Measurements of the Absolute Branching Fractions of
B
!
K
X
c
c
B. Aubert,
1
R. Barate,
1
D. Boutigny,
1
F. Couderc,
1
Y. Karyotakis,
1
J. P. Lees,
1
V. Poireau,
1
V. Tisserand,
1
A. Zghiche,
1
E. Grauges,
2
A. Palano,
3
M. Pappagallo,
3
A. Pompili,
3
J. C. Chen,
4
N. D. Qi,
4
G. Rong,
4
P. Wang,
4
Y. S. Zhu,
4
G. Eigen,
5
I. Ofte,
5
B. Stugu,
5
G. S. Abrams,
6
M. Battaglia,
6
A. B. Breon,
6
D. N. Brown,
6
J. Button-Shafer,
6
R. N. Cahn,
6
E. Charles,
6
C. T. Day,
6
M. S. Gill,
6
A. V. Gritsan,
6
Y. Groysman,
6
R. G. Jacobsen,
6
R. W. Kadel,
6
J. Kadyk,
6
L. T. Kerth,
6
Yu. G. Kolomensky,
6
G. Kukartsev,
6
G. Lynch,
6
L. M. Mir,
6
P. J. Oddone,
6
T. J. Orimoto,
6
M. Pripstein,
6
N. A. Roe,
6
M. T. Ronan,
6
W. A. Wenzel,
6
M. Barrett,
7
K. E. Ford,
7
T. J. Harrison,
7
A. J. Hart,
7
C. M. Hawkes,
7
S. E. Morgan,
7
A. T. Watson,
7
M. Fritsch,
8
K. Goetzen,
8
T. Held,
8
H. Koch,
8
B. Lewandowski,
8
M. Pelizaeus,
8
K. Peters,
8
T. Schroeder,
8
M. Steinke,
8
J. T. Boyd,
9
J. P. Burke,
9
N. Chevalier,
9
W. N. Cottingham,
9
T. Cuhadar-Donszelmann,
10
B. G. Fulsom,
10
C. Hearty,
10
N. S. Knecht,
10
T. S. Mattison,
10
J. A. McKenna,
10
A. Khan,
11
P. Kyberd,
11
M. Saleem,
11
L. Teodorescu,
11
A. E. Blinov,
12
V. E. Blinov,
12
A. D. Bukin,
12
V. P. Druzhinin,
12
V. B. Golubev,
12
E. A. Kravchenko,
12
A. P. Onuchin,
12
S. I. Serednyakov,
12
Yu. I. Skovpen,
12
E. P. Solodov,
12
A. N. Yushkov,
12
D. Best,
13
M. Bondioli,
13
M. Bruinsma,
13
M. Chao,
13
S. Curry,
13
I. Eschrich,
13
D. Kirkby,
13
A. J. Lankford,
13
P. Lund,
13
M. Mandelkern,
13
R. K. Mommsen,
13
W. Roethel,
13
D. P. Stoker,
13
C. Buchanan,
14
B. L. Hartfiel,
14
A. J. R. Weinstein,
14
S. D. Foulkes,
15
J. W. Gary,
15
O. Long,
15
B. C. Shen,
15
K. Wang,
15
L. Zhang,
15
D. del Re,
16
H. K. Hadavand,
16
E. J. Hill,
16
D. B. MacFarlane,
16
H. P. Paar,
16
S. Rahatlou,
16
V. Sharma,
16
J. W. Berryhill,
17
C. Campagnari,
17
A. Cunha,
17
B. Dahmes,
17
T. M. Hong,
17
M. A. Mazur,
17
J. D. Richman,
17
W. Verkerke,
17
T. W. Beck,
18
A. M. Eisner,
18
C. J. Flacco,
18
C. A. Heusch,
18
J. Kroseberg,
18
W. S. Lockman,
18
G. Nesom,
18
T. Schalk,
18
B. A. Schumm,
18
A. Seiden,
18
P. Spradlin,
18
D. C. Williams,
18
M. G. Wilson,
18
J. Albert,
19
E. Chen,
19
G. P. Dubois-Felsmann,
19
A. Dvoretskii,
19
D. G. Hitlin,
19
J. S. Minamora,
19
I. Narsky,
19
T. Piatenko,
19
F. C. Porter,
19
A. Ryd,
19
A. Samuel,
19
R. Andreassen,
20
G. Mancinelli,
20
B. T. Meadows,
20
M. D. Sokoloff,
20
F. Blanc,
21
P. Bloom,
21
S. Chen,
21
W. T. Ford,
21
J. F. Hirschauer,
21
A. Kreisel,
21
U. Nauenberg,
21
A. Olivas,
21
W. O. Ruddick,
21
J. G. Smith,
21
K. A. Ulmer,
21
S. R. Wagner,
21
J. Zhang,
21
A. Chen,
22
E. A. Eckhart,
22
A. Soffer,
22
W. H. Toki,
22
R. J. Wilson,
22
Q. Zeng,
22
D. Altenburg,
23
E. Feltresi,
23
A. Hauke,
23
B. Spaan,
23
T. Brandt,
24
J. Brose,
24
M. Dickopp,
24
V. Klose,
24
H. M. Lacker,
24
R. Nogowski,
24
S. Otto,
24
A. Petzold,
24
J. Schubert,
24
K. R. Schubert,
24
R. Schwierz,
24
J. E. Sundermann,
24
D. Bernard,
25
G. R. Bonneaud,
25
P. Grenier,
25
S. Schrenk,
25
Ch. Thiebaux,
25
G. Vasileiadis,
25
M. Verderi,
25
D. J. Bard,
26
P. J. Clark,
26
W. Gradl,
26
F. Muheim,
26
S. Playfer,
26
Y. Xie,
26
M. Andreotti,
27
V. Azzolini,
27
D. Bettoni,
27
C. Bozzi,
27
R. Calabrese,
27
G. Cibinetto,
27
E. Luppi,
27
M. Negrini,
27
L. Piemontese,
27
F. Anulli,
28
R. Baldini-Ferroli,
28
A. Calcaterra,
28
R. de Sangro,
28
G. Finocchiaro,
28
P. Patteri,
28
I. M. Peruzzi,
28,
*
M. Piccolo,
28
A. Zallo,
28
A. Buzzo,
29
R. Capra,
29
R. Contri,
29
M. Lo Vetere,
29
M. Macri,
29
M. R. Monge,
29
S. Passaggio,
29
C. Patrignani,
29
E. Robutti,
29
A. Santroni,
29
S. Tosi,
29
G. Brandenburg,
30
K. S. Chaisanguanthum,
30
M. Morii,
30
E. Won,
30
J. Wu,
30
R. S. Dubitzky,
31
U. Langenegger,
31
J. Marks,
31
S. Schenk,
31
U. Uwer,
31
G. Schott,
32
W. Bhimji,
33
D. A. Bowerman,
33
P. D. Dauncey,
33
U. Egede,
33
R. L. Flack,
33
J. R. Gaillard,
33
J. A. Nash,
33
M. B. Nikolich,
33
W. Panduro Vazquez,
33
X. Chai,
34
M. J. Charles,
34
W. F. Mader,
34
U. Mallik,
34
A. K. Mohapatra,
34
V. Ziegler,
34
