Sudakov Logarithm Resummation for Vector Boson Production at Hadron Colliders

A complete description of W and Z boson production at high-energy colliders requires the resummation of large Sudakov logarithms which dominate the production at small transverse momentum. Currently there are two techniques for performing this resummation: impact parameter space and transverse momentum space. We argue that the latter can be formulated in a way which retains the advantages of the former, while at the same time allowing a smooth transition to finite order dominance at high transverse momentum.Comment: 5 pages, LaTeX, 2 figures, epsfig, contribution to the proceedings of the UK Phenomenology Workshop on Collider Physics, 19-24 September 1999, Durham, to be published in J. Phys.

On the Resummation of Subleading Logarithms in the Transverse Momentum Distribution of Vector Bosons Produced at Hadron Colliders

The perturbation series for electroweak vector boson production at small transverse momentum is dominated by large double logarithms at each order in perturbation theory. An accurate theoretical prediction therefore requires a resummation of these logarithms. This can be performed either directly in transverse momentum space or in impact parameter (Fourier transform) space. While both approaches resum the same leading double logarithms, the subleading logarithms are, in general, treated differently. We comment on two recent approaches to this problem, emphasising the particular subleading logarithms resummed in each case and the numerical differences in the cross sections which result.Comment: 13 (Latex) pages, including 5 embedded figures, uses epsfig.st

People-Powered Music: Using User-Generated Tags and Structure in Recommendations

Music recommenders often rely on experts to classify song facets like genre and mood, but user-generated folksonomies hold some advantages over expert classifications—folksonomies can reflect the same real-world vocabularies and categorizations that end users employ. We present an approach for using crowd-sourced common sense knowledge to structure user-generated music tags into a folksonomy, and describe how to use this approach to make music recommendations. We then empirically evaluate our “people-powered” structured content recommender against a more traditional recommender. Our results show that participants slightly preferred the unstructured recommender, rating more of its recommendations as “perfect” than they did for our approach. An exploration of the reasons behind participants’ ratings revealed that users behaved differently when tagging songs than when evaluating recommendations, and we discuss the implications of our results for future tagging and recommendation approaches

Radio Frequency Fingerprinting Techniques through Preamble Modification in IEEE 802.11b

Wireless local area networks are particularly vulnerable to cyber attacks due to their contested transmission medium. Access point spoofing, route poisoning, and cryptographic attacks are some of the many mature threats faced by wireless networks. Recent work investigates physical-layer features such as received signal strength or radio frequency fingerprinting to identify and localize malicious devices. This thesis demonstrates a novel and complementary approach to exploiting physical-layer differences among wireless devices that is more energy efficient and invariant with respect to the environment than traditional fingerprinting techniques. Specifically, this methodology exploits subtle design differences among different transceiver hardware types. A software defined radio captures packets with standard-length IEEE 802.11b preambles, manipulates the recorded preambles by shortening their length, then replays the altered packets toward the transceivers under test. Wireless transceivers vary in their ability to receive packets with preambles shorter than the standard. By analyzing differences in packet reception with respect to preamble length, this methodology distinguishes amongst eight transceiver types from three manufacturers. All tests to successfully enumerate the transceivers achieve accuracy rates greater than 99%, while transmitting less than 60 test packets. This research extends previous work illustrating RF fingerprinting techniques through IEEE 802.15.4 wireless protocols. The results demonstrate that preamble manipulation is effective for multi-factor device authentication, network intrusion detection, and remote transceiver type fingerprinting in IEEE 802.11b

A Comparison of Predictions for SM Higgs Boson Production at the LHC

This paper describes a comparison of most of the available predictions for the cross section and transverse momentum distribution for a 125 GeV mass Higgs at the LHC, including those from the PYTHIA and HERWIG parton shower Monte Carlos and from four resummation calculations.Comment: 7 pages, submitted to proceedings of the Workshop on Physics at TeV Colliders, Les Houches 200

