arXiv subjects
Publications and source records attributed to John M. Campbell.
We present an integral representation of Kekulé numbers for $P_{2} (n)$ benzenoids. Related integrals of the form $\int_{-π}^π \frac{\cos(nx)}{\sin^{2}x +k} dx$ are evaluated. Conjectures relating double integrals of the form $\int_{0}^{m} \int_{-π}^π \frac{\cos (2nx)}{k+\sin^{2}x} dx dk $ to Smarandache sequences are presented.
We present phenomenological results for vector boson pair production at the LHC, obtained using the parton-level next-to-leading order program MCFM. We include the implementation of a new process in the code, pp -> γγ, and important updates to existing processes. We incorporate fragmentation contributions in order to allow for the experimental isolation of photons in γγ, Wγ, and Zγproduction and also account for gluon-gluon initial state contributions for all relevant processes. We present results for a variety of phenomenological scenarios, at the current operating energy of \sqrt{s} = 7 TeV and for the ultimate machine goal, \sqrt{s} = 14 TeV. We investigate the impact of our predictions on several important distributions that enter into searches for new physics at the LHC.
Infinite series are evaluated through the manipulation of a series for $\cos(2t \sin^{-1}x)$ resulting from Clausen's Product. Hypergeometric series equal to an expression involving $\frac{1} π$ are determined. Techniques to evaluate generalized hypergeometric series are discussed through perspectives of experimental mathematics.
We perform an analytic calculation of the one-loop amplitude for the W-boson mediated process 0 \to d u-bar Q Q-bar l-bar l, retaining the mass for the quark Q. The momentum of each of the massive quarks is expressed as the sum of two massless momenta and the corresponding heavy quark spinor is expressed as a sum of two massless spinors. Using a special choice for the heavy quark spinors we obtain analytic expressions for the one-loop amplitudes which are amenable to fast numerical evaluation. The full next-to-leading order (NLO) calculation of hadron+hadron \to W(\to e nu) b b-bar with massive b-quarks is included in the program MCFM. A comparison is performed with previous published work.
By dividing hypergeometric series representations of the inverse sine by sin^-1 (x) and integrating, new double series representations of integers and constants arise. Binomial coefficients and the sine integral are thus combined in double series.
By integrating a series provided by Knopp, a series representation of the Euler-Mascheroni constant arises. The infinite sum representation of γ is determined through Fourier series (sawtooth wave).
We present an update on the next-to-leading order calculation of the rate for Higgs boson production in association with two jets. Our new calculation incorporates the full analytic result for the one-loop virtual amplitude. Results are presented for the Tevatron, where implications for the Higgs search are sketched, and for the LHC at \sqrt{s}=7 TeV.
We perform an update of the next-to-leading order calculation of the rate for Higgs boson production in association with two jets. Our new calculation incorporates the full analytic result for the one-loop virtual amplitude. This new theoretical information allows us to construct a code including the decay of the Higgs boson without incurring a prohibitive penalty in computer running time. Results are presented for the Tevatron, where implications for the Higgs search are sketched, and also for a range of scenarios at the LHC.
We compute the one-loop amplitude for a Higgs boson, a quark-antiquark pair and a pair of gluons of negative helicity, i.e. for the next-to-maximally helicity violating (NMHV) case, A(H, qbar-, q+, g-, g-). The calculation is performed using an effective Lagrangian which is valid in the limit of very large top quark mass. As a result of this paper all amplitudes for the transition of a Higgs boson into 4 partons are now known analytically at one-loop order.
We present updated NLO predictions for the electroweak t-channel production of heavy quarks at the Tevatron and at the LHC. We consider production of single top and fourth generation t' starting from both 2 to 2 and 2 to 3 Born processes. Predictions for tb' and t'b' cross sections at NLO are also given for the first time. A thorough study of the theoretical uncertainties coming from parton distribution functions, renormalisation and factorisation scale dependence and heavy quark masses is performed.
We present the predictions at next-to-leading order (NLO) in the strong coupling for the single-top cross section in the t channel at the Tevatron and the LHC. Our calculation starts from the 2 -> 3 Born amplitude g q -> t bbar q', keeping the b-quark mass non-zero. A comparison is performed with a traditional NLO calculation of this channel based on the 2 -> 2 Born process with a bottom quark in the initial state. In particular, the effect of using kinematic approximations and resumming logarithms of the form log(Q^2/m_b^2) in the 2 -> 2 process is assessed. Our results show that the 2 -> 3 calculation is very well behaved and in substantial agreement with the predictions based on the 2 -> 2 process.
I review the status of theoretical predictions for events containing a W or Z boson and jets, one or more of which may include heavy quarks. Special attention is paid to comparisons between different theoretical approaches and with the latest experimental data.
We present numerical results for the production of a $W^+W^-$ pair in association with a jet at the LHC in QCD at next-to-leading order (NLO). We include effects of the decay of the massive vector bosons into leptons with spin correlations and contributions from the third generation of massive quarks. The calculation is performed using a semi-numerical method for the virtual corrections, and is implemented in MCFM. In addition to its importance {\it per se} as a test of the Standard Model, this process is an important background to searches for the Higgs boson and to many new physics searches. As an example, we study the impact of NLO corrections to $W^+W^-+$ jet production on the search for a Higgs boson at the LHC.
We present phenomenological results for the production of a Higgs boson in association with two jets at the LHC. The calculation is performed in the limit of large top mass and is accurate to next-to-leading order in the strong coupling, i.e. ${\cal O}(α_s^6)$