J. Cochran,
35
H. B. Crawley,
35
V. Eyges,
35
W. T. Meyer,
35
S. Prell,
35
E. I. Rosenberg,
35
A. E. Rubin,
35
J. Yi,
35
N. Arnaud,
36
M. Davier,
36
X. Giroux,
36
G. Grosdidier,
36
A. Ho
̈
cker,
36
F. Le Diberder,
36
V. Lepeltier,
36
A. M. Lutz,
36
A. Oyanguren,
36
T. C. Petersen,
36
S. Plaszczynski,
36
S. Rodier,
36
P. Roudeau,
36
M. H. Schune,
36
A. Stocchi,
36
G. Wormser,
36
C. H. Cheng,
37
D. J. Lange,
37
M. C. Simani,
37
D. M. Wright,
37
A. J. Bevan,
38
C. A. Chavez,
38
I. J. Forster,
38
J. R. Fry,
38
E. Gabathuler,
38
R. Gamet,
38
K. A. George,
38
D. E. Hutchcroft,
38
R. J. Parry,
38
D. J. Payne,
38
K. C. Schofield,
38
C. Touramanis,
38
C. M. Cormack,
39
F. Di Lodovico,
39
W. Menges,
39
R. Sacco,
39
C. L. Brown,
40
G. Cowan,
40
H. U. Flaecher,
40
M. G. Green,
40
D. A. Hopkins,
40
P. S. Jackson,
40
T. R. McMahon,
40
S. Ricciardi,
40
F. Salvatore,
40
D. Brown,
41
C. L. Davis,
41
J. Allison,
42
N. R. Barlow,
42
R. J. Barlow,
42
C. L. Edgar,
42
M. C. Hodgkinson,
42
M. P. Kelly,
42
G. D. Lafferty,
42
M. T. Naisbit,
42
J. C. Williams,
42
C. Chen,
43
W. D. Hulsbergen,
43
A. Jawahery,
43
D. Kovalskyi,
43
C. K. Lae,
43
D. A. Roberts,
43
G. Simi,
43
G. Blaylock,
44
C. Dallapiccola,
44
S. S. Hertzbach,
44
R. Kofler,
44
V. B. Koptchev,
44
X. Li,
44
T. B. Moore,
44
S. Saremi,
44
H. Staengle,
44
S. Willocq,
44
R. Cowan,
45
K. Koeneke,
45
G. Sciolla,
45
S. J. Sekula,
45
M. Spitznagel,
45
F. Taylor,
45
R. K. Yamamoto,
45
H. Kim,
46
P. M. Patel,
46
S. H. Robertson,
46
A. Lazzaro,
47
V. Lombardo,
47
F. Palombo,
47
J. M. Bauer,
48
L. Cremaldi,
48
V. Eschenburg,
48
R. Godang,
48
R. Kroeger,
48
J. Reidy,
48
D. A. Sanders,
48
D. J. Summers,
48
H. W. Zhao,
48
S. Brunet,
49
D. Co
ˆ
te
́
,
49
P. Taras,
49
B. Viaud,
49
H. Nicholson,
50
N. Cavallo,
51,†
G. De Nardo,
51
F. Fabozzi,
51,†
C. Gatto,
51
L. Lista,
51
D. Monorchio,
51
P. Paolucci,
51
D. Piccolo,
51
C. Sciacca,
51
M. Baak,
52
H. Bulten,
52
G. Raven,
52
H. L. Snoek,
52
L. Wilden,
52
C. P. Jessop,
53
J. M. LoSecco,
53
T. Allmendinger,
54
G. Benelli,
54
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
0031-9007
=
06
=
96(5)
=
052002(7)$23.00
052002-1
©
2006 The American Physical Society
K. K. Gan,
54
K. Honscheid,
54
D. Hufnagel,
54
P. D. Jackson,
54
H. Kagan,
54
R. Kass,
54
T. Pulliam,
54
A. M. Rahimi,
54
R. Ter-Antonyan,
54
Q. K. Wong,
54
J. Brau,
55
R. Frey,
55
O. Igonkina,
55
M. Lu,
55
C. T. Potter,
55
N. B. Sinev,
55
D. Strom,
55
J. Strube,
55
E. Torrence,
55
F. Galeazzi,
56
M. Margoni,
56
M. Morandin,
56
M. Posocco,
56
M. Rotondo,
56
F. Simonetto,
56
R. Stroili,
56
C. Voci,
56
M. Benayoun,
57
H. Briand,
57
J. Chauveau,
57
P. David,
57
L. Del Buono,
57
Ch. de la Vaissie
`
re,
57
O. Hamon,
57
M. J. J. John,
57
Ph. Leruste,
57
J. Malcle
`
s,
57
J. Ocariz,
57
L. Roos,
57
G. Therin,
57
P. K. Behera,
58
L. Gladney,
58
Q. H. Guo,
58
J. Panetta,
58
M. Biasini,
59
R. Covarelli,
59
S. Pacetti,
59
M. Pioppi,
59
C. Angelini,
60
G. Batignani,
60
S. Bettarini,
60
F. Bucci,
60
G. Calderini,
60
M. Carpinelli,
60
R. Cenci,
60
F. Forti,
60
M. A. Giorgi,
60
A. Lusiani,
60
G. Marchiori,
60
M. Morganti,
60
N. Neri,
60
E. Paoloni,
60
M. Rama,
60
G. Rizzo,
60
J. Walsh,
60
M. Haire,
61
D. Judd,
61
D. E. Wagoner,
61
J. Biesiada,
62
N. Danielson,
62
P. Elmer,
62
Y. P. Lau,
62
C. Lu,
62
J. Olsen,
62
A. J. S. Smith,
62
A. V. Telnov,
62
F. Bellini,
63
G. Cavoto,
63
A. D’Orazio,
63
E. Di Marco,
63
R. Faccini,
63
F. Ferrarotto,
63
F. Ferroni,
63
M. Gaspero,
63
L. Li Gioi,
63
M. A. Mazzoni,
63
S. Morganti,
63
G. Piredda,
63
F. Polci,
63
F. Safai Tehrani,
63
C. Voena,
63
H. Schro
̈
der,
64
G. Wagner,
64
R. Waldi,
64
T. Adye,
65
N. De Groot,
65
B. Franek,
65
G. P. Gopal,
65
E. O. Olaiya,
65
F. F. Wilson,
65
R. Aleksan,
66
S. Emery,
66
A. Gaidot,
66
S. F. Ganzhur,
66
G. Graziani,
66
G. Hamel de Monchenault,
66
W. Kozanecki,
66
M. Legendre,
66
G. W. London,
66
B. Mayer,
66
G. Vasseur,
66
Ch. Ye
`
che,
66
M. Zito,
66
M. V. Purohit,
67
A. W. Weidemann,
67
J. R. Wilson,
67
F. X. Yumiceva,
67
T. Abe,
68
M. T. Allen,
68
D. Aston,
68
R. Bartoldus,
68
N. Berger,
68
A. M. Boyarski,
68
