22,675 research outputs found

    Electroweak Radiative Corrections to Weak Boson Production at Hadron Colliders

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    We summarize the status of calculations of the electroweak radiative corrections to W and Z boson production via the Drell-Yan mechanism at hadron colliders. To fully exploit the precision physics potential of the high-luminosity environment of the Fermilab Tevatron pbar p (Run II) and the CERN LHC pp colliders, it is crucial that the theoretical predictions are well under control. The envisioned precision physics program includes a precise measurement of the W boson mass and width, and the (leptonic) weak mixing angle, as well as probing the Standard Model (SM) of electroweak interactions at the highest accessible center-of-mass energies. Some numerical results are presented.Comment: Latex, 5 pages, 4 figures, talk given by UB at RADCOR2002/Loops and Legs, Kloster Banz, Germany, Sep. 2002, to appear in the Proceeding

    Photon-Photon and Photon-Hadron Interactions at Relativistic Heavy Ion Colliders

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    In central collisions at relativistic heavy ion colliders like the Relativistic Heavy Ion Collider RHIC/Brookhaven and the Large Hadron Collider LHC (in its heavy ion mode) at CERN/Geneva, one aims at detecting a new form of hadronic matter --- the Quark Gluon Plasma. We discuss here a complementary aspect of these collisions, the very peripheral ones. Due to coherence, there are strong electromagnetic fields of short duration in such collisions. They give rise to photon-photon and photon-nucleus collisions with high flux up to an invariant mass region hitherto unexplored experimentally. After a general survey photon-photon luminosities in relativistic heavy ion collisions are discussed. Then photon-photon physics at various gamma-gamma-invariant mass scales is discussed. The region of several GeV, relevant for RHIC is dominated by QCD phenomena (meson and vector meson pair production). Invariant masses of up to about 100 GeV can be reached at LHC, and the potential for new physics is discussed. Lepton-pair production, especially electron-positron pair production is copious. Due to the strong fields there will be new phenomena, especially multiple e+e- pair production.Comment: 10 pages, Proceedings of the Erice Summer School on Heavy Ion Physics 199

    Direct Reactions with Exotic Nuclei, Nuclear Structure and Astrophysics

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    Intermediate energy Coulomb excitation and dissociation is a useful tool for nuclear structure and astrophysics studies. Low-lying strength in nuclei far from stability was discovered by this method. The effective range theory for low-lying strength in one-neutron halo nuclei is summarized and extended to two-neutron halo nuclei. This is of special interest in view of recent rather accurate experimental results on the low-lying electric dipole strength in 11^{11}Li. Another indirect approach to nuclear astrophysics is the Trojan horse method. It is pointed out that it is a suitable tool to investigate subthreshold resonances.Comment: 8 pages, 2 figures, Proceedings of the Erice School on 'Radioactive Beams, Nuclear Dynamics and Astrophysics' to be published in 'Prog. Part. Nucl. Phys.

    Theoretical Challenges for a Precision Measurement of the W Mass at Hadron Colliders

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    We discuss the O(alpha) electroweak radiative corrections to W and Z boson production and their impact on the measurement of the W mass at hadron colliders. The results of recent improved calculations are presented. We also briefly discuss the O(alpha) corrections to Drell-Yan production in the high invariant mass region.Comment: 12 pages latex, uses aipproc.sty, 6 postscript figures, to appear in the Proceedings of the MRST Conference, Rochester, NY, May 8-9, 200

    On Actualizing Public Reason

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    In this Essay, I examine some apparent difficulties with what I call the "actualization criterion" connected to Rawls's notion of public reason, that is, the criterion for determining when Rawlsian public reason is concretely actualized by citizens in their deliberating and deciding about constitutional essentials and matters of basic justice. While these apparent difficulties have led some commentators to reject Rawlsian public reason altogether, I offer an interpretation that might allow Rawlsian public reason to escape the difficulties. My reading involves the claim that Rawlsian public reason is to be understood essentially as an imperative or an ideal, and as not necessarily grounded in any stock of existing beliefs or opinions. I make this claim on the basis of the seemingly counterintuitive observation that it is possible for citizen-interlocutors to know that public reason has been violated without necessarily knowing who the violator is (and thus without being able to foreclose the possibility that the violator may even be oneself). This observation is based in turn on my analysis of the necessary reciprocity and self-referentiality built in to the very concept of public reason as such

    Genome-Wide Fine-Mapping Of Diabetic Traits

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    Type 2 diabetes results from both genes and the environment. Mapping genetic loci in animal models can help identify genes that are involved in type 2 diabetes to better understand the disease. Heterogeneous stock (HS) rats are derived from eight inbred founder strains and maintained in a breeding strategy that minimizes inbreeding. HS rats have a highly recombinant genome, which allows for rapid fine-mapping of complex traits genome-wide. However, this results in a complicated set of relationships between animals that is non-existent in traditional genetic mapping methods. To fine-map traits involved in type 2 diabetes, multiple diabetic phenotypes were collected in 1,038 HS male rats and these animals were genotyped using the Affymetrix 10K SNP array. Following ancestral haplotype reconstruction, a mixed modeling approach was used to identify genetic loci involved in two phenotypes suggestive of diabetes: fasting glucose and glucose area under the curve after a glucose tolerance test. Sibship was used as a random effect in the model to account for the complex family relationships. A genome-wide significant marker interval was detected on chromosome 11 for fasting glucose with a 95% confidence interval of 5.75 Mb. Genome-wide significant marker intervals were also detected on chromosomes 1,3, 10, and 13 for glucose area under the curve, with the average 95% confidence interval for these loci being only 3.15 Mb. A multilocus modeling technique involving resample model averaging was applied to the fasting glucose phenotype. This technique determines how frequently each locus is detected when resampling a portion of the original data-set, thus reducing potential false positives. Multilocus modeling results for fasting glucose coincided with the significant marker interval demonstrated in the mixed modeling approach. Both approaches are effective at detecting significant marker intervals that are expected to be involved in the phenotype of interest with a greater resolution over traditional methods

