Structural Relaxation and Frequency Dependent Specific Heat in a Supercooled Liquid

We have studied the relation between the structural relaxation and the frequency dependent thermal response or the specific heat, $c_p(\omega)$, in a supercooled liquid. The Mode Coupling Theory (MCT) results are used to obtain $c_p(\omega)$ corresponding to different wavevectors. Due to the two-step relaxation process present in the MCT, an extra peak, in addition to the low frequency peak, is predicted in specific heat at high frequency.Comment: 14 pages, 13 Figure

The project of a high-power FEL driven by an SC ERL at KAERI

The project of a high-power FEL at Korea Atomic Energy Research Institute and its recent status are described. The FEL is driven by a superconducting energy recovery linac. The first-stage machine will operate in the far IR region and its CW power is expected to be a few kW. Possible upgrade of the machine is also considered. The upgraded machine will operate in the near IR region and its expected power is a few tens kW.Описан проект мощного ЛСЭ в Корейском институте атомной энергии, а также текущее состояние дел. В ЛСЭ будет использован сверхпроводящий линак-рекуператор. Машина первой очереди будет работать в дальнем ИК-диапазоне, ее ожидаемая средняя мощность несколько киловатт. Рассматривается возможная модернизация машины. Модернизированная машина будет генерировать десятки киловатт средней мощности в ближнем ИК-диапазоне.Описано проект потужного ЛВЕ в Корейському інституті атомної енергії, а також поточний стан справ. У ЛВЕ буде використаний надпровідний лінак-рекуператор. Машина першої черги буде працювати в далекому ІЧ-діапазоні, її очікувана середня потужність − кілька кіловат. Розглядається можлива модернізація машини. Модернізована машина буде генерувати десятки кіловатів середньої потужності в ближньому ІЧ-діапазоні

Observation of the Smectic C -- Smectic I Critical Point

We report the first observation of the smectic C--smectic I (C--I) critical point by Xray diffraction studies on a binary system. This is in confirmity with the theoretical idea of Nelson and Halperin that coupling to the molecular tilt should induce hexatic order even in the C phase and as such both C and I (a tilted hexatic phase) should have the same symmetry. The results provide evidence in support of the recent theory of Defontaines and Prost proposing a new universality class for critical points in layered systems.Comment: 9 pages Latex and 5 postscript figures available from [email protected] on request, Phys.Rev.Lett. (in press

The project of a high-power FEL driven by an SC ERL at KAERI

The project of a high-power FEL at Korea Atomic Energy Research Institute and its recent status are described. The FEL is driven by a superconducting energy recovery linac. The first-stage machine will operate in the far IR region and its CW power is expected to be a few kW. Possible upgrade of the machine is also considered. The upgraded machine will operate in the near IR region and its expected power is a few tens kW.Описан проект мощного ЛСЭ в Корейском институте атомной энергии, а также текущее состояние дел. В ЛСЭ будет использован сверхпроводящий линак-рекуператор. Машина первой очереди будет работать в дальнем ИК-диапазоне, ее ожидаемая средняя мощность несколько киловатт. Рассматривается возможная модернизация машины. Модернизированная машина будет генерировать десятки киловатт средней мощности в ближнем ИК-диапазоне.Описано проект потужного ЛВЕ в Корейському інституті атомної енергії, а також поточний стан справ. У ЛВЕ буде використаний надпровідний лінак-рекуператор. Машина першої черги буде працювати в далекому ІЧ-діапазоні, її очікувана середня потужність − кілька кіловат. Розглядається можлива модернізація машини. Модернізована машина буде генерувати десятки кіловатів середньої потужності в ближньому ІЧ-діапазоні

Spin Fidelity for Three-qubit Greenberger-Horne-Zeilinger and W States Under Lorentz Transformations

Constructing the reduced density matrix for a system of three massive spin$-\frac{1}{2}$ particles described by a wave packet with Gaussian momentum distribution and a spin part in the form of GHZ or W state, the fidelity for the spin part of the system is investigated from the viewpoint of moving observers in the jargon of special relativity. Using a numerical approach, it turns out that by increasing the boost speed, the spin fidelity decreases and reaches to a non-zero asymptotic value that depends on the momentum distribution and the amount of momentum entanglement.Comment: 12pages, 2 figure

Magetic softening of Young's modulus of amorphous Fe90Zr10

The Young's modulus and the internal friction of amorphous Fe$_{90}$Zr$_{10}$ alloy were measured near the Curie temperature using the vibrating reed technique. The modulus shows softening around $T_c\approx 227K$ and the internal friction undergoes drastic increase at $T_c$. It is found that both the Young's modulus and the reciprocal of internal friction are inversely proportional to the magnetic susceptibility in the paramagnetic phase.Comment: 10 pages, RevTeX, 4 figures on request, POSTECH-amos-9400

HDAC6 modulates myofibril stiffness and diastolic function of the heart

Passive stiffness of the heart is determined largely by extracellular matrix and titin, which functions as a molecular spring within sarcomeres. Titin stiffening is associated with the development of diastolic dysfunction (DD), while augmented titin compliance appears to impair systolic performance in dilated cardiomyopathy. We found that myofibril stiffness was elevated in mice lacking histone deacetylase 6 (HDAC6). Cultured adult murine ventricular myocytes treated with a selective HDAC6 inhibitor also exhibited increased myofibril stiffness. Conversely, HDAC6 overexpression in cardiomyocytes led to decreased myofibril stiffness, as did ex vivo treatment of mouse, rat, and human myofibrils with recombinant HDAC6. Modulation of myofibril stiffness by HDAC6 was dependent on 282 amino acids encompassing a portion of the PEVK element of titin. HDAC6 colocalized with Z-disks, and proteomics analysis suggested that HDAC6 functions as a sarcomeric protein deacetylase. Finally, increased myofibril stiffness in HDAC6-deficient mice was associated with exacerbated DD in response to hypertension or aging. These findings define a role for a deacetylase in the control of myofibril function and myocardial passive stiffness, suggest that reversible acetylation alters titin compliance, and reveal the potential of targeting HDAC6 to manipulate the elastic properties of the heart to treat cardiac diseases

Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters