) collagen scaffolds, despite its importance in nutrient diffusion, waste removal and cell migration. The experimentally measured value reported here (5 × 10(-)(10)m(2)) is in good agreement with predictions based on Computational Fluid Dynamics simulation and broadly consistent with the Carman-Kozeny empirical estimate. It is however about three orders of magnitude higher than the single previously-reported value and this discrepancy is attributed at least partly to the high pressure gradient imposed in the previous study. The high porosity and interconnectivity of tissue engineering scaffolds result in highly compliant structures (ie large deflections under low applied loads). Characterisation is essential if these scaffolds are to be systematically optimised. Scaffold overstraining during characterisation can lead to misleading

  4. GammeV and GammeV-CHASE

    Energy Technology Data Exchange (ETDEWEB)

    Wester, W.; /Fermilab

    2011-11-01

    Physics beyond the Standard Model might include Weakly Interacting Slim Particles (WISPs) that address questions such as what is the nature of dark matter or even shed insight into the underlying nature of dark energy. WISPs are a general class of particles that include axions, axion-like particles, hidden sector photons, milli-charged particles, chameleons, etc. The GammeV (Gamma to milli-eV) experiment originated in 2007 in order to test a positive anomalous axion-like particle interpretation of the PVLAS experiment which was not evident in subsequent data. The experiment was also motivated as it was realized that the milli-eV scale appears naturally in a see-saw between the electroweak and Planck scales, neutrino mass differences, the dark energy density, and the possible mass for certain dark matter candidates. GammeV was first to exclude both a scalar and pseudoscalar axion-like particle interpretation of the anomalous PVLAS result setting a limit of around 3.1 x 10{sup -7} GeV{sup -1} on the coupling to photons for low mass axion-like particles. It has also been found that the parameter space of a variety of other WISP candidates is both largely unexplored and is accessible by modest experiments employing lasers and possibly accelerator magnets. GammeV data has also been used to set limits on possible hidden sector photons. Further work by the GammeV team has focused on a reconfiguration of the apparatus to be sensitive to possible chameleon particles. Chameleons are scalar (or pseudoscalar) particles that couple to the stress energy tensor in a potential such that their properties depend on their environment. In particular, a chameleon acquires an effective mass which increases with local matter density, {rho}. For a certain class of such potentials, the chameleon field has properties that might explain dark energy. GammeV set the first limits on the coupling of chameleons to photons. A dedicated follow-up experiment, GammeV-CHASE, (CHameleon Afterglow

  5. Characteristics of Atmospheric Circulation and Hydrologic Cycle over the North Pacific on Sub-seasonal Timescale

    Science.gov (United States)

    Ren, X.

    2016-12-01

    The air-sea system over the North Pacific region has multi-scale processes. Among them, the sub-seasonal timescale process has attracted literature due to its close linkage with persistent cold event or heavy rainfall event over east Asia and North American. In this study, we focused on the atmospheric circulation and hydrologic cycle over the North Pacific on sub-seasonal timescale. The EOF results showed that, there are two dominant modes of latent heat fluxes (evaporation) anomaly over the North Pacific ocean region on sub-seasonal timescale. The first mode exhibits an above normal/below normal latent heat release along the East Asian coastal region between 10º-45ºN, and below normal/above one to the east side. The first modes propagates downstream like the wave-train. The second mode shows a see-saw pattern, with positive anomaly over the Kuroshio and its extending region and negative one over the Northeast Pacific. It is seen that the associated anomalies in integrated vapor transport (IVT) and precipitation exhibit opposite sign with the anomaly in evaporation: increased/decreased evaporation from the ocean to the air is linkage with decreased/increased IVT and precipitation locally. Additionally, for the second mode, the increased IVT extends to the northwest part of the North America. The precipitation along the North American northwest coast increase significantly. The influences of the first mode is mainly located over the northwest Pacific and fades to the east of the dateline. The driver of the first mode is the southeastward propagation of a wave train across Eurasian mid and high latitudes. The invasion of the wave train into the northwest Pacific contributes to the first mode of latent heat anomaly over the North Pacific ocean region. The driver of the second mode is the intensified/weakened Aleutian low. When the Aleutian low is intensified on sub-seasonal timescale, the increased wind speed and colder air temperature induce above

  6. Does the "sleeping Dragon" Really Sleep?: the Case for Continuous Long-Term Monitoring at a Gulf of Mexico Cold Seep Site

    Science.gov (United States)

    Wilson, R. M.; Lapham, L.; Farr, N.; Lutken, C.; MacDonald, I. R.; Macelloni, L.; Riedel, M.; Sleeper, K.; Chanton, J.

    2011-12-01

    precipitated by changes in physical and chemical conditions at the site. We propose that the dynamics of hydrate stability may be compared to an oscillating "see-saw" where fluctuations in physical conditions tip the balance alternately in favor of dissociation/dissolution or hydrate growth. The chemical environment at MC118 results from the interaction among physical parameters, fluid/particle flux, and biological processes occurring near the hydrate surface. Given that these parameters may be varying on the scale of days, weeks, months, and possibly even years, long-term continuous monitoring will play a key role in understanding the stability conditions at MC118 and the potential for gas release from this methane reservoir should the dragon be awakened.

  7. Aspects of sedimentary basin evolution assessed through tectonic subsidence analysis. Example: northern Gulf of Thailand

    Science.gov (United States)

    Pigott, John D.; Sattayarak, Nares

    Tectonic subsidence and subsidence rate analyses were conducted using a forward burial technique for the Cenozoic sediments of the northern Gulf of Thailand, a region presently bounded and intersected by major strike-slip fault systems. Basins represented by the seven wells studied are the Thon Buri, Hua Hin, Chumphon, Kra, and Pattani basins. The total observed subsidence was stratigraphically calibrated using well biostratigraphy and/or regional seismic stratigraphy. Tectonic subsidence was subsequently determined assuming local Airy isostasy by correcting decompacted sediments for sediment loading and variations in paleowater depths. Statistical comparison of the observed tectonic subsidence profile versus the theoretical thermal subsidence profile reveals zero-intercept times of incipient thermal-rifting and furthermore helps differentiate times of thermal subsidence from episodes of fault-controlled mechanical subsidence. Differences in tectonic subsidence, tectonic subsidence rates, and in the zero-intercept times of thermal rifting imply the Paleogene thermal associated rifting of the northern Gulf of Thailand was neither restricted spatially nor universally synchronous among the basins, but instead both spatially and time transgressive. Although coupled thermal-mechanical subsidence played a major role in the evolution for most of these basins, in some basins, e.g. the Thon Buri and northern Kra basins, subsidence was not thermally initiated. Instead, these basins experienced relatively slow-paced sediment loaded subsidence until a sudden fault-associated acceleration commenced in the Pliocene. Additional evidence for temporal and spatial changes in local strain is demonstrated by observed asynchronous episodes of "see-saw" subsidence-uplift of the basin floors. For example, while the northern Hua Hin Basin experienced Miocene-Pliocene alternations of subsidence and uplift, portions of the Pattani Basin to the southeast underwent periods of subsidence and

  8. Northern Hemisphere hydroclimate patterns in the last 12 centuries

    Science.gov (United States)

    Charpentier Ljungqvist, Fredrik; Krusic, Paul J.; Sundqvist, Hanna S.; Zorita, Eduardo; Brattström, Gudrun; Frank, David

    2015-04-01

    Variations in local to continental-scale hydroclimate have a strong impact on ecosystem functioning, crop yields, and society's water resources. Consequently, the ability to model and predict with reasonable certainty the dynamic and spatial response of precipitation to global warming is essential. The uncertainty in hydroclimate projections from model simulations remains large as a consequence of significant gaps in our knowledge of preindustrial boundary conditions due to the short length of instrumental measurements of precipitation. In this study, we assembled an unprecedentedly large network of 196 records hydroclimatic records from the Northern Hemisphere (NH) to place recent hydrological changes and future precipitation scenarios in the context of spatially resolved and temporally persistent hydroclimatic variations over the last twelve centuries. The data from grid cells corresponding to the proxy locations were obtained from six CMIP5 last millennium simulations and treated in a similar way as the proxy data in order to facilitate a model-proxy comparison. The most extensive areas of low moisture availability are found during the 12th and 15th centuries. It is notable that the intensification of wet and dry anomalies during the 20th century shown in coupled atmosphere-ocean model simulations is not supported by empirical evidence. Our results reveals that prominent hydroclimatic see-saw patterns, also observed in instrumental data, of alternating moisture regimes between the east and west Mediterranean, southwest vs. northwest United States, east vs. west China have been operating consistently during the past millennium. Key findings: - Dry as well as wet conditions can prevail under both warm and cold climate states in most regions. - In some regions a tendency can be seen for either increased aridity or wetness with increasing or decreasing temperatures. - Such changes can be expressed in localized wet-dry seesaw patterns that climate models seems unable

  9. On the model discriminating power of mu to e conversion in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cirigliano, Vincenzo [Los Alamos National Laboratory; Kitano, Ryuichiro [JAPAN; Okada, Yashuiro [JAPAN; Tuzon, Paulo [ITALY

    2009-01-01

    } {yields} e conversion rate starting from a general effective theory description of the LFV physics. In Section 3 we explore the phenomenological consequence of the simplest possible models, in which only one effective LFV operator dominates. We extend this analysis in Section 4 to the class of models in which two operators dominate. In Section 5 we specialize our discussion to the SUSY see-saw model and summarize the conclusions of our analysis in Section 6.

  10. Synomone or kairomone?--Bulbophyllum apertum flower releases raspberry ketone to attract Bactrocera fruit flies.

    Science.gov (United States)

    Keng-Hong, Tan; Nishida, Ritsuo

    2005-03-01

    Bulbophyllum apertum flower (Orchidaceae) releases raspberry ketone (RK) in its fragrance, which attracts males of several fruit fly species belonging to the genus Bactrocera. Besides RK as a major component, the flower contains smaller amounts of 4-(4-hydroxylphenyl)-2-butanol, plus two minor volatile components, veratryl alcohol and vanillyl alcohol. Within the flower, the lip (labellum) had the highest concentration of RK with much smaller quantities present in petals; other flower parts had no detectable RK. Male fruit flies attracted to the flower belong to RK-sensitive species--such as Bactrocera albistragata, B. caudatus, B. cucurbitae (melon fly), and B. tau. Removal and attachment of the pollinarium to a fly's thoracic dorsum occurred when a male of B. albistragata was toppled into the floral column cavity, due to an imbalance caused by it shifting its body weight while feeding on the see-saw lip, and then freeing itself after being momentarily trapped between the lip and column. During this process, the stiff hamulus (the pollinia stalk protruding prominently towards the lip) acted as a crowbar when it was brushed downwards by the toppled fly and lifted the pollinia out of the anther. If the fly was big or long for the small triangular lip, it would not be toppled into the column cavity and would just walk across the column, during which time the pollinarium could be accidentally removed by the fly's leg, resulting in a failed transport of the pollinarium. This suggests an unstable situation, where the orchid relies only on a particular pollinator species in the complex ecosystem where many RK-sensitive species inhabit. Wild males of B. caudatus (most common visitors) captured on Bulbophyllum apertum flowers were found to sequester RK in their bodies as a potential pheromonal and allomonal ingredient. Thus, RK can act either as a floral synomone (pollinarium transported) or kairomone (accidental removal of pollinarium leading to total pollen wastage

  11. A systematic study of the impact of freshwater pulses with respect to different geographical locations

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Didier M.; Renssen, Hans [Vrije Universiteit Amsterdam, Section Climate Change and Landscape Dynamics, Department of Earth Sciences, Amsterdam (Netherlands); Wiersma, Ane P. [Deltares, Subsurface and Groundwater systems, Utrecht (Netherlands)

    2010-06-15

    that in order to obtain a consistent see-saw temperature pattern, addition of freshwater in the Northern Hemisphere at sites dynamically close to the deep water formation zones is needed. Finally a preliminary data - model comparison for the time of the Heinrich event 1 suggests that those sites are indeed the most favourable to explain the pattern of climate variability recorded in proxy data for this period. More importantly, this model - data comparison enables us to clearly reject a substantial fraction of the zones tested as potential source for large freshwater entering the ocean at that time. (orig.)

  12. A systematic study of the impact of freshwater pulses with respect to different geographical locations

    Science.gov (United States)

    Roche, Didier M.; Wiersma, Ane P.; Renssen, Hans

    2010-06-01

    that in order to obtain a consistent see-saw temperature pattern, addition of freshwater in the Northern Hemisphere at sites dynamically close to the deep water formation zones is needed. Finally a preliminary data—model comparison for the time of the Heinrich event 1 suggests that those sites are indeed the most favourable to explain the pattern of climate variability recorded in proxy data for this period. More importantly, this model—data comparison enables us to clearly reject a substantial fraction of the zones tested as potential source for large freshwater entering the ocean at that time.

  13. Search for vector-like quark production in the lepton+jets and dilepton+jets final states using 5.4 fb-1 of Run II data

    Energy Technology Data Exchange (ETDEWEB)

    Caughron, Seth [Columbia Univ., New York, NY (United States)

    2011-01-01

    The Standard Model of particle physics provides an excellent description of particle interactions at energies up to ~1 TeV, but it is expected to fail above that scale. Multiple models developed to describe phenomena above the TeV scale predict the existence of very massive, vector-like quarks. A search for single electroweak production of such particles in p$\\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV is performed in the W+jets and Z+jets channels. The data were collected by the DØ detector at the Fermilab Tevatron Collider and correspond to an integrated luminosity of 5.4 fb-1. Events consistent with a heavy object decaying to a vector boson and a jet are selected. We observe no significant excess in comparison to the background prediction and set 95% confidence level upper limits on production cross sections for vector-like quarks decaying to W+jet and Z+jet. Assuming a vector-like quark -- standard model quark coupling parameter $\\tilde{κ}$qQ of unity, we exclude vector-like quarks with mass below 693 GeV for decays to W+jet and mass below 449 GeV for decays to Z+jet. These represent the most sensitive limits to date.

  14. Physics prospects at the high luminosity LHC with ATLAS

    CERN Document Server

    Simioni, Eduard; The ATLAS collaboration

    2016-01-01

    The physics prospects at the luminosity upgrade of LHC, HL-LHC, with a data set equivalent to 3000 fb-1 simulated in the ATLAS detector, are presented and discussed. The ultimate precision attainable on measurements of 125 GeV Higgs boson couplings to elementary fermions and bosons is discussed, as well as the searches for partners associated with this new particle. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions at the LHC energy scale. Supersymmetry is still one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks. The sensitivity to electro-weakinos has reached the hundreds of GeV mass range. Benchmark studies are presented to show how the sensitivity improves at the future high-luminosity LHC runs. Prospects for searches for new heavy bosons and dark matter candidates at 14 TeV pp col...

  15. Search for Microscopic Black Hole Signatures at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Ka Vang [Brown Univ., Providence, RI (United States)

    2011-05-01

    A search for microscopic black hole production and decay in proton-proton collisions at a center-of-mass energy of 7 TeV has been conducted using Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider. A total integrated luminosity of 35 pb-1 data sample, taken by CMS Collaboration in year 2010, has been analyzed. A novel background estimation for multi-jet events beyond TeV scale has been developed. A good agreement with standard model backgrounds, dominated by multi-jet production, is observed for various final-state multiplicities. Using semi-classical approximation, upper limits on minimum black hole mass at 95% confidence level are set in the range of 3.5 - 4.5 TeV for values of the Planck scale up to 3 TeV. Model-independent limits are provided to further constrain microscopic black hole models with additional regions of parameter space, as well as new physics models with multiple energetic final states. These are the first limits on microscopic black hole production at a particle accelerator.

  16. 750 GeV diphoton resonance from singlets in an exceptional supersymmetric standard model

    Energy Technology Data Exchange (ETDEWEB)

    King, Stephen F. [Physics and Astronomy, University of Southampton,SO17 1BJ Southampton (United Kingdom); Nevzorov, Roman [ARC Centre of Excellence for Particle Physics at the Terascale,Department of Physics, The University of Adelaide,Adelaide, South Australia 5005 (Australia)

    2016-03-21

    The 750–760 GeV diphoton resonance may be identified as one or two scalars and/or one or two pseudoscalars contained in the two singlet superfields S{sub 1,2} arising from the three 27-dimensional representations of E{sub 6}. The three 27s also contain three copies of colour-triplet charge ∓1/3 vector-like fermions D,D̄ and two copies of charged inert Higgsinos H̃{sup +},H̃{sup −} to which the singlets S{sub 1,2} may couple. We propose a variant of the E{sub 6}SSM where the third singlet S{sub 3} breaks a gauged U(1){sub N} above the TeV scale, predicting Z{sub N}{sup ′}, D,D̄, H̃{sup +},H̃{sup −} at LHC Run 2, leaving the two lighter singlets S{sub 1,2} with masses around 750 GeV. We calculate the branching ratios and cross-sections for the two scalar and two pseudoscalar states associated with the S{sub 1,2} singlets, including possible degeneracies and maximal mixing, subject to the constraint that their couplings remain perturbative up to the unification scale.

  17. 750 GeV diphoton resonance from singlets in an exceptional supersymmetric standard model

    Science.gov (United States)

    King, Stephen F.; Nevzorov, Roman

    2016-03-01

    The 750-760 GeV diphoton resonance may be identified as one or two scalars and/or one or two pseudoscalars contained in the two singlet superfields S 1,2 arising from the three 27-dimensional representations of E 6. The three 27s also contain three copies of colour-triplet charge ∓1 /3 vector-like fermions D, overline{D} and two copies of charged inert Higgsinos {tilde{H}}+ , {tilde{H}}- to which the singlets S 1,2 may couple. We propose a variant of the E6SSM where the third singlet S 3 breaks a gauged U(1) N above the TeV scale, predicting Z N ' , D, overline{D} , {tilde{H}}+ , {tilde{H}}- at LHC Run 2, leaving the two lighter singlets S 1,2 with masses around 750 GeV. We calculate the branching ratios and cross-sections for the two scalar and two pseudoscalar states associated with the S 1,2 singlets, including possible degeneracies and maximal mixing, subject to the constraint that their couplings remain perturbative up to the unification scale.

  18. Academic Training - Technological challenges of CLIC

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 12, 13, 14, 15 and 16 June 11:00-12:00 - Auditorium, bldg 500 Technological challenges of CLIC R. Corsini, S. Doebert, S. Redaelli, T.Lefevre, CERN-AB and G. Arnau Izquierdo, H. Mainaud, CERN-TS Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&...

  19. Neutrino Masses from Neutral Top Partners

    CERN Document Server

    Batell, Brian

    2015-01-01

    We present theories of `Natural Neutrinos' in which neutral fermionic top partner fields are simultaneously the right-handed neutrinos (RHN), linking seemingly disparate aspects of the Standard Model structure: a) The RHN top partners are responsible for the observed small neutrino masses, b) They help ameliorate the tuning in the weak scale and address the little hierarchy problem, and c) The factor of $3$ arising from $N_c$ in the top-loop Higgs mass corrections is countered by a factor $3$ from the number of vector-like generations of RHN. The RHN top partners may arise in pseudo-Nambu-Goldstone-Boson (pNGB) Higgs models such as the Twin Higgs, as well as more general Composite, Little, and Orbifold Higgs scenarios, and three simple example models are presented. This framework firmly predicts a TeV-scale seesaw, as the RHN masses are bounded to be below the TeV scale by naturalness. The generation of light neutrino masses relies on a collective breaking of lepton number, allowing for comparatively large ne...

  20. Higgs mass naturalness and scale invariance in the UV

    CERN Document Server

    Tavares, Gustavo Marques; Skiba, Witold

    2014-01-01

    It has been suggested that electroweak symmetry breaking in the Standard Model may be natural if the Standard Model merges into a conformal field theory (CFT) at short distances. In such a scenario the Higgs mass would be protected from quantum corrections by the scale invariance of the CFT. In order for the Standard Model to merge into a CFT at least one new ultraviolet (UV) scale is required at which the couplings turn over from their usual Standard Model running to the fixed point behavior. We argue that the Higgs mass is sensitive to such a turn-over scale even if there are no associated massive particles and the scale arises purely from dimensional transmutation. We demonstrate this sensitivity to the turnover scale explicitly in toy models. Thus if scale invariance is responsible for Higgs mass naturalness, then the transition to CFT dynamics must occur near the TeV scale with observable consequences at colliders. In addition, the UV fixed point theory in such a scenario must be interacting because loga...

  1. Physics at HL-LHC with the upgraded ATLAS detector

    CERN Document Server

    Dell'Acqua, Andrea; The ATLAS collaboration

    2017-01-01

    The physics prospects at the luminosity upgrade of LHC, HL-LHC, with a data set equivalent to 3000 fb-1 simulated in the ATLAS detector, are presented and discussed. The ultimate precision attainable on measurements of 125 GeV Higgs boson couplings to elementary fermions and bosons is discussed, as well as the searches for partners associated with this new particle. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions at the LHC energy scale. Supersymmetry is still one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks. The sensitivity to electro-weakinos has reached the hundreds of GeV mass range. Benchmark studies are presented to show how the sensitivity improves at the future high-luminosity LHC runs. Prospects for searches for new heavy bosons and dark matter candidates at 14 TeV pp col...

  2. ATLAS Physics Prospects at the High-Luminosity LHC

    CERN Document Server

    Bindi, Marcello; The ATLAS collaboration

    2017-01-01

    The physics prospects at the luminosity upgrade of LHC, HL-LHC, with a data set equivalent to 3000 fb-1 simulated in the ATLAS detector, are presented and discussed. The ultimate precision attainable on measurements of 125 GeV Higgs boson couplings to elementary fermions and bosons is discussed, as well as the searches for partners associated with this new particle. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions at the LHC energy scale. Supersymmetry is still one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks. The sensitivity to electro-weakinos has reached the hundreds of GeV mass range. Benchmark studies are presented to show how the sensitivity improves at the future high-luminosity LHC runs. Prospects for searches for new heavy bosons and dark matter candidates at 14 TeV pp col...

  3. Particle physics -- Future directions

    Energy Technology Data Exchange (ETDEWEB)

    Chris Quigg

    2001-11-29

    Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities offered by a linear collider and a (muon storage ring) neutrino factory. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment. I describe some of the great questions before us and the challenges of providing the instruments that will be needed to define them more fully and eventually to answer them.

  4. ATLAS physics prospects at the high-luminosity LHC

    CERN Document Server

    Clark, Philip James; The ATLAS collaboration

    2014-01-01

    Run-I at the LHC has been very successful, including the discovery of a new particle with a mass of about 125 GeV compatible within uncertainties with the Higgs boson predicted by Standard Model. Precise measurements of the properties of this boson, and the discovery of new physics beyond the Standard Model, are primary goals of future running at the LHC. The physics prospects with a proton-proton centre-of-mass energy of 14 TeV are presented for 300 fb-1 (Phase I) and 3000 fb-1 at the high-luminositiy LHC (Phase II). The ultimate precision attainable on measurements of the couplings of the 125 GeV particle to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with this new object, predicted by several extensions of the standard theory. Supersymmetry is one of the best motivated and well-studied extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as ...

  5. 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.

