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Start Over Author "Blum, I." Publisher escholarship, university of california
31 results on '"Blum, I."'

1. Radiative decay of the ψ(2S) into two pseudoscalar mesons

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, AD, Chen, GP, Chen, HF, Chen, HS, Chen, J, Chen, JC, Chen, XD, Chen, Y, Chen, YB, Cheng, BS, Choi, JB, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Huang, GS, Huang, XP, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Kang, JS, Ke, ZJ, Kelsey, MH, Kim, BK, Kim, HJ, Kim, SK, Kim, TY, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, W, Li, WG, Li, XH, Li, XN, Li, XQ, Li, ZC, Liu, B, Liu, F, Liu, Feng, Liu, HM, Liu, J, Liu, JP, Liu, RG, Liu, Y, Liu, ZX, Lou, XC, Lowery, B, Lu, GR, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, Nie, J, Olsen, SL, Oyang, J, and Paluselli, D

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

Radiative decays of the radially excited charmonium resonance, (Formula presented) into (Formula presented) (Formula presented) and (Formula presented) final states have been measured in a sample of (Formula presented) (Formula presented) events collected by the BES Collaboration. The branching ratios (Formula presented) and (Formula presented) are obtained. When compared to the corresponding radiative (Formula presented) decays, the observed (Formula presented) radiative decay rates into (Formula presented) and (Formula presented) are consistent with the prediction of the “12%” rule. © 2003 The American Physical Society.

Published
2003

2. Radiative decay of the [Formula Presented] into two pseudoscalar mesons

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, AD, Chen, GP, Chen, HF, Chen, HS, Chen, J, Chen, JC, Chen, XD, Chen, Y, Chen, YB, Cheng, BS, Choi, JB, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Huang, GS, Huang, XP, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Kang, JS, Ke, ZJ, Kelsey, MH, Kim, BK, Kim, HJ, Kim, SK, Kim, TY, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, W, Li, WG, Li, XH, Li, XN, Li, XQ, Li, ZC, Liu, B, Liu, F, Liu, HM, Liu, J, Liu, JP, Liu, RG, Liu, Y, Liu, ZX, Lou, XC, Lowery, B, Lu, GR, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, Nie, J, Olsen, SL, Oyang, J, and Paluselli, D

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Radiative decays of the radially excited charmonium resonance, (Formula presented) into (Formula presented) (Formula presented) and (Formula presented) final states have been measured in a sample of (Formula presented) (Formula presented) events collected by the BES Collaboration. The branching ratios (Formula presented) and (Formula presented) are obtained. When compared to the corresponding radiative (Formula presented) decays, the observed (Formula presented) radiative decay rates into (Formula presented) and (Formula presented) are consistent with the prediction of the “12%” rule. © 2003 The American Physical Society.

Published
2003

3. First measurement of the branching fraction of the decay ψ(2S)→τ+τ-

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, AD, Chen, HF, Chen, HS, Chen, J, Chen, JC, Chen, XD, Chen, Y, Chen, YB, Cheng, BS, Chi, SP, Chu, YP, Choi, JB, Cui, XZ, Dai, YS, Dong, LY, Du, ZZ, Dunwoodie, W, Fu, HY, Fu, LP, Gao, CS, Gratton, P, Gu, SD, Gu, YF, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, He, X, Hong, T, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, QH, Hu, T, Huang, GS, Huang, XP, Huang, YZ, Izen, JM, Ji, XB, Jiang, CH, Jin, Y, Jones, BD, Kang, JS, Ke, ZJ, Kelsey, MH, Kim, BK, Kim, HJ, Kim, SK, Kim, TY, Kong, D, Lai, YF, Lankford, A, Li, D, Li, HB, Li, HH, Li, J, Li, JC, Li, PQ, Li, QJ, Li, RY, Li, W, Li, WG, Li, XN, Li, XQ, Liu, B, Liu, F, Liu, Feng, Liu, HM, Liu, J, Liu, JP, Liu, TR, Liu, RG, Liu, Y, Liu, ZX, Lou, XC, Lowery, B, Lu, GR, Lu, F, Lu, JG, Lu, ZJ, Luo, XL, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, Nie, J, and Nie, ZD

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

The branching fraction of the ψ(2S) decay into τ+τ - has been measured for the first time using the BES detector at the Beijing Electron-Positron Collider. The result is Bττ=(2.710. 43±0.55)× 10-3, where the first error is statistical and the second is systematic. This value, along with those for the branching fractions into e+e- and μ+ μ- of this resonance, satisfy well the relation predicted by the sequential lepton hypothesis. Combining all these values with the leptonic width of the resonance, the total width of the ψ(25) is determined to be (252±37) keV. ©2002 The American Physical Society.