O. L. Buchmueller,
68
R. Claus,
68
J. P. Coleman,
68
M. R. Convery,
68
M. Cristinziani,
68
J. C. Dingfelder,
68
D. Dong,
68
J. Dorfan,
68
D. Dujmic,
68
W. Dunwoodie,
68
S. Fan,
68
R. C. Field,
68
T. Glanzman,
68
S. J. Gowdy,
68
T. Hadig,
68
V. Halyo,
68
C. Hast,
68
T. Hryn’ova,
68
W. R. Innes,
68
M. H. Kelsey,
68
P. Kim,
68
M. L. Kocian,
68
D. W. G. S. Leith,
68
J. Libby,
68
S. Luitz,
68
V. Luth,
68
H. L. Lynch,
68
H. Marsiske,
68
R. Messner,
68
D. R. Muller,
68
C. P. O’Grady,
68
V. E. Ozcan,
68
A. Perazzo,
68
M. Perl,
68
B. N. Ratcliff,
68
A. Roodman,
68
A. A. Salnikov,
68
R. H. Schindler,
68
J. Schwiening,
68
A. Snyder,
68
J. Stelzer,
68
D. Su,
68
M. K. Sullivan,
68
K. Suzuki,
68
S. K. Swain,
68
J. M. Thompson,
68
J. Va’vra,
68
N. van Bakel,
68
M. Weaver,
68
W. J. Wisniewski,
68
M. Wittgen,
68
D. H. Wright,
68
A. K. Yarritu,
68
K. Yi,
68
C. C. Young,
68
P. R. Burchat,
69
A. J. Edwards,
69
S. A. Majewski,
69
B. A. Petersen,
69
C. Roat,
69
M. Ahmed,
70
S. Ahmed,
70
M. S. Alam,
70
R. Bula,
70
J. A. Ernst,
70
M. A. Saeed,
70
F. R. Wappler,
70
S. B. Zain,
70
W. Bugg,
71
M. Krishnamurthy,
71
S. M. Spanier,
71
R. Eckmann,
72
J. L. Ritchie,
72
A. Satpathy,
72
R. F. Schwitters,
72
J. M. Izen,
73
I. Kitayama,
73
X. C. Lou,
73
S. Ye,
73
F. Bianchi,
74
M. Bona,
74
F. Gallo,
74
D. Gamba,
74
M. Bomben,
75
L. Bosisio,
75
C. Cartaro,
75
F. Cossutti,
75
G. Della Ricca,
75
S. Dittongo,
75
S. Grancagnolo,
75
L. Lanceri,
75
L. Vitale,
75
F. Martinez-Vidal,
76
R. S. Panvini,
77,‡
Sw. Banerjee,
78
B. Bhuyan,
78
C. M. Brown,
78
D. Fortin,
78
K. Hamano,
78
R. Kowalewski,
78
J. M. Roney,
78
R. J. Sobie,
78
J. J. Back,
79
P. F. Harrison,
79
T. E. Latham,
79
G. B. Mohanty,
79
H. R. Band,
80
X. Chen,
80
B. Cheng,
80
S. Dasu,
80
M. Datta,
80
A. M. Eichenbaum,
80
K. T. Flood,
80
M. Graham,
80
J. J. Hollar,
80
J. R. Johnson,
80
P. E. Kutter,
80
H. Li,
80
R. Liu,
80
B. Mellado,
80
A. Mihalyi,
80
Y. Pan,
80
M. Pierini,
80
R. Prepost,
80
P. Tan,
80
S. L. Wu,
80
Z. Yu,
80
and H. Neal
81
(
B
A
B
AR
Collaboration)
1
Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux, France
2
IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain
3
Dipartimento di Fisica and INFN, Universita
`
di Bari, I-70126 Bari, Italy
4
Institute of High Energy Physics, Beijing 100039, China
5
Institute of Physics, University of Bergen, N-5007 Bergen, Norway
6
Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720, USA
7
University of Birmingham, Birmingham, B15 2TT, United Kingdom
8
Institut fu
̈
r Experimentalphysik 1, Ruhr Universita
̈
t Bochum, D-44780 Bochum, Germany
9
University of Bristol, Bristol BS8 1TL, United Kingdom
10
University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
11
Brunel University, Uxbridge, Middlesex UB8 3PH, United Kingdom
12
Budker Institute of Nuclear Physics, Novosibirsk 630090, Russia
13
University of California at Irvine, Irvine, California 92697, USA
14
University of California at Los Angeles, Los Angeles, California 90024, USA
15
University of California at Riverside, Riverside, California 92521, USA
16
University of California at San Diego, La Jolla, California 92093, USA
17
University of California at Santa Barbara, Santa Barbara, California 93106, USA
18
Institute for Particle Physics, University of California at Santa Cruz, Santa Cruz, California 95064, USA
19
California Institute of Technology, Pasadena, California 91125, USA
20
University of Cincinnati, Cincinnati, Ohio 45221, USA
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-2
21
University of Colorado, Boulder, Colorado 80309, USA
22
Colorado State University, Fort Collins, Colorado 80523, USA
23
Institut fu
̈
r Physik, Universita
̈
t Dortmund, D-44221 Dortmund, Germany
24
Institut fu
̈
r Kern- und Teilchenphysik, Technische Universita
̈
t Dresden, D-01062 Dresden, Germany
25
Ecole Polytechnique, LLR, F-91128 Palaiseau, France
26
University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
27
Dipartimento di Fisica and INFN, Universita
`
di Ferrara, I-44100 Ferrara, Italy
28
Laboratori Nazionali di Frascati dell’INFN, I-00044 Frascati, Italy