  6. Light Stops, Light Staus and the 125 GeV Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela; Gori, Stefania; Shah, Nausheen R.; Wagner, Carlos E.M.; Wang, Lian-Tao

    2013-08-01

    The ATLAS and CMS experiments have recently announced the discovery of a Higgs-like resonance with mass close to 125 GeV. Overall, the data is consistent with a Standard Model (SM)-like Higgs boson. Such a particle may arise in the minimal supersymmetric extension of the SM with average stop masses of the order of the TeV scale and a sizable stop mixing parameter. In this article we discuss properties of the SM-like Higgs production and decay rates induced by the possible presence of light staus and light stops. Light staus can affect the decay rate of the Higgs into di-photons and, in the case of sizable left-right mixing, induce an enhancement in this production channel up to $\\sim$ 50% of the Standard Model rate. Light stops may induce sizable modifications of the Higgs gluon fusion production rate and correlated modifications to the Higgs diphoton decay. Departures from SM values of the bottom-quark and tau-lepton couplings to the Higgs can be obtained due to Higgs mixing effects triggered by light third generation scalar superpartners. We describe the phenomenological implications of light staus on searches for light stops and non-standard Higgs bosons. Finally, we discuss the current status of the search for light staus produced in association with sneutrinos, in final states containing a $W$ gauge boson and a pair of $\\tau$s.

  7. Search for squarks and gluinos in final state with jets and missing transverse momentum with the ATLAS detector

    CERN Document Server

    Ronzani, Manfredi; The ATLAS collaboration

    2015-01-01

    Many extensions of the Standard Model (SM) include heavy coloured particles, such as the squarks and gluinos of supersymmetric (SUSY) theories, which could be accessible at the Large Hadron Collider (LHC) and detected by ATLAS. The current searches in the LHC Run-1 dataset have yielded sensitivity to TeV scale gluinos, as well as to squarks in the hundreds of GeV mass range. The discovery reach in Run-2 is expected to be greatly enhanced due to the large increase in the LHC centre-of-mass collision energy from 8 TeV to 13 TeV. In this poster, the most recent Run-1 results and interpretations from inclusive searches for squarks and gluinos in final states with jets and missing trasverse momentum are presented. Moreover, we present sensitivity studies for gluino pair production in the same final state with a full simulation of the ATLAS detector at a centre-of-mass energy of 13 TeV.

  8. $hh+\\text{jet}$ production at 100 TeV arXiv

    CERN Document Server

    Banerjee, Shankha; Mangano, Michelangelo L.; Selvaggi, Michele; Spannowsky, Michael

    Higgs pair production is a crucial phenomenological process in deciphering the nature of the TeV scale and the mechanism underlying electroweak symmetry breaking. At the Large Hadron Collider, this process is statistically limited. Pushing the energy frontier beyond the LHC's reach will create new opportunities to exploit the rich phenomenology at higher centre-of-mass energies and luminosities. In this work, we perform a comparative analysis of the $hh+\\text{jet}$ channel at a future 100 TeV hadron collider. We focus on the $hh\\to b\\bar b b\\bar b$ and $hh \\to b\\bar b \\tau^+\\tau^-$ channels and employ a range of analysis techniques to estimate the sensitivity potential that can be gained by including this jet-associated Higgs pair production to the list of sensitive collider processes in such an environment. In particular, we observe that $hh \\to b\\bar b \\tau^+\\tau^-$ in the boosted regime exhibits a large sensitivity to the Higgs boson self-coupling and the Higgs self-coupling could be constrained at the 8\\%...

  9. Synchrotron radiation in the interaction region for a Ring-Ring and Linac-Ring LHeC

    CERN Document Server

    Bernard, N; Thompson, L; Holzer, B; Tomas, R; Zimmermann, F; Klein, M; Kostka, P; Nagorny, B; Schneekloth, U

    2011-01-01

    The Large Hadron electron Collider (LHeC) aims at bringing hadron-lepton collisions to CERN with centre of mass energies in the TeV scale. The LHeC will utilise the existing LHC storage ring with the addition of a 60 GeV electron accelerator. The electron beam will be stored and accelerated in either a storage ring in the LHC tunnel (Ring-Ring) or a linac tangent to the LHC tunnel (Linac- Ring). Synchrotron Radiation (SR) in the Interaction Region (IR) of this machine requires an iterative design process in which luminosity is optimised while the SR is minimised. This process also requires attention to be given to the detector as the beam pipe must be designed such that disturbing effects, such as out-gassing and background scattering, are minimised while the tracker remains close to the IP thus maximising the acceptance of the experiment. The machinery of GEANT4 has been used to simulate the SR load in the IR and also to design absorbers/masks to shield SR from backscattering into the detector or propagating...

  10. Searches for top-antitop quark resonances at $\\sqrt{s}=13~\\mathrm{TeV}$ with the CMS detector

    CERN Document Server

    Missiroli, Marino

    2016-01-01

    We present the first results on searches for new massive resonances decaying to a top-antitop quark ($t\\bar{t}$) pair with the CMS detector at the LHC in proton-proton collisions with a center of mass energy of $\\sqrt{s}=13~\\mathrm{TeV}$. The data set considered corresponds to an integrated luminosity of $2.6~\\mathrm{fb}^{-1}$ recorded during the the first year of the LHC Run-2. Searches are performed by measuring the invariant mass distribution of the $t\\bar{t}$ system in semileptonic and fully-hadronic final states. Dedicated techniques are used to identify the decay of highly-boosted top quarks in order to maximize the analyses' sensitivity for $t\\bar{t}$ resonances with a mass above the TeV scale. No significant excess is observed in the data compared to the expected SM background and exclusion limits are set on the cross section of a $t\\bar{t}$ resonance in various new physics scenarios.

  11. (YSF) Searches for ttbar resonances with the CMS detector at 13 TeV

    CERN Document Server

    Missiroli, Marino

    2016-01-01

    We present the most recent results on searches for new massive resonances decaying to a top-antitop quark pair with the CMS detector at the LHC. Searches are performed by measuring the invariant mass distribution of the $t\\bar{t}$ system, both in semileptonic and fully-hadronic final states, using the data collected by the CMS experiment in pp collisions at $\\sqrt{s}=\\text{13 TeV}$ in 2015, the first year of the LHC Run-2. In order to maximize the analysis sensitivity for BSM resonances with a mass above the TeV scale, dedicated techniques are used to identify the decay of highly-boosted top quarks these methods include the identification of poorly isolated prompt leptons overlapping with a b-jet and the use of a top-tagging algorithm to reconstruct fully-merged jets with substructure properties. No significant excess is observed in the data compared to the expected SM background and exclusion limits are set on the cross section of a $t\\bar{t}$ resonance in different BSM scenarios.

  12. Hadronic recoil in the W boson production at LHC for a W mass measurement with the CMS experiment

    CERN Document Server

    AUTHOR|(CDS)2099463

    In the first chapter of this work, an overall picture of the theoretical basis is pre- sented. Starting from the foundations of the Standard Model, Higgs mechanism and electroweak symmetry breaking are introduced, focusing on their role of providing SM gauge boson with masses. The important facts of electroweak precision test are also introduced in the last part of the first chapter. After an overview of the Large Hadron Collider (LHC), which is currently operating at CERN, the second part of this work describes the Compact Muon Solenoid (CMS) experiment, aimed to explore in depth particle physics up to the TeV scale: the main features of the subdetectors are briefly described, together with the reconstruction al- gorithms; focus has been put mostly on those features of interest for W mass physics. The third chapter is devoted to discuss the past and the on going efforts for the W boson mass measurement. The original work developed during the thesis is fully discussed in chapters four, five and six. Two are t...

  13. Search for jet extinction in the inclusive jet-pt spectrum from proton-proton collisions at sqrt(s) = 8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, Vardan [Yerevan Physcis Institute (Armenia); et al.,

    2014-08-01

    The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 inverse femtobarns of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale.

  14. A study of rare B-meson decay with muons in the final state with the LHCb detector

    CERN Document Server

    Serra, N; Bonivento, W

    2008-01-01

    The Standard Model (SM) gives a successful description of known phenomena in particle physics, however there are many indications of the existence of New Physics (NP) at the TeV scale. Physicists are building a very large and expensive machine in this belief: the LHC (Large Hadron Collider), which is foreseen to start in the middle 2008. Three of the experiments of the LHC are mainly devoted to the search of NP. Among these, the LHCb experiment is dedicated to the physics of b-hadrons. It will look for indirect evidences of new particles or new degrees of freedom, measuring branching ratios, decay amplitudes and CP asymmetries, which can be sensitive to New Physics effects. Three analysis will be presented: the sensitivity to the $B_{s,d}^0 \\rightarrow e^{\\pm} \\mu^{\\mp}$ decays, the sensitivity to the $B_{s,d}^0 \\rightarrow \\mu^+ \\mu^- \\gamma$ decays and the correction of angular biases in the $B_d^0 \\rightarrow K^{*0} \\mu^+ \\mu^-$ decay. The $B_{s,d}^0 \\rightarrow e^{\\pm} \\mu^{\\mp}$ decays are forbidden in t...

  15. Design studies and sensor tests for the beam calorimeter of the ILC detector

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, E.

    2007-03-15

    The International Linear Collider (ILC) is being designed to explore particle physics at the TeV scale. The design of the Very Forward Region of the ILC detector is considered in the presented work. The Beam Calorimeter - one of two electromagnetic calorimeters situated there - is the subject of this thesis. The Beam Calorimeter has to provide a good hermeticity for high energy electrons, positrons and photons down to very low polar angles, serve for fast beam diagnostics and shield the inner part of the detector from backscattered beamstrahlung remnants and synchrotron radiation. As a possible technology for the Beam Calorimeter a diamond-tungsten sandwich calorimeter is considered. Detailed simulation studies are done in order to explore the suitability of the considered design for the Beam Calorimeter objectives. Detection efficiency, energy and angular resolution for electromagnetic showers are studied. At the simulation level the diamondtungsten design is shown to match the requirements on the Beam Calorimeter performance. Studies of polycrystalline chemical vapour deposition (pCVD) diamond as a sensor material for the Beam Calorimeter are done to explore the properties of the material. Results of the measurements performed with pCVD diamond samples produced by different manufacturers are presented. (orig.)

  16. CERN-Fermilab Hadron Collider Physics Summer School 2013 open for applications

    CERN Multimedia

    2013-01-01

    Mark your calendar for 28 August - 6 September 2013, when CERN will welcome students to the eighth CERN-Fermilab Hadron Collider Physics Summer School.   Experiments at hadron colliders will continue to provide our best tools for exploring physics at the TeV scale for some time. With the completion of the 7-8 TeV runs of the LHC, and the final results from the full Tevatron data sample becoming available, a new era in particle physics is beginning, heralded by the Higgs-like particle recently discovered at 125 GeV. To realize the full potential of these developments, CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the eighth edition, from 28 August to 6 September 2013. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school which particularly targets young postdocs in exper...

  17. Inflationary scenario from higher curvature warped spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Narayan [Indian Institute of Science Education and Research Kolkata, Department of Physical Sciences, Nadia, West Bengal (India); Paul, Tanmoy [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2017-10-15

    We consider a five dimensional warped spacetime, in presence of the higher curvature term like F(R) = R + αR{sup 2} in the bulk, in the context of the two-brane model. Our universe is identified with the TeV scale brane and emerges as a four dimensional effective theory. From the perspective of this effective theory, we examine the possibility of ''inflationary scenario'' by considering the on-brane metric ansatz as an FRW one. Our results reveal that the higher curvature term in the five dimensional bulk spacetime generates a potential term for the radion field. Due to the presence of radion potential, the very early universe undergoes a stage of accelerated expansion and, moreover, the accelerating period of the universe terminates in a finite time. We also find the spectral index of curvature perturbation (n{sub s}) and the tensor to scalar ratio (r) in the present context, which match with the observational results based on the observations of Planck (Astron. Astrophys. 594, A20, 2016). (orig.)

  18. Dark Matter and the elusive Z' in a dynamical Inverse Seesaw scenario

    Science.gov (United States)

    De Romeri, Valentina; Fernandez-Martinez, Enrique; Gehrlein, Julia; Machado, Pedro A. N.; Niro, Viviana

    2017-10-01

    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 - LZ' 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.

  19. On the importance of electroweak corrections for B anomalies

    Science.gov (United States)

    Feruglio, Ferruccio; Paradisi, Paride; Pattori, Andrea

    2017-09-01

    The growing experimental indication of Lepton Flavour Universality Violation (LFUV) both in charged- and neutral-current semileptonic B-decays, has triggered many theoretical interpretations of such non-standard phenomena. Focusing on popular scenarios where the explanation of these anomalies requires New Physics at the TeV scale, we emphasise the importance of including electroweak corrections to obtain trustable predictions for the models in question. We find that the most important quantum effects are the modifications of the leptonic couplings of the W and Z vector bosons and the generation of a purely leptonic effective Lagrangian. Although our results do not provide an inescapable no-go theorem for the explanation of the B anomalies, the tight experimental bounds on Z-pole observables and τ decays challenge an explanation of the current non-standard data. We illustrate how these effects arise, by providing a detailed discussion of the running and matching procedure which is necessary to derive the low-energy effective Lagrangian.

  20. GUT models at current and future hadron colliders and implications to dark matter searches

    Science.gov (United States)

    Arcadi, Giorgio; Lindner, Manfred; Mambrini, Yann; Pierre, Mathias; Queiroz, Farinaldo S.

    2017-08-01

    Grand Unified Theories (GUT) offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables arising from Abelian groups embedded in GUT constructions. That said, we use dilepton data (ee and μμ) that has been proven to be a golden channel for a wide variety of new phenomena expected in theories beyond the Standard Model to probe GUT-inspired models. Since heavy dilepton resonances feature high signal selection efficiencies and relatively well-understood backgrounds, stringent and reliable bounds can be placed on the mass of the Z‧ gauge boson arising in such theories. In this work, we obtain 95% C.L. limits on the Z‧ mass for several GUT-models using current and future proton-proton colliders with √{ s} = 13 TeV , 33 TeV ,and 100 TeV, and put them into perspective with dark matter searches in light of the next generation of direct detection experiments.

  1. Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection.

    Science.gov (United States)

    Ellis, John; Evans, Jason L; Luo, Feng; Nagata, Natsumi; Olive, Keith A; Sandick, Pearl

    We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale [Formula: see text]below the grand unification (GUT) scale [Formula: see text], a scenario referred to as 'sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if [Formula: see text] is close to [Formula: see text], but it may lie within its reach if [Formula: see text] GeV. Likewise, generalizing the CMSSM to allow non-universal supersymmetry-breaking contributions to the Higgs offers extensive possibilities for models within reach of the LZ experiment that have long proton lifetimes.

  2. From the CERN web: Standard Model, SESAME and more

    CERN Multimedia

    2015-01-01

    This section highlights articles, blog posts and press releases published in the CERN web environment over the past weeks. This way, you won’t miss a thing...   Left: ATLAS non-leptonic MWZ data. Right: ATLAS σ × B exclusion for W’ → WZ. Is the Standard Model about to crater? 28 October – CERN Courier The Standard Model is coming under more and more pressure from experiments. New results from the analysis of LHC’s Run 1 data show effects that, if confirmed, would be the signature of new interactions at the TeV scale. Continue to read…      Students and teachers participate in lectures about CERN science at the first ever SESAME teacher and students school. New CERN programme to develop network between SESAME schools 22 October - by Harriet Jarlett In September CERN welcomed 28 visitors from the Middle East for the first ever student and teacher school f...

  3. EWKino Production and Long-Lived particles at LHC

    CERN Document Server

    Verducci, M; The ATLAS collaboration

    2013-01-01

    The Large Hadron Collider has extended the reach of particle-physics experiments with a potential for discovery of new physics at the TeV scale and many searches have been carried out by both ATLAS and CMS. Searches for long-lived particles and electroweak “ino” production using 2012 LHV data have been carried by both ATLAS and CMS. The methodology of the searches (reconstruction techniques, background suppression, etc.) and the sensitivity of these searches are reviewed. Many models of physics beyond the Standard Model predict new particles with long lifetimes. Examples include Supersymmetry with R-parity violation, suppressed decays of the next-to-lightest Supersymmetric particle, or models with hidden sectors. The decay vertices of particles with lifetimes of order 10 ps to 10 ns can be efficiently identified by the ATLAS and CMS detectors. In addition, in quark and gluons collisions it is easy to produce coloured objects like gluinos and squarks, which decay typically to jets and MET, while the cross ...

  4. Search for new phenomena in jets plus missing transverse energy final states at the LHC

    CERN Document Server

    Caminal Armadans, Roger

    This Thesis presents a search for new phenomena in $pp$ collisions at $\\sqrt{s} = 8$ TeV recorded with the ATLAS detector at the LHC collider. The final state under investigation is defined by the presence of a very energetic jet, large missing transverse energy, a maximum of three reconstructed jets, and no reconstructed leptons, leading to a monojet-like configuration. The monojet final state constitutes a very clean and distinctive signature for new physics processes. After the discovery of the Higgs and the constraints on the masses of first and second generation squarks and gluinos up to the TeV scale, much attention has been put to searches for third generation squarks. These searches are motivated by naturalness arguments, which point to relatively light stops and sbottoms, and therefore allowing their production at the LHC. The monojet analysis is interpreted in terms of pair production of stops and sbottoms, and in terms of inclusive searches for pair production of squarks, and gluinos. In particula...

  5. Exotic diboson searches in the $\\ell\

    CERN Document Server

    Biesuz, Nicolo Vladi; The ATLAS collaboration

    2017-01-01

    Analyses searching for diboson resonances are very powerful tools to investigate many beyond the Standard Model (BSM) scenarios such as extension of the Higgs sector, Heavy Vector triplets (W’ and Z’) or excited states of Gravitons. These searches exploit the many decay channels of the two bosons allowing to select topologies with varied signal to background ratios and statistics. Among these searches the search for WW/WZ in the semileptonic final state finds a compromise between the high signal statistics allowed by the high branching ratio of the hadronic decay of the gauge boson while profiting of the good trigger and analysis signature of the lepton, decay product of the second gauge boson. The WW/WZ search for TeV scale resonances in the ℓνqq channel will be detailed, explaining the current boson-tagging techniques and the signal categorization used to improve sensitivity. The limit presently set in the various scenarios using 2015-2016 dataset will be reported.

  6. Études sur la reconstruction des électrons et mesure de la section efficace de production de paires de quarks top dans les canaux dileptoniques dans l’expérience ATLAS auprès du LHC

    CERN Document Server

    Theveneaux-Pelzer, Timothée

    The LHC produced proton-proton collision data with 7 TeV of center of mass energy corresponding to an integrated luminosity of 40 pb-1 in 2010 and of 5 fb-1 in 2011. The data collected by ATLAS have led to the validation the understanding of the detector, to the evaluation of its performance and to many measurements of physical quantities. In this context the top quark is a privileged field of study for TeV scale physics as well as for performance studies. After a reminder of the phenomenology of the standard model the first part of this thesis is devoted to the description of the detector and in particular of the liquid argon calorimeters for which the influence of the variations of the high voltage values is detailed. The second part is focused on studies about the reconstruction and the identification of electrons conducted on simulated data, but also on 2010 collision data thanks to J/psi->e+e- events with the tag-and-probe method. The last part is devoted to top quark studies. A description of the...

  7. Vector Boson Scattering, Triple Gauge-Boson Production, and Limits on Anomalous Quartic Gauge-Boson Couplings with the ATLAS Detector

    CERN Document Server

    Wang, Hulin; The ATLAS collaboration

    2016-01-01

    Vector-boson scattering processes provide a unique way to probe the mechanism of electroweak symmetry breaking. Similar physics can be probed by studying the production of three gauge bosons. The results can also be used for a model-independent search for new physics at the TeV scale via anomalous quartic gauge couplings. The ATLAS collaboration has studied vector boson scattering in final states with two gauge bosons and two forward jets in 20.3 /fb of 8TeV proton-proton collision data, in particular two same-sign W bosons, a WZ boson pair, and a W or Z boson in association with an isolated photon. The studies are complemented by a search for anomalous vector boson production of WW+WZ pairs in their semileptonic decays to lnujj in association with two forward jets. The collaboration has used this data set as well to study the production of three gauge bosons. A search was carried out for the production of three W bosons. The cross sections for the production of a W or Z boson in association with two isolated...

  8. CP Violation in Supersymmetric U(1)' Models

    CERN Document Server

    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 ...

  9. Holography and the Electroweak Phase Transition

    CERN Document Server

    Creminelli, Paolo; Rattazzi, Riccardo; Creminelli, Paolo; Nicolis, Alberto; Rattazzi, Riccardo

    2002-01-01

    We study through holography the compact Randall-Sundrum (RS) model at finite temperature. In the presence of radius stabilization, the system is described at low enough temperature by the RS solution. At high temperature it is described by the AdS-Schwarzshild solution with an event horizon replacing the TeV brane. We calculate the transition temperature T_c between the two phases and we find it to be somewhat smaller than the TeV scale. Assuming that the Universe starts out at T >> T_c and cools down by expansion, we study the rate of the transition to the RS phase. We find that the transition is too slow and the Universe ends up in an old inflation scenario unless tight bounds are satisfied by the model parameters. In particular we find that the AdS curvature must be comparable to the 5D Planck mass and that the radius stabilization mechanism must lead to a sizeable distortion of the basic RS metric.

  10. Universal seesaw and 0νββ in new 3331 left-right symmetric model

    Science.gov (United States)

    Borah, Debasish; Patra, Sudhanwa

    2017-08-01

    We consider a class of left-right symmetric model with enlarged gauge group SU(3)c × SU(3)L × SU(3)R × U(1)X without having scalar bitriplet. In the absence of scalar bitriplet, there is no Dirac mass term for fermions including usual quarks and leptons. We introduce new isosinglet vector-like fermions so that all the fermions get their masses through a universal seesaw mechanism. We extend our discussion to neutrino mass and its implications in neutrinoless double beta decay (0 νββ). We show that for TeV scale SU(3)R gauge bosons, the heavy-light neutrino mixing contributes dominantly to 0 νββ that can be observed at ongoing experiments. The new physics contributions arising from purely left-handed currents via exchange of keV scale right-handed neutrinos and the so called mixed helicity λ-diagram can saturate the KamLANDZen bound. We show that the right handed neutrinos in this model can have mass in the sub keV range and can be long lived compared to the age of the Universe. The contributions of these right handed neutrinos to flavour physics observables like μ → eγ and muon g - 2 is also discussed. Towards the end we also comment on different possible symmetry breaking patterns of this enlarged gauge symmetry to that of the standard model.

  11. Phenomenology of Compositeness at the LHC

    CERN Document Server

    Salvioni, Ennio; Zwirner, Fabio

    The hierarchy problem of the weak scale calls for extensions of the Standard Model at the TeV, and thus within the reach of the CERN Large Hadron Collider (LHC). One of the best motivated proposals builds on the idea that the Higgs could be a composite pseudo-Nambu-Goldstone boson. In this thesis we discuss several topics in the phenomenology of composite Higgs models, concentrating mainly on LHC physics. In Chapter 1 we introduce the hierarchy problem and the essential features of viable theories of compositeness at the TeV scale. Chapter 2 is dedicated to a review of concrete constructions realizing the composite Higgs idea, focusing mostly on models with partial compositeness. In Chapter 3 we present the effective Lagrangians suited for describing the Higgs boson and the constraints placed by electroweak precision tests on their parameters. Motivated by hints in the experimental results, we also reconsider the possibility of custodial breaking in the couplings of the Higgs to the W and Z. Chapter 4 is devo...

  12. Hitting sbottom in natural SUSY

    CERN Document Server

    Lee, Hyun Min; Trott, Michael

    2012-01-01

    We compare the experimental prospects of direct stop and sbottom pair production searches at the LHC. Such searches for stops are of great interest as they directly probe for states that are motivated by the SUSY solution to the hierarchy problem of the Higgs mass parameter - leading to a "Natural" SUSY spectrum. Noting that sbottom searches are less experimentally challenging and scale up in reach directly with the improvement on b-tagging algorithms, we discuss the interplay of small TeV scale custodial symmetry violation with sbottom direct pair production searches as a path to obtaining strong sub-TeV constraints on stops in a natural SUSY scenario. We argue that if a weak scale natural SUSY spectrum does not exist within the reach of LHC, then hopes for such a spectrum for large regions of parameter space should sbottom out. Conversely, the same arguments make clear that a discovery of such a spectrum is likely to proceed in a sbottom up manner.

