924 research outputs found

    Addendum: New approach to the resummation of logarithms in Higgs-boson decays to a vector quarkonium plus a photon [Phys. Rev. D 95, 054018 (2017)]

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    In this addendum to Phys.\ Rev.\ D {\bf 95}, 054018 (2017) we recompute the rates for the decays of the Higgs boson to a vector quarkonium plus a photon, where the vector quarkonium is J/ψJ/\psi, ΄(1S)\Upsilon(1S), ΄(2S)\Upsilon(2S), or ΄(3S)\Upsilon(3S). We correct an error in the Abel-Pad\'e summation formula that was used to carry out the evolution of the quarkonium light-cone distribution amplitude in Phys.\ Rev.\ D {\bf 95}, 054018 (2017). We also correct an error in the scale of quarkonium wave function at the origin in Phys.\ Rev.\ D {\bf 95}, 054018 (2017) and introduce several additional refinements in the calculation.Comment: 7 pages, [v2] Abel-Pade summation formula corrected, [v3] PRD versio

    ZZ-boson decays to a vector quarkonium plus a photon

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    We compute the decay rates for the processes Z→V+ÎłZ\to V+\gamma, where ZZ is the ZZ boson, Îł\gamma is the photon, and VV is one of the vector quarkonia J/ψJ/\psi or ΄(nS)\Upsilon(nS), with n=1n=1, 22, or 33. Our computations include corrections through relative orders αs\alpha_s and v2v^2 and resummations of logarithms of mZ2/mQ2m_Z^2/m_Q^2, to all orders in αs\alpha_s, at NLL accuracy. (vv is the velocity of the heavy quark QQ or the heavy antiquark Qˉ\bar{Q} in the quarkonium rest frame, and mZm_Z and mQm_Q are the masses of ZZ and QQ, respectively.) Our calculations are the first to include both the order-αs\alpha_s correction to the light-cone distributions amplitude and the resummation of logarithms of mZ2/mQ2m_Z^2/m_Q^2 and are the first calculations for the ΄(2S)\Upsilon(2S) and ΄(3S)\Upsilon(3S) final states. The resummations of logarithms of mZ2/mQ2m_Z^2/m_Q^2 that are associated with the order-αs\alpha_s and order-v2v^2 corrections are carried out by making use of the Abel-Pad\'e method. We confirm the analytic result for the order-v2v^2 correction that was presented in a previous publication, and we correct the relative sign of the direct and indirect amplitudes and some choices of scales in that publication. Our branching fractions for Z→J/ψ+ÎłZ\to J/\psi+\gamma and Z→΄(1S)+ÎłZ\to \Upsilon(1S)+\gamma differ by 2.0 σ2.0\,\sigma and −4.0 σ-4.0\,\sigma, respectively, from the branching fractions that are given in the most recent publication on this topic (in units of the uncertainties that are given in that publication). However, we argue that the uncertainties in the rates are underestimated in that publication.Comment: 26 pages, [v2] references added / [v3] Equation (27) modified, 3 sentences added after Eq. (27), Reference [17] added / [v4] PRD versio

    Types of problems elicited by verbal protocols for blind and sighted participants

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    Verbal protocols are often used in user-based studies of interactive technologies. This study investigated whether different types of problems are revealed by concurrent and retrospective verbal protocols (CVP and RVP) for blind and sighted participants. Eight blind and eight sighted participants undertook both CVP and RVP on four websites. Overall, interactivity problems were significantly more frequent in comparison to content or information architecture problems. In addition, RVP revealed significantly more interactivity problems than CVP for both user groups. Finally, blind participants encountered significantly more interactivity problems than sighted participants. The findings have implications for which protocol is appropriate, depending on the purpose of a particular study and the user groups involved

    Selectivity and Sustainability of Electroenzymatic Process for Glucose Conversion to Gluconic Acid

