1,222 research outputs found
CMS (LHC) Measurements and Unusual Cosmic Ray Events
At the LHC, for the first time, laboratory energies are sufficiently large to
reproduce the kind of reactions that occur when energetic cosmic rays strike
the top of the atmosphere. The reaction products of interest for cosmic ray
studies are produced at small angles, even with colliding beams. Most of the
emphasis at the LHC is on rare processes that are studied with detectors at
large angles. It is precision measurements at large angles that are expected to
lead to discoveries of Higgs bosons and super symmetric particles. CMS
currently has two small angle detectors, CASTOR and a Zero Degree Calorimeter
(ZDC). CASTOR, at down to , is designed to study
"Centauro" and "long penetrating" events, observed in VHE cosmic-ray data. As a
general purpose detector it also makes measurements of reaction products at
forward angles from p-p collisions, which provide input for cosmic ray shower
codes. The ZDC is small, 9 cm. wide, between the incoming and outgoing beam
pipes out at a distance of 140 m. The ZDC measures neutral objects that follow
the direction of the beam at the interaction point. If the long penetrating
objects are spectators they could be seen in the ZDC if their charge to mass
ratio, Z/A, is less than 0.2.Comment: Invited talk presented at the XVI International Symposium on Very
High Energy Cosmic Ray Interactions, ISVHECRI 2010, Batavia, IL, USA (28 June
- 2 July 2010). 4 pages, 5 figure
Status of Zero Degree Calorimeter for CMS Experiment
The Zero Degree Calorimeter (ZDC) is integral part of the CMS experiment,
especially, for heavy ion studies. The design of the ZDC includes two
independent calorimeter sections: an electromagnetic section and a hadronic
section. Sampling calorimeters using tungsten and quartz fibers have been
chosen for the energy measurements. An overview of the ZDC is presented along
with a current status of calorimeter's preparation for Day 1 of LHC.Comment: 8 pages, 5 figures, 1 table, to appear in the proceedings of CALOR06,
June 5-9, 2006 Chicago, US
Physics at Very Small Angles with CASTOR at CMS
CASTOR is a small (56 cm diameter) quartz-tungsten Cerenkov calorimeter covering the small angles 0.2-0.6 deg (5.2<="eta"<=6.4) in CMS, a major experiment at the LHC. Particularly with heavy-ion reactions a substantial fraction of the total reaction energy goes into this large "eta" region. CASTOR will function as a part of CMS and also as an independent detector to search for special types of events in the far-forward region. It is divided into 16 azimuthal sectors, each with 18 longitudinal segments to allow identification of particles by their energy-loss profiles. The most forward segments are smaller to better characterize electromagnetic events
Multifragmentation and nuclear phase transitions (liquid-fog and liquid-gas)
Thermal multifragmentation of hot nuclei is interpreted as the nuclear
liquid-fog phase transition. The charge distributions of the intermediate mass
fragments produced in p(3.6 GeV) + Au and p(8.1 GeV) + Au collisions are
analyzed within the statistical multifragmentation model with the critical
temperature for the nuclear liquid-gas phase transition Tc as a free parameter.
The analysis presented here provides strong support for a value of Tc > 15 MeV.Comment: 4 pages, 2 figures, Submittet to Proc. of NN2003 to be published in
Nucl. Phys.
Multifragmentation in Collisions of 4.4gev-Deuterons with Gold Target
The relative velocity correlation function of pairs of intermediate mass
fragments has been studied for d+Au collitions at 4.4 GeV. Experimental
correlation functions are compared to that obtained by multibody Coulomb
trajectory calculations under the assumption of various decay timees of the
fragmenting system. The combined approach with the empirically modified
intranuclear cascade code followed by the statistical multifragmentation model
was used to generate the starting conditions for these calculations. The
fragment emossion time is found to be less than 40 fm/c.Comment: Accepted for publication in Bulletin of the Russian Academy of
Sciences. Physic
Status of zero degree calorimeter for CMS experiment
The Zero Degree Calorimeter (ZDC) is integral part of the CMS experiment, especially, for heavy ion studies. The design of the ZDC includes two independent calorimeter sections: an electromagnetic section and a hadronic section. Sampling calorimeters using tungsten and quartz fibers have been chosen for the energy measurements. An overview of the ZDC is presented along with a current status of calorimeter's preparation for Day 1 of LHC
Research of Purchasing Management of C Shipbuilding Company
船舶制造行业,从2002年的蓬勃发展到2008年受金融危机影响至今的持续低迷,使得当前船舶制造行业面临着前所未有的巨大挑战,接单难、交船难、融资难成为船舶行业普遍的现象。如何生存下去成为当今我国船舶制造业极力需要解决的难题,而采购作为船舶行业发生成本最大的领域,充分挖掘采购作为企业的第三利润源泉的作用,对于降低成本,提高企业的竞争地位有着重大的战略意义,对此的研究也具有重大实际意义。 本论文从C船舶制造企业网络比价议标的采购模式分析入手,对这一新型采购管理模式进行了探索和研究。通过在C船企实际工作和大量调查,分析归纳C船企当前采购管理所存在的一些问题,并通过SWOT分析工具对C船企采购管理的...The shipbuilding industry was rapidly developed from 2002 to 2008, but remains downturn up to now by the financial crisis. So the current shipbuilding industry is facing many unprecedented challenges, such as the difficulty of the order, the difficulty of delivery of ship and financing become common phenomenon in the shipbuilding industry. Nowadays, How to survive is become a big problem, which ne...学位:管理学硕士院系专业:管理学院企业管理系_企业管理(含财务管理、市场营销、人力资源管理)学号:20071401
Measurement of the Rate Capability of Resistive Plate Chambers
This paper reports on detailed measurements of the performance of Resistive
Plate Chambers in a proton beam with variable intensity. Short term effects,
such as dead time, are studied using consecutive events. On larger time scales,
for various beam intensities the chamber.s efficiency is studied as a function
of time within a spill of particles. The correlation between the efficiency of
chambers placed in the same beam provides an indication of the lateral size of
the observed effects. The measurements are compared to the predictions of a
simple model based on the assumption that the resistive plates behave as pure
resistors
- …