123106617
Prospects for a new boson W±1 in the minimal Higgsless model at the LHC
The author list originally given in the above article (Ming-Shui Chen, Jian-Guo Bian, Guo-Ming Chen, Hong-Jian He, Chun-Hua Jiang, Zu-Hao Li, Song Liang, Xiang-Wei Meng, Yong-Hui Qi, Zhi-Cheng Tang, Jun-Quan Tao, Zheng Wang, Jian Wang, Jian Wang, Xian-You Wang, Jian-Xiong Wang, Hong Xiao, Min Yang, Jing-Jing Zang, Bin Zhang, Zhen Zhang and Zhen- Xia Zhang) is incorrect. The correct author list is: Ming-Shui Chen, Jian-Guo Bian, Guo-Ming Chen, Chun-Hua Jiang, Zu-Hao Li, Song Liang, Xiang-Wei Meng, Zhi-Cheng Tang, Jun-Quan Tao, Zheng Wang, Jian Wang, Jian Wang, Xian-You Wang, Jian-Xiong Wang, Hong Xiao, Min Yang, Jing-Jing Zang, Bin Zhang, Zhen Zhang and Zhen-Xia Zhang. Hong-Jian He and Yong-Hui Qi did not take part in the writing of this text and do not bear any responsibility for its contents. Also, reference [4] in the paper should be corrected to: [4] Hong-Jian He et al 2008 Phys. Rev. D 78 031701(R)
28828852
EtabFDC: An etab event generator in hadroproduction at LHC
The EtabFDC is a matrix-element event generator package for eta(b) hadroproduction at LHC. It generates pp -> eta X-b events for all possible parton-level 2 -> 2 leading-order processes with three commonly used 116 decay channels being implemented. The PYTHIA interface is used for parton-shower and hadronization to obtain the hadronic events. The FORTRAN codes of this package are generated by FDC (Feynman Diagram Calculation) system automatically. Program summary Program title: EtabFDC (Version 1.01) Catalogue identifier: AEBV_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEBV_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast. N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1840204 No. of bytes in distributed program, including test data, etc.: 18 018379 Distribution format: tar.gz Programming language: FORTRAN 77 Computer: Any computer with Linux operating system and GNU 77 Fortran compiler Operating system: Linux (with GNU FORTRAN 77 compiler) Classification: 11.1 External routines: CERNLIB 2001 (or CERNLIB 2003) Nature of problem: This package generates pp -> eta X-b events for partonic 2 -> 2 tree-level processes with implementing three eta(b) decay channels. It then interfaces with PYTHIA for parton-shower and hadronization to obtain the hadronic events. Solution method: The FORTRAN codes of this package are generated by FDC system [ I) automatically. Additional comments: This program could not be tested by the CPC Program Library as it requires the CERNLIB libraries. Running time: To generate 1000 events on a 3.2G Intel-P4 CPU platform (with hyper-technology). it will take approximate 20, 30 and 300 seconds for decay channel eta(b) J/psi gamma,eta(b)-> J/psi J/psi and eta b -> J/psi ccbar, respectively. References: [1] J.X. Wang, Nucl. Instrum. Methods A 534 (2004) 241, arXiv:hep-ph/0407058. (C) 2008 Elsevier B.V. All rights reserved.
119115722
CHANDRA HIGH-ENERGY GRATING OBSERVATIONS OF THE Fe Kα LINE CORE IN TYPE II SEYFERT GALAXIES: A COMPARISON WITH TYPE I NUCLEI
We present a study of the core of the Fe K{alpha} emission line at {approx}6.4 keV in a sample of type II Seyfert galaxies observed by the Chandra high-energy grating. The sample consists of 29 observations of 10 unique sources. We present measurements of the Fe K{alpha} line parameters with the highest spectral resolution currently available. In particular, we derive the most robust intrinsic line widths for some of the sources in the sample to date. We obtained a weighted mean full width at half-maximum (FWHM) of 2000 {+-} 160 km s{sup -1} for 8 out of 10 sources (the remaining sources had insufficient signal to noise). From a comparison with the optical emission-line widths obtained from spectropolarimetric observations, we found that the location of Fe K{alpha} line-emitting material is a factor of {approx}0.7-11 times the size of the optical broad-line region. Furthermore, compared to 13 type I active galactic nuclei (AGNs) for which the best Fe K{alpha} line FWHM constraints were obtained, we found no difference in the FWHM distribution or the mean FWHM, and this conclusion is independent of the central black hole mass. This result suggests that the bulk of the Fe K{alpha} line emission may originatemore » from a universal region at the same radius with respect to the gravitational radius, {approx}3 x 10{sup 4} r{sub g} on average. By examining the correlation between the Fe K{alpha} luminosity and the [O IV] line luminosity, we found a marginal difference in the Fe K{alpha} line flux between type I and type II AGNs, but the spread in the ratio of L{sub Fe} to L{sub [OIV]} is about two orders of magnitude. Our results confirm the theoretical expectation that the Fe K{alpha} emission-line luminosity cannot trivially be used as a proxy of the intrinsic AGN luminosity, unless a detailed comparison of the data with proper models is applied.« less
119220684
Search for the Signal of Monotop Production at the Early LHC
The main tasks of the LHC are to answer the fundamental questions in particle physics: whether the Higgs boson exist or not; are there new physics beyond the SM such as supersymmetry (SUSY), extra dimension, etc., at the TeV scale? The first stage of the LHC has discovered a scalar resonance closely resembling the SM Higgs boson, but provides no clue on the new physics beyond the SM.
