53361927
Resummation prediction on the jet mass spectrum in one-jet inclusive production at the LHC
A bstractWe study the factorization and resummation prediction on the jet mass spectrum in one-jet inclusive production at the LHC based on soft-collinear effective theory. The soft function with anti-kT algorithm is calculated at next-to-leading order and its validity is demonstrated by checking the agreement between the expanded leading singular terms with the exact fixed-order result. The large logarithms lnn(mJ2/pT2) and the global logarithms lnn(s4/pT2) in the process are resummed to all order at next-to-leading logarithmic and next-to-next-to-leading logarithmic level, respectively. The cross section is enhanced by about 23% from the next-to-leading logarithmic level to next-to-next-to- leading logarithmic level. Comparing our resummation predictions with those from Monte Carlo tool PYTHIA and ATLAS data at the 7 TeV LHC, we find that the peak positions of the jet mass spectra agree with those from PYTHIA at parton level, and the predictions of the jet mass spectra with non-perturbative effects are in coincidence with the ATLAS data. We also show the predictions at the future 13 TeV LHC.
119257780
Model independent analysis of top quark forward-backward asymmetry at the Tevatron up to $\mathcal{O}(\as^2/\Lambda^2)$
We present the complete calculations of the forward-backward asymmetry ($A_{\rm FB}$) and the total cross section of top quark pair production induced by dimension-six four quark operators at the Tevatron up to $\mathcal{O}(\as^2/\Lambda^2)$. Our results show that next-to-leading order (NLO) QCD corrections can change $A_{\rm FB}$ and the total cross section by about 10%. Moreover, NLO QCD corrections reduce the dependence of $A_{\rm FB}$ and total cross section on the renormalization and factorization scales significantly. We also evaluate the total cross section and the charge asymmetry ($A_{\rm C}$) induced by these operators at the Large Hadron Collider (LHC) up to $\mathcal{O}(\as^2/\Lambda^2)$, for the parameter space allowed by the Tevatron data. We find that the value of $A_{\rm C}$ induced by these operators is much larger than SM prediction, and LHC has potential to discover these NP effects when the measurement precision increases.
16136601
Precise QCD predictions on top quark pair production mediated by massive color-octet vector boson at hadron colliders
We present a theoretical framework for systematically calculating next-to-leading order (NLO) QCD effects to various experimental observables in models with massive COVB in a model independent way at hadron colliders. Specifically, we show the numerical results for the NLO QCD corrections to total cross sections, invariant mass distribution and AFB of top quark pairs production mediated by a massive COVB in both the fixed scale (top quark mass) scheme and the dynamical scale (top pair invariant mass) scheme. Our results show that the NLO QCD calculations in the dynamical scale scheme is more reasonable than the fixed scheme and the naive estimate of the NLO effects by simple rescaling of the LO results with the SM NLO K-factor is not appropriate.
118488744
Updated predictions for graviton and photon associated production at the LHC
Center for High Energy Physics, Peking University, Beijing, 100871, ChinaWe present updated predictions on the inclusive total cross sections, including the complete next-to-leading order QCD corrections, for the graviton and photon associated production process in thelarge extra dimensions model at the LHC with a center-of-mass energy of 7 and 8 TeV, using theparameters according to the requirements of the ATLAS and CMS Collaborations. Moreover, wealso discuss in detail the dependence on the transverse momentum cut and uncertainties due to thechoices of scales and parton distribution functions.
118552734
Next-to-leading order QCD effect of $W'$ on top quark Forward-Backward Asymmetry
We present the calculations of the complete next-to-leading order (NLO) QCD corrections to the total cross section, invariant mass distribution and the forward-backward asymmetry ($\rm A_{FB}$) of top quark pair production mediated by $W'$ boson. Our results show that in the best fit point in the parameter space allowed by data at the Tevatron, the NLO corrections change the new physics contributions to the total cross section slightly, but increase the $\rm A_{FB}$ in the large invariant mass region by about 9%. Moreover, we evaluate the total cross section and charge asymmetry ($\rm{A}_{\rm{C}}$) of top pair production at the LHC, and find that both total cross section and $A_{\rm C}$ can be used to distinguish NP from SM with the integrated luminosity increasing.