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    Electroenzymatic processes are interesting solutions for the development of new processes based on renewable feedstocks, renewable energies, and green catalysts. High-selectivity and sustainability of these processes are usually assumed. In this contribution, these two aspects were studied in more detail. In a membrane-less electroenzymatic reactor, 97% product selectivity at 80% glucose conversion to gluconic acid was determined. With the help of nuclear magnetic resonance spectroscopy, two main side products were identified. The yields of D-arabinose and formic acid can be controlled by the flow rate and the electroenzymatic reactor mode of operation (fuel cell or ion-pumping). The possible pathways for the side product formation have been discussed. The electroenzymatic cathode was found to be responsible for a decrease in selectivity. The choice of the enzymatic catalyst on the cathode side led to 100% selectivity of gluconic acid at somewhat reduced conversion. Furthermore, sustainability of the electroenzymatic process is estimated based on several sustainability indicators. Although some indicators (like Space Time Yield) are favorable for electroenzymatic process, the E-factor of electroenzymatic process has to improve significantly in order to compete with the fermentation process. This can be achieved by an increase of a cycle time and/or enzyme utilization which is currently low

    Are Race, Ethnicity, and Medical School Affiliation Associated with NIH R01 Type Award Probability for Physician Investigators?

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    This is a non-final version of an article published in final form in Acad Med. 2012 November ; 87(11): 1516–1524. doi:10.1097/ACM.0b013e31826d726b.PURPOSE: To analyze the relationship among NIH R01 Type 1 applicant degree, institution type, and race/ethnicity, and application award probability. METHOD: The authors used 2000–2006 data from the NIH IMPAC II grants database and other sources to determine which individual and institutional characteristics of applicants may affect the probability of applications being awarded funding. They used descriptive statistics and probit models to estimate correlations between race/ethnicity, degree (MD or PhD), and institution type (medical school or other institution), and application award probability, controlling for a large set of observable characteristics. RESULTS: Applications from medical schools were significantly more likely than those from other institutions to receive funding, as were applications from MDs versus PhDs. Overall, applications from blacks and Asians were less likely than those from whites to be awarded funding; however, among applications from MDs at medical schools, there was no difference in funding probability between whites and Asians and the difference between blacks and whites decreased to 7.8 percentage points. The inclusion of human subjects significantly decreased the likelihood of receiving funding. CONCLUSIONS: Compared with applications from whites, applications from blacks have a lower probability of being awarded R01 Type 1 funding, regardless of the investigator’s degree. However, funding probability is increased for applications with MD investigators and for those from medical schools. To some degree, these advantages combine so that applications from black MDs at medical schools have the smallest difference in funding probability compared with those from whites

    A traveling wave Zeeman decelerator

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    We developed a new-concept Zeeman decelerator which produces a traveling magnetic trap. Atoms and molecules possessing a magnetic dipole moment, in so-called low field seeking states, are trapped around a node of a propagating wave provided that the initial velocity of the wave matches a velocity populated in the supersonic beam. In addition, three dimensional confinement is achieved by controlling the radial orientation of the trap, which can be done fully independently from its longitudinal motion

    The Caffeine Dose Response in Habitual Consumers Performing a Maximal Anaerobic Test

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    Please view abstract in the attached PDF fil

    Race, Ethnicity, and NIH Research Awards

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    We investigated the association between a U.S. National Institutes of Health (NIH) R01 applicant’s self-identified race or ethnicity and the probability of receiving an award by using data from the NIH IMPAC II grant database, the Thomson Reuters Web of Science, and other sources. Although proposals with strong priority scores were equally likely to be funded regardless of race, we find that Asians are 4 percentage points and black or African-American applicants are 13 percentage points less likely to receive NIH investigator-initiated research funding compared with whites. After controlling for the applicant’s educational background, country of origin, training, previous research awards, publication record, and employer characteristics, we find that black applicants remain 10 percentage points less likely than whites to be awarded NIH research funding. Our results suggest some leverage points for policy intervention
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