Observation of the resonant character of the $Z(4430)^-$ state
R. Aaij
,
Y. Amhis
(1)
,
S. Barsuk
(1)
,
O. Callot
(1)
,
J. He
(1)
,
O. Kochebina
(1)
,
J. Lefrançois
(1)
,
F. Machefert
(1)
,
A. Martin Sanchez
(1)
,
M. Nicol
(1)
,
P. Robbe
(1)
,
M.-H. Schune
(1)
,
M. Teklishyn
(1)
,
A. Vallier
(1)
,
B. Viaud
(1)
,
E. Aslanides
(2)
,
J. Cogan
(2)
,
W. Kanso
(2)
,
R. Legac
(2)
,
O. Leroy
(2)
,
G. Mancinelli
(2)
,
A. Mordà
(2, 3)
,
M. Perrin-Terrin
(2)
,
M. Sapunov
(2)
,
J. Serrano
(2)
,
A. Tsaregorodtsev
(2)
,
Ziad Zj Ajaltouni
(4)
,
M. Baalouch
(4)
,
E. Cogneras
(4)
,
O. Deschamps
(4)
,
I. El Rifai
(4)
,
M. Grabalosa Gándara
(4)
,
Pierre Henrard
(4)
,
M. Hoballah
(4)
,
R. Lefèvre
(4)
,
J. Maratas
(4)
,
S. Monteil
(4)
,
V. Niess
(4)
,
Pascal Perret
(4)
,
Diego Alejandro Roa Romero
(4)
,
L. Beaucourt
(5)
,
D. Decamp
(5)
,
N. Déléage
(5)
,
Ph. Ghez
(5)
,
J.-P. Lees
(5)
,
J.F. Marchand
(5)
,
M.-N. Minard
(5)
,
B. Pietrzyk
(5)
,
W. Qian
(5)
,
S. t'Jampens
(5)
,
V. Tisserand
(5)
,
E. Tournefier
(5)
R. Aaij
- Function : Author
J. He
- Function : Author
- PersonId : 756138
- ORCID : 0000-0001-8179-417X
J. Cogan
- Function : Author
- PersonId : 750510
- IdHAL : julien-cogan
- ORCID : 0000-0001-7194-7566
- IdRef : 078779014
O. Leroy
- Function : Author
- PersonId : 171866
- IdHAL : olivier-leroy
- ORCID : 0000-0002-2589-240X
- IdRef : 169871835
M. Perrin-Terrin
- Function : Author
- PersonId : 741779
- IdHAL : perrin-terrin
- ORCID : 0000-0002-3568-1956
- IdRef : 179269666
J. Serrano
- Function : Author
- PersonId : 175327
- IdHAL : justine-serrano
- ORCID : 0000-0003-2489-7812
- IdRef : 127525521
Ziad Zj Ajaltouni
- Function : Author
- PersonId : 903794
E. Cogneras
- Function : Author
- PersonId : 743220
- IdHAL : eric-cogneras
- ORCID : 0000-0002-8933-9427
O. Deschamps
- Function : Author
- PersonId : 12089
- IdHAL : olivier-deschamps
- ORCID : 0000-0002-7047-6042
- IdRef : 161447368
Pierre Henrard
- Function : Author
- PersonId : 829303
M. Hoballah
- Function : Author
- PersonId : 1174785
- IdHAL : mostafa-adam-hoballah-hobart
Pascal Perret
- Function : Author
- PersonId : 739797
- IdHAL : pascal-perret
- ORCID : 0000-0002-5732-4343
Diego Alejandro Roa Romero
- Function : Author
- PersonId : 769524
- IdRef : 172096839
S. t'Jampens
- Function : Author
- PersonId : 736045
- IdHAL : stephane-tjampens
- ORCID : 0000-0003-4249-6641
Abstract
Resonant structures in $B^0\to\psi'\pi^-K^+$ decays are analyzed by performing a four-dimensional fit of the decay amplitude, using $pp$ collision data corresponding to $\rm 3 fb^{-1}$ collected with the LHCb detector. The data cannot be described with $K^+\pi^-$ resonances alone, which is confirmed with a model-independent approach. A highly significant $Z(4430)^-\to\psi'\pi^-$ component is required, thus confirming the existence of this state. The observed evolution of the $Z(4430)^-$ amplitude with the $\psi'\pi^-$ mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin-parity is determined unambiguously to be $1^+$.