118734439
Search for exotic resonances decaying into WZ/ZZ in pp collisions at $ \sqrt{s}=7 $ TeV
A bstractA search for new exotic particles decaying to the VZ final state is performed, where V is either a W or a Z boson decaying into two overlapping jets and the Z decays into a pair of electrons, muons or neutrinos. The analysis uses a data sample of pp collisions corresponding to an integrated luminosity of 5 fb−1 collected by the CMS experiment at the LHC at $ \sqrt{s}=7 $ TeV in 2011. No significant excess is observed in the mass distribution of the VZ candidates compared with the background expectation from standard model processes. Model-dependent upper limits at the 95% confidence level are set on the product of the cross section times the branching fraction of hypothetical particles decaying to the VZ final state as a function of mass. Sequential standard model W′ bosons with masses between 700 and 940 GeV are excluded. In the Randall-Sundrum model for graviton resonances with a coupling parameter of 0.05, masses between 750 and 880 GeV are also excluded.
118840032
Weighing Super-Massive Black Holes with Narrow Fe K$\alpha$ Line
It has been suggested that the narrow cores of the Fe Kα emission lines in Active Galactic Nuclei (AGNs) are likely produced in the torus, the inner radius of which can be measured by observing the lag time between the V and K band flux variations. In this paper, we compare the virial products of the infrared time lags, and the narrow Fe Kα widths for 10 type 1 AGNs, with the black hole masses from other techniques. We found the narrow Fe Kα line width is in average 2.6 −0.4 times broader than expected, assuming an isotropic velocity distribution of the torus at the distance measured by the infrared lags. We propose the thick disk model of the torus may explain the observed larger line width. Another possibility is the contamination by emission from the broad line region or the outer accretion disk. Alternatively, the narrow iron line might originate from the inner most part of the obscuring torus within the sublimation radius, while the infrared emission may be from the outer cooler part. We note the correlations between the black hole masses based on this new technique and those based on other known techniques are statistically insignificant. We argue that this could be attributed to the small sample size and the very large uncertainties in the measurements of iron K line widths. The next generation of X-ray observatories could help verify the origin of the narrow iron Kα line and the reliability of this new technique. Subject headings: black hole physics – galaxies: active – galaxies: nuclei – galaxies: Seyfert – X-rays: galaxies – infrared: galaxies
119233734
Constraining broad-line regions from time lags of broad emission lines relative to radio emission
In this paper, a new method is proposed to estimate the broad-line region sizes of ultraviolet (UV) lines RuvBLR. It is applied to 3C 273. First, we derive the time lags of radio emission relative to broad emission lines Lya and C iv by the z-transformed discrete correlation function (ZDCF) method. The broad lines lag the 5-, 8-, 15-, 22- and 37-GHz emission. The measured lags tuvob are of the order of years. For a given line, tuvob decreases as the radio frequency increases. This trend results from the radiative cooling of relativistic electrons. Both UV lines have a lag of tuvob=-2.74+0.06- 0.25 yr relative to the 37-GHz emission. These results are consistent with those derived from the Balmer lines in Paper I. Secondly, we derive the time lags of the lines Lya, C iv, H, H beta and Ha relative to the 37-GHz emission by the flux randomization/random subset selection (FR/RSS) Monte Carlo method. The measured lags are tob=-3.40+0.31- 0.05, -3.40+0.41- 0.14, -2.06+0.36- 0.92, -3.40+1.15- 0.20 and -3.56+0.35- 0.18 yr for the lines Lya, C iv, H, H beta and Ha, respectively. These estimated lags are consistent with those derived by the ZDCF method within the uncertainties. Based on the new method, we derive RuvBLR= 2.54+0.71- 0.35 to 4.01+0.90- 1.16 and 2.54+0.80- 0.43 to 4.01+0.98- 1.24 light-years for the Lya and C iv lines, respectively. Considering the uncertainties, these estimated sizes are consistent with those obtained in the classical reverberation mapping for the UV and the Balmer lines. This indicates that their emitting regions are not separated so large as in the classical mapping of the UV and optical lines. These results seem to depart from the stratified ionization structures obtained in the classical mapping.