Measurement of D+- production and the charm contribution to

a r X i v :h e p -e x /9908012v 3 3 A p r 2000Measurement of D ?±production and the charm contribution to F 2in deep inelastic scattering at HERA

ZEUS Collaboration Abstract The production of D ?±(2010)mesons in deep inelastic scattering has been measured in the ZEUS detector at HERA using an integrated luminosity of 37pb ?1.The decay channels D ?+→D 0π+(+c.c.),with D 0→K ?π+or D 0→K ?π?π+π+,have been used to identify the D mesons.The e +p cross section for inclusive D ?±production with 1

rises from ?10%at Q 2?1.8GeV 2to ?30%at Q 2?130GeV 2for x values in the range 10?4to 10?3.Eur.Phys.J.C 12(2000)35-52

The ZEUS Collaboration

J.Breitweg,S.Chekanov,M.Derrick,D.Krakauer,S.Magill,B.Musgrave,A.Pellegrino, J.Repond,R.Stanek,R.Yoshida

Argonne National Laboratory,Argonne,IL,USA p

M.C.K.Mattingly

Andrews University,Berrien Springs,MI,USA

G.Abbiendi,F.Anselmo,P.Antonioli,G.Bari,M.Basile,L.Bellagamba,D.Boscherini1, A.Bruni,G.Bruni,G.Cara Romeo,G.Castellini2,L.Cifarelli3,F.Cindolo,A.Contin,N.Cop-pola,M.Corradi,S.De Pasquale,P.Giusti,G.Iacobucci4,5543a31d650e52ea55189803urenti,G.Levi,A.Margotti, T.Massam,R.Nania,F.Palmonari,A.Pesci,A.Polini,G.Sartorelli,Y.Zamora Garcia5, A.Zichichi

University and INFN Bologna,Bologna,Italy f

C.Amelung,A.Bornheim,I.Brock,K.Cob¨o ken,J.Crittenden,R.De?ner,M.Eckert6, H.Hartmann,K.Heinloth,E.Hilger,H.-P.Jakob,A.Kappes,U.F.Katz,R.Kerger,E.Paul, J.Rautenberg7,

H.Schnurbusch,A.Stifutkin,J.Tandler,A.Weber,H.Wieber

Physikalisches Institut der Universit¨a t Bonn,Bonn,Germany c

D.S.Bailey,O.Barret,W.N.Cottingham,B.Foster8,G.P.Heath,H.F.Heath,J.D.McFall, D.Piccioni,J.Scott,R.J.Tapper

H.H.Wills Physics Laboratory,University of Bristol,Bristol,U.K.o

M.Capua,A.Mastroberardino,M.Schioppa,G.Susinno

Calabria University,Physics Dept.and INFN,Cosenza,Italy f

H.Y.Jeoung,J.Y.Kim,J.H.Lee,I.T.Lim,K.J.Ma,M.Y.Pac9

Chonnam National University,Kwangju,Korea h

A.Caldwell,W.Liu,X.Liu,

B.Mellado,J.A.Parsons,S.Ritz10,R.Sacchi,S.Sampson, F.Sciulli

Columbia University,Nevis Labs.,Irvington on Hudson,N.Y.,USA q

J.Chwastowski,A.Eskreys,J.Figiel,K.Klimek,K.Olkiewicz,M.B.Przybycie′n,P.Stopa, L.Zawiejski

Inst.of Nuclear Physics,Cracow,Poland j

L.Adamczyk11,B.Bednarek,K.Jele′n,D.Kisielewska,A.M.Kowal,T.Kowalski,M.Przyby-cie′n,E.Rulikowska-Zar?e bska,L.Suszycki,J.Zaj?a c

Faculty of Physics and Nuclear Techniques,Academy of Mining and Metallurgy,Cracow,Poland j Z.Duli′n ski,A.Kota′n ski

Jagellonian Univ.,Dept.of Physics,Cracow,Poland k

1

L.A.T.Bauerdick,U.Behrens,J.K.Bienlein,C.Burgard,K.Desler,G.Drews,A.Fox-Murphy, U.Fricke,F.Goebel,P.G¨o ttlicher,R.Graciani,T.Haas,W.Hain,G.F.Hartner,D.Hasell12, K.Hebbel,K.F.Johnson13,M.Kasemann14,W.Koch,U.K¨o tz,H.Kowalski,L.Lindemann, B.L¨o hr,M.Mart′?nez,5543a31d650e52ea55189803ewski15,5543a31d650e52ea55189803ite,T.Monteiro16,M.Moritz,D.Notz,F.Peluc-chi,M.C.Petrucci,K.Piotrzkowski,M.Rohde,P.R.B.Saull,A.A.Savin,U.Schneekloth, O.Schwarzer17,F.Selonke,M.Sievers,S.Stonjek,E.Tassi,G.Wolf,U.Wollmer,C.Young-man,W.Zeuner