    Incommensurable Goods, Alternative Possibilities, and the Self-Refutation of the Self-Refutation of Determinism

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    In his paper, "Free Choice, Incommensurable Goods and the Self-Refutation of Determinism,"' Joseph Boyle seeks to show how the argument for the self-refutation of determinism - first articulated over twenty-five years ago - is an argument whose force depends on (first) a proper understanding of just what free choice is, and (secondly) a proper understanding of how free choice is a principle of moral responsibility. According to Boyle, a person can make a genuinely free choice only if he is presented with alternative options that are incommensurable in their goodness or desirability. If the goodness or desirability of alternative options could be commensurated, or compared in accordance with some common standard, then it would be possible in principle for a person to determine which of the two options offered more, and which offered less, of the same sort of good represented by the two options. But if this sort of commensuration or comparison were possible, according to Boyle, then there would really be no need to choose. Rather, the only task that would have to be performed in order to determine the person's selection among alternative options would be the task clarifying or calculating which of the alternative options offered most fully what it is that makes both options desirable in the first place. Once the clarification or calculation is done, there would be no need-and in fact, no possibility--of really choosing: the calculation alone would settle which option is the best option, and thus which option is to be selected. Now if genuinely free choice requires that the choosing person be presented with options that are incommensurable in goodness or desirability, then it also seems to be the case that genuine choice-and the moral responsibility that goes along with it-requires that the person be presented with alternative possibilities from which to choose. And yet some compatibilist thinkers have held that moral responsibility does not really require the presence of alternative possibilities. In particular, Harry G. Frankfurt has sought to show (by means of counter-example) that a person can be a moral agent and morally responsible, even if the person did not, in fact, have any alternative possibilities available to him (that is, even if the person could not have done otherwise). Frankfurt's counter-example offers a direct challenge to the sort of incompatibilism that Boyle seeks to defend; and so Boyle is quite right to address Frankfurt head-on. For if Frankfurt is right, then it is erroneous to hold "the principle of alternative possibilities" (the principle that a person can be morally responsible for what he has done, only if he had alternative possibilities, or only if he could have done otherwise). But if it is erroneous to hold the principle of alternative possibilities, then it also seems erroneous to hold the more robust position that Boyle wishes to defend: namely, the position that moral responsibility requires not only alternative possibilities, but also alternative possibilities representing options that are incommensurable in their goodness

    The Language of Rights: Towards an Aristotelian-Thomistic Analysis

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    Alasdair MacIntyre has argued that our contemporary discourse about “rights,” and “natural rights” or “human rights,” is alien to the thought of Aristotleand Aquinas. His worry, it seems, is that our contemporary language of rights is often taken to imply that individuals may possess certain entitlement-conferringproperties or powers entirely in isolation from other individuals, and outside the context of any community or common good. In thispaper, I accept MacIntyre’s worries about our contemporary language of “rights”; however, I seek to show that some of our contemporary language or discourseabout “justice” and “rights” is not altogether misguided, but does—in fact—reflect a properly critical understanding of what is meant by“justice” and “rights.

    Physics Opportunities in Ultraperipheral Heavy Ion Collisions at LHC

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    Due to coherence, there are strong electromagnetic fields of short duration in very peripheral heavy ion collisions. They give rise to photon-photon and photon-nucleus collisions with high flux. Photon-photon and photon-hadron physics at various invariant mass scales are discussed.Comment: 9 pages, 4 figures Proceedings of the Workshop on Electromagnetic Probes of Fundamental Physics, Oct. 16-21,2001, Erice, Ital

    “The Authority to Interpret, the Purpose of Universities, and the Giving of Awards, Honors, or Platforms by Catholic Universities: Some Thoughts on ‘Catholics in Political Life’,”

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    With its June 2004 statement Catholics in Political Life, the United States Conference of Catholic Bishops opened an important and far-reaching discussion about how Catholic individuals ought to comport themselves in political life, and-indirectly-about how Catholic institutions-including Catholic law schools-ought to decide whether or not to give awards, honors, or platforms to those whose views about key moral and political issues may differ from the views expressed in the teachings of the Catholic Church. On the basis of a simple and straightforward reading of the 2004 statement, it might appear that the bishops wanted to say that no Catholic institution-and thus no Catholic law school-should give awards, honors, or platforms to those who endorse or promote views that differ from the fundamental moral teachings of the Church. An important part of the statement plainly declares: "The Catholic community and Catholic institutions should not honor those who act in defiance of our fundamental moral principles. They should not be given awards, honors or platforms which would suggest support for their actions." A few moments of reflection will reveal, however, that the issue here is somewhat more complicated than what one might infer from a simple and straightforward reading of the statement. The aim of the present paper is not to settle the question of whether and how a Catholic law school ought to give awards, honors, or platforms to certain individuals or groups. Instead, the aim is to begin articulating some of the underlying conceptual issues that perhaps ought to be addressed in preparation for answering the further question of whether and how a Catholic law school ought to give awards, honors, or platforms to certain individuals or groups
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