scispace - formally typeset
Search or ask a question
Author

Daniel R. Stump

Other affiliations: University of North Florida
Bio: Daniel R. Stump is an academic researcher from Michigan State University. The author has contributed to research in topics: Parton & Quantum chromodynamics. The author has an hindex of 30, co-authored 95 publications receiving 11270 citations. Previous affiliations of Daniel R. Stump include University of North Florida.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, a new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented, using a recently developed eigenvector-basis approach to the hessian method, which provides the means to quickly estimate the uncertainties of a wide range of physical processes at these high-energy hadron colliders, based on current knowledge of the parton distributions.
Abstract: A new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented. This work signiflcantly extends previous CTEQ and other global analyses on two fronts: (i) a full treatment of available experimental correlated systematic errorsforbothnewandolddata sets; (ii) asystematic and pragmatic treatment of uncertainties of the parton distributions and their physical predictions, using a recently developed eigenvector-basis approach to the hessian method. The new gluon distribution is considerably harder than that of previous standard flts. A numberofphysicsissues,particularlyrelatingtothebehaviorofthegluondistribution,are addressedinmorequantitativetermsthanbefore. Extensiveresultsontheuncertaintiesof parton distributions at various scales, and on parton luminosity functions at the Tevatron RunII and the LHC, are presented. The latter provide the means to quickly estimate the uncertainties of a wide range of physical processes at these high-energy hadron colliders, basedoncurrentknowledgeofthepartondistributions. Inparticular, theuncertaintieson the production cross sections of the W, Z at the Tevatron and the LHC are estimated to be§4% and§5%, respectively, and that of a light Higgs at the LHC to be§5%.

4,427 citations

Journal ArticleDOI
TL;DR: In this article, a method to constrain parton distribution function (PDF) uncertainties in LHC observables, by effectively exploiting PDF-induced correlations with benchmark standard model cross sections, is presented.
Abstract: The latest CTEQ6.6 parton distributions, obtained by global analysis of hard-scattering data in the framework of general-mass perturbative QCD, are employed to study theoretical predictions and their uncertainties for significant processes at the Fermilab Tevatron and CERN Large Hadron Collider. The previously observed increase in predicted cross sections for the standard-candle W and Z boson production processes in the general-mass scheme (compared to those in the zero-mass scheme) is further investigated and quantified. A novel method to constrain parton distribution function (PDF) uncertainties in LHC observables, by effectively exploiting PDF-induced correlations with benchmark standard model cross sections, is presented. Using this method, we show that the tt cross section can potentially serve as a standard-candle observable for the LHC processes dominated by initial-state gluon scattering. Among other benefits, precise measurements of tt cross sections would reduce PDF uncertainties in predictions for single top-quark and Higgs boson production in the standard model and minimal supersymmetric standard model.

1,527 citations

Journal ArticleDOI
TL;DR: Parton distribution functions (PDFs) are crucial ingredients for the calculation of the relevant cross sections for various scattering processes at the Large Hadron Collider (LHC). as mentioned in this paper found new PDFs, which will be important for the data analysis at the LHC Run-2.
Abstract: Parton distribution functions (PDFs) are crucial ingredients for the calculation of the relevant cross sections for various scattering processes at the Large Hadron Collider (LHC). Including data from several previous experiments, the authors find new PDFs, which will be important for the data analysis at the LHC Run-2.

1,521 citations

Journal ArticleDOI
TL;DR: In this article, next-to-next-toleading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group were presented, based on essentially the same global data sets used in the CT10 and CT10W NLO analyses.
Abstract: We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After exploring the goodness of the fits to the HERA combined data and the Tevatron jet data, we present various predictions at NNLO accuracy for both existing and forthcoming precision measurements from the CERN Large Hadron Collider. The range of variations in the gluon distribution introduced by correlated systematic effects in inclusive jet production is also examined.

520 citations

Journal ArticleDOI
TL;DR: In this article, the effects of this uncertainty, and of the remaining uncertainties in the NLO QCD theory, on jet cross section comparisons to Run 1b data are examined and the range of contributions still possible from any new physics.
Abstract: Jet production at the Tevatron probes some of the smallest distance scales currently accessible. A gluon distribution that is enhanced at large x compared to previous determinations provides a better description of the Run 1b jet data from both CDF and D?. However, considerable uncertainty still remains regarding the gluon distribution at high x. In this paper, we examine the effects of this uncertainty, and of the remaining uncertainties in the NLO QCD theory, on jet cross section comparisons to Run 1b data. We also calculate the range of contributions still possible from any new physics. Predictions are also made for the expanded kinematic range expected for the ongoing Run 2 at the Tevatron and for the LHC.

440 citations


Cited by
More filters
Journal ArticleDOI
Georges Aad1, T. Abajyan2, Brad Abbott3, Jalal Abdallah4  +2964 moreInstitutions (200)
TL;DR: In this article, a search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7×10−9.