29
Dipartimento di Fisica and INFN, Universita
`
di Genova, I-16146 Genova, Italy
30
Harvard University, Cambridge, Massachusetts 02138, USA
31
Physikalisches Institut, Universita
̈
t Heidelberg, Philosophenweg 12, D-69120 Heidelberg, Germany
32
Institut fu
̈
r Experimentelle Kernphysik, Universita
̈
t Karlsruhe, D-76021 Karlsruhe, Germany
33
Imperial College London, London, SW7 2AZ, United Kingdom
34
University of Iowa, Iowa City, Iowa 52242, USA
35
Iowa State University, Ames, Iowa 50011-3160, USA
36
Laboratoire de l’Acce
́
le
́
rateur Line
́
aire, F-91898 Orsay, France
37
Lawrence Livermore National Laboratory, Livermore, California 94550, USA
38
University of Liverpool, Liverpool L69 72E, United Kingdom
39
Queen Mary, University of London, E1 4NS, United Kingdom
40
University of London, Royal Holloway and Bedford New College, Egham, Surrey TW20 0EX, United Kingdom
41
University of Louisville, Louisville, Kentucky 40292, USA
42
University of Manchester, Manchester M13 9PL, United Kingdom
43
University of Maryland, College Park, Maryland 20742, USA
44
University of Massachusetts, Amherst, Massachusetts 01003, USA
45
Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
46
McGill University, Montre
́
al, Quebec, Canada H3A 2T8
47
Dipartimento di Fisica and INFN, Universita
`
di Milano, I-20133 Milano, Italy
48
University of Mississippi, University, Mississippi 38677, USA
49
Laboratoire Rene
́
J. A. Le
́
vesque, Universite
́
de Montre
́
al, Montre
́
al, Quebec, Canada H3C 3J7
50
Mount Holyoke College, South Hadley, Massachusetts 01075, USA
51
Dipartimento di Scienze Fisiche and INFN, Universita
`
di Napoli Federico II, I-80126, Napoli, Italy
52
NIKHEF, National Institute for Nuclear Physics and High Energy Physics, NL-1009 DB Amsterdam, The Netherlands
53
University of Notre Dame, Notre Dame, Indiana 46556, USA
54
Ohio State University, Columbus, Ohio 43210, USA
55
University of Oregon, Eugene, Oregon 97403, USA
56
Dipartimento di Fisica and INFN, Universita
`
di Padova, I-35131 Padova, Italy
57
Laboratoire de Physique Nucle
́
aire et de Hautes Energies, Universite
́
s Paris VI et VII, F-75252 Paris, France
58
University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
59
Dipartimento di Fisica and INFN, Universita
`
di Perugia, I-06100 Perugia, Italy
60
Dipartimento di Fisica, Scuola Normale Superiore and INFN, Universita
`
di Pisa, I-56127 Pisa, Italy
61
Prairie View A&M University, Prairie View, Texas 77446, USA
62
Princeton University, Princeton, New Jersey 08544, USA
63
Dipartimento di Fisica and INFN, Universita
`
di Roma La Sapienza, I-00185 Roma, Italy
64
Universita
̈
t Rostock, D-18051 Rostock, Germany
65
Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
66
DSM/Dapnia, CEA/Saclay, F-91191 Gif-sur-Yvette, France
67
University of South Carolina, Columbia, South Carolina 29208, USA
68
Stanford Linear Accelerator Center, Stanford, California 94309, USA
69
Stanford University, Stanford, California 94305-4060, USA
70
State University of New York, Albany, New York 12222, USA
71
University of Tennessee, Knoxville, Tennessee 37996, USA
72
University of Texas at Austin, Austin, Texas 78712, USA
73
University of Texas at Dallas, Richardson, Texas 75083, USA
74
Dipartimento di Fisica Sperimentale and INFN, Universita
`
di Torino, I-10125 Torino, Italy
75
Dipartimento di Fisica and INFN, Universita
`
di Trieste, I-34127 Trieste, Italy
76
IFIC, Universitat de Valencia-CSIC, E-46071 Valencia, Spain
77
Vanderbilt University, Nashville, Tennessee 37235, USA
78
University of Victoria, Victoria, British Columbia, Canada V8W 3P6
79
Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
80
University of Wisconsin, Madison, Wisconsin 53706, USA
81
Yale University, New Haven, Connecticut 06511, USA
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-3
(Received 27 October 2005; published 8 February 2006)
We study the two-body decays of
B
mesons to
K
and a charmonium state
X
c
c
in a sample of
210
:
5fb
1
of data from the
BABAR
experiment. We perform measurements of absolute branching
fractions
B
B
!
