Miguel Albaladejo (IFIC, Valencia) In collaboration with: P. Fern´ andez-Soler, F. K. Guo, C. Hidalgo-Duque, J. Nieves 3900 ) : experiment xperiment, the theory ory, lattic lattice Z c ( 3900 Based on: [arXiv:1512.03638,Phys.Lett.B 755 ,337 (2016)] [arXiv:1606.03008,Eur.Phys.J.C (under review)] 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Outline Experiment 1 Theory 2 Lattice 3 Conclusions 4
Outline Experiment 1 Theory 2 Lattice 3 Conclusions 4
Experiment Theory Lattice Conclusions Charmonium-like sector Charmonium-like sector Recent reviews (2015-2016): [Olsen, Front. Phys. 10, 121(’15)] [Chen et al. ,Phys. Rept. 639, 1(’16)] [Hosaka et al. ,PTEP 2016, 062C01(’16)] All the c ¯ c states predicted by QM below D ¯ D threshold have been found In 2003, X ( 3872 ) is discovered [Belle Collab., PRL,91,262001] D 0 threshold. Very close to D 0 ¯ Close to (but lower) χ c 1 ( 2 3 P 1 ) . Lattice QCD : [Prelovsek, Leskovec, PRL,111,192001] candidate for X ( 3872 ) only if c ¯ c + D ∗ components are considered D ¯ together ( Taken from: [Olsen, Front. Phys. 10, 121(’15)]) 1 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Experimental information on Zc ( 3885 ) / Zc ( 3900 ) Experimental information on Z c ( 3885 ) / Z c ( 3900 ) Z c ( 3900 ) first seen by BESIII and Belle Collabs. in J /ψπ ± invariant mass spectrum in e + e − → Y ( 4260 ) → J /ψπ + π − [PRL,110,252001(’13)][PRL,110,252002(’13)] Later on, CLEO-c data confirmed Z c ( 3900 ) in e + e − → ψ ( 4160 ) → J /ψπ + π − [PL,B727,366(’13)] BESIII analyses e + e − → Y ( 4260 ) → ¯ D ∗ D π , and sees Z c ( 3885 ) in ¯ D ∗ D invariant mass spectrum. J P = 1 + favoured. [PRL,112,022001(’14)] D ∗ D spectrum at different e + e − c.m. energies BESIII confirms Z c ( 3885 ) in ¯ [PR,D92,092006(’15)] Γ ( Z c → D ¯ D ∗ ) If they are the same object, Ratio: Γ( Z c → J /ψπ ) = 6 . 2 ± 2 . 9 110 100 Y ( 4260 ) → J / ψππ 90 80 Events / 20 MeV/ c 2 70 60 50 40 30 20 10 0 3200 3400 3600 3800 4000 M J / ψπ − (MeV) 2 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Experimental information on Zc ( 3885 ) / Zc ( 3900 ) Experimental information on Z c ( 3885 ) / Z c ( 3900 ) Z c ( 3900 ) first seen by BESIII and Belle Collabs. in J /ψπ ± invariant mass spectrum in e + e − → Y ( 4260 ) → J /ψπ + π − [PRL,110,252001(’13)][PRL,110,252002(’13)] Later on, CLEO-c data confirmed Z c ( 3900 ) in e + e − → ψ ( 4160 ) → J /ψπ + π − [PL,B727,366(’13)] BESIII analyses e + e − → Y ( 4260 ) → ¯ D ∗ D π , and sees Z c ( 3885 ) in ¯ D ∗ D invariant mass spectrum. J P = 1 + favoured. [PRL,112,022001(’14)] D ∗ D spectrum at different e + e − c.m. energies BESIII confirms Z c ( 3885 ) in ¯ [PR,D92,092006(’15)] Γ ( Z c → D ¯ D ∗ ) If they are the same object, Ratio: Γ( Z c → J /ψπ ) = 6 . 2 ± 2 . 9 110 100 Y ( 4260 ) → J / ψππ 90 80 Events / 20 MeV/ c 2 70 60 50 40 30 20 10 0 3200 3400 3600 3800 4000 M J / ψπ − (MeV) 2 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Experimental information on Zc ( 3885 ) / Zc ( 3900 ) Experimental information on Z c ( 3885 ) / Z c ( 3900 ) Z c ( 3900 ) first seen by BESIII and Belle Collabs. in J /ψπ ± invariant mass spectrum in e + e − → Y ( 4260 ) → J /ψπ + π − [PRL,110,252001(’13)][PRL,110,252002(’13)] Later on, CLEO-c data confirmed Z c ( 3900 ) in e + e − → ψ ( 4160 ) → J /ψπ + π − [PL,B727,366(’13)] BESIII analyses e + e − → Y ( 4260 ) → ¯ D ∗ D π , and sees Z c ( 3885 ) in ¯ D ∗ D invariant mass spectrum. J P = 1 + favoured. [PRL,112,022001(’14)] D ∗ D spectrum at different e + e − c.m. energies BESIII confirms Z c ( 3885 ) in ¯ [PR,D92,092006(’15)] Γ ( Z c → D ¯ D ∗ ) If they are the same object, Ratio: Γ( Z c → J /ψπ ) = 6 . 2 ± 2 . 