9,282 citations

Journal ArticleDOI
TL;DR: In this paper, results from searches for the standard model Higgs boson in proton-proton collisions at 7 and 8 TeV in the CMS experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.8 standard deviations.

8,857 citations

Journal ArticleDOI
TL;DR: In this paper, a new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented, using a recently developed eigenvector-basis approach to the hessian method, which provides the means to quickly estimate the uncertainties of a wide range of physical processes at these high-energy hadron colliders, based on current knowledge of the parton distributions.
Abstract: A new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented. This work signiflcantly extends previous CTEQ and other global analyses on two fronts: (i) a full treatment of available experimental correlated systematic errorsforbothnewandolddata sets; (ii) asystematic and pragmatic treatment of uncertainties of the parton distributions and their physical predictions, using a recently developed eigenvector-basis approach to the hessian method. The new gluon distribution is considerably harder than that of previous standard flts. A numberofphysicsissues,particularlyrelatingtothebehaviorofthegluondistribution,are addressedinmorequantitativetermsthanbefore. Extensiveresultsontheuncertaintiesof parton distributions at various scales, and on parton luminosity functions at the Tevatron RunII and the LHC, are presented. The latter provide the means to quickly estimate the uncertainties of a wide range of physical processes at these high-energy hadron colliders, basedoncurrentknowledgeofthepartondistributions. Inparticular, theuncertaintieson the production cross sections of the W, Z at the Tevatron and the LHC are estimated to be§4% and§5%, respectively, and that of a light Higgs at the LHC to be§5%.

4,427 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented an updated leading-order, next-to-leading order and next-next-ordering order parton distribution function (MSTW 2008) determined from global analysis of hard-scattering data within the standard framework of leading-twist fixed-order collinear factorisation in the $\overline{\mathrm{MS}}$¯¯$¯¯¯¯¯
Abstract: We present updated leading-order, next-to-leading order and next-to-next-to-leading order parton distribution functions (“MSTW 2008”) determined from global analysis of hard-scattering data within the standard framework of leading-twist fixed-order collinear factorisation in the $\overline{\mathrm{MS}}$ scheme. These parton distributions supersede the previously available “MRST” sets and should be used for the first LHC data taking and for the associated theoretical calculations. New data sets fitted include CCFR/NuTeV dimuon cross sections, which constrain the strange-quark and -antiquark distributions, and Tevatron Run II data on inclusive jet production, the lepton charge asymmetry from W decays and the Z rapidity distribution. Uncertainties are propagated from the experimental errors on the fitted data points using a new dynamic procedure for each eigenvector of the covariance matrix. We discuss the major changes compared to previous MRST fits, briefly compare to parton distributions obtained by other fitting groups, and give predictions for the W and Z total cross sections at the Tevatron and LHC.

3,546 citations

01 Dec 1982
TL;DR: In this article, it was shown that any black hole will create and emit particles such as neutrinos or photons at just the rate that one would expect if the black hole was a body with a temperature of (κ/2π) (ħ/2k) ≈ 10−6 (M/M)K where κ is the surface gravity of the body.
Abstract: QUANTUM gravitational effects are usually ignored in calculations of the formation and evolution of black holes. The justification for this is that the radius of curvature of space-time outside the event horizon is very large compared to the Planck length (Għ/c3)1/2 ≈ 10−33 cm, the length scale on which quantum fluctuations of the metric are expected to be of order unity. This means that the energy density of particles created by the gravitational field is small compared to the space-time curvature. Even though quantum effects may be small locally, they may still, however, add up to produce a significant effect over the lifetime of the Universe ≈ 1017 s which is very long compared to the Planck time ≈ 10−43 s. The purpose of this letter is to show that this indeed may be the case: it seems that any black hole will create and emit particles such as neutrinos or photons at just the rate that one would expect if the black hole was a body with a temperature of (κ/2π) (ħ/2k) ≈ 10−6 (M/M)K where κ is the surface gravity of the black hole1. As a black hole emits this thermal radiation one would expect it to lose mass. This in turn would increase the surface gravity and so increase the rate of emission. The black hole would therefore have a finite life of the order of 1071 (M/M)−3 s. For a black hole of solar mass this is much longer than the age of the Universe. There might, however, be much smaller black holes which were formed by fluctuations in the early Universe2. Any such black hole of mass less than 1015 g would have evaporated by now. Near the end of its life the rate of emission would be very high and about 1030 erg would be released in the last 0.1 s. This is a fairly small explosion by astronomical standards but it is equivalent to about 1 million 1 Mton hydrogen bombs. It is often said that nothing can escape from a black hole. But in 1974, Stephen Hawking realized that, owing to quantum effects, black holes should emit particles with a thermal distribution of energies — as if the black hole had a temperature inversely proportional to its mass. In addition to putting black-hole thermodynamics on a firmer footing, this discovery led Hawking to postulate 'black hole explosions', as primordial black holes end their lives in an accelerating release of energy.

2,947 citations