K
X
c
c
using a missing mass technique, and report several new or improved results.
In particular, the upper limit
B
B
!
K
X
3872
<
3
:
2
10
4
at 90% C.L. and the inferred lower limit
B
X
3872
!
J=
>
4
:
2%
will help in understanding the nature of the recently discovered
X
3872
.
DOI:
10.1103/PhysRevLett.96.052002
PACS numbers: 14.40.Gx, 13.25.Hw
Several exclusive decays of
B
mesons of the form
B
!
K
X
c
c
(where
X
c
c
is one of the charmonium states
c
,
J=
,
c
0
,
c
1
,
0
c
,
0
,
00
) have been observed by recon-
structing the charmonium state from its decay to some
known final state,
f
[1,2]. In principle, such
B
decays
provide a direct probe of charmonium properties since
the phase space is large for all known states and all should
be produced roughly equally, in the absence of a strong
selection rule [3]. However, with this technique only the
product of the two branching fractions
B
B
!
K
X
c
c
B
X
c
c
!
f
is measured, thereby reducing the precision of
B
B
!
K
X
c
c
when the daughter branching fraction is
poorly known.
We describe here a complementary approach, based on
the measurement of the kaon momentum spectrum in the
B
center-of-mass frame, where two-body decays can be iden-
tified by their characteristic monochromatic line, allowing
an absolute determination of
B
B
!
K
X
c
c
. Knowl-
edge of the
B
center-of-mass system is obtained by ex-
clusive reconstruction of the other
B
meson from a
4
S
decay. In addition to obtaining new information on known
charmonium states, this method is used to search for the
X
3872
state, recently observed in
B
!
K
X
3872
decays by Belle [4] and
BABAR
[5], in the subsequent
decay
X
3872
!
J=
. The same method allows a
search for charged partners of the
X
3872
in
B
0
decays,
independent of the
X
3872
decay mode. The nature of
X
3872
resonance is still unclear; different interpretations
[6] have been proposed but more experimental data will be
needed to discriminate between them.
For this analysis we use a data sample of
210
:
5fb
1
integrated luminosity, corresponding to
231
:
8
10
6
B
B
pairs. The data have been collected with the
BABAR
de-
tector at the SLAC PEP-II asymmetric-energy collider,
where 9 GeV electrons and 3.1 GeV positrons collide at a
center-of-mass energy 10.58 GeV, corresponding to the
mass of the
4
S
resonance. A detailed description of
the
BABAR
detector can be found in [7]. Charged tracks are
reconstructed with a 5 layer silicon vertex tracker (SVT)
and a 40 layer drift chamber (DCH), located in a 1.5 T
magnetic field generated by a superconducting solenoid.
The energy of photons and electrons is measured with an
electromagnetic calorimeter made up of CsI(Tl) crystals.
Charged hadron identification is done with ionization mea-
surements in the SVT and DCH and with an internally
reflecting ring imaging Cherenkov detector. The instru-
mented flux return of the solenoid is used to identify
muons.
The analysis is performed on a sample of events where a
B
meson is fully reconstructed (
B
recon
). For these events,
the momentum of the other
B
(
B
signal
) can be calculated
from the momentum of
B
recon
and the beam parameters. We
select events with a
K
not used for the reconstruction of
B
recon
and calculate its momentum (
p
K
) in the
B
signal
center-of-mass system.
B
recon
mesons are reconstructed in their decays to ex-
clusive
D
H
final states, where
H
is one of several
combinations of
,
K
,
0
, and
K
0
S
hadrons; a detailed
description of the method can be found in [8].
The number of
B
events in the data is determined with
a fit to the distribution of the beam energy substituted mass
m
ES
E
2
CM
=
4
p
2
B
q
, where
E
CM
is the total center-of-
mass energy, determined from the beam parameters, and
p
B
is the measured momentum of
B
recon
in the center-of-
mass frame. The fit function is the sum of a Crystal Ball
function [9] describing the signal and an ARGUS function
[10] for each background component (
e
e
!
q
q
where
q
is
u
,
d
,
s
,or
c
or misreconstructed
B
s), the relative weights
of which are obtained from a Monte Carlo simulation
(MC), while the total normalization factor is determined
from the data. A total of
378 580
1110
events with a
fully reconstructed
B
is obtained.
