2018/11/19 The Recent Results of (Pseudo-)Scalar Mesons/Glueballs at BES2 XU Guofa J/ Group IHEP,Beijing 2018/11/19 《全国第七届高能物理年会》 《全国第七届高能物理年会》

Introduction (1) Glueballs should be favored over ordinary mesons in the central region of high energy scattering processes, away from beam and target quarks. The fJ(1710) and possibly the f0(1500) have been seen in the central region in pp collisions Glueballs should be produced in proton-antiproton annihilation, where the destruction of quarks creates opportunity for gluons to be manifested. in which detailed decay systematics of f0(1500) have been studied. The (1440) is clearly seen in ppbar annihilation Glueballs should be enhanced compared to ordinary mesons in radiative quarkonium decay. 2018/11/19 《全国第七届高能物理年会》

Instroduction (2) Lattice QCD predicts that the lightest ‘‘ideal’’ (i.e., quenched approximation) glueball will be 0++, with state-of-the-art mass predictions of ~1.6 GeV Amsler and Close have pointed out that the f0(1500) shares features expected for a glueball that is mixed with the nearby isoscalar members of the 3P0 qqbar nonet. If the fJ(1710) proves to have J=2, then it is not a candidate for the ground state glueball and the f0(1500) will be essentially unchallenged. On the other hand, if the fJ(1710) has J=0, it becomes a potentially interesting glueball candidate (b(f0(1710)gg)0.52±0.07 ) 0- Glueball ~2.1 GeV 2018/11/19 《全国第七届高能物理年会》

study  in study  in study f0(980), f0(1370), f0(1500), f0(1710) and f0(1790) in 0++ 2018/11/19 《全国第七届高能物理年会》

PWA of J/   (hep-ex/0603048) 58M J/ Samples at BESII PWA of J/   (hep-ex/0603048) The  threshold enhancement in J/   (PRL96(2006)162002) Study of J/   (PRD73(2006)112007) 2018/11/19 《全国第七届高能物理年会》

f0(1710) Clear f0(1710) peak in J/  KK. No f0(1710) observed in J/   ! f0(1710) NO f0(1710) 2018/11/19 Phys. Lett. B 603 (2004) 138 《全国第七届高能物理年会》

f0(1710) PWA analysis shows one scalar in 1.7 GeV region Phys. Rev. D 68 (2003) 052003 2018/11/19 《全国第七届高能物理年会》

J/+- , J/00 BKG: J/ J/’ BKG: J/ f0(1500) 2018/11/19 《全国第七届高能物理年会》

PWA of J/   For global fit, the channels fitted in PWA fix the parameters of f2(1810),f0(2020), f2(2150) and f4(2050) to PDG values. 2018/11/19 《全国第七届高能物理年会》

J/+- , J/00 2018/11/19 《全国第七届高能物理年会》

J/+- , J/00 PDG: <0.11 ~ 5.8 2018/11/19 《全国第七届高能物理年会》

J/+- , J/00 2018/11/19 《全国第七届高能物理年会》

J/+- , J/00 2018/11/19 《全国第七届高能物理年会》

Observation of  threshold enhancement in J/   DOZI OZI 2018/11/19 《全国第七届高能物理年会》

J/    2018/11/19 《全国第七届高能物理年会》

J/   2018/11/19 《全国第七届高能物理年会》

J/ c check  Side-bands  Side-bands 2018/11/19 《全国第七届高能物理年会》

Further look in , K*K*,  …. is desirable ! The DOZI decay of J/ is observed and measured with 58M J/ data. An enhancement in  is found near the threshold. PWA shows: the enhancement favors 0++ . Is it the same 0++ observed in KK or , or is it a glueball, or a hybrid …..? Further look in , K*K*,  …. is desirable ! Phys. Rev. Lett., 96 (2006) 162002 2018/11/19 《全国第七届高能物理年会》

J/(+-0)    sideband w signal with multiple entries M(+-0)(GeV/c2) M(+-0)(GeV/c2) M(+-0)(GeV/c2) M(+-0)(GeV/c2)  sideband w signal with multiple entries w signal after best candidate selection (best w masses) 2018/11/19 《全国第七届高能物理年会》

J/ 2018/11/19 《全国第七届高能物理年会》

J/ 2018/11/19 《全国第七届高能物理年会》

J/ 2018/11/19 《全国第七届高能物理年会》

J/ 2018/11/19 《全国第七届高能物理年会》

Summary (58M J/ Samples at BESII) 2018/11/19 Summary (58M J/ Samples at BESII) Mass(MeV/c2) Width(MeV/c2 ) Br 10-4 f0(1710) (J/) 1765±43±12 145±8±69 2.64±0.04±0.71 (1760) (J/) 3.1±0.2±0.8 1744±10±15 244+24-21±25 19.8±0.8±3.2 f0(1800)(?) (J/) 1812±1926 ±18 105± 20±28 2.61±0.27±0.65 2018/11/19 《全国第七届高能物理年会》 《全国第七届高能物理年会》

Thanks! 2018/11/19 《全国第七届高能物理年会》