  13. Probing RS scenarios of flavour at LHC via leptonic channels

    CERN Document Server

    Ledroit, F; Morel, J

    2007-01-01

    We study a purely leptonic signature of the Randall-Sundrum scenario with Standard Model fields in the bulk at LHC: the contribution from the exchange of Kaluza-Klein (KK) excitations of gauge bosons to the clear Drell-Yan reaction. We show that this contribution is detectable (even with the low luminosities of the LHC initial regime) for KK masses around the TeV scale and for sufficiently large lepton couplings to KK gauge bosons. Such large couplings can be compatible with ElectroWeak precision data on the Zff coupling in the framework of the custodial O(3) symmetry recently proposed, for specific configurations of lepton localizations (along the extra dimension). These configurations can simultaneously reproduce the correct lepton masses, while generating acceptably small Flavour Changing Neutral Current (FCNC) effects. This LHC phenomenological analysis is realistic in the sense that it is based on fermion localizations which reproduce all the quark/lepton masses plus mixing angles and respect FCNC constr...

  14. Search for resonant WW and WZ production in ppbar collisions at ?s = 1.96 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF; Ancu, Lucian Stefan; /Nijmegen U. /Fermilab

    2010-11-01

    The standard model of particle physics is expected to be a low energy effective theory valid for particle interactions below the TeV scale. Above this scale, extensions to the standard model (SM) augment the existing particle content, leading to enhanced production of many final states at colliders. Specifically, the production and decay of massive charged or neutral particles can produce an excess of W boson pairs for neutral particles or W and Z boson pairs for charged particles. We search for resonant WW or WZ production using up to 5.4 fb{sup -1} of integrated luminosity collected by the D0 experiment in Run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass using the sequential standard model (SSM) W{prime} boson and the Randall-Sundrum model graviton G as benchmarks. We exclude an SSM W{prime} boson in the mass range 180-690 GeV and a Randall-Sundrum graviton in the range 300-754 GeV at 95% CL.

  15. Double beta decay - physics beyond the standard model now, and in future (Genius)

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V.

    1998-08-01

    Nuclear double beta decay provides an extraordinarily broad potential to search for beyond standard model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso - probes the electron mass now in the sub eV region and will reach a limit of {proportional_to}0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg double beta group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), compositeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc. Second, future perspectives of {beta}{beta} research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. (orig.)

  16. Search for jet extinction in the inclusive jet-$p_T$ spectrum from proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Luyckx, Sten; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Daci, Nadir; Heracleous, Natalie; Kalogeropoulos, Alexis; Keaveney, James; Kim, Tae Jeong; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Dobur, Didar; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Léonard, Alexandre; Mohammadi, Abdollah; Perniè, Luca; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Crucy, Shannon; Dildick, Sven; Fagot, Alexis; Garcia, Guillaume; Klein, Benjamin; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Liao, Junhui; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; Dos Reis Martins, Thiago; Pol, Maria Elena; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Malek, Magdalena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santaolalla, Javier; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Aleksandrov, Aleksandar; Genchev, Vladimir; Iaydjiev, Plamen; Marinov, Andrey; Piperov, Stefan; Rodozov, Mircho; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Du, Ran; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Plestina, Roko; Tao, Junquan; Wang, Xianyou; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Qiang; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Nayak, Aruna; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Mastrolorenzo, Luca; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Veelken, Christian; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Beaupere, Nicolas; Boudoul, Gaelle; Brochet, Sébastien; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Bontenackels, Michael; Calpas, Betty; Edelhoff, Matthias; Feld, Lutz; Hindrichs, Otto; Klein, Katja; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Lingemann, Joschka; Nowack, Andreas; Nugent, Ian Michael; Perchalla, Lars; Pooth, Oliver; Stahl, Achim; Asin, Ivan; Bartosik, Nazar; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bell, Alan James; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Garay Garcia, Jasone; Geiser, Achim; Gunnellini, Paolo; Hauk, Johannes; Hellwig, Gregor; Hempel, Maria; Horton, Dean; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Krücker, Dirk; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Novgorodova, Olga; Nowak, Friederike; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Ron, Elias; Sahin, Mehmet Özgür; Salfeld-Nebgen, Jakob; Saxena, Pooja; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Schröder, Matthias; Spannagel, Simon; Vargas Trevino, Andrea Del Rocio; Walsh, Roberval; Wissing, Christoph; Aldaya Martin, Maria; Blobel, Volker; Centis Vignali, Matteo; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Görner, Martin; Gosselink, Martijn; Haller, Johannes; Höing, Rebekka Sophie; Kirschenmann, Henning; Klanner, Robert; Kogler, Roman; Lange, Jörn; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Ott, Jochen; Peiffer, Thomas; Pietsch, Niklas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Seidel, Markus; Poehlsen, Jennifer; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Hartmann, Frank; Hauth, Thomas; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Kuznetsova, Ekaterina; Lobelle Pardo, Patricia; Mozer, Matthias Ulrich; Müller, Thomas; Nürnberg, Andreas; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Röcker, Steffen; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Markou, Athanasios; Markou, Christos; Psallidas, Andreas; Topsis-Giotis, Iasonas; Gouskos, Loukas; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Aslanoglou, Xenofon; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Swain, Sanjay Kumar; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Kalsi, Amandeep Kaur; Kaur, Manjit; Mittal, Monika; Nishu, Nishu; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Modak, Atanu; Mukherjee, Swagata; Roy, Debarati; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Jafari, Abideh; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Venditti, Rosamaria; Verwilligen, Piet; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gallo, Elisabetta; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Ferro, Fabrizio; Lo Vetere, Maurizio; Robutti, Enrico; Tosi, Silvano; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Lucchini, Marco Toliman; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Dall'Osso, Martino; Dorigo, Tommaso; Galanti, Mario; Gasparini, Fabrizio; Giubilato, Piero; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Passaseo, Marina; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Salvini, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Moon, Chang-Seong; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Vernieri, Caterina; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Grassi, Marco; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Soffi, Livia; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Degano, Alessandro; Demaria, Natale; Finco, Linda; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Ortona, Giacomo; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Montanino, Damiana; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Chang, Sunghyun; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Park, Hyangkyu; Sakharov, Alexandre; Son, Dong-Chul; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kyong Sei; Park, Sung Keun; Roh, Youn; Choi, Minkyoo; Kim, Ji Hyun; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kwon, Eunhyang; Lee, Jongseok; Seo, Hyunkwan; Yu, Intae; Juodagalvis, Andrius; Komaragiri, Jyothsna Rani; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michał; Wolszczak, Weronika; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Spiridonov, Alexander; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Dordevic, Milos; Ekmedzic, Marko; Milosevic, Jovan; Alcaraz Maestre, Juan; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Navarro De Martino, Eduardo; Pérez Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Duarte Campderros, Jordi; Fernandez, Marcos; Gomez, Gervasio; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Bondu, Olivier; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; David Tinoco Mendes, Andre; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Eugster, Jürg; Franzoni, Giovanni; Funk, Wolfgang; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Musella, Pasquale; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Plagge, Michael; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Treille, Daniel; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wardle, Nicholas; Wöhri, Hermine Katharina; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Grab, Christoph; Hits, Dmitry; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Meister, Daniel; Mohr, Niklas; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pauss, Felicitas; Peruzzi, Marco; Quittnat, Milena; Rebane, Liis; Ronga, Frederic Jean; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Theofilatos, Konstantinos; Wallny, Rainer; Weber, Hannsjoerg Artur; Amsler, Claude; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Hinzmann, Andreas; Hreus, Tomas; Ivova Rikova, Mirena; Kilminster, Benjamin; Millan Mejias, Barbara; Ngadiuba, Jennifer; Robmann, Peter; Snoek, Hella; Taroni, Silvia; Verzetti, Mauro; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Ferro, Cristina; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Volpe, Roberta; Yu, Shin-Shan; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Kao, Kai-Yi; Lei, Yeong-Jyi; Liu, Yueh-Feng; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Shi, Xin; Tzeng, Yeng-Ming; Wilken, Rachel; Asavapibhop, Burin; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Gamsizkan, Halil; Karapinar, Guler; Ocalan, Kadir; Surat, Ugur Emrah; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Bahtiyar, Hüseyin; Barlas, Esra; Cankocak, Kerem; Vardarli, Fuat Ilkehan; Yücel, Mete; Levchuk, Leonid; Sorokin, Pavel; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Burton, Darren; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Dunne, Patrick; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Hall, Geoffrey; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Marrouche, Jad; Mathias, Bryn; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Seez, Christopher; Sharp, Peter; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Dittmann, Jay; Hatakeyama, Kenichi; Kasmi, Azeddine; Liu, Hongxuan; Scarborough, Tara; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Heister, Arno; Lawson, Philip; Richardson, Clint; Rohlf, James; Sperka, David; St John, Jason; Sulak, Lawrence; Alimena, Juliette; Bhattacharya, Saptaparna; Christopher, Grant; Cutts, David; Demiragli, Zeynep; Ferapontov, Alexey; Garabedian, Alex; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Swanson, Joshua; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Miceli, Tia; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Searle, Matthew; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Rakness, Gregory; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Babb, John; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Nguyen, Harold; Shrinivas, Amithabh; Sturdy, Jared; Sumowidagdo, Suharyo; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Evans, David; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Palmer, Christopher; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Würthwein, Frank; Yagil, Avraham; Yoo, Jaehyeok; Barge, Derek; Bradmiller-Feld, John; Campagnari, Claudio; Danielson, Thomas; Dishaw, Adam; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Incandela, Joe; Justus, Christopher; Mccoll, Nickolas; Richman, Jeffrey; Stuart, David; To, Wing; West, Christopher; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Di Marco, Emanuele; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Rogan, Christopher; Spiropulu, Maria; Timciuc, Vladlen; Wilkinson, Richard; Xie, Si; Zhu, Ren-Yuan; Azzolini, Virginia; Calamba, Aristotle; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Drell, Brian Robert; Ford, William T; Gaz, Alessandro; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Hopkins, Walter; Kreis, Benjamin; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Skinnari, Louise; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Kaadze, Ketino; Klima, Boaz; Kwan, Simon; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitbeck, Andrew; Whitmore, Juliana; Yang, Fan; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Carver, Matthew; Cheng, Tongguang; Curry, David; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Field, Richard D; Fisher, Matthew; Furic, Ivan-Kresimir; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Rinkevicius, Aurelijus; Shchutska, Lesya; Skhirtladze, Nikoloz; Snowball, Matthew; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Hohlmann, Marcus; Kalakhety, Himali; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Bazterra, Victor Eduardo; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Kurt, Pelin; Moon, Dong Ho; O'Brien, Christine; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Duru, Firdevs; Haytmyradov, Maksat; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Rahmat, Rahmat; Sen, Sercan; Tan, Ping; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Swartz, Morris; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Gray, Julia; Kenny III, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Sekaric, Jadranka; Stringer, Robert; Wang, Quan; Wood, Jeffrey Scott; Barfuss, Anne-Fleur; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Saini, Lovedeep Kaur; Shrestha, Shruti; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Pedro, Kevin; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Bauer, Gerry; Busza, Wit; Cali, Ivan Amos; Chan, Matthew; Di Matteo, Leonardo; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Klute, Markus; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Ma, Teng; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Velicanu, Dragos; Veverka, Jan; Wyslouch, Bolek; Yang, Mingming; Zanetti, Marco; Zhukova, Victoria; Dahmes, Bryan; De Benedetti, Abraham; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Gonzalez Suarez, Rebeca; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Lazo-Flores, Jose; Malik, Sudhir; Meier, Frank; Snow, Gregory R; Dolen, James; Godshalk, Andrew; Iashvili, Ia; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Sung, Kevin; Velasco, Mayda; Won, Steven; Brinkerhoff, Andrew; Chan, Kwok Ming; Drozdetskiy, Alexey; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Pearson, Tessa; Planer, Michael; Ruchti, Randy; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Smith, Geoffrey; Vuosalo, Carl; Winer, Brian L; Wolfe, Homer; Wulsin, Howard Wells; Berry, Edmund; Driga, Olga; Elmer, Peter; Hebda, Philip; Hunt, Adam; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zenz, Seth Conrad; Zuranski, Andrzej; Brownson, Eric; Mendez, Hector; Ramirez Vargas, Juan Eduardo; Alagoz, Enver; Barnes, Virgil E; Benedetti, Daniele; Bolla, Gino; Bortoletto, Daniela; De Mattia, Marco; Everett, Adam; Hu, Zhen; Jha, Manoj; Jones, Matthew; Jung, Kurt; Kress, Matthew; Leonardo, Nuno; Lopes Pegna, David; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Khukhunaishvili, Aleko; Miner, Daniel Carl; Petrillo, Gianluca; Vishnevskiy, Dmitry; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Krutelyov, Vyacheslav; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Rose, Anthony; Safonov, Alexei; Sakuma, Tai; Suarez, Indara; Tatarinov, Aysen; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kovitanggoon, Kittikul; Kunori, Shuichi; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Wood, John; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Duric, Senka; Friis, Evan; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Levine, Aaron; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ross, Ian; Sarangi, Tapas; Savin, Alexander; Smith, Wesley H; Woods, Nathaniel

    2014-08-18

    The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 inverse-femtobarns of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale.

  17. First Look at the Physics Case of TLEP

    CERN Document Server

    Bicer, M.; Yildiz, I.; Coignet, G.; Delmastro, M.; Alexopoulos, T.; Grojean, C.; Antusch, S.; Sen, T.; He, H.J.; Potamianos, K.; Haug, S.; Moreno, A.; Heister, A.; Sanz, V.; Gomez-Ceballos, G.; Klute, M.; Zanetti, M.; Wang, L.T.; Dam, M.; Boehm, C.; Glover, N.; Krauss, F.; Lenz, A.; Syphers, M.; Leonidopoulos, C.; Ciulli, V.; Lenzi, P.; Sguazzoni, G.; Antonelli, M.; Boscolo, M.; Frasciello, O.; Milardi, C.; Venanzoni, G.; Zobov, M.; van der Bij, J.; de Gruttola, M.; Kim, D.W.; Bachtis, M.; Butterworth, A.; Bernet, C.; Botta, C.; Carminati, F.; David, A.; d'Enterria, D.; Ganis, G.; Goddard, B.; Giudice, G.; Janot, P.; Jowett, J. M.; Lourenço, C.; Malgeri, L.; Meschi, E.; Moortgat, F.; Musella, P.; Osborne, J.A.; Perrozzi, L.; Pierini, M.; Rinolfi, L.; de Roeck, A.; Rojo, J.; Roy, G.; Sciabà, A.; Valassi, A.; Waaijer, C.S.; Wenninger, J.; Woehri, H.; Zimmermann, F.; Blondel, A.; Koratzinos, M.; Mermod, P.; Onel, Y.; Talman, R.; Castaneda Miranda, E.; Bulyak, E.; Porsuk, D.; Kovalskyi, D.; Padhi, S.; Faccioli, P.; Ellis, J. R.; Campanelli, M.; Bai, Y.; Chamizo, M.; Appleby, R.B.; Owen, H.; Maury Cuna, H.; Gracios, C.; Munoz-Hernandez, G.A.; Trentadue, L.; Torrente-Lujan, E.; Wang, S.; Bertsche, D.; Gramolin, A.; Telnov, V.; Petroff, P.; Azzi, P.; Nicrosini, O.; Piccinini, F.; Montagna, G.; Kapusta, F.; Laplace, S.; da Silva, W.; Gizani, N.; Craig, N.; Han, T.; Luci, C.; Mele, B.; Silvestrini, L.; Ciuchini, M.; Cakir, R.; Aleksan, R.; Couderc, F.; Ganjour, S.; Lançon, E.; Locci, E.; Schwemling, P.; Spiro, M.; Tanguy, C.; Zinn-Justin, J.; Moretti, S.; Kikuchi, M.; Koiso, H.; Ohmi, K.; Oide, K.; Pauletta, G.; Ruiz de Austri, R.; Gouzevitch, M.; Chattopadhyay, S.

    2014-01-01

    The discovery by the ATLAS and CMS experiments of a new boson with mass around 125 GeV and with measured properties compatible with those of a Standard-Model Higgs boson, coupled with the absence of discoveries of phenomena beyond the Standard Model at the TeV scale, has triggered interest in ideas for future Higgs factories. A new circular e+e- collider hosted in a 80 to 100 km tunnel, TLEP, is among the most attractive solutions proposed so far. It has a clean experimental environment, produces high luminosity for top-quark, Higgs boson, W and Z studies, accommodates multiple detectors, and can reach energies up to the t-tbar threshold and beyond. It will enable measurements of the Higgs boson properties and of Electroweak Symmetry-Breaking (EWSB) parameters with unequalled precision, offering exploration of physics beyond the Standard Model in the multi-TeV range. Moreover, being the natural precursor of the VHE-LHC, a 100 TeV hadron machine in the same tunnel, it builds up a long-term vision for particle ...

  18. Precision measurements of electroweak observables with the ATLAS Detector

    CERN Document Server

    Vittori, Camilla; The ATLAS collaboration

    2017-01-01

    Measurements of the Drell-Yan production of W and Z/gamma bosons at the LHC provide a benchmark of our understanding of perturbative QCD and probe the proton structure in a unique way. The ATLAS collaboration measured the di-lepton mass range up to the TeV scale as well as the triple differential cross-section measurement as a function of Mll, dilepton rapidity and cosθ defined in the Collins-Soper frame. This measurement provides sensitivity to the PDFs and the weak mixing angle. The latest results of the ATLAS collaboration will be presented. A second important observable in the electroweak sector is the W boson mass in order to test the overall consistency of the Standard Model. Since the discovery of a Higgs Boson, the the W boson mass is predicted to 7 MeV precision, while the world average of all measurements is 15 MeV, making the improved measurement an important goal. Large samples of leptonic decays of W and Z bosons were collected with efficient single lepton triggers in the 7 TeV data set correspo...

  19. A Hybrid Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Schafer-Nameki, Sakura; Tamarit, Carlos; /Santa Barbara, KITP; Torroba, Gonzalo; /SLAC /Santa Barbara, KITP

    2010-08-26

    We construct composite Higgs models admitting a weakly coupled Seiberg dual description. We focus on the possibility that only the up-type Higgs is an elementary field, while the down-type Higgs arises as a composite hadron. The model, based on a confining SQCD theory, breaks supersymmetry and electroweak symmetry dynamically and calculably. This simultaneously solves the {mu}/B{sub {mu}} problem and explains the smallness of the bottom and tau masses compared to the top mass. The proposal is then applied to a class of models where the same confining dynamics is used to generate the Standard Model flavor hierarchy by quark and lepton compositeness. This provides a unified framework for flavor, supersymmetry breaking and electroweak physics. The weakly coupled dual is used to explicitly compute the MSSM parameters in terms of a few microscopic couplings, giving interesting relations between the electroweak and soft parameters. The RG evolution down to the TeV scale is obtained and salient phenomenological predictions of this class of 'single-sector' models are discussed.

  20. MARMOSET: The Path from LHC Data to the New Standard Model via On-Shell Effective Theories

    Energy Technology Data Exchange (ETDEWEB)

    Arkani-Hamed, Nima; Schuster, Philip; Toro, Natalia; /Harvard U., Phys. Dept.; Thaler, Jesse; /UC, Berkeley /LBL, Berkeley; Wang, Lian-Tao; /Princeton U.; Knuteson, Bruce; /MIT, LNS; Mrenna, Stephen; /Fermilab

    2007-03-01

    We describe a coherent strategy and set of tools for reconstructing the fundamental theory of the TeV scale from LHC data. We show that On-Shell Effective Theories (OSETs) effectively characterize hadron collider data in terms of masses, production cross sections, and decay modes of candidate new particles. An OSET description of the data strongly constrains the underlying new physics, and sharply motivates the construction of its Lagrangian. Simulating OSETs allows efficient analysis of new-physics signals, especially when they arise from complicated production and decay topologies. To this end, we present MARMOSET, a Monte Carlo tool for simulating the OSET version of essentially any new-physics model. MARMOSET enables rapid testing of theoretical hypotheses suggested by both data and model-building intuition, which together chart a path to the underlying theory. We illustrate this process by working through a number of data challenges, where the most important features of TeV-scale physics are reconstructed with as little as 5 fb{sup -1} of simulated LHC signals.

  1. Search for vector-like quarks and excited quarks at CMS

    CERN Document Server

    Rauco, Giorgia

    2017-01-01

    We present the results of the latest searches for new hypothetical heavy quarks using proton-proton collisions data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Vector-like quarks are postulated to solve the hierarchy problem and stabilize the Higgs mass and they are not constrained by the Higgs discovery and electroweak measurements, as for the case of a fourth generation of fermions. They can either be produced singly or pair-wise and their decays result in a variety of final states, containing massive standard model quarks and bosons (Z, W, H). Being these new particles expected to be appearing at the TeV scale, they give rise to boosted topologies, in which jet substructures techniques play a fundamental role. An alternative type of heavy quark resonance are the excited quarks, which are predicted by the compositeness model, being their evidence a clear signature of the composite structure of the ordinary matter. Their decay leads to the corresponding ordinary qua...

  2. Universal seesaw and 0νββ in new 3331 left-right symmetric model

    Directory of Open Access Journals (Sweden)

    Debasish Borah

    2017-08-01

    Full Text Available We consider a class of left-right symmetric model with enlarged gauge group SU(3c×SU(3L×SU(3R×U(1X without having scalar bitriplet. In the absence of scalar bitriplet, there is no Dirac mass term for fermions including usual quarks and leptons. We introduce new isosinglet vector-like fermions so that all the fermions get their masses through a universal seesaw mechanism. We extend our discussion to neutrino mass and its implications in neutrinoless double beta decay (0νββ. We show that for TeV scale SU(3R gauge bosons, the heavy-light neutrino mixing contributes dominantly to 0νββ that can be observed at ongoing experiments. The new physics contributions arising from purely left-handed currents via exchange of keV scale right-handed neutrinos and the so called mixed helicity λ-diagram can saturate the KamLANDZen bound. We show that the right handed neutrinos in this model can have mass in the sub keV range and can be long lived compared to the age of the Universe. The contributions of these right handed neutrinos to flavour physics observables like μ→eγ and muon g−2 is also discussed. Towards the end we also comment on different possible symmetry breaking patterns of this enlarged gauge symmetry to that of the standard model.

  3. Model Unspecific Search for New Physics with High pT Photons in CMS

    CERN Document Server

    Schmitz, Stefan Antonius

    2009-01-01

    In 2009 the LHC collider at the European center of particle physics CERN will start operations, colliding protons with a center of mass energy of up to 14 TeV. Designed as a large multi purpose detector CMS 3 will then start taking collision data. CMS will perform precision measurements within the Standard Model of particle physics and expand the search for new physical phenomena into regions that have not yet been probed by previous experiments. Many theories about what physics beyond the Standard Model at the TeV scale might look like have been proposed. Together these models leave room for a broad spectrum of possible experimental signatures that one might look for in the data. Various analyses focus on processing the available information with the aim of finding evidence for a specific model of choice. MUSiC as a Model Unspecific Search in CMS provides a complementary approach by scanning the data for noteworthy deviations from the Standard Model expectation while making only basic assumptions about the n...