Fifteen variables related to the
B
recon
decay character-
istics, its production kinematics, the topology of the full
event, and the angular correlation between
B
recon
and the
rest of the event are used in a neural network (NN1) to
reduce the large background, mainly due to non-
B
events.
The network has 80% signal efficiency while rejecting
90% of the background. The
m
ES
distribution after this
selection is shown in Fig. 1. Only events with
5
:
275
<
m
ES
<
5
:
285 GeV
=c
2
are used in the analysis.
We now consider only tracks not associated with
B
recon
.
Most
K
produced in
B
decays originate from
D
mesons
and their spectrum, although broad, peaks at low
p
K
. In the
B
rest frame, these
K
are embedded in a ‘‘minijet’’ of
D
decay products, while signal
K
recoil against a massive
(
3
–
4 GeV
=c
2
) state and therefore tend to be more isolated.
A second neural network (NN2) rejects background from
secondary
K
by using 15 input variables describing the
energy and track multiplicities measured in the
K
hemi-
sphere, the sphericity of the recoil system, and the angular
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-4
correlations between the
K
and the recoil system. These
variables have been chosen to be independent of the par-
ticular decay topology of the recoil system. Since the
topology of the event changes with the recoil mass, we
have considered separately two recoil mass regions in the
training of this neural network: the ‘‘high-mass’’ region,
corresponding to
1
:
0
<p
K
<
1
:
5 GeV
=c
and the ‘‘low-
mass’’ region, for
1
:
5
<p
K
<
2
:
0 GeV
=c
. The signal
training sample is
B
!
K
X
c
c
MC simulation while
the background sample consists of simulated
K
from
D
meson decays in the same momentum range. The chosen
cuts on the NN2 outputs correspond to 85% signal effi-
ciency; the background rejection factor varies between 2.5
in the
X
3872
and
0
region and 1.5 in the
J=
region. The
selection criteria are optimized for MC signal significance
with the high-mass region blinded.
The kaon momentum distribution shows a series of
peaks due to the two-body decays
B
!
K
X
c
c
corre-
sponding to the different
X
c
c
masses, superimposed on a
smooth spectrum due to
K
coming from multibody
B
decays, or non-
B
background. The mass of the
X
c
c
state
(
m
X
) can be calculated directly from
p
K
using
m
X
m
2
B
m
2
K
2
E
K
m
B
q
, where
m
B
and
m
K
are the
B
and
K
masses and
E
K
is the
K
energy. The resonance width
X
can be obtained from the Breit-Wigner width of the
peak in the
p
K
spectrum
K
, obtained after deconvolution
with the momentum resolution function, using
X
K
K
m
B
=m
X
, where
K
p
K
=E
K
.
We determine the number of
B
!
K
X
c
c
events (
N
X
)
from a fit to the
p
K
distribution. The branching fraction for
the decay channel is calculated as:
B
B
!
K
X
c
c
N
X
X
N
B
;
where
X
is the efficiency determined from the MC simu-
lation and
N
B
the number of
B
mesons in the sample. An
alternative method, which we use to improve the branching
fraction measurement in the case of
c
, is to normalize to
the channel
B
!
K
J=
, which is well measured in the
literature [11], according to:
B
B
!
K
X
c
c
N
X
N
J=
J=
X
B
B
!
K
J=
:
In this relative measurement, the systematic errors that are
common to both resonances cancel in the ratio. The two
methods are combined to extract
B
B
!
K
c
, taking
into account the correlations between them.
We fit the
p
K
spectrum using an unbinned maximum
likelihood method. The background is well modeled by a
third degree polynomial and each signal is a Breit-Wigner
function folded with a resolution function. The masses and
widths of the
c
and
0
c
mesons are left free; all others are
fixed to values from Ref. [11]. The resolution function has
two parts: a Gaussian with
varying from
6 MeV
=c
at
p
K
’
1
:
1 GeV
=c
to
12 MeV
=c
at
p
K
’
1
:
7 GeV
=c
de-
scribes the 72.5% of the signal where
B
recon
is correctly
reconstructed; if
B
recon
is incorrect, but has
m
ES
within our
range, the
p
K
resolution is a bifurcated Gaussian with
78
and
52 MeV
=c
on the left- and right-hand side of the
peak, respectively.
The spectrum in the low-mass region is expected to
exhibit two peaks, at
p
K
1
:
683 GeV
=c
corresponding
to the
J=
, and at
p
K
1
:
754 GeV
=c
for the
c
meson.
These two peaks are clearly seen in Fig. 2(a); both have a
significance of
7
. The number of events under each
peak obtained from the fit is
N
J=
259
41
and
N
c
273
43
.
The spectrum in the high-mass region is fitted with a
background and seven signal functions, corresponding to
the following states:
0
,
c
0
,
c
1
,
c
2
,
00
,
0
c
, and
X
3872
.
The resulting fit is shown in Fig. 2(b), with the yields given
in Table I. The
h
c
charmonium state lies near the
c
1
, and it
is difficult to distinguish the peaks from these two decays.
A fit including the
h
c
yields a number of
h
c
events con-
sistent with zero, and a fit performed with free
c
1
mass
and width gives values consistent with a narrow
c
1
; there-
fore, we have no evidence for
h
c
production.
