Upper limits on gravitational wave emission from 78 radio pulsars [Physical Review D - Particles, Fields, Gravitation and Cosmology (2007) 76, (042001)]

This paper was published online on 3 August 2007 with a formatting error in the fifty-first affiliation in the author list.The affiliation should read as ‘‘University of Western Australia, Crawley, WA 6009, Australia.’’ The affiliation has beencorrected as of 4 March 2008. The affiliation is incorrect in the printed version of the journal

Erratum: First cross-correlation analysis of interferometric and resonant-bar gravitational-wave data for stochastic backgrounds (Physical Review D - Particles, Fields, Gravitation and Cosmology (2007) 76, (022001))

This paper was published online on 9 July 2007 with incorrect affiliation numbering in the author list. The affiliations have been corrected as of 23 July 2007. The text is correct in the printed version of the journal

All-sky search for periodic gravitational waves in LIGO S4 data (Physical Review D - Particles, Fields, Gravitation and Cosmology (2008) 77, (022001))

This paper was published online on 10 January 2008 with a formatting error in the forty-ninth affiliation in the author list. The affiliation should read as ‘‘University of Western Australia, Crawley, WA 6009, Australia.’’ The affiliation hasbeen corrected as of 29 February 2008. The affiliation is incorrect in the printed version of the journal

First cross-correlation analysis of interferometric and resonant-bar gravitational-wave data for stochastic backgrounds (Physical Review D - Particles, Fields, Gravitation and Cosmology (2007) 76, (022001))

This paper was published online on 9 July 2007 with a formatting error in the fiftieth affiliation in the author list. Theaffiliation should read as ‘‘University of Western Australia, Crawley, WA 6009, Australia.’’ The affiliation has beencorrected as of 4 March 2008. The affiliation is incorrect in the printed version of the journal

Inflation with a constant ratio of scalar and tensor perturbation amplitudes

The single scalar field inflationary models that lead to scalar and tensor perturbation spectra with amplitudes varying in direct proportion to one another are reconstructed by solving the Stewart-Lyth inverse problem to next-to-leading order in the slow-roll approximation. The potentials asymptote at high energies to an exponential form, corresponding to power law inflation, but diverge from this model at low energies, indicating that power law inflation is a repellor in this case. This feature implies that a fine-tuning of initial conditions is required if such models are to reproduce the observations. The required initial conditions might be set through the eternal inflation mechanism. If this is the case, it will imply that the spectral indices must be nearly constant, making the underlying model observationally indistinguishable from power law inflation.Comment: 20 pages, 7 figures. Major changes to the Introduction following referee's comments. One figure added. Some other minor changes. No conclusion was modifie

(Anti-)self-dual homogeneous vacuum gluon field as an origin of confinement and SUL(NF)×SUR(NF)SU_L(N_F)\times SU_R(N_F) symmetry breaking in QCD

It is shown that an (anti-)self-dual homogeneous vacuum gluon field appears in a natural way within the problem of calculation of the QCD partition function in the form of Euclidean functional integral with periodic boundary conditions. There is no violation of cluster property within this formulation, nor are parity, color and rotational symmetries broken explicitly. The massless limit of the product of the quark masses and condensates, $m_f \langle \bar\psi_f \psi_f \rangle$, is calculated to all loop orders. This quantity does not vanish and is proportional to the gluon condensate appearing due to the nonzero strength of the vacuum gluon field. We conclude that the gluon condensate can be considered as an order parameter both for confinement and chiral symmetry breaking.Comment: 16 pages, LaTe

Search for direct stau production in events with two hadronic τ-leptons in √s = 13 TeV pp collisions with the ATLAS detector

Contains fulltext : 217206.pdf (publisher's version ) (Open Access

Au+Au Reactions at the AGS: Experiments E866 and E917

Particle production and correlation functions from Au+Au reactions have been measured as a function of both beam energy (2-10.7AGeV) and impact parameter. These results are used to probe the dynamics of heavy-ion reactions, confront hadronic models over a wide range of conditions and to search for the onset of new phenomena.Comment: 12 pages, 14 figures, Talk presented at Quark Matter '9

Improved Determination of the Mass of the 1−+1^{-+} Light Hybrid Meson From QCD Sum Rules

We calculate the next-to-leading order (NLO) $\alpha_s$-corrections to the contributions of the condensates $$ and $^2$ in the current-current correlator of the hybrid current g\barq(x)\gamma_{\nu}iF_{\mu\nu}^aT^aq(x) using the external field method in Feynman gauge. After incorporating these NLO contributions into the Laplace sum-rules, the mass of the $J^{PC}$=$1^{-+}$ light hybrid meson is recalculated using the QCD sum rule approach. We find that the sum rules exhibit enhanced stability when the NLO $\alpha_s$-corrections are included in the sum rule analysis, resulting in a $1^{-+}$ light hybrid meson mass of approximately 1.6 GeV.Comment: revtex4, 10 pages, 7 eps figures embedded in manuscrip

The Strong CP Problem and Axions

I describe how the QCD vacuum structure, necessary to resolve the $U(1)_A$ problem, predicts the presence of a P, T and CP violating term proportional to the vacuum angle $\bar{\theta}$. To agree with experimental bounds, however, this parameter must be very small $(\bar{\theta} \leq 10^{-9}$). After briefly discussing some possible other solutions to this, so-called, strong CP problem, I concentrate on the chiral solution proposed by Peccei and Quinn which has associated with it a light pseudoscalar particle, the axion. I discuss in detail the properties and dynamics of axions, focusing particularly on invisible axion models where axions are very light, very weakly coupled and very long-lived. Astrophysical and cosmological bounds on invisible axions are also briefly touched upon.Comment: 14 pages, to appear in the Lecture Notes in Physics volume on Axions, (Springer Verlag