Deutsches Elektronen-Synchrotron DESY,Hamburg,Germany

B.D.Burow18,

C.Coldewey,H.J.Grabosch, A.Lopez-Duran Viani, A.Meyer,K.M¨o nig, S.Schlenstedt,P.B.Straub

DESY Zeuthen,Zeuthen,Germany

G.Barbagli,E.Gallo,P.Pelfer

University and INFN,Florence,Italy f

G.Maccarrone,L.Votano

INFN,Laboratori Nazionali di Frascati,Frascati,Italy f

A.Bamberger,S.Eisenhardt19,P.Markun,H.Raach,S.W¨o l?e

Fakult¨a t f¨u r Physik der Universit¨a t Freiburg i.Br.,Freiburg i.Br.,Germany c

N.H.Brook20,P.J.Bussey,A.T.Doyle,S.W.Lee,N.Macdonald,G.J.McCance,D.H.Saxon, L.E.Sinclair,I.O.Skillicorn,E.Strickland,R.Waugh

Dept.of Physics and Astronomy,University of Glasgow,Glasgow,U.K.o

I.Bohnet,N.Gendner,U.Holm,A.Meyer-Larsen,H.Salehi,K.Wick

Hamburg University,I.Institute of Exp.Physics,Hamburg,Germany c

A.Garfagnini,I.Gialas21,L.K.Gladilin22,D.K?c ira23,R.Klanner,E.Lohrmann,G.Poelz, F.Zetsche

Hamburg University,II.Institute of Exp.Physics,Hamburg,Germany c

T.C.Bacon,J.E.Cole,G.Howell,5543a31d650e52ea55189803mberti24,K.R.Long,5543a31d650e52ea55189803ler,A.Prinias25,J.K.Sedg-beer,D.Sideris,A.D.Tapper,R.Walker

Imperial College London,High Energy Nuclear Physics Group,London,U.K.o

U.Mallik,S.M.Wang

University of Iowa,Physics and Astronomy Dept.,Iowa City,USA p

P.Cloth,D.Filges

Forschungszentrum J¨u lich,Institut f¨u r Kernphysik,J¨u lich,Germany

T.Ishii,M.Kuze,I.Suzuki26,K.Tokushuku27,S.Yamada,K.Yamauchi,Y.Yamazaki Institute of Particle and Nuclear Studies,KEK,Tsukuba,Japan g

S.H.Ahn,S.H.An,S.J.Hong,S.B.Lee,S.W.Nam28,S.K.Park

Korea University,Seoul,Korea h

H.Lim,I.H.Park,D.Son

Kyungpook National University,Taegu,Korea h

2

F.Barreiro,J.P.Fern′a ndez,

G.Garc′?a,C.Glasman29,J.M.Hern′a ndez30,5543a31d650e52ea55189803barga,J.del Peso, J.Puga,I.Redondo31,J.Terr′o n

Univer.Aut′o noma Madrid,Depto de F′?sica Te′o rica,Madrid,Spain n

F.Corriveau,D.S.Hanna,J.Hartmann32,W.N.Murray33,A.Ochs,S.Padhi,M.Riveline, D.

G.Stairs,M.St-Laurent,M.Wing

McGill University,Dept.of Physics,Montr′e al,Qu′e bec,Canada a,b

T.Tsurugai

Meiji Gakuin University,Faculty of General Education,Yokohama,Japan

V.Bashkirov34,B.A.Dolgoshein

Moscow Engineering Physics Institute,Moscow,Russia l

G.L.Bashindzhagyan,P.F.Ermolov,Yu.A.Golubkov,L.A.Khein,N.A.Korotkova,I.A.Ko-rzhavina,V.A.Kuzmin,O.Yu.Lukina,A.S.Proskuryakov,L.M.Shcheglova35,A.N.Solomin35, S.A.Zotkin

Moscow State University,Institute of Nuclear Physics,Moscow,Russia m

C.Bokel,M.Botje,N.Br¨u mmer,J.Engelen,E.Ko?eman,P.Kooijman,A.van Sighem, H.Tiecke,N.Tuning,J.J.Velthuis,W.Verkerke,J.Vossebeld,L.Wiggers,E.de Wolf NIKHEF and University of Amsterdam,Amsterdam,Netherlands i

D.Acosta36,B.Bylsma,L.S.Durkin,J.Gilmore,C.M.Ginsburg,C.L.Kim,T.Y.Ling,P.Ny-lander