Several sources of systematic error affecting these mea-
surements have been evaluated. The relative errors on
absolute measurements are the same for all states; many
of these cancel partially in relative measurements, and all
are summarized in Table II. ‘‘
B
counting’’ refers to un-
certainties in the fit parametrization used to determine the
number of fully reconstructed
B
recon
. It is one of the largest
errors in absolute measurements, and cancels in ratios. The
mass scale is verified to a precision of
1
:
5 MeV
=c
in
p
K
by
floating the masses of the well-measured
J=
,
c
1
, and
0
peaks; we assign a systematic error corresponding to this
shift. We also consider variations in the background and
signal model parametrizations, which partially cancel in
the case of ratios. Errors in the
K
track reconstruction and
)
2
(GeV/c
ES
m
5.24
5.25
5.26
5.27
5.28
5.29
5.3
2
Events/1 MeV/c
0
1000
2000
3000
4000
5000
6000
7000
FIG. 1. The
m
ES
distribution of all
B
recon
after the NN1 selec-
tion. The solid line represents a fit described in the text; cumu-
lative background contributions from
e
e
!
q
q
where
q
is
u
,
d
,
s
,or
c
(dashed line),
B
0
(dotted line),
B
(dash-dotted line)
events are shown. The arrows indicate the cuts used in the
analysis (see text).
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-5
identification efficiency are evaluated by comparing data
and MC control samples. The systematic error in the NN1
and NN2 selections is evaluated by comparing efficiencies
and distributions in data and MC, and studying efficiency
variation with
p
K
. We verified that the NN2 selection is not
dependent on visible energy or multiplicity of the recoil
part of the
B
meson decay. Adding in quadrature, the total
relative error on an absolute measurement is 9.0%. The
total is reduced to 3.3% for the relative measurement of
J=
and
c
, and to 5.9% for states in the high-mass region
relative to
J=
. For the extraction of relative branching
fractions, an additional 4% error, labeled (ext) in the
following, comes from the present uncertainty of
B
B
!
K
J=
10
:
0
0
:
4
10
4
[11].
In the high-mass region, clear signals are found for
c
1
and
0
(with significance 6.0 and
3
:
2
, respectively), an
excess of events is present for
0
c
and
00
[12], while no
signal is found for
c
0
,
c
2
, and
X
3872
. The branching
fractions and upper limits are summarized in Table I.
In the low-mass region, our
J=
measurement is con-
sistent with the world average. From the
c
and
J=
yields
and the reference branching fraction we can derive the
result with the relative measurement method
B
B
!
K
c
rel
10
:
6
2
:
3
stat
0
:
4
sys
0
:
4
ext
10
4
. We combine this result with the absolute measure-
ment of Table I, taking the correlated errors into account, to
obtain
B
B
!
K
c
8
:
7
1
:
5
10
4
.
We obtain from our fits the
c
and
0
c
masses and widths
and find
m
c
2982
5 MeV
=c
2
,
c
<
43 MeV
, and
m
0
c
3639
7 MeV
=c
2
,
0
c
<
23 MeV
, where the
width limits are both at 90% C.L.
Taking
B
B
!
K
X
3872
<
3
:
2
10
4
, and using
an average of the Belle [4] and
BABAR
[5] measurements
of
B
B
!
K
X
3872
B
X
3872
!
J=
we
set a lower limit
B
X
3872
!
J=
>
4
:
2%
at
90% C.L. This branching fraction, for which there are
not yet any predictions, is sensitive to the distribution of
charm quarks inside the
X
3872
. A search for charged
partners of the
X
3872
is performed by examining
K
recoiling from a sample of 245.6 k reconstructed
B
0
de-
cays. No signal is seen and we find
B
B
0
!
K
X
3872
<
5
10
4
at 90% C.L.
TABLE II.
Summary of systematic errors in percent for abso-
lute and the
J=
:
c
relative measurement.
Source
Absolute (%)
J=
:
c
(%)
B counting
4.5
0
Mass scale
1
1
Background model
3.5
1.7
Resolution model
2.3
1.0
K
reconstruction
1.3
0
K
identification
5
1
B mass selection
0.5
0
NN1 selection
2.2
2.0
NN2 selection
3.2
1.0
Total
9.0
3.3
Kaon momentum (GeV/c)
1.5
1.55
1.6
1.65
1.7
1.75
1.8
1.85
1.9
1.95
2
Events/10 MeV/c
0
50
100
150
200
250
300
Kaon momentum (GeV/c)
1.5
1.55
1.6
1.65
1.7
1.75
1.8
1.85
1.9
1.95
2
Events/10 MeV/c
0
50
100
150
200
250
300
c
η
ψ
J/
(a)
Kaon momentum (GeV/c)
1.1
1.15
1.2
1.25
1.3
1.35
1.4
1.45
1.5
Events/10 MeV/c
0
100
200
300
400
500
600
700
Kaon momentum (GeV/c)
1.1
1.15
1.2
1.25
1.3
1.35
1.4
1.45
1.5
Events/10 MeV/c
0
100
200
300
400
500
600
700
X(3872)
’’
ψ
’
ψ
’
c
η
2
χ
1
χ
c
h
0
χ
(b)
FIG. 2 (color online).
Kaon momentum spectrum for the (a) low-mass and (b) high-mass regions. The lines represent the fit
described in the text. Arrows show the expected positions of known charmonium states.
TABLE I. Event yields and absolute branching fractions
B
B
!
K
X
c
c
from the fits to the
p
K
spectrum. The first
error is statistical, the second systematic, and
B
upper limits are
given at 90% C.L., taking into account the 9.0% systematic error.
The last column shows the signal statistical significance
,
derived from the fit likelihood assuming 0 signal events
L
0
:
2 log
L
0
p
. For the
c
, both results for absolute and
relative measurement, and their combination, are reported (see
text).