  4. The Hunt for New Physics at the Large Hadron Collider

    Science.gov (United States)

    Nath, Pran; Nelson, Brent; Davoudiasl, Hooman; Dutta, Bhaskar; Feldman, Daniel; Liu, Zuowei; Han, Tao; Langacker, Paul; Mohapatra, Rabi; Valle, Jose; Pilaftsis, Apostolos; Zerwas, Dirk; AbdusSalam, Shehu; Adam-Bourdarios, Claire; Aguilar-Saavedra, J. A.; Allanach, Benjamin; Altunkaynak, B.; Anchordoqui, Luis A.; Baer, Howard; Bajc, Borut; Buchmueller, O.; Carena, M.; Cavanaugh, R.; Chang, S.; Choi, Kiwoon; Csáki, C.; Dawson, S.; de Campos, F.; De Roeck, A.; Dührssen, M.; Éboli, O. J. P.; Ellis, J. R.; Flächer, H.; Goldberg, H.; Grimus, W.; Haisch, U.; Heinemeyer, S.; Hirsch, M.; Holmes, M.; Ibrahim, Tarek; Isidori, G.; Kane, Gordon; Kong, K.; Lafaye, Remi; Landsberg, G.; Lavoura, L.; Lee, Jae Sik; Lee, Seung J.; Lisanti, M.; Lüst, Dieter; Magro, M. B.; Mahbubani, R.; Malinsky, M.; Maltoni, Fabio; Morisi, S.; Mühlleitner, M. M.; Mukhopadhyaya, B.; Neubert, M.; Olive, K. A.; Perez, Gilad; Pérez, Pavel Fileviez; Plehn, T.; Pontón, E.; Porod, Werner; Quevedo, F.; Rauch, M.; Restrepo, D.; Rizzo, T. G.; Romão, J. C.; Ronga, F. J.; Santiago, J.; Schechter, J.; Senjanović, G.; Shao, J.; Spira, M.; Stieberger, S.; Sullivan, Zack; Tait, Tim M. P.; Tata, Xerxes; Taylor, T. R.; Toharia, M.; Wacker, J.; Wagner, C. E. M.; Wang, Lian-Tao; Weiglein, G.; Zeppenfeld, D.; Zurek, K.

    2010-03-01

    The Large Hadron Collider presents an unprecedented opportunity to probe the realm of new physics in the TeV region and shed light on some of the core unresolved issues of particle physics. These include the nature of electroweak symmetry breaking, the origin of mass, the possible constituent of cold dark matter, new sources of CP violation needed to explain the baryon excess in the universe, the possible existence of extra gauge groups and extra matter, and importantly the path Nature chooses to resolve the hierarchy problem - is it supersymmetry or extra dimensions. Many models of new physics beyond the standard model contain a hidden sector which can be probed at the LHC. Additionally, the LHC will be a top factory and accurate measurements of the properties of the top and its rare decays will provide a window to new physics. Further, the LHC could shed light on the origin of neutralino masses if the new physics associated with their generation lies in the TeV region. Finally, the LHC is also a laboratory to test the hypothesis of TeV scale strings and D brane models. An overview of these possibilities is presented in the spirit that it will serve as a companion to the Technical Design Reports (TDRs) by the particle detector groups ATLAS and CMS to facilitate the test of the new theoretical ideas at the LHC. Which of these ideas stands the test of the LHC data will govern the course of particle physics in the subsequent decades.

  5. Search For Resonances In The Dijet Mass Spectrum With The ATLAS Experiment At The LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00339090

    The unprecedented collision energy reached and the considerable integrated luminosity produced by the LHC allow its experiments to investigate the existence of new physics phenomena beyond the Standard Model of particle physics at the TeV scale. This thesis presents the search performed by the ATLAS Collaboration for evidence of new physics manifesting as localised resonances in the dijet invariant mass distribution of events with large transverse momenta. No evidence of resonant phenomena outside of the Standard Model have been observed in the 20.3 fb$^{-1}$ of data collected in 2012 at $\\sqrt{s}$ = 8 TeV nor in the 3.6 fb$^{-1}$ of data collected in 2015 at $\\sqrt{s}$ = 13 TeV. Limits have been set at 95% Credibility Level on the cross-section times acceptance of selected benchmark models. Excited quarks with masses below 4.06 TeV and Quantum Black Holes, QBH, with masses below 5.2 TeV have been excluded using the 2012 datasets. These limits have then been further extended to 5.66 TeV (excited quarks) and ...

  6. Search for Top Quark Pair Resonances with the CMS Detector at the LHC

    CERN Document Server

    AUTHOR|(CDS)2159607

    2013-07-15

    The Standard Model of particle physics is not the final theory. It breaks at larger (TeV) scales and thus can not explain the hierarchy problem, the unification of couplings and some physical phenomena. Several physical models, referred to as Beyond the Standard Model, have been proposed to account for the phenomena which are not explained by the Standard Model, and to answer to some of these open questions. As the top quark has as an enormous mass of about 173.3 GeV, it plays an essential role in searches for new physics. Various models beyond the Standard Model predict the existence of heavy particles decaying into top quark pairs. These particles manifest themselves as resonant structures in the invariant mass spectrum of the top quark pairs. In this thesis, a model-independent search has been performed for top quark pair resonances in the mass range close to the top quark pair production threshold. The Topcolor Z' model is considered as a reference model. The presented search focuses on top quark pair eve...

  7. Search of New Physics with Boosted Higgs Boson in Hadronic Final States with ATLAS Detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00387563

    The discovery of a Higgs boson at the Large Hadron Collider (LHC) confirms the validity of the Standard Model (SM) in the description of particle interactions at electroweak scale. However, radioactive corrections to the Higgs mass drives its value to the model's validity limit, indicating either extreme fine-tuning or the presence of new physics at higher energy scale. Since 2015, the LHC starts its Run 2 journey with unprecedented center of mass energy of 13 TeV. Along with increase in luminosity, this greatly extends the sensitivity of ATLAS experiment to heavy new particles at TeV scale. In particular, many new physics models beyond the Standard Model manifest themselves through significant coupling to the Higgs boson in decays of new particles to a Higgs boson and other SM particles. In this work, two searches for resonances decaying to either pair of Higgs bosons or a Higgs boson associated with another SM vector boson in all hadronic final states are presented using data collected by ATLAS during Run 2...

  8. Large mass hierarchies from strongly-coupled dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Athenodorou, Andreas [Department of Physics, University of Cyprus,B.O. Box 20537, 1678 Nicosia (Cyprus); Bennett, Ed [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea SA2 8PP (United Kingdom); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI),Nagoya University,Furo, Chikusa, Nagoya 464-8602 (Japan); Bergner, Georg [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics,University of Bern,Sidlerstrasse 5, CH-3012 Bern (Switzerland); Elander, Daniel [National Institute for Theoretical Physics, School of Physics andMandelstam Institute for Theoretical Physics, University of the Witwatersrand,1 Jan Smuts Avenue, Johannesburg, Wits 2050 (South Africa); Lin, C.-J. David [Institute of Physics, National Chiao-Tung University,1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan (China); CNRS, Aix Marseille Université, Université de Toulon, Centre de Physique Théorique,UMR 7332, F-13288 Marseille (France); Lucini, Biagio; Piai, Maurizio [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea SA2 8PP (United Kingdom)

    2016-06-20

    Besides the Higgs particle discovered in 2012, with mass 125 GeV, recent LHC data show tentative signals for new resonances in diboson as well as diphoton searches at high center-of-mass energies (2 TeV and 750 GeV, respectively). If these signals are confirmed (or other new resonances are discovered at the TeV scale), the large hierarchies between masses of new bosons require a dynamical explanation. Motivated by these tentative signals of new physics, we investigate the theoretical possibility that large hierarchies in the masses of glueballs could arise dynamically in new strongly-coupled gauge theories extending the standard model of particle physics. We study lattice data on non-Abelian gauge theories in the (near-)conformal regime as well as a simple toy model in the context of gauge/gravity dualities. We focus our attention on the ratio R between the mass of the lightest spin-2 and spin-0 resonances, that for technical reasons is a particularly convenient and clean observable to study. For models in which (non-perturbative) large anomalous dimensions arise dynamically, we show indications that this mass ratio can be large, with R>5. Moreover, our results suggest that R might be related to universal properties of the IR fixed point. Our findings provide an interesting step towards understanding large mass ratios in the non-perturbative regime of quantum field theories with (near) IR conformal behaviour.

  9. How the inverse seesaw mechanism can reveal itself natural, canonical, and independent of the right-handed neutrino mass

    Science.gov (United States)

    Dias, A. G.; de S. Pires, C. A.; Rodrigues da Silva, P. S.

    2011-09-01

    The common lore in the literature of neutrino mass generation is that the canonical seesaw mechanism beautifully offers an explanation for the tiny neutrino mass but at the cost of introducing right-handed neutrinos at a scale that is out of range for the current experiments. The inverse seesaw mechanism is an interesting alternative to the canonical one once it leads to tiny neutrino masses with the advantage of being testable at the TeV scale. However, this last mechanism suffers from an issue of naturalness concerning the scale responsible for such small masses, namely, the parameter μ that is related to lepton number violation and is supposed to be at the keV scale, much lower than the electroweak one. However, no theoretical framework was built that offers an explanation for obtaining this specific scale. In this work, we propose a variation of the inverse seesaw mechanism by assuming a minimal scalar and fermionic set of singlet fields, along with a Z5⊗Z2 symmetry, that allows a dynamical explanation for the smallness of μ, recovering the neat canonical seesaw formula and with right-handed (RH) neutrinos free to be at the electroweak scale, thus testable at LHC and current neutrino experiments.

  10. Nonuniversal anomaly-free U(1) model with three Higgs doublets and one singlet scalar field

    Science.gov (United States)

    Mantilla, S. F.; Martinez, R.

    2017-11-01

    The flavor problem, neutrino physics, and the fermion mass hierarchy are important motivations to extend the Standard Model to the TeV scale. A new family nonuniversal extension is presented with three Higgs doublets, one Higgs singlet, and one scalar dark matter candidate. Exotic fermions are included in order to cancel chiral anomalies and to allow family nonuniversal U(1 ) X charges. By implementing an additional Z2 symmetry, the Yukawa coupling terms are suited in such a way that the fermion mass hierarchy is obtained without fine-tuning. The neutrino sector includes Majorana fermions to implement the inverse seesaw mechanism. The effective mass matrix for Standard Model neutrinos is fitted to current neutrino oscillation data to check the consistency of the model with experimental evidence, obtaining that the normal-ordering scheme is preferred over the inverse ones, and the values of the neutrino Yukawa coupling constants are shown. Finally, the h →τ μ lepton-flavor-violation process is addressed with the rotation matrices of the C P -even scalars, left- and right-handed charged leptons, yielding definite regions where the model is consistent with CMS reports of BR (h →τ μ ).

  11. Commissioning and First Operation of the Large Hadron Collider (LHC)

    CERN Document Server

    Lebrun, Ph

    2010-01-01

    After some fifteen years of construction, the Large Hadron Collider (LHC) was commissioned at CERN, the European Organization for Nuclear Research in 2008. This high-energy particle accelerator of 26.7 km circumference – the largest scientific instrument ever built – brings into collision intense beams of protons and ions to probe the structure of matter and study the forces acting on its elementary components at the TeV scale, an order of magnitude higher than the previous stateof-the-art. To guide and focus its particle beams, the LHC uses several thousands high-field superconducting magnets operating in superfluid helium at 1.9 K. The project therefore constitutes a technological feat: all its components were developed, industrialized and series produced by industrial companies according to demanding specifications. Started as a CERN undertaking – by decision of the CERN Council and its twenty European member states – the project soon became global with special contributions from Canada, India, Jap...

  12. Search for Higgs bosons and for Supersymmetric particles at particle collider experiments

    CERN Document Server

    Muanza, Steve

    The corner stone of the Standard Model (SM) of Particle Physics is the Higgs mechanism. It explains how the bosons W, Z and H acquire a mass via weak interactions. In addition it explains how the charged fermions also acquire a mass through Yukawa interactions. And on top of this, it regularizes the scattering of longitudinal W and Z bosons at high energy. The discovery of a Higgs boson by the ATLAS and the CMS collaborations in 2012 marked the culminating success of the SM at explaining most of the known phenomena. However a few other phenomena such as the Dark Matter and the Dark energy cannot be explained by the SM particles. What's more, the SM leaves several open questions such as a quest for a quantum theory for gravity, the naturalness in the Higgs sector, a possible Grand Unification,... The common thread in topics presented in this habilitation thesis is the search for manifestations of a TeV scale supersymmetric (SUSY) extension of the Standard Model at particle collider experiments. Among the predi...

  13. Search for Quantum Black Holes in Lepton+Jet Final State Using pp-Collisions at $\\sqrt{s}$ = 8 TeV with the ATLAS

    CERN Document Server

    Karpova, Zoya; The ATLAS collaboration; ATLAS Collaboration

    2015-01-01

    Search for quantum black holes (QBHs) was performed with proton-proton collision data collected by the ATLAS detector at the LHC in 2012 at a center-of-mass energy $\\sqrt{s}$ = 8 TeV with the integrated luminosity of 20.3 fb$^{-1}$. The QBH production is modeled with the ADD-model with the number of large extra dimensions $n$ = 6. The QBH is assumed to decay into a final state with a lepton (electron or muon) and a jet. This final state is preferred in the above model and it is assumed to be sensitive to the TeV scale gravity. There are no events with a lepton-jet invariant mass of 3.5 TeV or more in both electron and muon channel. The measurement is consistent with the expected background. The combined 95\\% confidence level upper limit on product of the QBH production cross sections and the branching fractions of decay into the lepton+jet is equal to 0.18 fb. The upper limit constrains the threshold quantum black-hole mass to be above 5.3 TeV in the model considered.

  14. Tuning of event generators to measurements of $t\\bar{t}$ production and a general search for new physics with the ATLAS experiment

    CERN Document Server

    AUTHOR|(SzGeCERN)676067

    The start of the Large Hadron Collider provides an unprecedent opportunity for the exploration of physics at the \\TeV{} scale. It is expected to perform precise tests of the structure of the Standard Model and to hint at the structure of the physical laws at a more fundamental level. \\paragraph{} The first part of this work describes a tune of the initial- and final-state radiation parameters in the \\textsc{Pythia8} Monte Carlo generator, using ATLAS measurements of \\ttbar{} production at $\\sqrt{s}=7$ \\TeV{}. The results are compared to previous tunes to the $Z$ boson transverse momentum at the LHC, and to the LEP event shapes in $Z$ boson hadronic decays, testing of the universality of the parton shower model. The tune of Pythia8 to the \\ttbar{} measurements is applied to the next-to-leading order generators MadGraph5\\_aMC@NLO and Powheg, and additional parameters of these generators are tuned to the \\ttbar{} data. For the first time in the context of Monte Carlo tuning, the correlation of the experimental ...

  15. Asymmetric dark matter from spontaneous cogenesis in the supersymmetric standard model

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics

    2012-01-15

    The observational relation between the density of baryon and dark matter in the Universe, {omega}{sub DM}/{omega}{sub B}{approx_equal}5, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of baryon asymmetry is transferred to charge asymmetry D that dark matter carries, if a symmetry violating interaction that works at high temperature breaks not only B-L but also D symmetries simultaneously. In this case, the present number density of baryon and dark matter can be same order if the symmetric part of dark matter annihilates sufficiently. Moreover, the baryon number density can be enhanced as compared to that of dark matter if another B-L violating interaction is still in thermal equilibrium after the spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric dark matter model. (orig.)

  16. Low energy probes of PeV scale sfermions

    Energy Technology Data Exchange (ETDEWEB)

    Altmannshofer, Wolfgang; Harnik, Roni; Zupan, Jure

    2013-11-27

    We derive bounds on squark and slepton masses in mini-split supersymmetry scenario using low energy experiments. In this setup gauginos are at the TeV scale, while sfermions are heavier by a loop factor. We cover the most sensitive low energy probes including electric dipole moments (EDMs), meson oscillations and charged lepton flavor violation (LFV) transitions. A leading log resummation of the large logs of gluino to sfermion mass ratio is performed. A sensitivity to PeV squark masses is obtained at present from kaon mixing measurements. A number of observables, including neutron EDMs, mu->e transitions and charmed meson mixing, will start probing sfermion masses in the 100 TeV-1000 TeV range with the projected improvements in the experimental sensitivities. We also discuss the implications of our results for a variety of models that address the flavor hierarchy of quarks and leptons. We find that EDM searches will be a robust probe of models in which fermion masses are generated radiatively, while LFV searches remain sensitive to simple-texture based flavor models.

  17. New physics in B→K * μμ?

    Energy Technology Data Exchange (ETDEWEB)

    Altmannshofer, Wolfgang; Straub, David M.

    2013-11-26

    Recent experimental results on angular observables in the rare decay $B\\to K^*\\mu^+\\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining all relevant data on $b \\to s$ rare decays, we show that a consistent explanation of most anomalies can be obtained by new physics contributing simultaneously to the semi-leptonic vector operator $O_9$ and its chirality-flipped counterpart $O_9'$. A partial explanation is possible with new physics in $O_9$ or in dipole operators only. We study in detail the implications for models of new physics, in particular the minimal supersymmetric standard model, models with partial compositeness and generic models with flavour-changing $Z^\\prime$ bosons. In all considered models, contributions to $B\\to K^*\\mu^+\\mu^-$ of the preferred size imply a spectrum close to the TeV scale. We stress that measurements of CP asymmetries in $B\\to K^*\\mu^+\\mu^-$ could provide valuable information to narrow down possible new physics explanations.

  18. Mesure de la section efficace de production de paires de photons isolés dans l'expérience ATLAS au LHC et étude des couplages à quatre photons

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00387311; Schoeffel, Laurent

    The LHC, which is the most powerful proton-proton collider in the world located at CERN (Switzerland), brings unprecedented opportunities to test our knowledge of the fundamental interactions at the TeV scale. In this work, two main projects have been achieved for this purpose. First, the production cross section measurement of at least two photons in the final state ($pp\\rightarrow\\gamma\\gamma+X$) is performed with data taken at a center-of-mass energy of 8 TeV by the ATLAS detector, which is one of the multipurpose detector installed around the LHC ring. Photons are interesting probes to test the theory of strong interactions (Quantum chromodynamics or QCD) since they couple significantly to quarks but do not hadronize and thus still allow to perform high resolution measurements. The measurement of their production rate at the LHC allows to test QCD in both the perturbative and the non-perturbative domain. It is also sensitive to the emission of soft particles in the initial-state, which is tricky to handle...

  19. Measurement of the ZZ(*) and Zgamma production cross sections at 8 TeV and 13 TeV and limits on anomalous triple gauge couplings with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00372074; The ATLAS collaboration

    2016-01-01

    Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has measured inclusive and differential cross sections of the production of ZZ pairs and Z and photon pairs, using final states with the Z decaying to charged leptons or neutrinos. First inte- grated measurements of the ZZ pair production cross sections using fully leptonic final states at 13 TeV using data corresponding to 3.2 /fb are presented. Detailed studies of integrated and differen- tial cross sections have been performed using data corresponding to 20.3 /fb at a centre-of-mass energy of 8 TeV. The measurements are performed as a function of a variety of kinematic vari- ables calculated from the leptons, like the transverse momentum or rapidity of the vector bosons. For the case of the production of four charged leptons a me...

  20. Diboson Production, Vector Boson Fusion and Vector Boson Scattering measurements with the ATLAS detector

    CERN Document Server

    Geng, Cong; The ATLAS collaboration

    2017-01-01

    Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has performed detailed measurements of integrated and differential cross sections of the production of heavy di-boson pairs, such as WW, WZ and ZZ, in the fully-leptonic and partially in the semi-leptonic final states at centre-of-mass energies of 8 and 13 TeV. Moreover, searches for the production of three W bosons or of a W boson and a photon together with a Z or W boson at a center of mass energy of 8 TeV will be presented. These studies are closely connected to the electroweak production of a heavy boson and a photon together with two jets. Evidence has been found for the exclusive production of W boson pairs, which will be presented in this talk. When selecting two jets at high invariant mass in addition to the production of th...

  1. LHC signals of the SO(5×U(1 gauge-Higgs unification

    Directory of Open Access Journals (Sweden)

    Shimotani Takuya

    2015-01-01

    Full Text Available We study the LHC signals of SO(5×U(1 gauge-Higgs unification as a beyond the standard model (SM. When the extra dimensional space is not simply-connected, dynamics of the Aharonov-Bohm (AB phase, θH, in the extra dimension can induce dynamical gauge symmetry breaking by the Hosotani mechanism. The Kaluza-Klein (KK mass spectra of γ, Z, ZR and Higgs self couplings obey universal relations with θH in the fifth dimension. In our model, three neutral gauge bosons, Z′ bosons, appear at TeV scale. Z′ bosons are the first KK modes ZR(1, Z(1, and γ(1. We analyze Z′ bosons through dilepton events at LHC. For θH = 0.114, the mass and decay width of ZR(1, Z(1, and γ(1 are (5.73, 482, (6.07, 342, and (6.08 TeV, 886 GeV, respectively. For θH = 0.073 their masses are 8.00 ∼ 8.61 TeV. An excess of events in the dilepton invariant mass should be observed in the Z′ search at the upgraded LHC at 14 TeV.

  2. Deciphering the MSSM Higgs mass at future hadron colliders

    Science.gov (United States)

    Agrawal, Prateek; Fan, JiJi; Reece, Matthew; Xue, Wei

    2017-06-01

    Future hadron colliders will have a remarkable capacity to discover massive new particles, but their capabilities for precision measurements of couplings that can reveal underlying mechanisms have received less study. In this work we study the capability of future hadron colliders to shed light on a precise, focused question: is the higgs mass of 125 GeV explained by the MSSM? If supersymmetry is realized near the TeV scale, a future hadron collider could produce huge numbers of gluinos and electroweakinos. We explore whether precision measurements of their properties could allow inference of the scalar masses and tan β with sufficient accuracy to test whether physics beyond the MSSM is needed to explain the higgs mass. We also discuss dark matter direct detection and precision higgs physics as complementary probes of tan β. For concreteness, we focus on the mini-split regime of MSSM parameter space at a 100 TeV pp collider, with scalar masses ranging from 10s to about 1000 TeV.

  3. Charged composite scalar dark matter

    Science.gov (United States)

    Balkin, Reuven; Ruhdorfer, Maximilian; Salvioni, Ennio; Weiler, Andreas

    2017-11-01

    We consider a composite model where both the Higgs and a complex scalar χ, which is the dark matter (DM) candidate, arise as light pseudo Nambu-Goldstone bosons (pNGBs) from a strongly coupled sector with TeV scale confinement. The global symmetry structure is SO(7)/SO(6), and the DM is charged under an exact U(1)DM ⊂ SO(6) that ensures its stability. Depending on whether the χ shift symmetry is respected or broken by the coupling of the top quark to the strong sector, the DM can be much lighter than the Higgs or have a weak-scale mass. Here we focus primarily on the latter possibility. We introduce the lowest-lying composite resonances and impose calculability of the scalar potential via generalized Weinberg sum rules. Compared to previous analyses of pNGB DM, the computation of the relic density is improved by fully accounting for the effects of the fermionic top partners. This plays a crucial role in relaxing the tension with the current DM direct detection constraints. The spectrum of resonances contains exotic top partners charged under the U(1)DM, whose LHC phenomenology is analyzed. We identify a region of parameters with f = 1.4 TeV and 200 GeV ≲ m χ ≲ 400 GeV that satisfies all existing bounds. This DM candidate will be tested by XENON1T in the near future.

