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Title: Study of the Z c + channel using lattice QCD

Recently experimentalists have discovered several charged charmoniumlike hadrons $$Z^{+}_{c}$$ with unconventional quark content $$\bar{c}c\bar{d} u$$ We perform a search for $$Z^{+}_{c}$$ with mass below 4.2 GeV in the channel $$I^G(J^{PC}) = 1^+ (^{1+-})$$ using lattice QCD. The major challenge is presented by the two-meson states $$J/ψπ, ψ_{2s}π, ψ_{1D}π, D\bar{D}^*, D^*\bar{D}^*, η_cρ$$ that are inevitably present in this channel. The spectrum of eigenstates is extracted using a number of meson-meson and diquark-antidiquark interpolating fields. For our pion mass of 266 MeV we find all the expected two-meson states but no additional candidate for $$Z^{+}_{c}$$ below 4.2 GeV. Possible reasons for not seeing an additional eigenstate related to $$Z^{+}_{c}$$ are discussed. We also illustrate how a simulation incorporating interpolators with a structure resembling low-lying two-meson states seems to render a $$Z^{+}_{c}$$ candidate, which is however not robust after further two-meson states around 4.2 GeV are implemented.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Univ. of Ljubljana (Slovenia). Dept. of Physics; Jozef Stefan Inst. (IJS), Ljubljana (Slovenia)
  2. Univ. of Graz (Austria). Inst. of Physics
  3. Jozef Stefan Inst. (IJS), Ljubljana (Slovenia)
  4. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Publication Date:
OSTI Identifier:
1295681
Report Number(s):
FERMILAB-PUB-14-144-T; arXiv:1405.7623
Journal ID: ISSN 1550-7998; 1298510
Grant/Contract Number:
AC02-07CH11359
Type:
Accepted Manuscript
Journal Name:
Physical Review. D, Particles, Fields, Gravitation and Cosmology
Additional Journal Information:
Journal Volume: 91; Journal Issue: 1; Journal ID: ISSN 1550-7998
Publisher:
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS