122652147
A quark way to asymptopia
117312086
Search for fast particles produced at large lab angles at NAL
An experiment is proposed to look for charged particles emitted at large lab angles that are normally forbidden kinematically. These particles if found would correspond to hitherto unobserved events such as the production of particles with imaginary mass values (''tachyons''). Also, they wish to look for fractionally-charged particles produced at these angles. These particles, if found, would correspond to strongly-bound quark-quark states formed in a dissociation of the target nucleon. The detection system will consist of wire-chambers, dE/dx and time-of-flight counters. The basic hardware is under construction and the final system will be ready for test runs at a lower-energy machine in six months. The detection telescope will view interactions of the primary proton beam from backward (in lab) directions and the first choice experimental site is the straight section B with a thin internal target. They would like to use the highest available beam at NAL and since the beam transport and intensity requirements are very minimal, they will be able to run parasitically during the tuning periods of the NAL machine in the next year. The machine time required for this experiment is about three months.
117351482
Bubble chamber study of (10÷100) GeV cosmic-ray muons at all zenith angles
SummaryCosmic-ray muons have been studied by analysis of tracks recorded in a large high-field heavy-liquid bubble chamber. From a sample of 50 000 pictures approximately 2 000 muons with energies above 10 GeV were examined for energy and zenith-angle distributions over the complete range from 0° to 90°. In the vertical direction the integral spectrum up to energies exceeding 100 GeV is consistent with depth intensity data and somewhat higher than observed in unshielded vertical magnetic spectrometers. At other zenith angles we find the expected variations, which approach a cos2ϑ attenuation for muons in the 10 GeV region, and tend towards a secϑ enhancement for muon energies above 100 GeV.RiassuntoSi sono studiati i muoni dei raggi cosmici analizzando le tracce fotografate in una grande camera a bolle a liquido pesante con forte campo magnetico. Da un campione di 50 000 fotogrammi si sono esaminati approssimativamente 2 000 muoni con energie superiori a 10 GeV per le distribuzioni di energia e dell’angolo zenitale nell’intero intervallo da 0° a 90°. Nella direzione verticale lo spettro integrale fino ad energie superiori ai 100 GeV è coerente con i dati sull’intensità in profondità ed è leggermente superiore a quello osservato in spettrometri magnetici verticali non schermati. Ad altri angoli zenitali si trovano le variazioni previste, che approssimano una attenuazione del tipo cos2ϑ per muoni nella regione di 10 GeV, e tendono verso un incremento del tipo secϑ per energie dei muoni al di sopra dei 100 GeV.РеэюмеБыли исследованы мюоны в космических лучах посредством аналиэа треков, эарегистрированных в пуэырьковой камере с тяжелой жидкостью, помешенной в сильном поле. Иэ выборки 50000 снимков были исследованы приблиэительно 2000 мюонов с знергиями около 10 ГзВ для получения знергетических распределений и распределений по эенитному углу во всей области углов от 0° до 90°. В вертикальном направлении интегральный спектр вплоть до знергий, превыщаюших 100 ГзВ, согласуется с данными глубинной интенсивности и до некоторой степени выще, чем наблюденный в незкранированных вертикальных магнитных спектрометрах. При других эенитных углах мы обнаружили предполагаемые иэменения, которые почти похожи на ослабление соs2 ϑ для мюонов в области 10 ГзВ и стремятся к увеличению вес ϑ для знергий мюонов выще 100 ГзВ.
124504029
The search for quarks in terrestrial matter
Abstract Recent experimental searches for physical quarks stopped in terrestrial matter are reviewed and summarized.
115768104
CURRENT STATUS OF THE QUEST FOR QUARKS.
122338380
COSMIC RAY MUONS FROM LOW GALACTIC LATITUDE
Occasional spurious tracks are found on photographs taken during routine observations with the 40-inch heavy-liquid bubble chamber (HLBC) at the Argonne National Laboratory (Roe, Sinclair, and Vander Vilde 1964). These tracks are caused by cosmic ray muons, and are rather similar to streaks caused by meteors on photographs of the sky. The HLBC is located at Ν 41°42'03" latitude and W 87°59'24" longitude, and at an altitude of 227.38 meters above sea level. It has a field of view in the form of a strip 50° wide centered on the north-zenith-south meridian. The strip extends from horizon to horizon. As the earth turns, 87 percent of the celestial sphere passes through the field of view. The product of the cross-sectional capture area of the HLBC times its field of view is 1.7 meter2 steradian. Each picture covers the entire field of view and has a sensitive time of six milliseconds. The chamber is ex-
5924990
BARYON DENSITY AND THE DILATED CHIRAL QUARK MODEL
We calculate perturbatively the effect of density on hadronic properties using the chiral quark model implemented by the QCD trace anomaly to see the possibility of constructing a Lorentz-invariant Lagrangian at finite density. We calculate the density-dependent masses of the constituent quark, the scalar field, and the pion in one-loop order using the technique of thermofield dynamics. In the chiral limit, the pion remains massless at finite density. It is found that the tadpole-type corrections lead to decreasing masses with increasing baryon density, while the radiative corrections induce Lorentz-symmetry-breaking terms. We found in the large N{sub c} limit with large scalar mass that the tadpoles dominate and the mean-field approximation is reliable, giving rise to a Lorentz-invariant Lagrangian with masses decreasing as the baryon density increases. {copyright} {ital 1997} {ital The American Physical Society}
123143192
Three‐particle symmetry classifications according to the method of Dirac
It is shown that the method of Dirac is an effective way of teaching three‐particle symmetry classifications to students in the first‐year quantum mechanics class, who wish to understand the symmetry properties associated with elementary particles before or without learning group theory. According to the method spelled out for the N‐particle case by Dirac in Secs. 55 and 56 of his classic book Principles of Quantum Mechanics, explicit calculations are carried out for three particles. It is shown that this method leads to the three‐particle wave functions and their symmetric combinations as given by Feynman et al. In the following paper, the general principles derived here are applied to the quark model of hadrons.
120211993
Space-time symmetries of confined quarks
The first paragraph of Rotbart's recent paper is amplified. It is shown that the minimum symmetry for the spacetime separation of the confined quarks is that of the O(3)-like little group of the Poincare group for massive hadrons. It is then pointed out that the existence of additional coordinate dependences is determined from the way in which specific models are constructed.
11157984
Growth time of the longitudinal coupled bunch mode beam instability at the Duke FEL facility
To determine the required power of an amplifier for the longitudinal feedback (LFB) system, the growth time of the strongest longitudinal coupled bunch mode instability (CBMI) in the Duke storage ring should be measured in advance. In 2005, we measured strength of the strongest longitudinal beam instability in the Duke storage ring with four and eight symmetrically filled buckets. By analyzing measured data, the growth time of the strongest dipole mode of the longitudinal CBMI in the Duke storage ring can be estimated. At a beam energy of 274 MeV, the growth time is about 0.365 ms for a total stored beam current of 160 mA. From the measured growth time, we estimated the required power of the amplifier for the LFB system. To damp all harmful longitudinal CBMIs with an energy deviation of 0.1 % (rms) within its growth time of 0.365 ms, we have to supply about HOW (rms) to an LFB kicker whose a central frequency is 937.3875 MHz. In this paper, we describe the growth time of the longitudinal CBMI at the Duke storage ring and the estimation of the required power for the LFB system to damp all CBMIs within 0.365 ms.
121093451
Stable operation of a self-amplified spontaneous-emission free-electron laser in the extremely ultraviolet region