  4. Academic Training: Physics at e+e- linear collider

    CERN Multimedia

    Françoise Benz

    2004-01-01

    15, 16, 17, 18, 19 November 2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES from 11.00 to 12.00hrs - Main Auditorium, bldg. 500 Physics at e+e- linear collider K. DESCH / Desy, Hamburg, D Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale to very high precision. The lecture series introduces the possibilities of a TeV linear collider (the International Linear Collider, ILC) in the fields of Higgs physics, alternative Electro-weak Symmetry Breaking scenarios, Supersymmetry, Extra Dimensions, and more exotic models. Also the prospects for highly improved measurements of SM parameters such as the top quark mass and electro-weak gauge boson properties are discussed. The implications for the design of an appropriate detector are outlined and current R&D developments are explained. Particular emphasis will be given to the complementarity and intimate interplay of physics at the LHC and the ILC. The additional benefit of multi-TeV e+e- collisions as envisaged i...

  5. Theoretical constraints on masses of heavy particles in Left-Right symmetric models

    Directory of Open Access Journals (Sweden)

    J. Chakrabortty

    2016-08-01

    Full Text Available Left-Right symmetric models with general gL≠gR gauge couplings which include bidoublet and triplet scalar multiplets are studied. Possible scalar mass spectra are outlined by imposing Tree-Unitarity, and Vacuum Stability criteria and also using the bounds on neutral scalar masses MHFCNC which assure the absence of Flavour Changing Neutral Currents (FCNC. We are focusing on mass spectra relevant for the LHC analysis, i.e., the scalar masses are around TeV scale. As all non-standard heavy particle masses are related to the vacuum expectation value (VEV of the right-handed triplet (vR, the combined effects of relevant Higgs potential parameters and MHFCNC regulate the lower limits of heavy gauge boson masses. The complete set of Renormalization Group Evolutions for all couplings are provided at the 1-loop level, including the mixing effects in the Yukawa sector. Most of the scalar couplings suffer from the Landau poles at the intermediate scale Q∼106.5 GeV, which in general coincides with violation of the Tree-Unitarity bounds.

  6. Unified Explanation of the eejj, Diboson, and Dijet Resonances at the LHC.

    Science.gov (United States)

    Dev, P S Bhupal; Mohapatra, R N

    2015-10-30

    We show that the excess events observed in a number of recent LHC resonance searches can be simultaneously explained within a nonsupersymmetric left-right inverse seesaw model for neutrino masses with W_{R} mass around 1.9 TeV. The minimal particle content that leads to gauge coupling unification in this model predicts g_{R}≃0.51 at the TeV scale, which is consistent with data. The extra color singlet, SU(2)-triplet fermions required for unification can be interpreted as the dark matter of the Universe. Future measurements of the ratio of same-sign to opposite-sign dilepton events can provide a way to distinguish this scenario from the canonical cases of type-I and inverse seesaw, i.e., provide a measure of the relative magnitudes of the Dirac and Majorana masses of the right-handed neutrinos in the SU(2)_{R} doublet of the left-right symmetric model.

  7. Study of Multiboson Production with the ATLAS detector

    CERN Document Server

    Kubota, Takashi; The ATLAS collaboration

    2017-01-01

    Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has performed detailed measurements of integrated and differential cross sections of the production of heavy di-boson pairs, such as WW, WZ and ZZ, in the fully-leptonic and partially in the semi-leptonic final states at centre-of-mass energies of 8 and 13 TeV. Moreover, searches for the production of three W bosons or of a W boson and a photon together with a Z or W boson at a center of mass energy of 8 TeV will be presented. These studies are closely connected to the electroweak production of a heavy boson and a photon together with two jets. Evidence has been found for the exclusive production of W boson pairs, which will be presented in this talk.

  8. Axial, Scalar and Tensor Charges of the Nucleon from 2+1+1-flavor Lattice QCD

    CERN Document Server

    Bhattacharya, Tanmoy; Cohen, Saul; Gupta, Rajan; Lin, Huey-Wen; Yoon, Boram

    2016-01-01

    We present results for the isovector axial, scalar and tensor charges $g^{u-d}_A$, $g^{u-d}_S$ and $g^{u-d}_T$ of the nucleon needed to probe the Standard Model and novel physics. The axial charge is a fundamental parameter describing the weak interactions of nucleons. The scalar and tensor charges probe novel interactions at the TeV scale in neutron and nuclear $\\beta$-decays, and the flavor-diagonal tensor charges $g^{u}_T$, $g^{d}_T$ and $g^{s}_T$ are needed to quantify the contribution of the quark electric dipole moment (EDM) to the neutron EDM. The lattice-QCD calculations were done using nine ensembles of gauge configurations generated by the MILC Collaboration using the HISQ action with 2+1+1 dynamical flavors. These ensembles span three lattice spacings $a \\approx 0.06, 0.09$ and $0.12$ fm and light-quark masses corresponding to the pion masses $M_\\pi \\approx$ 135, 225 and 315 MeV. High-statistics estimates on five ensembles using the all-mode-averaging method allow us to quantify all systematic unce...

  9. Technological challenges of CLIC

    CERN Multimedia

    CERN. Geneva; Döbert, Steffen; Arnau-Izquierdo, G; Redaelli, Stefano; Mainaud, Helène; Lefèvre, Thibaut

    2006-01-01

    Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&D effort is presently developed by the CLIC international collaboration to demonstrate its feasibility by 2010, when the first physics results from LHC should be available to guide the choice of the centre-of-mass energy better suited to explore the futu...

  10. Constraints on parton distributions and the strong coupling from LHC jet data

    Science.gov (United States)

    Rojo, Juan

    2015-11-01

    Jet production at hadron colliders provides powerful constraints on the parton distribution functions (PDFs) of the proton, in particular on the gluon PDF. Jet production can also be used to extract the QCD coupling αs(Q) and to test its running with the momentum transfer up to the TeV region. In this review, I summarize the information on PDFs and the strong coupling that has been provided by Run I LHC jet data. First of all, I discuss why jet production is directly sensitive to the gluon and quark PDFs at large-x, and then review the state-of-the-art perturbative calculations for jet production at hadron colliders and the corresponding fast calculations required for PDF fitting. Then I present the results of various recent studies on the impact on PDFs, in particular the gluon, that have been performed using as input jet measurements from ATLAS and CMS. I also review the available determinations of the strong coupling constant based on ATLAS and CMS jet data, with emphasis on the fact that LHC jet data provides, for the first time, a direct test of the αs(Q) running at the TeV scale. I conclude with a brief outlook on possible future developments.

  11. ATLAS Physics Prospects for the Upgraded LHC

    CERN Document Server

    Ilic, N; The ATLAS collaboration

    2015-01-01

    The 2010-2012 operation period at the LHC has been very successful, including the discovery of a new particle with a mass of about 125 GeV compatible within uncertainties with the Higgs boson predicted by Standard Model. Precise measurements of the properties of this boson, and the discovery of new physics beyond the Standard Model, are primary goals of future running at the LHC. The physics prospects with a proton-proton centre-of-mass energy of 14 TeV are presented for 300 fb-1 and 3000 fb-1 at the high-luminositiy LHC. The ultimate precision attainable on measurements of the couplings of the 125 GeV particle to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with this new object, predicted by several extensions of the standard theory. Supersymmetry is one of the best motivated and well-studied extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well...

  12. Rapid Asymmetric Inflation and Early Cosmology in Theories with Sub-Millimeter Dimensions

    CERN Document Server

    Arkani-Hamed, N; Kaloper, Nemanja; March-Russell, John David; Arkani-Hamed, Nima; Dimopoulos, Savas; Kaloper, Nemanja; March-Russell, John

    2000-01-01

    It was recently pointed out that the fundamental Planck mass could be close to the TeV scale with the observed weakness of gravity at long distances being due the existence of new sub-millimeter spatial dimensions. In this picture the standard model fields are localized to a $(3+1)$-dimensional wall or ``3-brane''. We show that in such theories there exist attractive models of inflation that occur while the size of the new dimensions are still small. We show that it is easy to produce the required number of efoldings, and further that the density perturbations $\\delta\\rho/\\rho$ as measured by COBE can be easily reproduced, both in overall magnitude and in their approximately scale-invariant spectrum. In the minimal approach, the inflaton field is just the moduli describing the size of the internal dimensions, the role of the inflationary potential being played by the stabilizing potential of the internal space. We show that under quite general conditions, the inflationary era is followed by an epoch of contra...

  13. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  14. Search for $t\\bar{t}$ resonances in the lepton+jets channel in proton-proton collisions at $\\sqrt{s} = 8$ TeV with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00335580

    The Standard Model of Particle Physics is a well proven model for the understanding of the constituents and interactions of ordinary matter. Remaining open questions hint at new physics beyond the Standard Model, motivating theories comprising extensions with new heavy particles decaying into top/anti-top pairs. The ATLAS experiment at the Large Hadron Collider at CERN recorded an integrated luminosity of 21.3 fb$^{-1}$ of data in 2012 at a center of mass energy of $\\sqrt{s} = 8$ TeV, providing an increased sensitivity for heavy resonances with invariant masses in the TeV scale. This thesis presents an analysis of top/anti-top decays with the full 2012 dataset, reconstructing the full decay of the top/anti-top system in the lepton+jets channel with a signature of 4 jets, one charged lepton (electron or muon) and missing transverse energy. The decays are analyzed in resolved and boosted event topologies with different reconstruction and tagging techniques of the decay products. Special emphasis is set on the c...

  15. ATLAS measurements of vector boson production

    CERN Document Server

    Vittori, Camilla; The ATLAS collaboration

    2016-01-01

    Measurements of the Drell­Yan production of W and Z/gamma* bosons at the LHC provide a benchmark of our understanding of perturbative QCD and probe the proton structure in a unique way. The ATLAS collaboration has performed new high precision measurements at center­of­mass energies of 8 and 13 TeV. In the 8 TeV data, we present recent measurements in the di­lepton mass range up to the TeV scale, double­differentially in dilepton mass and rapidity(­separation). The measurements are compared to state­of­the­art calculations at NNLO in QCD and constrain the photon content of the proton. First precise inclusive measurements of W and Z production at 13 TeV are presented. W/Z and W charge ratios profit from a cancellation of experimental uncertainties. The angular distributions of the Drell­Yan lepton pairs around the Z­boson mass peak probe the underlying QCD dynamic of the Z­boson production mechanisms. We present a measurement of the complete set of angular coefficients describing these distributions...

  16. Neutrino mass, leptogenesis and FIMP dark matter in a U(1)_{B-L} model

    Science.gov (United States)

    Biswas, Anirban; Choubey, Sandhya; Khan, Sarif

    2017-12-01

    The Standard Model (SM) is inadequate to explain the origin of tiny neutrino masses, the dark matter (DM) relic abundance and the baryon asymmetry of the Universe. In this work, to address all three puzzles, we extend the SM by a local U(1)_{B-L} gauge symmetry, three right-handed (RH) neutrinos for the cancellation of gauge anomalies and two complex scalars having non-zero U(1)_{B-L} charges. All the newly added particles become massive after the breaking of the U(1)_{B-L} symmetry by the vacuum expectation value (VEV) of one of the scalar fields φ _H. The other scalar field, φ _DM, which does not have any VEV, becomes automatically stable and can be a viable DM candidate. Neutrino masses are generated using the Type-I seesaw mechanism, while the required lepton asymmetry to reproduce the observed baryon asymmetry can be attained from the CP violating out of equilibrium decays of the RH neutrinos in TeV scale. More importantly within this framework, we study in detail the production of DM via the freeze-in mechanism considering all possible annihilation and decay processes. Finally, we find a situation when DM is dominantly produced from the annihilation of the RH neutrinos, which are at the same time also responsible for neutrino mass generation and leptogenesis.

  17. Search for the Supersymmetric Partner to the Top Quark Using Recoils Against Strong Initial State Radiation

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00375257

    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...

  18. GUT models at current and future hadron colliders and implications to dark matter searches

    Directory of Open Access Journals (Sweden)

    Giorgio Arcadi

    2017-08-01

    Full Text Available Grand Unified Theories (GUT offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables arising from Abelian groups embedded in GUT constructions. That said, we use dilepton data (ee and μμ that has been proven to be a golden channel for a wide variety of new phenomena expected in theories beyond the Standard Model to probe GUT-inspired models. Since heavy dilepton resonances feature high signal selection efficiencies and relatively well-understood backgrounds, stringent and reliable bounds can be placed on the mass of the Z′ gauge boson arising in such theories. In this work, we obtain 95% C.L. limits on the Z′ mass for several GUT-models using current and future proton–proton colliders with s=13 TeV,33 TeV,and100 TeV, and put them into perspective with dark matter searches in light of the next generation of direct detection experiments.

  19. Supersymmetric model for dark matter and baryogenesis motivated by the recent CDMS result.

    Science.gov (United States)

    Allahverdi, Rouzbeh; Dutta, Bhaskar; Mohapatra, Rabindra N; Sinha, Kuver

    2013-08-02

    We discuss a supersymmetric model for cogenesis of dark and baryonic matter where the dark matter (DM) has mass in the 8-10 GeV range as indicated by several direct detection searches, including most recently the CDMS experiment with the desired cross section. The DM candidate is a real scalar field. Two key distinguishing features of the model are the following: (i) in contrast with the conventional weakly interacting massive particle dark matter scenarios where thermal freeze-out is responsible for the observed relic density, our model uses nonthermal production of dark matter after reheating of the Universe caused by moduli decay at temperatures below the QCD phase transition, a feature which alleviates the relic overabundance problem caused by small annihilation cross section of light DM particles and (ii) baryogenesis occurs also at similar low temperatures from the decay of TeV scale mediator particles arising from moduli decay. A possible test of this model is the existence of colored particles with TeV masses accessible at the LHC.

  20. A Precision Low-Energy Measurement of the Weak Mixing Angle in Moller Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Mastromarino, P.

    2005-01-26

    The E-158 experiment at the Stanford Linear Accelerator Center (SLAC) measures the parity-violating cross-section asymmetry in electron-electron (Moeller) scattering at low Q{sup 2}. This asymmetry, whose Standard Model prediction is roughly -150 parts per billion (ppb), is directly proportional to (1-4 sin{sup 2} {theta}{sub W}), where {theta}{sub W} is the weak mixing angle. Measuring this asymmetry to within 10% provides an important test of the Standard Model at the quantum loop level and probes for new physics at the TeV scale. The experiment employs the SLAC 50 GeV electron beam, scattering it off a liquid hydrogen target. A system of magnets and collimators is used to isolate and focus the Moeller scattering events into an integrating calorimeter. The electron beam is generated at the source using a strained, gradient-doped GaAs photocathode, which produces roughly 5 x 10{sup 11} electrons/pulse (at a beam rate of 120 Hz) with {approx} 80% longitudinal polarization. The helicity of the beam can be rapidly switched, eliminating problems associated with slow drifts. Helicity-correlations in the beam parameters (charge, position, angle and energy) are minimized at the source and corrected for using precision beam monitoring devices.

  1. Identification of Hadronic Tau Lepton Decays at the ATLAS Detector Using Artificial Neural Networks

    CERN Document Server

    AUTHOR|(CDS)2093068; Zuber, Kai

    Tau leptons play an important role in a wide range of physics analyses at the LHC, such as the verification of the Standard Model at the TeV scale or the determination of Higgs boson properties. For the identification of hadronically decaying tau leptons with the ATLAS detector, a sophisticated, multi-variate algorithm is required. This is due to the high production cross section for QCD jets, the dominant background. Artificial neural networks (ANNs) have gained much attention in recent years by winning several pattern recognition contests. In this thesis, a survey of ANNs is given with a focus on developments of the past 20 years. Based on this work, a novel, ANN-based tau identification is presented which is competitive to the current BDT-based approach. The influence of various hyperparameters on the identification is studied and optimized. Both stability and performance are enhanced through formation of ANN ensembles. Additionally, a score-flattening algorithm is presented that is beneficial to physics a...

  2. Probing physics beyond the standard model with neutrinoless double beta decay

    Science.gov (United States)

    Hirsch, M.; Klapdor-Kleingrothaus, H. V.

    1997-01-01

    Neutrinoless double beta decay (0νββ) is the most sensitive low-energy probe for physics beyond the standard model. Usually the lower limit of 0νββ decay half-lives is interpreted in terms of an upper limit on the effective Majorana neutrino mass. However, numerous further possible extensions of the standard model can be tested by 0νββ decay. Among the models which can contribute to 0νββ decay are left-right symmetric models of the weak interaction, R-parity violating supersymmetric theories and models of light leptoquarks. We review the constraints on these models which can be derived currently from the non-observation of 0νββ decay and discuss the impacts of these results on accelerator searches and other experiments. Interestingly, it is found that 0νββ decay probes already now the TeV scale on which new physics should manifest itself according to present theoretical expectations.

  3. Uncover compressed supersymmetry via boosted bosons from the heavier stop/sbottom

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Zhaofeng; Li, Jinmian [Korea Institute for Advanced Study, School of Physics, Seoul (Korea, Republic of); Zhang, Mengchao [Institute for Basic Science (IBS), Center for Theoretical Physics of the Universe, Daejeon (Korea, Republic of)

    2017-06-15

    A light stop around the weak scale is a hopeful messenger of natural supersymmetry (SUSY), but it has not shown up at the current stage of LHC. Such a situation raises the question of the fate of natural SUSY. Actually, a relatively light stop can easily be hidden in a compressed spectra such as mild mass degeneracy between stop and neutralino plus top quark. Searching for such a stop at the LHC is a challenge. On the other hand, in terms of the argument of natural SUSY, other members in the stop sector, including a heavier stop t{sub 2} and lighter sbottom b{sub 1} (both assumed to be left-handed-like), are also supposed to be relatively light and therefore searching for them would provide an alternative method to probe natural SUSY with a compressed spectra. In this paper we consider quasi-natural SUSY which tolerates relatively heavy colored partners near the TeV scale, with a moderately large mass gap between the heavier members and the lightest stop. Then W/Z/h as companions of t{sub 2} and b{sub 1} decaying into t{sub 1} generically are well boosted, and they, along with other visible particles from t{sub 1} decay, are a good probe to study compressed SUSY. We find that the resulting search strategy with boosted bosons can have better sensitivity than those utilizing multi-leptons. (orig.)

  4. 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 physics signals or just background fluctuations. In a careful evaluation of the loop-corrected scalar potential we then identify parameter regions in which the vacuum with the phenomenologically correct symmetry-breaking properties is stable. Conveniently, those regions favour low left-right symmetry breaking scales which are accessible at the LHC. In a slightly modified version of this model where a U(1){sub R} x U(1){sub B-L} gauge symmetry survives down to the TeV scale, we implement a minimal gauge-mediated supersymmetry breaking mechanism for which we calculate the boundary conditions in the presence of gauge kinetic mixing. We show how the presence of the extended gauge group raises the tree-level Higgs mass considerably so that the need for heavy supersymmetric spectra is relaxed. Taking the constraints from the Higgs sector into account, we then explore the LHC phenomenology of this model and point out where the expected collider signatures can be distinguished from standard scenarios. In particular if neutrino masses are explained by low-scale seesaw mechanisms as is done throughout this work, there are potentially spectacular signals at low-energy experiments which search for charged lepton flavour violation. The last part of this thesis is dedicated to the detailed exploration of processes like μ→eγ, μ→3e or μ-e conversion in nuclei in a supersymmetric framework with an inverse seesaw mechanism. In particular, we disprove claims about a non-decoupling effect in Z-mediated three-body decays and study the prospects for discovering and distinguishing signals at near-future experiments. In this context we identify the possibility to deduce from ratios like BR(τ→3μ)/BR(τ→μe{sup +}e{sup -}) whether the contributions from ν-W loops dominate over supersymmetric contributions or vice versa.

  5. Complementarity of Symmetry Tests at the Energy and Intensity Frontiers

    Science.gov (United States)

    Peng, Tao

    We studied several symmetries and interactions beyond the Standard Model and their phenomenology in both high energy colliders and low energy experiments. The lepton number conservation is not a fundamental symmetry in Standard Model (SM). The nature of the neutrino depends on whether or not lepton number is violated. Leptogenesis also requires lepton number violation (LNV). So we want to know whether lepton number is a good symmetry or not, and we want to compare the sensitivity of high energy collider and low energy neutrinoless double-beta decay (0nubetabeta) experiments. To do this, We included the QCD running effects, the background analysis, and the long-distance contributions to nuclear matrix elements. Our result shows that the reach of future tonne-scale 0nubetabeta decay experiments generally exceeds the reach of the 14 TeV LHC for a class of simplified models. For a range of heavy particle masses at the TeV scale, the high luminosity 14 TeV LHC and tonne-scale 0nubetabeta decay experiments may provide complementary probles. The 100 TeV collider with a luminosity of 30 ab-1 exceeds the reach of the tonne-scale 0nubetabeta experiments for most of the range of the heavy particle masses at the TeV scale. We considered a non-Abelian kinetic mixing between the Standard Model gauge bosons and a U(1)' gauge group dark photon, with the existence of an SU(2)L scalar triplet. The coupling constant between the dark photon and the SM gauge bosons epsilon is determined by the triplet vacuum expectation value (vev), the scale of the effective theory Lambda, and the effective operator Wiloson coefficient. The triplet vev is constrained to ≤ 4 GeV. By taking the effective operator Wiloson coefficient to be O(1) and Lambda > 1 TeV, we will have a small value of epsilon which is consistent with the experimental constraint. We outlined the possible LHC signatures and recasted the current ATLAS dark photon experimental results into our non-Abelian mixing scenario. We analyzed the QCD corrections to dark matter (DM) interactions with SM quarks and gluons. Because we like to know the new physics at high scale and the effect of the direct detection of DM at low scale, we studied the QCD running for a list of dark matter effective operators. These corrections are important in precision DM physics. Currently little is known about the short-distance physics of DM. We find that the short-distance QCD corrections generate a finite matching correction when integrating out the electroweak gauge bosons. The high precision measurements of electroweak precision observables can provide crucial input in the search for supersymmetry (SUSY) and play an important role in testing the universality of the SM charged current interaction. We studied the SUSY corrections to such observables DeltaCKM and Deltae/mu, with the experimental constraints on the parameter space. Their corrections are generally of order O(10 -4). Future experiments need to reach this precision to search for SUSY using these observables.

  6. A Precision Measurement of Parity Violation in Moller Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Relyea, D

    2004-05-13

    This thesis reports on E158, an experiment located in End Station A at the Stanford Linear Accelerator Center (SLAC). E158 has made the first observation of the parity violating right-left asymmetry (A{sub PV}) in fixed-target low-Q{sup 2} Moeller scattering. At tree level, A{sub PV} (expected to be around -150 ppb) is directly proportional to 1/4 - sin{sup 2} {theta}{sub W}. A precision measurement of A{sub PV} at low Q{sup 2} allows the running of sin{sup 2} {theta}{sub W} to be compared to the Standard Model prediction. Disagreements between the two might provide evidence for new physics at the TeV scale. This thesis presents the first physics data from E158, taken in the spring of 2002. The data were taken by scattering longitudinally polarized electrons at 45.0 and 48.3 GeV off a liquid hydrogen target at a Q{sup 2} of 0.027 GeV{sup 2}. A 60 meter long spectrometer/collimator system and a cooper-quartz calorimeter were used to detect the Moeller signal electrons. Both devices will be described in detail. The right-left parity violating asymmetry in Moeller scattering has been measured to be -152.3 {+-} 29.0(stat) {+-} 30.9(syst) ppb. The value of sin{sup 2} {theta}{sub W} derived from this measurement is 0.2370 {+-} 0.0025(stat) {+-} 0.0026(syst), in comparison with the Standard Model prediction of 0.2387 {+-} 0.0007.