118458984
Next-to-leading order QCD predictions for the signal of dark matter and photon associated production at the LHC
We study the potential of the LHC to discover the signal of dark matter associated production with a photon induced by a dimension six effective operator, including next-to-leading order QCD corrections. We investigate the main backgrounds from the standard model, i.e. $Z$ boson and a photon associated production with invisible decay of $Z$ boson, and $Z$ boson and a jet production with the jet misidentified as a photon. We find that the ${p}_{T}^{\ensuremath{\gamma}}$ distributions of the backgrounds decrease faster than that of the signal with increasing of the transverse momentum of the photon. The ${\ensuremath{\eta}}^{\ensuremath{\gamma}}$ distributions of the backgrounds are almost flat in the full range of ${\ensuremath{\eta}}^{\ensuremath{\gamma}}$. In contrast, the signal lies mainly in the central region of ${\ensuremath{\eta}}^{\ensuremath{\gamma}}$. These characteristics may help to select the events in experiments. We show that in the parameter space allowed by the relic abundance constraint, which we have calculated at the next-to-leading-order QCD level, the LHC with $\sqrt{S}=7\text{ }\text{ }\mathrm{TeV}$ may discover this signal at the $5\ensuremath{\sigma}$ level after collecting an integrated luminosity of $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. On the other hand, if this signal is not observed at the LHC, we can set a lower limit on the new physics scale at the $3\ensuremath{\sigma}$ level.
20110707
Measurement of the inclusive 3-jet production differential cross section in proton–proton collisions at 7 TeV and determination of the strong coupling constant in the TeV range
This paper presents a measurement of the inclusive 3-jet production differential cross section at a proton–proton centre-of-mass energy of 7 TeV using data corresponding to an integrated luminosity of 5$$\,\mathrm{fb}^{-1}$$fb-1collected with the CMS detector. The analysis is based on the three jets with the highest transverse momenta. The cross section is measured as a function of the invariant mass of the three jets in a range of 445–3270 GeV and in two bins of the maximum rapidity of the jets up to a value of 2. A comparison between the measurement and the prediction from perturbative QCD at next-to-leading order is performed. Within uncertainties, data and theory are in agreement. The sensitivity of the observable to the strong coupling constant $$\alpha _\mathrm {S}$$αS is studied. A fit to all data points with 3-jet masses larger than 664 GeV gives a value of the strong coupling constant of $$\alpha _S(M_\mathrm{Z}) = 0.1171 \pm 0.0013\,\text {(exp)} \,^{+0.0073}_{-0.0047}\,\text {(theo)} $$αS(MZ)=0.1171±0.0013(exp)-0.0047+0.0073(theo).
119959444
VARIATIONAL-CUMULANT EXPANSION TREATMENT OF SU(2) MIXED MODEL IN LATTICE GAUGE THEORY
The phase diagrams of the SU(2) mixed model are calculated in four and five dimensions by using the variational method with the cumulant expansion as its corrections. The results are much better than that of the original variational treatment. Comparison with the Monte Carlo results and other approximate analytic results are given.
20026118
The ninth data release of the sloan digital sky survey: first spectroscopic data from the sdss-iiI baryon oscillation spectroscopic survey
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z ~ 0.52), 102,100 new quasar spectra (median z ~ 2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T eff -0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SEGUE-2. The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the APOGEE along with another year of data from BOSS, followed by the final SDSS-III data release in 2014 December.
12501278
An upgraded version of the generator BCVEGPY2.0 for hadronic production of Bc meson and its excited states
An upgraded version of the package BCVEGPY2.0: [C.-H. Chang, J.-X. Wang, X.-G. Wu, Comput. Phys. Common. 174 (2006) 241] is presented, which works under LINUX system and is named as BCVEGPY2.1. With the version and a GNU C compiler additionally, users may simulate the B-c-events in various experimental environments very conveniently. It has been manipulated in better modularity and code reusability (less cross communication among various modules) than BCVEGPY2.0 has. Furthermore, in the upgraded version a special execution is arranged as that the GNU command make compiles a requested code with the help of a master makefile in main code directory, and then builds an executable file with the default name run. Finally, this paper may also be considered as an erratum, i.e., typo errors in BCVEGPY2.0 and corrections accordingly have been listed.
119116907
Studies of jet mass in dijet and W/Z + jet events
A bstract
 Invariant mass spectra for jets reconstructed using the anti-kT and CambridgeAachen algorithms are studied for different jet “grooming” techniques in data corresponding to an integrated luminosity of 5 fb−1, recorded with the CMS detector in proton-proton collisions at the LHC at a center-of-mass energy of 7 TeV. Leading-order QCD predictions for inclusive dijet and W/Z+jet production combined with parton-shower Monte Carlo models are found to agree overall with the data, and the agreement improves with the implementation of jet grooming methods used to distinguish merged jets of large transverse momentum from softer QCD gluon radiation.