Ohio State University,Physics Department,Columbus,Ohio,USA p

H.E.Blaikley,S.Boogert,R.J.Cashmore16,A.M.Cooper-Sarkar,R.C.E.Devenish,J.K.Ed-monds,J.Gro?e-Knetter37,N.Harnew,T.Matsushita,V.A.Noyes38,A.Quadt16,O.Ruske, M.R.Sutton,R.Walczak,D.S.Waters

Department of Physics,University of Oxford,Oxford,U.K.o

A.Bertolin,R.Brugnera,R.Carlin,F.Dal Corso,S.Dondana,U.Dosselli,S.Dusini,S.Li-mentani,M.Morandin,M.Posocco,L.Stanco,R.Stroili,C.Voci

Dipartimento di Fisica dell’Universit`a and INFN,Padova,Italy f

L.Iannotti39,B.Y.Oh,J.R.Okrasi′n ski,W.S.Toothacker,J.J.Whitmore

Pennsylvania State University,Dept.of Physics,University Park,PA,USA q

Y.Iga

Polytechnic University,Sagamihara,Japan g

G.D’Agostini,G.Marini,A.Nigro,M.Raso

Dipartimento di Fisica,Univ.’La Sapienza’and INFN,Rome,Italy f

C.Cormack,J.C.Hart,N.A.McCubbin,T.P.Shah

Rutherford Appleton Laboratory,Chilton,Didcot,Oxon,U.K.o

D.Epperson,C.Heusch,H.F.-W.Sadrozinski,A.Seiden,R.Wichmann,D.C.Williams University of California,Santa Cruz,CA,USA p

N.Pavel

Fachbereich Physik der Universit¨a t-Gesamthochschule Siegen,Germany c

3

H.Abramowicz40,S.Dagan41,S.Kananov41,A.Kreisel,A.Levy41

Raymond and Beverly Sackler Faculty of Exact Sciences,School of Physics,Tel-Aviv University, Tel-Aviv,Israel e

T.Abe,T.Fusayasu,M.Inuzuka,K.Nagano,K.Umemori,T.Yamashita

Department of Physics,University of Tokyo,Tokyo,Japan g

R.Hamatsu,T.Hirose,K.Homma42,S.Kitamura43,T.Nishimura

Tokyo Metropolitan University,Dept.of Physics,Tokyo,Japan g

M.Arneodo44,N.Cartiglia,R.Cirio,M.Costa,M.I.Ferrero,S.Maselli,V.Monaco,C.Peroni, M.Ruspa,A.Solano,A.Staiano

Universit`a di Torino,Dipartimento di Fisica Sperimentale and INFN,Torino,Italy f

M.Dardo

II Faculty of Sciences,Torino University and INFN-Alessandria,Italy f

D.C.Bailey,C.-P.Fagerstroem,R.Galea,T.Koop,G.M.Levman,J.F.Martin,R.S.Orr, S.Polenz,A.Sabetfakhri,D.Simmons

University of Toronto,Dept.of Physics,Toronto,Ont.,Canada a

J.M.Butterworth,C.D.Catterall,M.E.Hayes,E.A.Heaphy,T.W.Jones,5543a31d650e52ea55189803ne,B.J.West University College London,Physics and Astronomy Dept.,London,U.K.o

J.Ciborowski,R.Ciesielski,G.Grzelak,R.J.Nowak,J.M.Pawlak,R.Pawlak,B.Smalska, T.Tymieniecka,A.K.Wr′o blewski,J.A.Zakrzewski,A.F.˙Zarnecki

Warsaw University,Institute of Experimental Physics,Warsaw,Poland j

M.Adamus,T.Gadaj

Institute for Nuclear Studies,Warsaw,Poland j

O.Deppe,Y.Eisenberg41,D.Hochman,U.Karshon41

Weizmann Institute,Department of Particle Physics,Rehovot,Israel d

W.F.Badgett,D.Chapin,R.Cross,C.Foudas,S.Mattingly,D.D.Reeder,W.H.Smith, A.Vaiciulis45,T.Wildschek,M.Wodarczyk

University of Wisconsin,Dept.of Physics,Madison,WI,USA p

A.Deshpande,S.Dhawan,V.W.Hughes

Yale University,Department of Physics,New Haven,CT,USA p

S.Bhadra,W.R.Frisken,R.Hall-Wilton,M.Khakzad,S.Menary,W.B.Schmidke

York University,Dept.of Physics,Toronto,Ont.,Canada a

4

1now visiting scientist at DESY

2also at IROE Florence,Italy

3now at Univ.of Salerno and INFN Napoli,Italy

4also at DESY

5supported by Worldlab,Lausanne,Switzerland

6now at BSG Systemplanung AG,53757St.Augustin

7drafted to the German military service

8also at University of Hamburg,Alexander von Humboldt Research Award