https://doi.org/10.1140/epjc/s10052-017-4961-z
Regular Article - Theoretical Physics
Different pole structures in line shapes of the X(3872)
Departamento de Física, Universidad de Murcia, 30071, Murcia, Spain
* e-mail: oller@um.es
Received:
2
January
2017
Accepted:
31
May
2017
Published online:
15
June
2017
We introduce a near-threshold parameterization that is more general than the effective-range expansion up to and including the effective range because it can also handle a near-threshold zero in the 
S-wave. In terms of it we analyze the CDF data on inclusive 
scattering to 
, and the Belle and BaBar data on B decays to 
and 
around the threshold. It is shown that data can be reproduced with similar quality for X(3872) being a bound and/or a virtual state. We also find that X(3872) might be a higher-order virtual-state pole (double or triplet pole), in the limit in which the small 
width vanishes. Once the latter is restored the corrections to the pole position are non-analytic and much bigger than the width itself. The X(3872) compositeness coefficient in ranges from nearly 0 up to 1 in the different scenarios.
© The Author(s), 2017