  7. Soft SUSY breaking parameters and RG running of squark and slepton masses in large volume Swiss Cheese compactifications

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2010-03-01

    We consider type IIB large volume compactifications involving orientifolds of the Swiss Cheese Calabi-Yau WCP[1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the “big” divisor ΣB (as opposed to the “small” divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of [1] (Misra and Shukla, 2010) for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our results of [1] (Misra and Shukla, 2010) on soft supersymmetry breaking terms and open-string moduli masses, we discuss the one-loop RG running of the squark and slepton masses in mSUGRA-like models (using the running of the gaugino masses) to the EW scale in the large volume limit. Phenomenological constraints and some of the calculated soft SUSY parameters identify the D7-brane Wilson line moduli as the first two generations/families of squarks and sleptons and the D3-brane (restricted to the big divisor) position moduli as the two Higgses for MSSM-like models at TeV scale. We also discuss how the obtained open-string/matter moduli make it easier to impose FCNC constraints, as well as RG flow of off-diagonal squark mass(-squared) matrix elements.

  8. J. J. Sakurai Prize for Theoretical Particle Physics Talk: The Boundless Horizons of Supercollider Physics

    Science.gov (United States)

    Quigg, Chris

    2011-04-01

    The Large Hadron Collider at CERN is moving the experimental frontier of particle physics to the domain of electroweak symmetry breaking, reaching energies around one trillion electron volts for collisions among the basic constituents of matter. We do not know what the new wave of exploration will find, but the discoveries we make and the new puzzles we encounter are certain to change the face of particle physics and echo through neighboring sciences. In this new world, we confidently expect to learn what sets electromagnetism apart from the weak interactions, with profound implications for deceptively simple questions: Why are there atoms? Why chemistry? What makes stable structures possible? A pivotal step will be finding the Higgs boson-or whatever takes its place -and exploring its properties. But we hope for much more. More predictive extensions of the electroweak theory, including dynamical symmetry breaking and supersymmetry, imply new kinds of matter that would be within reach of LHC experiments. We suspect that candidates for the dark matter of the Universe could also await discovery on the TeV scale. The strong interactions may hold their own surprises. As we unravel the riddle of electroweak symmetry breaking, prospects arise for other new insights: into the different forms of matter, the unity of quarks and leptons, and the nature of spacetime. The questions in play all seem linked to one another-and to the kinship of the weak and electromagnetic interactions. I will speak of the evolving dialogue between theory and experiment, highlighting the work before us. Fermilab is operated by the Fermi Research Alliance under contract no. DE-AC02-07CH11359 with the U.S. Department of Energy.

  9. A supersymmetric standard model from a local E{sub 6} GUT

    Energy Technology Data Exchange (ETDEWEB)

    Braam, Felix Klaus

    2012-02-15

    In this thesis we have investigated to what extent the exceptional Lie-group E{sub 6} can serve as unified gauge group. In the presence of the full E{sub 6} matter content, unifcation can be realized by increasing the degree of gauge symmetry above some intermediate scale. We found that a full E{sub 6} gauge invariant theory is disfavoured by phenomenological observations like proton stability and the smallness of flavour changing neutral currents. An appropriate framework to embed E{sub 6} into a model for particle physics are higher dimensional orbifold constructions, where E{sub 6} is the gauge group in the bulk and the intermediate symmetry group is the common subset of E{sub 6} subgroups residing at the fixed-points of the orbifold. In this way the degree of symmetry in four space-time dimensions is reduced, such that the operators leading to the aforementioned dsastrous phenomenological consequences can be forbidden independently. In order to derive the implications of the model for the current experiments at the Large Hadron Collider (LHC), we developed an automated spectrum generator. It uses Monte-Carlo Markov-Chain techniques to cope with the high dimensionality of the space of input parameters and the complex interdependencies in the evolution of the Lagrangian parameters from the orbifold compactification scale to the TeV scale. For the spectra obtained with this program, we performed Monte-Carlo simulations of the production and decay of the Z{sup '} boson stemming from the additional U(1){sup '}, using our own implementation of the model into the event generator WHIZARD.

  10. Predictive Landscapes and New Physics at a TeV

    Energy Technology Data Exchange (ETDEWEB)

    Arkani-Hamed, N.

    2005-01-28

    We propose that the Standard Model is coupled to a sector with an enormous landscape of vacua, where only the dimensionful parameters--the vacuum energy and Higgs masses--are finely ''scanned'' from one vacuum to another, while dimensionless couplings are effectively fixed. This allows us to preserve achievements of the usual unique-vacuum approach in relating dimensionless couplings while also accounting for the success of the anthropic approach to the cosmological constant problem. It can also explain the proximity of the weak scale to the geometric mean of the Planck and vacuum energy scales. We realize this idea with field theory landscapes consisting of N fields and 2{sup N} vacua, where the fractional variation of couplings is smaller than 1/{radical}N. These lead to a variety of low-energy theories including the Standard Model, the MSSM, and Split SUSY. This picture suggests sharp new rules for model-building, providing the first framework in which to simultaneously address the cosmological constant problem together with the big and little hierarchy problems. Requiring the existence of atoms can fix ratio of the QCD scale to the weak scale, thereby providing a possible solution to the hierarchy problem as well as related puzzles such as the {mu} and doublet-triplet splitting problems. We also present new approaches to the hierarchy problem, where the fine-tuning of the Higgs mass to exponentially small scales is understood by even more basic environmental requirements such as vacuum stability and the existence of baryons. These theories predict new physics at the TeV scale, including a dark matter candidate. The simplest theory has weak-scale ''Higgsinos'' as the only new particles charged under the Standard Model, with gauge coupling unification near 10{sup 14} GeV.

  11. Emergent spacetime in stochastically evolving dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Afshordi, Niayesh [Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1 (Canada); HEPCOS, Department of Physics, SUNY at Buffalo, Buffalo, NY 14260-1500 (United States); Stojkovic, Dejan, E-mail: ds77@buffalo.edu [Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada); HEPCOS, Department of Physics, SUNY at Buffalo, Buffalo, NY 14260-1500 (United States)

    2014-12-12

    Changing the dimensionality of the space–time at the smallest and largest distances has manifold theoretical advantages. If the space is lower dimensional in the high energy regime, then there are no ultraviolet divergencies in field theories, it is possible to quantize gravity, and the theory of matter plus gravity is free of divergencies or renormalizable. If the space is higher dimensional at cosmological scales, then some cosmological problems (including the cosmological constant problem) can be attacked from a completely new perspective. In this paper, we construct an explicit model of “evolving dimensions” in which the dimensions open up as the temperature of the universe drops. We adopt the string theory framework in which the dimensions are fields that live on the string worldsheet, and add temperature dependent mass terms for them. At the Big Bang, all the dimensions are very heavy and are not excited. As the universe cools down, dimensions open up one by one. Thus, the dimensionality of the space we live in depends on the energy or temperature that we are probing. In particular, we provide a kinematic Brandenberger–Vafa argument for how a discrete causal set, and eventually a continuum (3+1)-dim spacetime along with Einstein gravity emerges in the Infrared from the worldsheet action. The (3+1)-dim Planck mass and the string scale become directly related, without any compactification. Amongst other predictions, we argue that LHC might be blind to new physics even if it comes at the TeV scale. In contrast, cosmic ray experiments, especially those that can register the very beginning of the shower, and collisions with high multiplicity and density of particles, might be sensitive to the dimensional cross-over.

  12. Emergent spacetime in stochastically evolving dimensions

    Science.gov (United States)

    Afshordi, Niayesh; Stojkovic, Dejan

    2014-12-01

    Changing the dimensionality of the space-time at the smallest and largest distances has manifold theoretical advantages. If the space is lower dimensional in the high energy regime, then there are no ultraviolet divergencies in field theories, it is possible to quantize gravity, and the theory of matter plus gravity is free of divergencies or renormalizable. If the space is higher dimensional at cosmological scales, then some cosmological problems (including the cosmological constant problem) can be attacked from a completely new perspective. In this paper, we construct an explicit model of ;evolving dimensions; in which the dimensions open up as the temperature of the universe drops. We adopt the string theory framework in which the dimensions are fields that live on the string worldsheet, and add temperature dependent mass terms for them. At the Big Bang, all the dimensions are very heavy and are not excited. As the universe cools down, dimensions open up one by one. Thus, the dimensionality of the space we live in depends on the energy or temperature that we are probing. In particular, we provide a kinematic Brandenberger-Vafa argument for how a discrete causal set, and eventually a continuum (3 + 1)-dim spacetime along with Einstein gravity emerges in the Infrared from the worldsheet action. The (3 + 1)-dim Planck mass and the string scale become directly related, without any compactification. Amongst other predictions, we argue that LHC might be blind to new physics even if it comes at the TeV scale. In contrast, cosmic ray experiments, especially those that can register the very beginning of the shower, and collisions with high multiplicity and density of particles, might be sensitive to the dimensional cross-over.

  13. Boosted di-boson from a mixed heavy stop

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Diptimoy

    2013-12-01

    The lighter mass eigenstate ($\\widetilde{t}_1$) of the two top squarks, the scalar superpartners of the top quark, is extremely difficult to discover if it is almost degenerate with the lightest neutralino ($\\widetilde{\\chi}_1^0$), the lightest and stable supersymmetric particle in the R-parity conserving supersymmetry. The current experimental bound on $\\widetilde{t}_1$ mass in this scenario stands only around 200 GeV. For such a light $\\widetilde{t}_1$, the heavier top squark ($\\widetilde{t}_2$) can also be around the TeV scale. Moreover, the high value of the higgs ($h$) mass prefers the left and right handed top squarks to be highly mixed allowing the possibility of a considerable branching ratio for $\\widetilde{t}_2 \\to \\widetilde{t}_1 h$ and $\\widetilde{t}_2 \\to \\widetilde{t}_1 Z$. In this paper, we explore the above possibility together with the pair production of $\\widetilde{t}_2$ $\\widetilde{t}_2^*$ giving rise to the spectacular di-boson + missing transverse energy final state. For an approximately 1 TeV $\\widetilde{t}_2$ and a few hundred GeV $\\widetilde{t}_1$ the final state particles can be moderately boosted which encourages us to propose a novel search strategy employing the jet substructure technique to tag the boosted $h$ and $Z$. The reconstruction of the $h$ and $Z$ momenta also allows us to construct the stransverse mass $M_{T2}$ providing an additional efficient handle to fight the backgrounds. We show that a 4--5$\\sigma$ signal can be observed at the 14 TeV LHC for $\\sim$ 1 TeV $\\widetilde{t}_2$ with 100 fb$^{-1}$ integrated luminosity.

  14. A Measurement of the Weak Charge of the Proton through Parity Violating Electron Scattering using the Qweak Apparatus: A 21% Result

    Energy Technology Data Exchange (ETDEWEB)

    Beminiwattha, Rakitha [Ohio Univ., Athens, OH (United States)

    2013-08-01

    After a decade of preparations, the Qweak experiment at Jefferson Lab is making the first direct measurement of the weak charge of the proton, Q^p_W. This quantity is suppressed in the Standard Model making a good candidate for search for new physics beyond the SM at the TeV scale. Operationally, we measure a small (about -0.200 ppm) parity-violating asymmetry in elastic electron-proton scattering in integrating mode while flipping the helicity of the electrons 1000 times per second. Commissioning took place Fall 2010, and we finished taking data in early summer 2012. This dissertation is based on the data taken on an initial two weeks period (Wien0). It will provide an overview of the Qweak apparatus, description of the data acquisition and analysis software systems, and final analysis and results from the Wien0 data set. The result is a 16% measurement of the parity violating electron-proton scattering asymmetry, A = -0.2788 +/- 0.0348 (stat.) +/- 0.0290 (syst.) ppm at Q^2 = 0.0250 +/- 0.0006 (GeV)^2. From this a 21% measurement of the weak charge of the proton, Q_w^p(msr)= +0.0952 +/- 0.0155 (stat.) +/- 0.0131 (syst.) +/- 0.0015 (theory) is extracted. From this a 2% measurement of the weak mixing angle, sin^2theta_W(msr)= +0.2328 +/- 0.0039 (stat.) +/- 0.0033 (syst.) +/- 0.0004 (theory) and improved constraints on isoscalar/isovector effective coupling constants of the weak neutral hadronic currents are extracted. These results deviate from the Standard Model by one standard deviation. The Wien0 results are a proof of principle of the Qweak data analysis and a highlight of the road ahead for obtaining full results.

  15. Physics with e{sup +}e{sup -} Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, Timothy L

    2003-05-05

    We describe the physics potential of e{sup +}e{sup -} linear colliders in this report. These machines are planned to operate in the first phase at a center-of-mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of the operation, a final energy of about 2 TeV is expected. The machines will allow us to perform precision tests of the heavy particles in the Standard Model, the top quark and the electroweak bosons. They are ideal facilities for exploring the properties of Higgs particles, in particular in the intermediate mass range. New vector bosons and novel matter particles in extended gauge theories can be searched for and studied thoroughly. The machines provide unique opportunities for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the supersymmetric partners of the electroweak gauge and Higgs bosons, and of the matter particles. High precision analyses of their properties and interactions will allow for extrapolations to energy scales close to the Planck scale where gravity becomes significant. In alternative scenarios, like compositeness models, novel matter particles and interactions can be discovered and investigated in the energy range above the existing colliders up to the TeV scale. Whatever scenario is realized in Nature, the discovery potential of e{sup +}e{sup -} linear colliders and the high-precision with which the properties of particles and their interactions can be analyzed, define an exciting physics programme complementary to hadron machines.

  16. Hierarchy spectrum of SM fermions: from top quark to electron neutrino

    Science.gov (United States)

    Xue, She-Sheng

    2016-11-01

    In the SM gauge symmetries and fermion content of neutrinos, charged leptons and quarks, we study the effective four-fermion operators of Einstein-Cartan type and their contributions to the Schwinger-Dyson equations of fermion self-energy functions. The study is motivated by the speculation that these four-fermion operators are probably originated due to the quantum gravity, which provides the natural regularization for chiral-symmetric gauge field theories. In the chiral-gauge symmetry breaking phase, as to achieve the energetically favorable ground state, only the top-quark mass is generated via the spontaneous symmetry breaking, and other fermion masses are generated via the explicit symmetry breaking induced by the top-quark mass, four-fermion interactions and fermion-flavor mixing matrices. A phase transition from the symmetry breaking phase to the chiral-gauge symmetric phase at TeV scale occurs and the drastically fine-tuning problem can be resolved. In the infrared fixed-point domain of the four-fermion coupling for the SM at low energies, we qualitatively obtain the hierarchy patterns of the SM fermion Dirac masses, Yukawa couplings and family-flavor mixing matrices with three additional right-handed neutrinos ν R f . Large Majorana masses and lepton-number symmetry breaking are originated by the four-fermion interactions among ν R f and their left-handed conjugated fields ν R fc . Light masses of gauged Majorana neutrinos in the normal hierarchy (10-5 - 10-2 eV) are obtained consistently with neutrino oscillations. We present some discussions on the composite Higgs phenomenology and forward-backward asymmetry of toverline{t} -production, as well as remarks on the candidates of light and heavy dark matter particles (fermions, scalar and pseudoscalar bosons).

  17. Emergent spacetime in stochastically evolving dimensions

    Directory of Open Access Journals (Sweden)

    Niayesh Afshordi

    2014-12-01

    Full Text Available Changing the dimensionality of the space–time at the smallest and largest distances has manifold theoretical advantages. If the space is lower dimensional in the high energy regime, then there are no ultraviolet divergencies in field theories, it is possible to quantize gravity, and the theory of matter plus gravity is free of divergencies or renormalizable. If the space is higher dimensional at cosmological scales, then some cosmological problems (including the cosmological constant problem can be attacked from a completely new perspective. In this paper, we construct an explicit model of “evolving dimensions” in which the dimensions open up as the temperature of the universe drops. We adopt the string theory framework in which the dimensions are fields that live on the string worldsheet, and add temperature dependent mass terms for them. At the Big Bang, all the dimensions are very heavy and are not excited. As the universe cools down, dimensions open up one by one. Thus, the dimensionality of the space we live in depends on the energy or temperature that we are probing. In particular, we provide a kinematic Brandenberger–Vafa argument for how a discrete causal set, and eventually a continuum (3+1-dim spacetime along with Einstein gravity emerges in the Infrared from the worldsheet action. The (3+1-dim Planck mass and the string scale become directly related, without any compactification. Amongst other predictions, we argue that LHC might be blind to new physics even if it comes at the TeV scale. In contrast, cosmic ray experiments, especially those that can register the very beginning of the shower, and collisions with high multiplicity and density of particles, might be sensitive to the dimensional cross-over.

  18. Towards a Precision Measurement of Parity-Violating e-p Elastic Scattering at Low Momentum Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Jie [Univ. of Manitoba, Winnipeg (Canada)

    2012-01-01

    The goal of the Q-weak experiment is to make a measurement of the proton's weak charge QWp = 1 - 4 sin2W2(θW2(θWWp by measuring the parity violating asymmetry in elastic electron-proton scattering at low momentum transfer Q2 = 0.026 (GeV/c)2 and forward angles (8 degrees). The anticipated size of the asymmetry, based on the SM, is about 230 parts per billion (ppb). With the proposed accuracy, the experiment may probe new physics beyond Standard Model at the TeV scale. This thesis focuses on my contributions to the experiment, including track reconstruction for momentum transfer determination of the scattering process, and the focal plane scanner, a detector I designed and built to measure the flux profile of scattered electrons on the focal plane of the Q-weak spectrometer to assist in the extrapolation of low beam current tracking results to high beam current. Preliminary results from the commissioning and the first run period of the Q-weak experiment are reported and discussed.

  19. The importance of calorimetry for highly-boosted jet substructure

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Evan [Brown U.; Freytsis, Marat [Oregon U.; Hinzmann, Andreas [Hamburg U.; Narain, Meenakshi [Brown U.; Thaler, Jesse [MIT, Cambridge, CTP; Tran, Nhan [Fermilab; Vernieri, Caterina [Fermilab

    2017-09-25

    Jet substructure techniques are playing an essential role in exploring the TeV scale at the Large Hadron Collider (LHC), since they facilitate the efficient reconstruction and identification of highly-boosted objects. Both for the LHC and for future colliders, there is a growing interest in using jet substructure methods based only on charged-particle information. The reason is that silicon-based tracking detectors offer excellent granularity and precise vertexing, which can improve the angular resolution on highly-collimated jets and mitigate the impact of pileup. In this paper, we assess how much jet substructure performance degrades by using track-only information, and we demonstrate physics contexts in which calorimetry is most beneficial. Specifically, we consider five different hadronic final states - W bosons, Z bosons, top quarks, light quarks, gluons - and test the pairwise discrimination power with a multi-variate combination of substructure observables. In the idealized case of perfect reconstruction, we quantify the loss in discrimination performance when using just charged particles compared to using all detected particles. We also consider the intermediate case of using charged particles plus photons, which provides valuable information about neutral pions. In the more realistic case of a segmented calorimeter, we assess the potential performance gains from improving calorimeter granularity and resolution, comparing a CMS-like detector to more ambitious future detector concepts. Broadly speaking, we find large performance gains from neutral-particle information and from improved calorimetry in cases where jet mass resolution drives the discrimination power, whereas the gains are more modest if an absolute mass scale calibration is not required.

  20. Hierarchy spectrum of SM fermions: from top quark to electron neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Xue, She-Sheng [ICRANet,Piazza della Repubblica 10, 65122 Pescara (Italy); Physics Department, Sapienza University of Rome,Piazzale Aldo Moro 5, 00185 Roma (Italy)

    2016-11-10

    In the SM gauge symmetries and fermion content of neutrinos, charged leptons and quarks, we study the effective four-fermion operators of Einstein-Cartan type and their contributions to the Schwinger-Dyson equations of fermion self-energy functions. The study is motivated by the speculation that these four-fermion operators are probably originated due to the quantum gravity, which provides the natural regularization for chiral-symmetric gauge field theories. In the chiral-gauge symmetry breaking phase, as to achieve the energetically favorable ground state, only the top-quark mass is generated via the spontaneous symmetry breaking, and other fermion masses are generated via the explicit symmetry breaking induced by the top-quark mass, four-fermion interactions and fermion-flavor mixing matrices. A phase transition from the symmetry breaking phase to the chiral-gauge symmetric phase at TeV scale occurs and the drastically fine-tuning problem can be resolved. In the infrared fixed-point domain of the four-fermion coupling for the SM at low energies, we qualitatively obtain the hierarchy patterns of the SM fermion Dirac masses, Yukawa couplings and family-flavor mixing matrices with three additional right-handed neutrinos ν{sub R}{sup f}. Large Majorana masses and lepton-number symmetry breaking are originated by the four-fermion interactions among ν{sub R}{sup f} and their left-handed conjugated fields ν{sub R}{sup fc}. Light masses of gauged Majorana neutrinos in the normal hierarchy (10{sup −5}−10{sup −2} eV) are obtained consistently with neutrino oscillations. We present some discussions on the composite Higgs phenomenology and forward-backward asymmetry of tt̄-production, as well as remarks on the candidates of light and heavy dark matter particles (fermions, scalar and pseudoscalar bosons).

  1. A Precision Measurement of the Weak Mixing Angle in Moller Scattering at Low Q^2

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G.

    2005-01-28

    The electroweak theory has been probed to a high level of precision at the mass scale of the Z{sup 0} through the joint contributions of LEP at CERN and the SLC at SLAC. The E158 experiment at SLAC complements these results by measuring the weak mixing angle at a Q{sup 2} of 0.026 (GeV/c){sup 2}, far below the weak scale. The experiment utilizes a 48 GeV longitudinally polarized electron beam on unpolarized atomic electrons in a target of liquid hydrogen to measure the parity-violating asymmetry A{sup PV} in Moeller scattering. The tree-level prediction for A{sup PV} is proportional to 1-4 sin{sup 2} {theta}{sub W}. Since sin{sup 2} {theta}{sub W} {approx} 0.25, the effect of radiative corrections is enhanced, allowing the E158 experiment to probe for physics effects beyond the Standard Model at the TeV scale. This work presents the results from the first two physics runs of the experiment, covering data collected in the year 2002. The parity-violating asymmetry A{sup PV} was measured to be A{sup PV} = -158 ppb {+-} 21 ppb (stat) {+-} 17 ppb (sys). The result represents the first demonstration of parity violation in Moeller scattering. The observed value of A{sup PV} corresponds to a measurement of the weak mixing angle of sin{sup 2} {theta}{sub W}{sup eff} = 0.2380 {+-} 0.0016(stat) {+-} 0.0013(sys), which is in good agreement with the theoretical prediction of sin{sup 2} {theta}{sub W}{sup eff} = 0.2385 {+-} 0.0006 (theory).

  2. The importance of calorimetry for highly-boosted jet substructure

    Science.gov (United States)

    Coleman, E.; Freytsis, M.; Hinzmann, A.; Narain, M.; Thaler, J.; Tran, N.; Vernieri, C.

    2018-01-01

    Jet substructure techniques are playing an essential role in exploring the TeV scale at the Large Hadron Collider (LHC), since they facilitate the efficient reconstruction and identification of highly-boosted objects. Both for the LHC and for future colliders, there is a growing interest in using jet substructure methods based only on charged-particle information. The reason is that silicon-based tracking detectors offer excellent granularity and precise vertexing, which can improve the angular resolution on highly-collimated jets and mitigate the impact of pileup. In this paper, we assess how much jet substructure performance degrades by using track-only information, and we demonstrate physics contexts in which calorimetry is most beneficial. Specifically, we consider five different hadronic final states—W bosons, Z bosons, top quarks, light quarks, gluons—and test the pairwise discrimination power with a multi-variate combination of substructure observables. In the idealized case of perfect reconstruction, we quantify the loss in discrimination performance when using just charged particles compared to using all detected particles. We also consider the intermediate case of using charged particles plus photons, which provides valuable information about neutral pions. In the more realistic case of a segmented calorimeter, we assess the potential performance gains from improving calorimeter granularity and resolution, comparing a CMS-like detector to more ambitious future detector concepts. Broadly speaking, we find large performance gains from neutral-particle information and from improved calorimetry in cases where jet mass resolution drives the discrimination power, whereas the gains are more modest if an absolute mass scale calibration is not required.