Yes, there is a medial nucleus of the trapezoid body in humans

The medial nucleus of the trapezoid body (MNTB) is a collection of brainstem neurons that function within the ascending auditory pathway. MNTB neurons are associated with a number of anatomical and physiological specializations which make these cells especially well-equipped to provide extremely fast and precise glycinergic inhibition to its target neurons in the superior olivary complex and ventral nucleus of the lateral lemniscus. The inhibitory influence of MNTB neurons plays essentials roles in the localization of sound sources and encoding temporal features of complex sounds. The morphology, afferent and efferent connections and physiological response properties of MNTB neurons have been well-characterized in a number of laboratory rodents and some carnivores. Furthermore, the MNTB has been positively identified in all mammals examined, ranging from opossum and mice to chimpanzees. From the early 1970s through 2009, a number of studies denied the existence of the MNTB in humans and consequentially, the existence of this nucleus in the human brain has been debated for nearly 50 years. The absence of the MNTB from the human brain would negate current principles of sound localization and would require a number of novel adaptations, entirely unique to humans. However, a number of recent studies of human post-mortem tissue have provided evidence supporting the existence of the MNTB in humans. It therefore seems timely to review the structure and function of the MNTB, critically review the literature which led to the denial of the human MNTB and then review recent investigations supporting the existence of the MNTB in the human brain

Transverse momentum distribution of Upsilon production in hadronic collisions

We calculate the transverse momentum p_T distribution for production of the Upsilon states in hadronic reactions. For small $p_T (\leq M_\Upsilon)$, we resum to all orders in the strong coupling alpha_s the process-independent large logarithmic contributions that arise from initial-state gluon showers. We demonstrate that the p_T distribution at low p_T is dominated by the region of small impact parameter b and that it may be computed reliably in perturbation theory. We express the cross section at large p_T by the alpha_s^3 lowest-order non-vanishing perturbative contribution. Our results are consistent with data from the Fermilab Tevatron collider.Comment: 24 pages latex; 9 postscript files of figures. Presentation improved; new figure and references added; conclusions unaltered. Version to be published in Physical Review

Prawo do informacji publicznej. Wybrane wątpliwości interpretacyjne w doktrynie i orzecznictwie sądów administracyjnych

The provisions of the Act on Access to Public Information regulate, among others, the subjective and objective scope of the right to public information, reasons for restricting access to information, procedure and form of disclosure, rules for creating and publishing information in the Public Information Bulletin, costs of activities leading to the disclosure of information and the establishment of complaint proceedings in the event of refusal to provide the public information requested. Therefore, it is worth to pay attention to several problems arising from the analysis of statutory provisions and the practical consequences of applying the Act of 6 September 2001 on Access to Public Information. The current, extremely extensive, output of doctrine and jurisprudence allows for a fairly “efficient” summary of the considerations made in both literature and judicial and administrative case law.Przepisy ustawy o dostępie do informacji publicznej regulują m.in. zakres podmiotowy i przedmiotowy prawa do informacji publicznej, przyczyny ograniczenia udostępnienia informacji, procedurę i formę udostępniania, zasady tworzenia i publikowania informacji w Biuletynie Informacji Publicznej, koszty działań prowadzących do udostępnienia informacji oraz założenia postępowania skargowego w przypadku odmowy udostępnienia żądanych informacji publicznych. Warto zwrócić uwagę na kilka problemów wynikających z analizy przepisów ustawowych oraz na konsekwencje praktyczne stosowania ustawy z dnia 6 września 2001 r. o dostępie do informacji publicznej. Dotychczasowy, niezwykle już obszerny dorobek doktryny i judykatury pozwala na dość „sprawne” podsumowanie rozważań poczynionych zarówno w literaturze, jak i orzecznictwie sądowo-administracyjnym

W production at large transverse momentum at the Large Hadron Collider

We study the production of W bosons at large transverse momentum in pp collisions at the Large Hadron Collider (LHC). We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable theoretical prediction.Comment: 12 pages, 7 figure