Particle
Yield
B
10
4
c
273
43
8
:
4
1
:
3
0
:
8
7.3
c
relative
10
:
6
2
:
3
0
:
4
0
:
4
c
combined
8
:
7
1
:
5
J=
259
41
8
:
1
1
:
3
0
:
7
6.9
c
0
9
21
<
1
:
8
c
1
227
40
8
:
0
1
:
4
0
:
7
6.0
c
2
0
36
<
2
:
0
0
c
98
52
3
:
4
1
:
8
0
:
3
1.8
0
139
44
4
:
9
1
:
6
0
:
4
3.2
00
99
69
3
:
5
2
:
5
0
:
3
1.4
X
3872
15
39
<
3
:
2
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-6
We combine our
B
B
!
K
c
with a previous
BABAR
measurement of
B
B
!
K
c
B
c
!
K
K
[13] to obtain
B
c
!
K
K
8
:
5
1
:
8
%
, sig-
nificantly improving the precision of the world average
[11]. Since this branching fraction is used as a reference
for all
c
yield measurements, our result will lead to more
precise
c
partial widths and more stringent comparisons
with theoretical models. For example, from an average of
B
J=
!
c
B
c
!
K
K
measured by Mark-III
[14], DM2 [15], and BES [16], we obtain
B
J=
!
c
0
:
79
0
:
20
%
, and using the value
c
!
B
c
!
K
K
0
:
48
0
:
06 keV
[11] we calcu-
late
c
!
5
:
6
1
:
4
keV
. Both results are
more precise than the world average [11]. Similarly, we
obtain
B
0
c
!
K
K
8
5
%
and
0
c
!
0
:
9
0
:
5
keV
.
In conclusion, a novel technique is used to measure
directly the absolute branching fractions of the various
charmonium states
X
c
c
in two-body decays
B
!
K
X
c
c
(Table I). The results for
X
c
c
c
;J= ;
0
are in agree-
ment with previous measurements, and the
c
result sig-
nificantly improves the present world average. Upper
limits are set for
c
0
and
c
2
, confirming factorization
suppression [17]. Measurements of
B
!
K
0
c
and
B
!
K
00
branching fractions are reported, although
with poor significance. Upper limits are given for
X
3872
and for production of a possible charged partner
in
B
0
decays.
We are grateful for the excellent luminosity and machine
conditions provided by our PEP II colleagues, and for the
substantial dedicated effort from the computing organiza-
tions that support
BABAR
. The collaborating institutions
wish to thank SLAC for its support and kind hospitality.
This work is supported by DOE and NSF (USA), NSERC
(Canada), IHEP (China), CEA and CNRS-IN2P3 (France),
BMBF and DFG (Germany), INFN (Italy), FOM (The
Netherlands), NFR (Norway), MIST (Russia), and
PPARC (United Kingdom). Individuals have received sup-
port from CONACyT (Mexico), A. P. Sloan Foundation,
Research Corporation, and Alexander von Humboldt
Foundation.
*Also with Dipartimento di Fisica, Universita
`
di Perugia,
Perugia, Italy.
†
Also with Universita
`
della Basilicata, Potenza, Italy.
‡
Deceased.
[1] B. Aubert
et al.
(
BABAR
Collaboration), Phys. Rev. D
67
,
032002 (2003).
[2] S. K. Choi
et al.
(Belle Collaboration), Phys. Rev. Lett.
89
,
102001 (2002);
89
, 129901(E) (2002).
[3] C. Quigg, hep-ph/0403187, and references therein.
[4] S. K. Choi
et al.
(Belle Collaboration), Phys. Rev. Lett.
91
,
262001 (2003).
[5] B. Aubert
et al.
(
BABAR
Collaboration), Phys. Rev. D
71
,
071103 (2005).
[6] T. Barnes and S. Godfrey, Phys. Rev. D
69
, 054008 (2004);
E. J. Eichten, K. Lane, and C. Quigg, Phys. Rev. D
69
,
094019 (2004); E. S. Swanson, Phys. Lett. B
588
, 189
(2004); N. A. Tornqvist, Phys. Lett. B
590
, 209 (2004);
L. Maiani, F. Piccinini, A. D. Polosa, and V. Riquer, Phys.
Rev. D
71
, 014028 (2005).
[7] B. Aubert
et al.
(
BABAR
Collaboration), Nucl. Instrum.
Methods Phys. Res., Sect. A
479
, 1 (2002).
[8] B. Aubert
et al.
(
BABAR
Collaboration), Phys. Rev. Lett.
92
, 071802 (2004).
[9] The Crystal Ball function is a Gaussian with a small
power-law term added to the left, used to describe the
mass spectrum in exclusive
B
decays. T. Skwarnicki
et al.
(Crystal Ball Collaboration), DESY Report No. F31-86-
02, 1986 (unpublished).
[10] The Argus function is commonly used to describe con-
tinuum background in
B
mass spectra. H. Albrecht
et al.
(ARGUS Collaboration), Phys. Lett. B
316
, 608 (1993).
[11] S. Eidelman
et al.
(Particle Data Group), Phys. Lett. B
592
, 1 (2004).
[12] K. Abe
et al.
(Belle Collaboration), Phys. Rev. Lett.
93
,
051803 (2004).
[13] B. Aubert
et al.
(
BABAR
Collaboration), Phys. Rev. D
70
,
011101 (2004).
[14] R. M. Baltrusaitis
et al.
(Mark-III Collaboration), Phys.
Rev. D
33
, 629 (1986).
[15] D. Bisello
et al.
(DM2 collaboration), Nucl. Phys.
B350
,1
(1991).
[16] J. Z. Bai
et al.
(BES Collaboration), Phys. Lett. B
578
,16
(2004).
[17] C. Meng, Y. J. Gao, and K. T. Chao, hep-ph/0502240; hep-
ph/0506222.
PRL
96,
052002 (2006)
PHYSICAL REVIEW LETTERS
week ending
10 FEBRUARY 2006
052002-7