11,158 research outputs found
Detailed L3 measurements of Bose-Einstein correlations and a region of anti-correlations in hadronic Z^0 decays at LEP
L3 preliminary data of two-particle Bose-Einstein correlations are reported
for hadronic Z^0 decays in e+e- annihilation at LEP. The invariant relative
momentum Q is identified as the eigenvariable of the measured correlation
function. Significant anti-correlations are observed in the Bose-Einstein
correlation function in a broad region of 0.5 - 1.6 GeV with a minimum at Q
close to 0.8 GeV. Absence of Bose-Einstein correlations is demonstrated in the
region above Q >= 1.6 GeV. The effective source size is found to decrease with
increasing value of the transverse mass of the pair, similarly to hadron-hadron
and heavy ion reactions. These feautes and our data are described well by the
non-thermal tau-model, which is based on strong space-time
momentum-correlations.Comment: 5 pages, 1 figure, invited talk at the XXXIXth International
Symposium on Multiparticle Dynamics, Gomel, Belarus, September 200
Bose-Einstein or HBT correlations and the anomalous dimension of QCD
Bose-Einstein (or HBT) correlation functions are evaluated for the fractal
structure of QCD jets. These correlation functions have a stretched exponential
(or Levy-stable) form. The anomalous dimension of QCD determines the Levy index
of stability, thus the running coupling constant of QCD becomes measurable with
the help of two-particle Bose-Einstein correlation functions. These
considerations are tested on NA22 and UA1 two-pion correlation data.Comment: 8 pages, 5 figures, presented by T. Csorgo at the XXXIV International
Symposium on Multiparticle Dynamics, Sonoma County, California, USA, July
2004, to appear in Acta Physica Polonica
Bose-Einstein or HBT correlation signature of a second order QCD phase transition
For particles emerging from a second order QCD phase transition, we show that
a recently introduced shape parameter of the Bose-Einstein correlation
function, the Levy index of stability equals to the correlation exponent - one
of the critical exponents that characterize the behavior of the matter in the
vicinity of the second order phase transition point. Hence the shape of the
Bose-Einstein / HBT correlation functions, when measured as a function of
bombarding energy and centrality in various heavy ion reactions, can be
utilized to locate experimentally the second order phase transition and the
critical end point of the first order phase transition line in QCD.Comment: 8 pages, talk given by T. Csorgo at the Workshop on Particle
Correlations and Femtoscopy 2005, Kromeriz, Czech Republic, August 200
Inter-relations between advanced processing techniques, integrated circuits, materials development and analysis Quarterly report, 1 Mar. - 31 May 1969
Gyrator tuned circuit amplifier and microcircuit interconnection
Pump-Probe Experiments on the Single-Molecule Magnet Fe8 : Measurement of Excited Level Lifetimes
We present magnetization measurements on the single molecule magnet Fe8 in
the presence of pulsed microwave radiation. A pump-probe technique is used with
two microwave pulses with frequencies of 107 GHz and 118 GHz and pulse lengths
of several nanoseconds to study the spin dynamics via time-resolved
magnetization measurements using a Hall probe magnetometer. We find evidence
for short spin-phonon relaxation times of the order of one microsecond. The
temperature dependence of the spin-phonon relaxation time in our experiments is
in good agreement with previously published theoretical results. We also
established the presence of very short energy diffusion times, that act on a
timescale of about 70 ns.Comment: submitted to Phys. Rev. Lett. (01 March 2007
Disproportionation Transition at Critical Interaction Strength: NaCoO
Charge disproportionation (CD) and spin differentiation in NaCoO
are studied using the correlated band theory approach. The simultaneous CD and
gap opening seen previously is followed through a first order charge
disproportionation transition 2Co Co+Co, whose ionic
identities are connected more closely to spin (S=0, S=1/2 respectively) than to
real charge. Disproportionation in the Co orbital is compensated by
opposing charge rearrangement in other 3d orbitals. At the transition large and
opposing discontinuities in the (all-electron) kinetic and potential energies
are slightly more than balanced by a gain in correlation energy. The CD state
is compared to characteristics of the observed charge-ordered insulating phase
in NaCoO, suggesting the Coulomb repulsion value is
concentration-dependent, with 3.5 eV.Comment: 4 pages and 4 embedded figure
New Record of \u3ci\u3eBrachycercus Maculatus\u3c/i\u3e Berner (Ephemeroptera: Caenidae) From New York and a Key to Larvae of Northeastern Species
Brachycercus maculatus, a member of a rare group of mayflies, is now recorded for the first time from New York State in the upper Hudson River. An illustrated key to the Brachycercus larvae of northeastern North America is provided to spur further study of the genus in the region
Fashioning a Soldier: Male Clothing, Union Volunteers, and the Adaptation of a Soldierly Image
Despite hundreds of images of Union soldiers and countless accounts by veterans of their appearance during the Civil War, little is known as to how and why the soldiers looked the way they did throughout the conflict. The generalized image that emerges from the war centers around the four-button fatigue blouse prescribed in the 1861 regulations that was issued to every Union soldier at some point during the war. In understanding the origins of the fatigue blouse\u27s design and the impact it had on the image of the ideal soldier in America through the end of the nineteenth century, greater connections can be made between the male fashions of the period and choices that soldiers made about their uniforms. By analyzing Quartermaster Department records, period photographs, letters, memoirs, and period newspapers, a cultural pattern emerges where the Union soldier based his clothing choices out of utility and comfort, but also through style considerations and changing beliefs surrounding the ideal male image. These conclusions connect to the broader literature of clothing and material culture studies in attempting to understand the cultural and social meanings behind historical garments
“ALL inferiors are required to obey strictly…” Disciplinary Issues in the Army of the Potomac under Grant during the Overland Campaign
Between May and June 1864, the Army of the Potomac conducted yet another push toward Richmond. The intense weather, extended time under fire, and unprecedented slaughter took its toll on the rank and file. For many of the army’s best and most hardened veterans, this would be their last campaign. As their anticipation for home grew, however, their disdain for the new style of warfare grew with it. Fresh troops arrived almost daily from the cities across the north. Many of whom were conscripts or bounty men. Even the soldiers who chose not to reenlist expressed their low expectations for these men. Soon, soldiers began to become lax in their disciplinary efforts: straggling, shirking, skulking, insubordination and even the most heinous crime, desertion. This lack of discipline exasperated the army commanders, leading them to enact harsh penalties and make examples of their men. The citizens of the north saw a different and partisan picture of the army, images of Grant the Butcher, Meade the inept, and bloody losses took the place of the soldier’s story of ill-discipline and hardship. The new style of warfare that began during the Overland Campaign led to a breakdown of military discipline that infused the Army of the Potomac and left a northern populace stunned with its effects. [excerpt
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