9 110 100 100 90 Y ( 4260 ) → J / ψππ 90 Y ( 4260 ) → ¯ D ∗ D π 80 80 Events / 20 MeV/ c 2 70 Events / 4 MeV/ c 2 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 3200 3400 3600 3800 4000 3900 3950 4000 4050 4100 M J / ψπ − (MeV) M D ∗− D 0 (MeV) 2 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Experimental information on Zc ( 3885 ) / Zc ( 3900 ) Experimental information on Z c ( 3885 ) / Z c ( 3900 ) Z c ( 3900 ) first seen by BESIII and Belle Collabs. in J /ψπ ± invariant mass spectrum in e + e − → Y ( 4260 ) → J /ψπ + π − [PRL,110,252001(’13)][PRL,110,252002(’13)] Later on, CLEO-c data confirmed Z c ( 3900 ) in e + e − → ψ ( 4160 ) → J /ψπ + π − [PL,B727,366(’13)] BESIII analyses e + e − → Y ( 4260 ) → ¯ D ∗ D π , and sees Z c ( 3885 ) in ¯ D ∗ D invariant mass spectrum. J P = 1 + favoured. [PRL,112,022001(’14)] D ∗ D spectrum at different e + e − c.m. energies BESIII confirms Z c ( 3885 ) in ¯ [PR,D92,092006(’15)] Γ ( Z c → D ¯ D ∗ ) If they are the same object, Ratio: Γ( Z c → J /ψπ ) = 6 . 2 ± 2 . 9 110 100 35 100 90 Y ( 4260 ) → ¯ D ∗ D π 30 Y ( 4260 ) → J / ψππ 90 Y ( 4260 ) → ¯ D ∗ D π 80 (updated data) 80 Events / 20 MeV/ c 2 25 70 Events / 4 MeV/ c 2 Events / 4 MeV/ c 2 70 60 20 60 50 50 15 40 40 30 10 30 20 20 5 10 10 0 0 0 3200 3400 3600 3800 4000 3900 3950 4000 4050 4100 3900 3950 4000 4050 4100 M J / ψπ − (MeV) M D ∗− D 0 (MeV) M D ∗− D 0 (MeV) 2 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Experimental information on Zc ( 3885 ) / Zc ( 3900 ) Experimental information on Z c ( 3885 ) / Z c ( 3900 ) Z c ( 3900 ) first seen by BESIII and Belle Collabs. in J /ψπ ± invariant mass spectrum in e + e − → Y ( 4260 ) → J /ψπ + π − [PRL,110,252001(’13)][PRL,110,252002(’13)] Later on, CLEO-c data confirmed Z c ( 3900 ) in e + e − → ψ ( 4160 ) → J /ψπ + π − [PL,B727,366(’13)] BESIII analyses e + e − → Y ( 4260 ) → ¯ D ∗ D π , and sees Z c ( 3885 ) in ¯ D ∗ D invariant mass spectrum. J P = 1 + favoured. [PRL,112,022001(’14)] D ∗ D spectrum at different e + e − c.m. energies BESIII confirms Z c ( 3885 ) in ¯ [PR,D92,092006(’15)] Γ ( Z c → D ¯ D ∗ ) If they are the same object, Ratio: Γ( Z c → J /ψπ ) = 6 . 2 ± 2 . 9 110 100 35 100 90 Y ( 4260 ) → ¯ D ∗ D π 30 Y ( 4260 ) → J / ψππ 90 Y ( 4260 ) → ¯ D ∗ D π 80 (updated data) 80 Events / 20 MeV/ c 2 25 70 Events / 4 MeV/ c 2 Events / 4 MeV/ c 2 70 60 20 60 50 50 15 40 40 30 10 30 20 20 5 10 10 0 0 0 3200 3400 3600 3800 4000 3900 3950 4000 4050 4100 3900 3950 4000 4050 4100 M J / ψπ − (MeV) M D ∗− D 0 (MeV) M D ∗− D 0 (MeV) 2 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Introduction: theoretical speculation Introduction: theoretical speculation “One of the most interesting resonances”: couples strongly to charmonium ( ∼ ¯ cc ) and yet it has charge ( ∼ ¯ ud ). Minimal quark constituent is four [ ¯ cc ¯ ud ]. Many different interpretations have been given (see reviews mentioned before): Tetraquark ¯ D ∗ D molecular state Simply a kinematical effect Hadrocharmonium It has also been searched for in lattice QCD D 0 “Tetraquark” D ∗− c c d ¯ d c ¯ ¯ c u ¯ u What is still missing? A joint study of both reactions in which the Z c structure has been seen 3 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Experiment Theory Lattice Conclusions Introduction: theoretical speculation Introduction: theoretical speculation “One of the most interesting resonances”: couples strongly to charmonium ( ∼ ¯ cc ) and yet it has charge ( ∼ ¯ ud ). Minimal quark constituent is four [ ¯ cc ¯ ud ]. Many different interpretations have been given (see reviews mentioned before): Tetraquark ¯ D ∗ D molecular state Simply a kinematical effect (ruled out) Hadrocharmonium It has also been searched for in lattice QCD D 0 “Tetraquark” D ∗− c c d ¯ d c ¯ ¯ c u ¯ u What is still missing? A joint study of both reactions in which the Z c structure has been seen 3 / 19 M. Albaladejo (IFIC, Valencia): Zc ( 3900 ) : experiment, theory, lattice 2nd Hadron Spanish Network Days, Sept. 8-9, 2016
Outline Experiment 1 Theory 2 Lattice 3 Conclusions 4
Recommend
More recommend
