Study of charm production in Z decays

被引：120

作者：

Barate, R ^{[1
]}

Decamp, D

Ghez, P

Goy, C

Lees, JP

Merle, E

Minard, MN

Pietrzyk, B

Alemany, R

Casado, MP

Chmeissani, M

Crespo, JM

Fernandez, E

Fernandez-Bosman, M

Garrido, L

Graugès, E

Juste, A

Martinez, M

Merino, G

Miquel, R

Mir, LM

Pacheco, A

Park, IC

Riu, I

Colaleo, A

Creanza, D

de Palma, M

Iaselli, G

Maggi, G

Maggi, M

Nuzzo, S

Ranieri, A

Raso, G

Ruggieri, F

Selvaggi, G

Silvestris, L

Tempesta, P

Tricomi, A

Zito, G

Huang, X

Lin, J

Ouyang, Q

Wang, T

Xie, Y

Xu, R

Xue, S

Zhang, J

Zhang, L

Zhao, W

Abbaneo, D

机构：

[1] Phys Particules Lab, IN2P3, CNRS, F-74019 Annecy Le Vieux, France

[2] Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Barcelona, Spain

[3] Ist Nazl Fis Nucl, Inst Fis, Sez Bari, I-70126 Bari, Italy

[4] Acad Sinica, Inst High Energy Phys, Beijing, Peoples R China

[5] CERN, European Lab Particle Phys, CH-1211 Geneva 23, Switzerland

[6] Univ Clermont Ferrand, Phys Corpusculaire Lab, IN2P3, CNRS, F-63177 Clermont Ferrand, Aubiere, France

[7] Niels Bohr Inst, DK-2100 Copenhagen, Denmark

[8] Democritos Nucl Res Ctr, Athens 15310, Greece

[9] Ecole Polytech, Lab Phys Nucl & Hautes Energies, IN2P3, CNRS, F-91128 Palaiseau, France

[10] Univ Florence, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Firenze, I-50125 Florence, Italy

[11] Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA

[12] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy

[13] Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland

[14] Heidelberg Univ, Inst Hochenergiephys, D-69120 Heidelberg, Germany

[15] Univ London Imperial Coll Sci Technol & Med, Dept Phys, London SW7 2BZ, England

[16] Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria

[17] Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England

[18] Johannes Gutenberg Univ Mainz, Dept Phys, D-55099 Mainz, Germany

[19] Fac Sci Luminy, Ctr Phys Particules, IN2P3, CNRS, F-13288 Marseille, France

[20] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy

[21] Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy

[22] Max Planck Inst Phys & Astrophys, Werner Heisenberg Inst, D-80805 Munich, Germany

[23] Univ Paris 11, Lab Accelerateur Lineaire, IN2P3, CNRS, F-91898 Orsay, France

[24] Univ Pisa, Dipartimento Fis, I-56010 Pisa, Italy

[25] Ist Nazl Fis Nucl, Sez Pisa, I-56010 Pisa, Italy

[26] Scuola Normale Super Pisa, I-56010 Pisa, Italy

[27] Univ London, Royal Holloway & Bedford New Coll, Dept Phys, Egham TW20 0EX, Surrey, England

[28] Rutherford Appleton Lab, Particle Phys Dept, Didcot OX11 0QX, Oxon, England

[29] Ctr Etud Saclay, CEA, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France

[30] Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA

[31] Univ Siegen, Fachbereich Phys, D-57068 Siegen, Germany

[32] Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy

[33] Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy

[34] Univ Washington, Seattle, WA 98195 USA

[35] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA

[36] CERN, CH-1211 Geneva 23, Switzerland

[37] Ist Nazl Fis Nucl, Ctr Siciliano Fis Nucl & Struttura Mat, Sez Catania, I-95129 Catania, Italy

[38] Univ Turin, Ist Fis Gen, I-10125 Turin, Italy

[39] CNR, Ist Cosmogeofis, I-10133 Turin, Italy

[40] Univ Barcelona, Barcelona 08208, Spain

来源：

EUROPEAN PHYSICAL JOURNAL C | 2000年 / 16卷 / 04期

关键词：

D O I：

10.1007/s100520000421

中图分类号：

O412 [相对论、场论]; O572.2 [粒子物理学];

学科分类号：

摘要：

The production rates of D*+/- D-s(*+/-), D+/-, D-0/(D) over bar(0), D-s(+/-), and Lambda(c)(+)/<(Lambda)over bar>(-)(c) in Z --> c (c) over bar decays are measured using the LEP I data sample recorded by the ALEPH detector. The fractional energy spectrum of the D*+/- is well described as the sum of three contributions: charm hadronisation, b hadron decays and gluon splitting into a pair of heavy quarks. The probability for a c quark to hadronise into a D*+ is found to be f(c --> D*+) = 0.233 +/- 0.010(stat.) +/- 0.011(syst.). The average fraction of the beam energy carried by D*+/- mesons in Z --> c (c) over bar events is measured to be (X-E(D*+/-))(c (c) over bar) = 0.4878 +/- 0.0046(stat.) +/- 0.0061(syst.). The D*+/- energy and the hemisphere mass imbalance distributions are simultaneously used to measure the fraction of hadronic Z decays in which a gluon splits to a c (c) over bar pair: (n) over bar(g --> c (c) over bar) = (3.23 +/- 0.48(stat.) +/- 0.53(syst.))%. The ratio of the Vector/(Vector+Pseudoscalar) production rates in charmed mesons is found to be P-V = 0.595 +/- 0.045. The fractional decay width of the Z into cc pairs is determined from the sum of the production rates for various weakly decaying charmed states to be R-c = 0.1738 +/- 0.0047(stat.) +/- 0.0116(syst.).

引用

页码：597 / 611

页数：15

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Barate, R ;

Buskulic, D ;

Decamp, D ;

Ghez, P ;

Goy, C ;

Lees, JP ;

Lucotte, A ;

Merle, E ;

Minard, MN ;

Nief, JY ;

Pietrzyk, B ;

Alemany, R ;

Boix, G ;

Casado, MP ;

Chmeissani, M ;

Crespo, JM ;

Delfino, M ;

Fernandez, E ;

Fernandez-Bosman, M ;

Garrido, I ;

Grauges, E ;

Juste, A ;

Martinez, M ;

Merino, G ;

Miquel, R ;

Mir, LM ;

Park, IC ;

Pascual, A ;

Perlas, JA ;

Riu, I ;

Sanchez, F ;

Colaleo, A ;

Creanza, D ;

de Palma, M ;

Gelao, G ;

Iaselli, G ;

Maggi, G ;

Maggi, M ;

Nuzzo, S ;

Ranieri, A ;

Raso, G ;

Ruggieri, F ;

Selvaggi, G ;

Silvestris, L ;

Tempesta, P ;

Tricomi, A ;

Zito, G ;

Huang, X ;

Lin, J ;

Ouyang, Q .

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