  3. Search for new physics in final states with a high energy electron and large missing transverse energy

    Energy Technology Data Exchange (ETDEWEB)

    Schuh, Natascha

    2017-01-13

    The most successful and comprehensive theory describing the microcosm is the Standard Model of particle physics (SM). It comprises all known elementary particles and describes in high precision the basic processes of three of the four fundamental interactions. But still, not all experimental observations and theoretical challenges are covered. Many models exist that take the SM as a good approximation of natural phenomena in already discovered energy regions, but extend it in various ways. The Large Hadron Collider (LHC) provides the opportunity to look into these high energy regions using proton-proton collisions at significantly higher center-of-mass energies than previous experiments. This dissertation searches for physics beyond the SM especially in final states with one highly energetic electron (respectively positron) and large missing transverse energy. With the data set recorded in 2012 by the ATLAS detector, a large multi-purpose detector making use of the LHC, the spectrum of the related combined transverse mass can be measured up to the TeV scale. To find any evidence to the existence of new physics beyond the SM, it was searched for significant deviations between the observed data and the expectations due to SM processes. Unfortunately, no significant excess could be observed and exclusion limits in the context of three different new physics scenarios are provided. Besides a so-called Sequential Standard Model (SSM) predicting additional vector gauge bosons, also the possible existence of (charged) chiral bosons is analyzed. Also inferences about dark matter candidates called ''weakly interacting massive particles (WIMP)'' are drawn. With the aid of a Bayesian ansatz, the observed (expected) exclusion limit on the boson pole mass is set to 3.13 TeV(3.13 TeV) for a SSM W' boson and to 3.08 TeV(3.08 TeV) for charged chiral W{sup *} bosons (at 95% C.L.).

  4. Dansgaard Oeschger Dynamics: Clearly Revealed in a Comprehensive Model of Glacial Climate

    Science.gov (United States)

    Peltier, W. Richard; Vettoretti, Guido

    2017-04-01

    More than 30 years ago, Willi Dansgaard in Copenhagen and Hans Oeschger in Bern established the existence of millennium timescale oscillations in oxygen isotope stratigraphies from Greenland ice cores. This isotopic signal was interpreted as implying large amplitude variations in surface air temperature. Until the publication of Peltier and Vettoretti (2014, GRL) the prevalent view had been that this exclusively ice-age phenomenon, thought to be linked to variability in the strength of the Atlantic MOC, was considered to be forced by the episodic release of freshwater from the continental ice sheets, each oscillation requiring its own freshwater input. In Peltier and Vettoretti (2014) this phenomenon was recovered for the first time in a comprehensive model of glacial climate, specifically the CESM1 model of the NCAR laboratory. Attention was drawn to the fact that individual D-O oscillations, or Bond Cycle clusters of such oscillations, were inevitably preceded by individual Heinrich events. In Peltier and Vettoretti (2014) it was shown that, following the "spin-up" of CESM1 into the glacial state, with continental ice sheet volume held fixed, a sequence of nonlinear unforced and therefor "free" oscillations of the MOC occurred, following a sharp Heinrich event-like sharp suppression of MOC strength. All of the salient characteristics of the D-O process inferred on the basis of ice core evidence from both hemispheres were fully captured in these high (CMIP5) resolution simulations, namely: (i) the pulse shape of the individual oscillations characterized by an extremely rapid shift from cold stadial to warm interstadial conditions followed by a slow return to the stadial state, (ii) the peak-to-peak variations in Greenland surface air temperature of 10-15 degrees Centigrade during individual oscillations, (iii) the "bi-polar see saw" connection between this Northern Hemisphere process and that recorded in the EDML and WAIS Divide ice cores from Antarctica, (iv) the

  5. Global S U (3 )C×S U (2 )L×U (1 )Y linear sigma model: Axial-vector Ward-Takahashi identities and decoupling of certain heavy BSM particles due to the Goldstone theorem

    Science.gov (United States)

    Lynn, Bryan W.; Starkman, Glenn D.

    2017-09-01

    again cause all UVQD and finite relevant operators to vanish, in the νDSMtb τ ντ+Heavy G model. We demonstrate this with two examples: a singlet MS2≫mWeak2 real scalar field S with discrete Z2 symmetry and ⟨S ⟩=0 ; and a singlet right-handed type I see-saw Majorana neutrino νR with MνR 2≫mWeak2 . Specifically, we prove that these heavy degrees of freedom decouple completely from the low-energy νDSMtb τ ντ G effective Lagrangian, contributing only irrelevant operators after quartic-coupling renormalization.

  6. Search for top quark pair resonances with the CMS detector at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Wael Haj

    2013-05-29

    The Standard Model of particle physics is not the final theory. It breaks at larger (TeV) scales and thus can not explain the hierarchy problem, the unification of couplings and some physical phenomena. Several physical models, referred to as Beyond the Standard Model, have been proposed to account for the phenomena which are not explained by the Standard Model, and to answer to some of these open questions. As the top quark has as an enormous mass of about 173.3 GeV, it plays an essential role in searches for new physics. Various models beyond the Standard Model predict the existence of heavy particles decaying into top quark pairs. These particles manifest themselves as resonant structures in the invariant mass spectrum of the top quark pairs. In this thesis, a model-independent search has been performed for top quark pair resonances in the mass range close to the top quark pair production threshold. The Topcolor Z' model is considered as a reference model. The presented search focuses on top quark pair events selected from data samples corresponding to 1.09 fb{sup -1} of integrated luminosity collected with the CMS detector in the 2011 run period at a center-of-mass energy of {radical}(s)=7 TeV at the large hadron collider (LHC). A cut based selection is implemented to identify top quark pair candidates decaying in the muon+jets channel, by requiring one isolated muon, missing transverse energy and at least four jets. The identified final state objects are used to reconstruct the invariant top quark pair mass spectrum. No excess is observed in the CMS data over the expectation of the standard model processes, namely no considerable evidence of new physics was found. Therefore, a limit is set on the topcolor Z' boson production cross section as a function of the Z' mass. Leptophobic topcolor Z' bosons with narrow (wide) width 1.2% (10%) are excluded at 95% confidence level for masses below 710 (1145) GeV.

  7. WIMP search and a Cherenkov detector prototype for ILC polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Christoph

    2011-10-15

    The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e{sup +}e{sup -} {yields} {chi}{chi}{gamma}, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb{sup -1}, the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of {delta} P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the required precision. At ILC, these methods could reduce the luminosity spent on calibration scans considerably. The observed dynamic range and systematic uncertainties of the prototype detector are compatible with those expected for polarization measurements in an ILC-like environment. (orig.)

  8. Argonne lectures on particles accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Devred, A

    1999-09-01

    The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundred to several thousand) high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high-current-density, low-critical-temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (lecture 1), we briefly recall the origins of superconductivity and we review the parameters of existing superconducting particle accelerators (lecture 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb{sub 3}Sn) and we explain in details the manufacturing of NbTi wires and cables (lecture 3). We also present the difficulties of processing and insulating Nb{sub 3}Sn conductors, which so far have limited the use of this material in spite of its superior performances. We continue by discussing the two dimensional current distributions which are the most appropriate for generating pure dipole and quadrupole fields and we explain how these ideal distributions can be approximated by so called cos{theta} and cos 2{theta} coil designs (lecture 4). We also present a few alternative designs which are being investigated and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that are used in existing accelerator magnets (lecture 5) and we describe how the magnets are assembled (lecture 6). Some of the toughest requirements on the performance of accelerator magnets are related to field quality Lecture 7 summarizes the different sources of field errors (lecture 7). We follow by a brief overview of the cooling schemes which have been implemented in the various accelerator rings and we discuss the issues related to quench performance (lecture 8). Finally, we detail the quench protection schemes which are needed to ensure safe operations of the magnets (lecture 9). (author)

  9. 1999 Review of superconducting dipole and quadrupole magnets for particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Devred, A. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France); CERN, Conseil Europeen pour la recherche nucleaire, Laboratoire europeen pour la physique des particules Geneve (Switzerland)

    1999-12-01

    The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron-type accelerator, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundreds to several thousands) of high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high current density, low critical temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (section 1), we present a brief history of large superconducting particle accelerators, and we detail ongoing superconducting accelerator magnet R and D programs around the world (Section 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb3Sn), and we describe the manufacturing of NbTi wires and cables (section 3). We also present the difficulties of processing and insulating Nb3Sn conductors which, so far, have limited the use of this material in spite of its superior performances. We continue by presenting the complex formalism used to represent two-dimensional fields (section 4), and we discuss the two-dimensional current distributions that are the most appropriate for generating pure dipole and pure quadrupole fields (section 5). We explain how these ideal distributions can be approximated by so-called cos{theta} and cos{sup 2}{theta} coil designs and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that have been developed to restrain magnet coils and to ensure proper conductor positioning (section 6). We also show how these concepts have evolved in time to accommodate higher and higher Lorentz forces. We follow by presenting the complex formalism used to describe magnetic measurement systems based on rotating pick-up coil arrays (section 7), and we summarize the various sources of field errors (section 8). Finally, after describing the cooling schemes that have been implemented in large superconducting particle accelerators (section 9), we discuss issues related to quench performance (section 10) and to quench protection (section 11). (authors)

  10. Anatomy and phenomenology of flavor and CP violation in supersymmetric theories

    Energy Technology Data Exchange (ETDEWEB)

    Altmannshofer, Wolfgang

    2010-07-20

    The main subject of this PhD thesis is a comprehensive and systematic analysis of flavor and CP violating low energy processes in the framework of the MSSM, the minimal supersymmetric extension of the Standard Model. Supersymmetric (SUSY) models are among the best motivated and most thoroughly analyzed New Physics (NP) models. The new degrees of freedom predicted by Supersymmetry are expected to have masses of the order of the TeV scale and the direct search for these particles is one of the major goals at the LHC. A complementary strategy to probe the MSSM is given by the analysis of low energy high-precision observables, that can be modified through virtual effects of the new degrees of freedom. Of particular importance in this respect are so-called Flavor Changing Neutral Current (FCNC) processes that, forbidden in the Standard Model at the tree level, are highly sensitive probes of the flavor structure of NP models. We first analyze model independently low energy processes that show high sensitivity to the new sources of flavor and CP violation contained in the MSSM. Next, we discuss in detail the rich flavor structure of the MSSM and the implied SUSY contributions to FCNC and CP violating observables both in the low and high tan {beta} regime. In fact, well measured low energy observables lead to remarkably strong constraints on the MSSM parameter space, which is often referred to as the SUSY flavor problem. We outline possibilities to control dangerously large SUSY effects in such observables and analyze the implied predictions for those low energy processes that are not measured with high precision, yet. We consider both the Minimal Flavor Violating MSSM and SUSY models based on abelian and non-abelian flavor symmetries that show representative flavor structures in the soft SUSY breaking terms. We identify the distinctive patterns of SUSY effects in the low energy observables, focussing in particular on CP violation in the b {yields} s{gamma} transition, the B{sub s} mixing phase, the branching ratio of the rare B{sub s} {yields} {mu}{sup +}{mu}{sup -} decay, CP violation in D{sup 0} - anti D{sup 0} mixing and electric dipole moments. We emphasize that the characteristic correlations among the SUSY effects in these processes allow to distinguish between the different models. (orig.)

  11. An Inclusive Search for Supersymmetry in 13 TeV Proton-Proton Collision Data

    Science.gov (United States)

    Bradmiller-Feld, John William

    The second run of pp collisions at the Large Hadron Collider (LHC) at CERN marks one of the most anticipated eras in the field of particle physics. Already the largest and most powerful science experiment of its kind, the LHC has outdone itself, running at a record center of mass energy of √s = 13 TeV and colliding protons at rates of over 600 million collisions per second. The incredible performance of the machine allows for unprecedented exploration of the TeV scale. No elementary particles have ever been observed at these energies, yet many are hypothesized as extensions to the standard model (SM), the most complete and widely accepted model of elementary particles and their interactions. Among the most sought-after hypothetical particles are those proposed by the theory of supersymmetry (SUSY). In this thesis, results are presented from a generic search for strongly produced supersymmetric particles in pp collisions in the multijet + missing transverse momentum final state. The largest analyzed data sample corresponds to 35.9 fb-1 recorded by the CMS experiment at √s = 13 TeV in 2016. This search is motivated by SUSY models that avoid fine-tuning of the Higgs mass. In such models, strongly produced SUSY particles, including the gluino and top squark, are predicted to have masses on the order of a TeV. These particles also have some of the highest production cross sections in SUSY and give rise to final states with distinct, high jet multiplicity event signatures. To make the analysis sensitive to a wide range of such final states, events are classified by the number of jets, the scalar sum of the transverse momenta of the jets, the vector sum of the transverse momenta of the jets, and the number of b-tagged jets. All SM backgrounds are measured using dedicated control samples in data. No significant excess is observed beyond the measured SM expectation. The results are interpreted as limits on simplified SUSY models. In these models, gluinos with masses as high as 1970 GeV and squarks with masses as high as 1450 GeV are excluded at 95% CL for scenarios with low [special characters omitted] mass, far exceeding the limits set in Run I.

  12. No-scale μ-term hybrid inflation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lina [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Beijing (China); Hu, Shan [Hubei University, Department of Physics, Faculty of Physics and Electronic Sciences, Wuhan (China); Li, Tianjun [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China)

    2017-03-15

    To solve the fine-tuning problem in μ-term hybrid inflation, we will realize the supersymmetry scenario with the TeV-scale supersymmetric particles and intermediate-scale gravitino from anomaly mediation, which can be consistent with the WMAP and Planck experiments. Moreover, we for the first time propose the μ-term hybrid inflation in no-scale supergravity. With four scenarios for the SU(3){sub C} x SU(2){sub L} x SU(2){sub R} x U(1){sub B-L} model, we show that the correct scalar spectral index n{sub s} can be obtained, while the tensor-to-scalar ratio r is predicted to be tiny, about 10{sup -10}-10{sup -8}. Also, the SU(2){sub R} x U(1){sub B-L} symmetry breaking scale is around 10{sup 14} GeV, and all the supersymmetric particles except gravitino are around the TeV scale, while the gravitino mass is around 10{sup 9}-10{sup 10} GeV. Considering the complete potential terms linear in S, we for the first time show that the tadpole term, which is the key for such kind of inflationary models to be consistent with the observed scalar spectral index, vanishes after inflation. Thus, to obtain the μ term, we need to generate the supersymmetry breaking soft term A{sup SΦΦ{sup '}{sub κ}} κS ΦΦ{sup '} due to A{sup SΦΦ{sup '}{sub κ}} = 0 in no-scale supergravity, where Φ and Φ{sup '} are vector-like Higgs fields at high energy. We show that the proper A{sup SΦΦ{sup '}{sub κ}} κS ΦΦ{sup '} term can be obtained in the M-theory inspired no-scale supergravity. We also point out that A{sup SΦΦ{sup '}{sub κ}} around 700 GeV can be generated via the renormalization group equation running from string scale. We briefly comment on the supersymmetry phenomenological consequences as well. (orig.)

  13. Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Fitterer, Miriam

    2013-02-22

    With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

  14. Combinatorial and off-shell effects in new physics cascades

    Energy Technology Data Exchange (ETDEWEB)

    Wiesler, Daniel

    2012-12-15

    Up to now, the Standard Model of elementary particle physics is in very good agreement with most data. However, it has various shortcomings which motivate the presence of new physics at the TeV scale. The first major step following a potential discovery of new particles at the Large Hadron Collider (LHC) is the determination of their intrinsic properties, foremost masses and spins. Event topologies of new physics signals with a conserved parity motivated by precision data and the dark matter paradigm require for sophisticated measurement procedures, which have been developed in recent years. These techniques often rely on simplifying assumptions, albeit they need not necessarily be fulfilled. In this thesis we investigate the impact of combinatorial and off-shell effects on new physics cascades in three different contexts. A detailed understanding of these effects is essential for the topic of model parameter determination of new physics signatures at the LHC. First, we study the non-resonant contributions of a broad gluino on mass and spin measurements as a prime example for the importance of off-shell effects. A phenomenological scan over the gluino's width-to-mass ratio yields a severe smearing of invariant mass distributions and as a consequence thereof drastically shifted endpoint positions. Spin determinations, on the other hand, are barely affected and a model discrimination of the two prime candidates SUSY and UED is not at risk. In the second part, we assess the feasibility of the gluino dijet endpoint measurement in three fully inclusive scenarios at the LHC to investigate the impact of combinatorial and SUSY backgrounds on its precise determination. We develop a method to disentangle two major signal contributions and extract their associated edges with good accuracy. For this we use existent kinematic variables and propose new ones to overcome the former's deficiencies. The last part governs the issue of so-called 'fake combinatorics', where distorted mass edges originate from additional particles with non-standard quantum numbers'' instead of false assignments of decay configurations. We study the contributions of exotic fermions within standard SUSY cascades, highlight their impact on affected invariant mass variables and discuss how their presence may be distinguished from ordinary, plain SUSY signals. (orig.)

  15. Measurement of the inclusive jet cross section in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Voutilainen, Mikko Antero [Univ. of Helsinki (Finland)

    2008-07-01

    This thesis studies the high-energy collisions of protons and antiprotons. The data used in the measurement were collected during 2004-2005 with the D0 detector at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to 0.7 fb-1 of integrated luminosity. High energy hadron collisions usually produce collimated sprays of particles called jets. The energy of the jets is measured using a liquid Argon-Uranium calorimeter and the production angle is determined with the help of silicon microstrip and scintillating fiber trackers. The inclusive jet cross section in proton-antiproton collisions is measured as a function of jet transverse momentum pT in six bins of jet rapidity at the center-of-mass energy √s = 1.96 TeV. The measurement covers jet transerve momenta from 50 GeV up to 600 GeV and jet rapidities up to |y| = 2.4. The data are collected using a set of seven single jet triggers. Event and jet cuts are applied to remove non-physical backgrounds and cosmic-ray interactions. The data are corrected for jet energy calibration, cut and trigger efficiencies and finite jet pT resolution. The corrections are determined from data and the methods are tested with Monte Carlo simulation. The main experimental challenges in the measurement are the calibration of jet energies and the determination of the jet pT resolution. New methods are developed for the jet energy calibration that take into account physical differences between the {gamma}+jet and dijet calibration samples arising from quark and gluon jet differences. The uncertainty correlations are studied and provided as a set of uncertainty sources. The production of particle jets in hadron collisions is described by the theory of quantum chromodynamics (QCD). When the transverse jet momentum is large, the contributions from long-distance physics processes are small and the production rates of jets can be predicted by perturbative QCD. The inclusive jet cross section in p$\\bar{p}$ collisions at large pT is directly sensitive to the strong coupling constant (αs) and the parton distribution functions (PDFs) of the proton. This measurement can be used to constrain the PDFs, in particular the gluon PDF at high proton momentum fraction x, and to look for quark substructure at the TeV scale. The data are compared to the theory predictions with perturbative QCD in the next-to-leading order precision and a good agreement between data and theory is observed.

  16. Prospecting for new physics in the Higgs and flavor sectors

    Energy Technology Data Exchange (ETDEWEB)

    Bishara, Fady [Univ. of Cincinnati, OH (United States)

    2015-05-01

    We explore two directions in beyond the standard model physics: dark matter model building and probing new sources of CP violation. In dark matter model building, we consider two scenarios where the stability of dark matter derives from the flavor symmetries of the standard model. The first model contains a flavor singlet dark matter candidate whose couplings to the visible sector are proportional to the flavor breaking parameters. This leads to a metastable dark matter with TeV scale mediators. In the second model, we consider a fully gauged SU(3)3 flavor model with a flavor triplet dark matter. Consequently, the dark matter multiplet is charged while the standard model fields are neutral under a remnant Z3 which ensures dark matter stability. We show that a Dirac fermion dark matter with radiative splitting in the multiplet must have a mass in the range [0:5; 5] TeV in order to satisfy all experimental constraints. We then turn our attention to Higgs portal dark matter and investigate the possibility of obtaining bounds on the up, down, and strange quark Yukawa couplings. If Higgs portal dark matter is discovered, we find that direct detection rates are insensitive to vanishing light quark Yukawa couplings. We then review flavor models and give the expected enhancement or suppression of the Yukawa couplings in those models. Finally, in the last two chapters, we develop techniques for probing CP violation in the Higgs coupling to photons and in rare radiative decays of B mesons. While theoretically clean, we find that these methods are not practical with current and planned detectors. However, these techniques can be useful with a dedicated detector (e.g., a gaseous TPC). In the case of radiative B meson decay B0 → (K* → Kππ) γ, the techniques we develop also allow the extraction of the photon polarization fraction which is sensitive to new physics contributions since, in the standard model, the right(left) handed polarization fraction is of O( ΛQCD=mb) for $\\bar{B}^{0}$(B0) meson decays.

  17. A review of Early Weichselian climate (MIS 5d-a) in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Wohlfarth, Barbara [Dept. of Geological Sciences, Stockholm Univ., Stockholm (Sweden)

    2013-06-15

    remained cold, Greenland started to warm just before 110 ka, suggesting the start of the so-called bipolar see-saw mechanism. The first marked cooling over Greenland at 110108 ka (GS25) was accompanied by a distinct drop in North Atlantic sea surface temperatures (C24 event), by an increase in ice-rafted debris and by marked vegetation changes in southern Europe. This shift in vegetation defines the end of the terrestrial Eemian in southern Europe, which in comparison to marine records, occurred during MIS 5d. Paleo records thus suggest that the response of the vegetation to North Atlantic cooling events was delayed in southern Europe by at least 5 ka as compared to northern Europe.

  18. Expression of Interest: A Muon to Electron Conversion Experiment at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Prebys, E.J.; Bogert, D.; Broemmelsiek, D.R.; Ankenbrandt, C.M.; Brice, S.J.; DeJongh, D.F.; Geer, S.; Johnson, D.E.; Martens, M.A.; Neuffer, D.V.; Popovic, M.; /Fermilab /Boston U. /Brookhaven /UC, Berkeley /Idaho State U. /Illinois U., Urbana /Moscow, INR /Massachusetts U., Amherst /MUONS Inc., Batavia /Syracuse U. /Virginia U.

