25-29 September 2017
Salamanca, Spain
Europe/Zurich timezone

Lambda_b --> J/Psi phi Lambda decay and search for exotic hadrons

29 Sep 2017, 10:25
20m
Aula 2.7

Aula 2.7

Talk Exotic states and candidates Exotic states and candidates

Speaker

Volodymyr Magas (Departament de Fisica Quantica i Astrofisica and Institut de Ciencies del Cosmos, Universitat de Barcelona)

Description

We study the weak decay of the $\Lambda_b$ baryon into $J/\Psi \phi \Lambda$ states and the possibility of producing exotic hadrons via final state interaction in $J/\Psi \phi$ and $J/\Psi \Lambda$ channels.

The elementary weak transition at the quark level proceeds via the creation of a $J/\Psi (\bar{c} c)$ meson and an excited sud system with I = 0, which upon hadronization leads to $\phi \Lambda$ and $\bar{K} N$ meson-baryon pairs, the later one undergoing final state interaction in coupled channels and ending up as an observed $\phi \Lambda$ pair.

The hidden-charm pentaquark $P_c(4450)$ observed recently by the LHCb collab-
oration [1] may be of molecular nature, as advocated by some unitary approaches
that also predict pentaquark partners in the strangeness S=-1 sector [2]. This
strange hidden charm pentaquark can be produced via $J/\Psi \Lambda$ final state interaction in our reaction and, as we shall see, such a state could be seen in $\Lambda_b \rightarrow J/\Psi \phi \Lambda$ decay as a peak in the $J/\Psi \Lambda$ invariant mass distribution. A similar study and conclusions have been performed in [3], but looking at the $\Lambda_b$ decay into $J/\Psi \eta \Lambda$ final states.

On the other hand, studying the invariant mass spectrum of $J/\Psi \phi$ pairs from $\Lambda_b \rightarrow J/\Psi \phi \Lambda$ decay, one can also observe the peaks corresponding to the $X(4140)$ and $X(4274)$ exotic hadrons discovered by CDF [4] and recently reconfirmed in B decay at LHCb [5].

[1] R. Aaij, B. [LHCb collaboration], Phys. Rev. Lett. 115, 072001 (2015).

[2] J.J. Wu, R. Molina, E. Oset and B.S. Zou, Phys. Rev. Lett. 105, 232001
(2010); Phys.Rev. C84, 015202 (2011).

[3] A. Feijoo, V.K. Magas, A. Ramos and E. Oset, Phys. Rev. D92, 076015
(2015).

[4] T. Aaltonen et al. [CDF Collaboration], Phys. Rev. Lett. 102, 242002 (2009).

[5] R. Aaij et al. [LHCb Collaboration], Phys. Rev. Lett. 118 (2017) no.2, 022003.

Primary authors

Volodymyr Magas (Departament de Fisica Quantica i Astrofisica and Institut de Ciencies del Cosmos, Universitat de Barcelona) Àngels Ramos (University of Barcelona) Ms Julia Tena Vidal (University of Barcelona)

Presentation Materials