skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.

Abstract

We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing overmore » broad x-range. With the present PHENIX detector, heavy-quark production has been measured indirectly through the observation of single electrons. These measurements are inherently limited in accuracy by systematic uncertainties resulting from the large electron background from Dalitz decays and photon conversions. In particular, the statistical nature of the analysis does not allow for a model-independent separation of the charm and beauty contributions. The VTX detector will provide vertex tracking with a resolution of <50 {micro}m over a large coverage both in rapidity (|{eta}| < 1.2) and in azimuthal angle ({Delta}{phi} {approx} 2{pi}). With this device, significantly enhanced and qualitatively new data can be obtained. A more robust and accurate measurement of heavy-quark production over a wide kinematics range will be possible. The main benefits are in three areas. Firstly, by selecting electrons with a distance of closest approach (DCA) to the primary vertex larger than {approx}100 {micro}m, the background will be suppressed by several orders of magnitude and thereby a clean and robust measurement of heavy flavor production in the single electron channel will become available. Secondly, because the lifetime of mesons with beauty is significantly larger than that of mesons with charm, the VTX information will allow us to disentangle charm from beauty production over a broad p{sub T} range. Thirdly, a DCA cut on hadrons will reduce the combinatorial background of K{pi} to an extent that a direct measurement of D mesons through this decay channel will become possible. In addition, the VTX detector will substantially extend our p{sub T} coverage in high p{sub T} charged particles, and it also will enable us to measure {gamma}+jet correlations.« less

Authors:
Publication Date:
Research Org.:
BROOKHAVEN NATIONAL LABORATORY (US)
Sponsoring Org.:
DOE/OFFICE OF SCIENCE (US)
OSTI Identifier:
15007383
Report Number(s):
BNL-72204-2004
R&D Project: 08845; KB0202012; TRN: US0401756
DOE Contract Number:  
AC02-98CH10886
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 30 Mar 2004
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; CHARGED PARTICLES; D MESONS; ELECTRONS; GLUONS; HADRONS; HEAVY IONS; MESONS; NUCLEONS; PARTICLE RAPIDITY; PHOTONS; QUANTUM CHROMODYNAMICS; QUARKONIUM; SILICON; SPECTROSCOPY

Citation Formats

AKIBA, Y. PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.. United States: N. p., 2004. Web. doi:10.2172/15007383.
AKIBA, Y. PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.. United States. https://doi.org/10.2172/15007383
AKIBA, Y. 2004. "PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.". United States. https://doi.org/10.2172/15007383. https://www.osti.gov/servlets/purl/15007383.
@article{osti_15007383,
title = {PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.},
author = {AKIBA, Y},
abstractNote = {We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over broad x-range. With the present PHENIX detector, heavy-quark production has been measured indirectly through the observation of single electrons. These measurements are inherently limited in accuracy by systematic uncertainties resulting from the large electron background from Dalitz decays and photon conversions. In particular, the statistical nature of the analysis does not allow for a model-independent separation of the charm and beauty contributions. The VTX detector will provide vertex tracking with a resolution of <50 {micro}m over a large coverage both in rapidity (|{eta}| < 1.2) and in azimuthal angle ({Delta}{phi} {approx} 2{pi}). With this device, significantly enhanced and qualitatively new data can be obtained. A more robust and accurate measurement of heavy-quark production over a wide kinematics range will be possible. The main benefits are in three areas. Firstly, by selecting electrons with a distance of closest approach (DCA) to the primary vertex larger than {approx}100 {micro}m, the background will be suppressed by several orders of magnitude and thereby a clean and robust measurement of heavy flavor production in the single electron channel will become available. Secondly, because the lifetime of mesons with beauty is significantly larger than that of mesons with charm, the VTX information will allow us to disentangle charm from beauty production over a broad p{sub T} range. Thirdly, a DCA cut on hadrons will reduce the combinatorial background of K{pi} to an extent that a direct measurement of D mesons through this decay channel will become possible. In addition, the VTX detector will substantially extend our p{sub T} coverage in high p{sub T} charged particles, and it also will enable us to measure {gamma}+jet correlations.},
doi = {10.2172/15007383},
url = {https://www.osti.gov/biblio/15007383}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {3}
}