    2007-08-01

    We are writing this letter to express our interest in pursuing an experiment at Fermilab to search for neutrinoless conversion of muons into electrons in the field of a nucleus, which is a lepton flavor-violating (LFV) reaction. The sensitivity goal of this experiment, improving on existing limits for this process by more than a factor of 10000, is very similar to that of previous experiments that have been proposed but never built. It would provide the most sensitive test of LFV, a unique and essential window on new physics unavailable at the high energy frontier. We present a conceptual scheme that would exploit the existing Accumulator and Debuncher rings to generate the required characteristics of the primary proton beam. The proposal requires only modest modifications to the accelerator complex after including those already planned for the NOvA experiment, with which this experiment would be fully compatible. The search for lepton flavor violation (LFV) has long played an important role in the evolution of our understanding of electroweak interactions. The neutrinoless conversion of a muon to an electron in the field of a nucleus is a particularly interesting example of an LFV process involving charged leptons. In the Standard Model, such conversions would take place via loop diagrams involving virtual neutrino mixing, at a rate far below the threshold of any currently conceivable experiment. Indeed, any detectable signal would be a definite indication, albeit indirect, of new dynamics at multi-TeV energy scales. Enhanced rate for this process is an almost universal feature of beyond the Standard Model physics, and the fact that such a process has not been observed has constrained or eliminated many models [1]. While it is widely believed that new physics will appear at LHC energies, the LHC is not well-equipped to study LFV directly. An often-quoted example is in the case of supersymmetry. The LHC will probe slepton masses, but it cannot compete with muon decay experiments in constraining the slepton mixing angles. Sensitive searches for rare or forbidden leptonic and semi-leptonic LFV processes, especially those involving charged leptons, are essential for the comprehensive characterization of new high energy physics. While there are several potential reactions that can be used to probe LFV, muon to electron conversion has the remarkable feature that it does not require the coincidence of two final-state particles. The spectacular signature is a single conversion electron of well-defined energy, separated from most of the sources of background. As a result, very high muon data rates can be handled and an unusually sensitive search for LFV becomes feasible. Indeed, at the level of sensitivity discussed below, a large class of supersymmetric models would predict 100's of conversion events. Additionally, compositeness and Z{prime} models would be probed at the multi-TeV scale in a manner complementary to direct LHC searches. Lepto-quarks would be probed at the 3000 TeV scale. Muon to electron conversion is therefore sensitive to many new physics scenarios at energy scales that cannot be probed by direct searches using other foreseeable accelerators.

  19. Particle Physics in a Season of Change

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris

    2012-02-01

    A digest of the authors opening remarks at the 2011 Hadron Collider Physics Symposium. I have chosen my title to reflect the transitions we are living through, in particle physics overall and in hadron collider physics in particular. Data-taking has ended at the Tevatron, with {approx} 12 fb{sup -1} of {bar p}p interactions delivered to CDF and D0 at {radical}s = 1.96 TeV. The Large Hadron Collider has registered a spectacular first full-year run, with ATLAS and CMS seeing > 5 fb{sup -1}, LHCb recording {approx} 1 fb{sup -1}, and ALICE logging nearly 5 pb{sup -1} of pp data at {radical}s = 7 TeV, plus a healthy dose of Pb-Pb collisions. The transition to a new energy regime and new realms of instantaneous luminosity exceeding 3.5 x 10{sup 33} cm{sup -2} s{sup -1} has brought the advantage of enhanced physics reach and the challenge of pile-up reaching {approx} 15 interactions per beam crossing. I am happy to record that what the experiments have (not) found so far has roused some of my theoretical colleagues from years of complacency and stimulated them to think anew about what the TeV scale might hold. We theorists have had plenty of time to explore many proposals for electroweak symmetry breaking and for new physics that might lie beyond established knowledge. With so many different theoretical inventions in circulation, it is in the nature of things that most will be wrong. Keep in mind that we learn from what experiment tells us is not there, even if it is uncommon to throw a party for ruling something out. Some non-observations may be especially telling: the persistent absence of flavor-changing neutral currents, for example, seems to me more and more an important clue that we have not yet deciphered. It is natural that the search for the avatar of electroweak symmetry breaking preoccupies participants and spectators alike. But it is essential to conceive the physics opportunities before us in their full richness. I would advocate a three-fold approach: Explore, Search, Measure! The first phase of running at the LHC has brought us to two new lands - in proton-proton and lead-lead collisions - and we may well enter other new lands with each change of energy or increase of sensitivity. I believe that it will prove very rewarding to spend some time simply exploring each new landscape, without strong preconceptions, to learn what is there and, perhaps, to encounter interesting surprises. Directed searches, for which we have made extensive preparations, are of self-evident interest. Here the challenge will be to broaden the searches over time, so the searches are not too narrowly directed. Our very successful conception of particles and forces is highly idealized. We have a great opportunity to learn just how comprehensive is our network of understanding by making precise measurements and probing for weak spots, or finding more sweeping accord between theory and experiment.

  20. Measurement of the Weak Mixing Angle in Moller Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Klejda, B.

    2005-01-28

    The weak mixing parameter, sin{sup 2} {theta}{sub w}, is one of the fundamental parameters of the Standard Model. Its tree-level value has been measured with high precision at energies near the Z{sup 0} pole; however, due to radiative corrections at the one-loop level, the value of sin{sup 2} {theta}{sub w} is expected to change with the interaction energy. As a result, a measurement of sin{sup 2} {theta}{sub w} at low energy (Q{sup 2} << m{sub Z}, where Q{sup 2} is the momentum transfer and m{sub Z} is the Z boson mass), provides a test of the Standard Model at the one-loop level, and a probe for new physics beyond the Standard Model. One way of obtaining sin{sup 2} {theta}{sub w} at low energy is from measuring the left-right, parity-violating asymmetry in electron-electron (Moeller) scattering: A{sub PV} = {sigma}{sub R}-{sigma}{sub L}/{sigma}{sub R}+{sigma}{sub L}, where {sigma}{sub R} and {sigma}{sub L} are the cross sections for right- and left-handed incident electrons, respectively. The parity violating asymmetry is proportional to the pseudo-scalar weak neutral current coupling in Moeller scattering, g{sub ee}. At tree level g{sub ee} = (1/4 -sin{sup 2} {theta}{sub w}). A precision measurement of the parity-violating asymmetry in Moeller scattering was performed by Experiment E158 at the Stanford Linear Accelerator Center (SLAC). During the experiment, {approx}50 GeV longitudinally polarized electrons scattered off unpolarized atomic electrons in a liquid hydrogen target, corresponding to an average momentum transfer Q{sup 2} {approx} 0.03 (GeV/c){sup 2}. The tree-level prediction for A{sub PV} at such energy is {approx}300 ppb. However one-loop radiative corrections reduce its value by {approx}40%. This document reports the E158 results from the 2002 data collection period. The parity-violating asymmetry was found to be A{sub PV} = -160 {+-} 21 (stat.) {+-} 17 (syst.) ppb, which represents the first observation of a parity-violating asymmetry in Moeller scattering. This value corresponds to a weak mixing angle at Q{sup 2} = 0.026 (GeV/c){sup 2} of sin{sup 2} {theta}{sub w{ovr MS}} = 0.2379 {+-} 0.0016 (stat.) {+-} 0.0013 (syst.), which is -0.3 standard deviations away from the Standard Model prediction: sin{sup 2} {theta}{sub w{ovr MS}}{sup predicted} = 0.2385 {+-} 0.0006 (theory). The E158 measurement of sin{sup 2} {theta}{sub w} at a precision of {delta}(sin{sup 2} {theta}{sub w}) = 0.0020 provides new physics sensitivity at the TeV scale.

  1. LHC phenomenology of the three-site Higgsless model

    Energy Technology Data Exchange (ETDEWEB)

    Speckner, Christian

    2009-07-01

    In the last years, extra dimensional models have been proposed which can evade these constraints by delocalizing the Standard Model fermions within the extra dimension, thus allowing to tune the couplings to the new resonances in order to avoid these constraints. This way, such models are a viable method of breaking the electroweak symmetry and retaining perturbative TeV scale unitarity without introducing a fundamental Higgs field. However, extra dimensional models (excluding trivial cases) are intrinsically nonrenormalizable and valid only below a cutoff scale, with most of the new resonances lying in fact above the cutoff. Conceptionally, a honest extension of the Standard Model should only contain the structure below this cutoff, incorporating the extra dimensional mechanism of breaking the symmetry and delaying unitarity violation without making assumptions on the high energy physics above the cutoff scale. The Three-Site Higgsless Model is a minimal implementation of this idea. While it can be motivated by extra dimensional Higgsless models of electroweak symmetry breaking, it in fact contains only one set of extra resonances which lies below the cutoff, delaying unitarity violation to {approx}2-3 TeV. The non-Standard Model part of the spectrum consists of a set of heavy partners for all Standard Model particles with the exception of photon and gluon. The analysis of the experimental constraints reveals that, while the model is consistent with the precision observables, the couplings between the new heavy gauge bosons and the Standard Model fermions have to be exceedingly small ({approx}1% of the isospin gauge coupling) while the new fermions are constrained to be rather heavy with masses above 1.8 TeV. In this thesis, we explored the LHC phenomenology of this scenario. To this end, we calculated the couplings and widths of all the new particles and implemented the model into the Monte-Carlo event generator and WHIZARD / O'Mega. With this implementation, we simulated the parton-level production of the gauge boson and fermion partners in different channels possibly suitable for their discovery at the LHC. The results are presented in this work together with an introduction to the model and a discussion of the properties and couplings of the model. We find that, while the fermiophobic nature of the new heavy gauge bosons does make them intrinsically difficult to observe at a collider, the LHC should be able to establish the existence of both resonances and even give some hints about the properties of their couplings which would be a vital test of the consistency of such a scenario. For the heavy fermions, we find that their large mass is accompanied by relative widths of more than 10%, making them ill-suited for a direct discovery at the LHC. Nevertheless, our simulations reveal that there is a part of parameter space where, given enough time, patience and a good understanding of detector and backgrounds, a direct discovery might be possible. (orig.)

  2. The QCD/SM working group: Summary report

    Energy Technology Data Exchange (ETDEWEB)

    W. Giele et al.

    2004-01-12

    Quantum Chromo-Dynamics (QCD), and more generally the physics of the Standard Model (SM), enter in many ways in high energy processes at TeV Colliders, and especially in hadron colliders (the Tevatron at Fermilab and the forthcoming LHC at CERN), First of all, at hadron colliders, QCD controls the parton luminosity, which rules the production rates of any particle or system with large invariant mass and/or large transverse momentum. Accurate predictions for any signal of possible ''New Physics'' sought at hadron colliders, as well as the corresponding backgrounds, require an improvement in the control of uncertainties on the determination of PDF and of the propagation of these uncertainties in the predictions. Furthermore, to fully exploit these new types of PDF with uncertainties, uniform tools (computer interfaces, standardization of the PDF evolution codes used by the various groups fitting PDF's) need to be proposed and developed. The dynamics of colour also affects, both in normalization and shape, various observables of the signals of any possible ''New Physics'' sought at the TeV scale, such as, e.g. the production rate, or the distributions in transverse momentum of the Higgs boson. Last, but not least, QCD governs many backgrounds to the searches for this ''New Physics''. Large and important QCD corrections may come from extra hard parton emission (and the corresponding virtual corrections), involving multi-leg and/or multi-loop amplitudes. This requires complex higher order calculations, and new methods have to be designed to compute the required multi-legs and/or multi-loop corrections in a tractable form. In the case of semi-inclusive observables, logarithmically enhanced contributions coming from multiple soft and collinear gluon emission require sophisticated QCD resummation techniques. Resummation is a catch-all name for efforts to extend the predictive power of QCD by summing the large logarithmic corrections to all orders in perturbation theory. In practice, the resummation formalism depends on the observable at issue, through the type of logarithm to be resummed, and the resummation methods. In parallel with this perturbative QCD-oriented working programme, the implementation of both QCD/SM and New physics in Monte Carlo event generators is confronted with a number of issues which deserve uniformization or improvements. The important issues are: (1) the problem of interfacing partonic event generators to showering Monte-Carlos; (2) an implementation using this interface to calculate backgrounds which are poorly simulated by the showering Monte-Carlos alone; (3) a comparison of the HERWIG and PYTHIA parton shower models with the predictions of soft gluon resummation; (4) studies of the underlying events at hadron colliders to check how well they are modeled by the Monte-Carlo generators.

  3. Identification of hadronic {tau} decays and observation potentional of CP-violating effects in SUSY at ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Gosdzik, Bjoern

    2011-03-15

    In November 2009 the ATLAS experiment started operation at the Large Hadron Collider (LHC) at CERN. The detector is optimized to search for the Higgs Boson and new physics at the TeV scale. Until the end of the data-taking period with proton-proton collisions on November 3rd, 2010, the ATLAS detector recorded an integrated luminosity of 45.0 pb{sup -1} at a center-of-mass energy of {radical}(s) = 7 TeV. In many signals of the Standard Model and new physics (e.g. SUSY and Higgs) {tau}-leptons play an important role. A cut-based approach for the identification of hadronically decaying {tau}-leptons is being used, particularly for the first data-taking period. Using Monte Carlo Data, the development of a cut-based identification method for hadronically decaying {tau}-lepton with the ATLAS detector at the Large Hadron Collider (LHC) with a center-of-mass energy of {radical}(s) = 14 TeV is presented. The separation of signal and the large QCD jet background is a challenge to the identification of hadronically decaying {tau}-lepton. The identification is separated into two methods: the calorimeter-based method uses exclusive calorimeter information, while the calorimeter+track-based method combines calorimeter and tracking information. The cut optimization is separately accomplished for {tau} candidates with one charged decay product (1-prong) and {tau} candidates with three charged decay products (3-prong). Additionally the optimisation is split into bins of the visible transverse energy of the {tau} candidate (E{sub T}{sup vis}). First of all the optimization is presented and afterwards the performance of the cut-based identification method is discussed. The reconstruction efficiency for {tau}-leptons is determined by comparing first data corresponding to an integrated luminosity of 244 nb{sup -1} and Monte Carlo simulation. The effect of systematic uncertainties is investigated. The CP violation predicted by the Standard Model is not sufficient to explain the matter - anti-matter asymmetry in the universe of the order of O(10{sup -10}). Hence new sources of CP violation are required. One possible approach is CP violation in the supersymmetric extension of the Standard Model. The CP violation can be evoked in models with so-called 'minimal supergravity' (mSUGRA) by introducing a complex phase. In such models the lightest supersymmetric particle (LSP) is the neutralino one. The triple product of the final state in cascade decay chains with two- or three-body decays is sensitive for CP-violating effects. For this purpose the mass and momentum of all decay products must be known. The potential to observe CP violation in t cascade decay chains with the ATLAS detector is investigated, with the CP violation added to the trilinear coupling {phi}{sub A}. The momentum reconstruction of the neutralino one as well as the determination of the triple product asymmetry are presented. (orig.)

  4. Characterisation and application of radiation hard sensors for LHC and ILC

    Energy Technology Data Exchange (ETDEWEB)

    Novgorodova, Olga

    2013-11-15

    The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles discovered at the LHC with higher precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle overage. In the current detector concepts for linear collider two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both sides of the interaction region. They monitor the beam conditions to protect the inner CMS detectors from adverse beam conditions and ensure high quality data for CMS. In this thesis, BCM1F data is evaluated for its intrinsic time resolution and performance under harsh radiation conditions. Furthermore, it is investigated if it can be used for a bunch by bunch on-line luminosity measurement. The second type of sensor, made of GaAs:Cr, was produced in Tomsk State University and tested as a candidate for the BeamCal for future ILC and CLIC detectors. Several GaAs:Cr sensors were characterized in the laboratory for leakage current and capacitances and used for the test beam investigations. Two sensors were assembled with a fan-out, front-end and ADC ASICs to build a fully functional prototype of a sensor plane. Several test beam campaigns were done to measure the performance of the system.

  5. Analysis of n-in-p type silicon detectors for high radiation environment with fast analogue and binary readout systems

    Energy Technology Data Exchange (ETDEWEB)

    Printz, Martin

    2016-01-22

    The Large Hadron Collider at CERN is the most powerful particle accelerator ever built. The collision of high intensity proton beams at a center of mass energy of up to 14 TeV allows the exploration of the undiscovered territory at the TeV scale with great detail. The high energy physics frontier covers detailed Standard Model (SM) physics like the search for the SM Higgs boson which has been found in July 2012 but also physics beyond the SM like the Supersymmetry or studies of the quark-gluon plasma. The production rate of certain events is correlated to the instantaneous luminosity which is a measure for the number of detected events with in a certain time with respect to the interaction cross-section. In order to increase the statistics by collecting more data the integrated luminosity is maximized as far as possible. Simultaneously an increase of the particle energy and the luminosity reveals challenging experimental requirements for the trigger and detector systems present at the LHC. After a successful Run 1 of the machine between 2010 and 2013, the energy and the instantaneous luminosity of the machine are sequentially increased up to the last so called Phase II Upgrade planned for the years 2024 and 2025. The high luminosity LHC will provide particle beams with the final 14 TeV center of mass energy at an instantaneous luminosity of 5 x 10{sup 34} cm{sup -2}s{sup -1} which is five to seven times the nominal design luminosity. In the course of the Upgrade, the experiments will face extraordinary radiation environments and particle densities and have to be upgraded as well in order to cope with the challenging demands. The Compact Muon Solenoid (CMS) at CERN is a general purpose experiment with a diverse physics measurement program. It is built of several subdetectors. The most inner part consists of the pixel detector and the silicon strip tracker. The latter will be replaced completely during the Phase II Upgrade by a new layout whereas a different silicon sensor technology and module design will be deployed. Silicon strip and macro-pixel sensors in the future CMS experiment will face a fluence of up to Φ=1 x 10{sup 15} n{sub eq}cm{sup -2}s{sup -1} after an integrated luminosity of 3000 fb{sup -1} and 10 years of operation in HL-LHC conditions. Therefore the radiation hardness of the sensors must guarantee high charge collection efficiency which degrades with increasing radiation damage. Therefore extensive radiation damage and charge collection studies have been exercised in order to find the most suitable sensor material and layout which will withstand the harsh operation environment. The key technology has been decided to be p-type substrate whereby electrons with a high mobility and less trapping effects are collected by the readout electrodes. However, this technology requires detailed investigations of the necessary isolation layer which prevents a build up of an accumulation layer below the sensor surface which would directly lead to a lower resolution of the tracker. Furthermore, an elevated particle or track density requires a higher granularity. Hence the strip length of the sensors and the strip pitch will be reduced resulting in more channels and as a direct consequence more data which has to be transmitted out of the tracker volume. In contrary to the current tracker, the signal level will be compared to a threshold by the new binary readout chip CBC and just the binary hit information will be processed to the next instance. In addition, the tracker will contribute to the global Level-1 trigger decision. The contribution will be achieved by the correlation logic of the binary readout chip which detects hits on two stacked sensors in one module. Depending on the particle curvature in the CMS 3.8 T magnetic field, the transverse momentum p{sub T} of the traversing particles is estimated on-chip and compared to a programable threshold. Simulations indicate, that rejecting hits from low momentum particles in the range below 2 GeV/c reduces the data amount by several orders of magnitude. Within this work, the radiation hardness of silicon strip sensors for the Phase II Upgrade has been investigated with respect to the breakdown voltage and charge collection efficiency. Furthermore, the concept of the transverse momentum discriminating trigger modules has been studied.

  6. Model independent spin determination at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Edelhaeuser, Lisa

    2012-04-25

    By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s{sub ff} of the adjacent particles. In this thesis we first study the influence of higher than dimension 4 operators on spin determination in such decay chains. We write down the relevant dimension 5 and 6 operators and calculate their contributions to the invariant mass distribution. We discuss how they affect the determination of spin and couplings. We then address two scenarios which do not involve decay chains in the usual sense. In three body decays, the method pointed out above cannot be applied since it can only be used if the mediating particle is produced on-shell. For off-shell decays, which are important e.g. in split-Supersymmetry or split-Universal Extra Dimensions, the narrow width approximation cannot be made which previously led to the simple relation between spin and the highest power of s{sub ff}. We work out a strategy for these three body decays that can distinguish between the different spin scenarios. The method relies on the fact that the differential decay width d{Gamma}/ds{sub ff} can be rewritten in this limit as a global phase space function and a polynomial in s{sub ff}. The coefficients in this polynomial are functions of masses and couplings and we show that they have distinct signs or ratios depending on the spins involved in the decay. We test the strategy in a series of Monte Carlo studies and discuss the influence of the intermediate particle's mass. In the last part we consider a topology with very short decay chains. Again one cannot use the relation between spin and invariant mass. We investigate one variable that has been invented for the discrimination of Supersymmetry and Universal Extra Dimensions in the high energy limit which reduces the problem to the underlying production process. We show how this variable can also be used in new physics scenarios where the high energy limit is not a viable approximation. We include all possible spin scenarios with renormalizable interactions and study in detail the influence of the involved masses and couplings on the discrimination power of this variable. We find for example that the scenario containing the supersymmetric case is well distinguishable from most other spin scenarios.

  7. EDITORIAL: Lectures from the European RTN Winter School on Strings, Supergravity and Gauge Theories, CERN, 21 25 January 2008

    Science.gov (United States)

    Derendinger, J.-P.; Orlando, D.; Uranga, A.

    2008-11-01

    This special issue is devoted to the proceedings of the conference 'RTN Winter School on Strings, Supergravity and Gauge Theories', which took place at CERN, the European Centre for Nuclear Research, in Geneva, Switzerland, on the 21 25 January 2008. This event was organized in the framework of the European Mobility Research and Training Network entitled 'Constituents, Fundamental Forces and Symmetries of the Universe'. It is part of a yearly series of scientific schools, which represents what is by now a well established tradition. The previous ones have been held at SISSA, in Trieste, Italy, in February 2005 and at CERN in January 2006. The next one will again take place at CERN, in February 2009. The school was primarily meant for young doctoral students and postdoctoral researchers working in the area of string theory. It consisted of several general lectures of four hours each, whose notes are published in the present proceedings, and five working group discussion sessions, focused on specific topics of the network research program. It was attended by approximatively 250 participants. The topics of the lectures were chosen to provide an introduction to some of the areas of recent progress, and to the open problems, in string theory. One of the most active areas in string theory in recent years is the AdS/CFT or gauge/gravity correspondence, which proposes the complete equivalence of string theory on (asymptotically) anti-de Sitter spacetimes with gauge theories. The duality relates the weak coupling regime of one system to the strongly coupled regime of the other, and is therefore very non-trivial to test beyond the supersymmetry-protected BPS sector. One of the key ideas to quantitatively match several quantities on both sides is the use of integrability, both in the gauge theory and the string side. The lecture notes by Nick Dorey provide a pedagogical introduction to the fascinating topic of integrability in AdS/CFT. On the string theory side, progress has been limited by the difficulties of quantizing the worldsheet theory in the presence of RR backgrounds. There is increasing hope that these difficulties can be overcome, using the pure spinor formulation of string theory. The lectures by Yaron Oz overview the present status of this proposal. The gauge/gravity correspondence is already leading to important insights into questions of quantum gravity, like the entropy of black holes and its interpretation in terms of microstates. These questions can be addressed in string theory, for certain classes of supersymmetric black holes. The lectures by Vijay Balasubramanian, Jan de Boer, Sheer El-Showk and Ilies Messamah review recent progress in this direction. Throughout the years, formal developments in string theory have systematically led to improved understanding on how it may relate to nature. In this respect, the lectures by Henning Samtleben describe how the formal developments on gauged supergravities can be used to describe compactification vacua in string theory, and their implications for moduli stabilization and supersymmetry breaking. Indeed, softly broken supersymmetry is one of the leading proposals to describe particle physics at the TeV energy range, as described in the lectures by Gian Giudice (not covered in this issue). This connection with TeV scale physics is most appropriate and timely, given that this energy range will shortly become experimentally accessible in the LHC at CERN. The conference was financially supported by the European Commission under contract MRTN-CT-2004-005104 and by CERN. It was jointly organized by the Physics Institute of the University of Neuchâtel and the Theory Unit of the Physics Division of CERN. It is a great pleasure for us to warmly thank the Theory Unit of CERN for its very kind hospitality and for the high quality of the assistance and the infrastructure that it has provided. We also acknowledge helpful administrative assistance from the Physics Institute of the University of Neuchâtel. Special thanks also go to Denis Frank, for his very valuable help in preparing the conference web pages. Group photo