234 research outputs found

    Inclusive production of a Higgs or Z boson in association with heavy quarks

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    We calculate the cross section for the production of a Z boson in association with heavy quarks. We suggest that this cross section can be measured using an inclusive heavy-quark tagging technique. This could be used as a feasibility study for the search for a Higgs boson produced in association with bottom quarks. We argue that the best formalism for calculating that cross section is based on the leading-order process b b -> h, and that it is valid for all Higgs masses of interest at both the Fermilab Tevatron and the CERN Large Hadron Collider.Comment: 14 page

    Choosing the Factorization Scale in Perturbative QCD

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    We define the collinear factorization scheme, which absorbs only the collinear physics into the parton distribution functions. In order to isolate the collinear physics, we introduce a procedure to combine real and virtual corrections, canceling infrared singularities prior to integration. In the collinear scheme, the factorization scale μ\mu has a simple physical interpretation as a collinear cutoff. We present a method for choosing the factorization scale and apply it to the Drell-Yan process; we find μQ/2\mu \approx Q/2, where QQ is the vector-boson invariant mass. We show that, for a wide variety of collision energies and QQ, the radiative corrections are small in the collinear scheme for this choice of factorization scale.Comment: 25 pages, 18 figure

    Top Pair Forward-Backward Asymmetry from Loops of New Strongly Coupled Quarks

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    We examine loop-mediated effects of new heavy quarks Q=(t',b') on t tbar production at hadron colliders, using a phenomenological model with flavor off-diagonal couplings of charged and neutral scalars phi=(phi^+-,phi^0) to Q. We show that an invariant-mass-dependent asymmetry, in the t tbar center of mass, consistent with those recently reported by the CDF collaboration can be obtained for quark masses around 350-500 GeV, scalar masses of order 100-200 GeV, and modest to strong Yukawa couplings. The requisite strong interactions suggest a non-perturbative electroweak symmetry breaking mechanism and composite states at the weak scale. A typical prediction of this framework is that the new heavy quarks decay dominantly into t phi final states.Comment: 6 pages 6 figures; version published in Physical Review

    Grand Unification and Light Color-Octet Scalars at the LHC

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    We study the properties and production mechanisms of color-octet scalars at the LHC. We focus on the single production of both charged and neutral members of an (8,2)_1/2 doublet through bottom quark initial states. These channels provide a window to the underlying Yukawa structure of the scalar sector. Color-octet scalars naturally appear in grand unified theories based on the SU(5) gauge symmetry. In the context of adjoint SU(5) these fields are expected to be light to satisfy constraints coming from unification and proton decay, and may have TeV-scale masses. One combination of their couplings is defined by the relation between the down-quark and charged-lepton Yukawa couplings. Observation of these states at the LHC gives an upper bound on the proton lifetime if they truly arise from this grand unified theory. We demonstrate that TeV-mass scalars can be observed over background at the LHC using boosted top quark final states, and study how well the scalar Yukawa parameters can be measured.Comment: 22 pages, LaTeX, 5 figures; typos corrected, references adde

    Precocious Diphoton Signals of the Little Radion at Hadron Colliders

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    In Little Randall-Sundrum models, the bulk couplings of the radion to massless gauge fields can yield a greatly enhanced diphoton signal at hadron colliders. We examine the implications of the Tevatron data for the Little radion and also show that the 7 TeV run at the Large Hadron Collider will have an impressive reach in this channel. The diphoton signal is crucial in the search for a light radion, or the dual dilaton, and can potentially probe the ultraviolet scale of the theory.Comment: 5 pages, 2 figures. Errors in the WW and ZZ branching fraction curves in Fig.1 and the related numerical results in Fig.2 have been corrected. New references have been added. Our main conclusions regarding the enhanced diphoton signal of the Little radion remain qualitatively the same and quantitatively similar to the previous result

    Economy in Clothing Selection: Cotton Materials

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    Cotton has been called the crop that clothes the world for it is estimated 1that three-fourths to nine-tenths of the world\u27s clothing supply is made of cotton fabrics. The fiber is of more value to mankind than any other textile fiber because of its cheapness, its availability and its varied usefulness

    Care of Clothing

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    The ideal appearance of clothing cannot long be maintained without a systematic management of clothing in storage and the reconditioning of garments for wear. These are the secrets of a well-controlled wardrobe. Different occupations require specific types of garments. The selection of clothing is then a problem of choosing values in materials suited to the demand of different activities. An ideal wardrobe contains combinations for different costumes planned for the intensive service and the varied purposes which we find our environment requires. The costume should be becoming and appropriate to the occasion. It need not be expensive or new but it must be neat, clean, fresh and orderly

    The Radion as a Harbinger of Deca-TeV Physics

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    Precision data generally require the threshold for physics beyond the Standard Model to be at the deca-TeV (10 TeV) scale or higher. This raises the question of whether there are interesting deca-TeV models for which the LHC may find direct clues. A possible scenario for such physics is a 5D warped model of fermion masses and mixing, with Kaluza-Klein masses m_KK ~ 10 TeV, allowing it to avoid tension with stringent constraints, especially from flavor data. Discovery of a Standard-Model-like Higgs boson, for which there are some hints at ~125 GeV at the LHC, would also require the KK masses to be at or above 10 TeV. These warped models generically predict the appearance of a much lighter radion scalar. We find that, in viable warped models of flavor, a radion with a mass of a few hundred GeV and an inverse coupling of order m_KK ~ 10 TeV could typically be accessible to the LHC experiments -- with sqrt(s) = 14 TeV and 100 fb^-1 of data. The above statements can be applied, mutatis mutandis, to 4D dual models, where conformal dynamics and a dilaton replace warping and the radion, respectively. Detection of such a light and narrow scalar could thus herald the proximity of a new physical threshold and motivate experiments that would directly probe the deca-TeV mass scale.Comment: 18 pages, 5 figures; version published in Physical Review

    Alone/together : the production of religious culture in a church for the unchurched

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    Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Professor Mary Jo Neitz.Vita.Ph.D. University of Missouri--Columbia 2009 .One perennial problem for maintaining religion's place in the modern world is the question of how to make the traditions (the old) new and relevant, while conversely, relating the new and rapidly changing culture to the traditions of the past. This is more than a question of recruitment and growth, though these are certainly concerns of the modern era. It is also a question of where, how, and in what contexts do religious bodies negotiate the distinction between the sacred and the secular on an ever-shifting cultural field. My dissertation employs ethnographic data gathered from a large Mid-Western evangelical Protestant congregation to track the shifting boundary between the sacred and secular as it is elaborated in everyday practices. Employing theoretical and methodological tools from cultural sociology and the sociology of music, I explore the relationship between popular culture and religious experience arguing that this relationship is gendered and in part mediated through emotion.Includes bibliographical references
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