Published
2002

4. BES upgrade

Author

Bai, JZ, Bao, HC, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Chu, XM, Cui, XZ, Ding, HL, Ding, WY, Dong, LY, Du, YY, Du, ZZ, Dunwoodie, W, Fang, J, Fang, WZ, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Guo, YN, Han, HG, Han, SW, Harris, FA, Han, Y, He, J, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HB, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, GS, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jiang, YY, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, F, Li, HB, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, WH, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, QJ, Liu, RG, Liu, Y, Liu, ZX, Lou, JS, Lou, XC, Lowery, B, Lu, HY, Lu, JG, Luo, H, Luo, SQ, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, and Mu, LG

Subjects
detectors, DAQ, drift chambers, scintillation counters, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The Beijing Spectrometer (BES) detector is a general purpose solenoid detector at the Beijing Electron Positron Collider in Beijing, China. The recent upgrade of the initial BES detector to the improved BES II detector is described. A new drift chamber, time-of-flight counter, luminosity monitor compatible with a low-β lattice was built as well as the vertex chamber.

Published
2001

5. The BES upgrade

Author

Bai, JZ, Bao, HC, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Chu, XM, Cui, XZ, Ding, HL, Ding, WY, Dong, LY, Du, YY, Du, ZZ, Dunwoodie, W, Fang, J, Fang, WZ, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Guo, YN, Han, HG, Han, SW, Harris, FA, Han, Y, He, J, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HB, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, GS, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jiang, YY, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, F, Li, HB, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, WH, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, Jun, Liu, Q, Liu, QJ, Liu, RG, Liu, Y, Liu, ZX, Lou, JS, Lou, XC, Lowery, B, Lu, HY, Lu, JG, Luo, H, Luo, SQ, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, and Mu, LG

Subjects
detectors, DAQ, drift chambers, scintillation counters, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics
Abstract

The Beijing Spectrometer (BES) detector is a general purpose solenoid detector at the Beijing Electron Positron Collider in Beijing, China. The recent upgrade of the initial BES detector to the improved BES II detector is described. A new drift chamber, time-of-flight counter, luminosity monitor compatible with a low-β lattice was built as well as the vertex chamber.

Published
2001

6. Direct measurement of B(D0→φX0) and B(D+→φX+)

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Huang, GS, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Schmid, B, and Schultz, J

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

The first measurement of (Formula presented) and an upper limit for (Formula presented) are determined from 22.3 (Formula presented) of (Formula presented) annihilation data at a c.m. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from (Formula presented) reconstructed (Formula presented) (Formula presented) mesons. The branching fractions (Formula presented) and (Formula presented) are determined from 10 events with a reconstructed D and a recoiling (Formula presented) In addition, a 90% C.L. upper limit of (Formula presented) is determined from a search for semileptonic decays of the (Formula presented) © 2000 The American Physical Society.

Published
2000

7. ψ(2S)→π+π-J/ψ decay distributions

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, ZJ, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, GS, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, and Shen, DL

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

Using a sample of 3.8 M (Formula presented) events accumulated with the BES detector, the process (Formula presented) is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the (Formula presented) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter (Formula presented) predicts that D wave pions should be present. We determine (Formula presented) based on the joint (Formula presented) distribution. The fraction of D wave amplitude as a function of (Formula presented) is found to decrease with increasing (Formula presented) in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. © 2000 The American Physical Society.

Published
2000

8. Measurement of the inclusive charm cross section at 4.03 GeV and 4.14 GeV

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Huang, GS, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Schmid, B, and Schultz, J

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

The cross section for charmed meson production at √s=4.03 and 4.14 GeV has been measured with the Beijing Spectrometer. The measurement was made using 22.3 pb-1 of e+e- data collected at 4.03 GeV and 1.5 pb-1 of e+e- data collected at 4.14 GeV. Inclusive observed cross sections for the production of charged and neutral D mesons and momentum spectra are presented. Observed cross sections were radiatively corrected to obtain tree level cross sections. Measurements of the total hadronic cross section are obtained from the charmed meson cross section and an extrapolation of results from below the charm threshold. ©2000 The American Physical Society.

Published
2000

9. [formula presented] decay distributions

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, ZJ, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, GS, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, and Shen, DL

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Using a sample of 3.8 M (Formula presented) events accumulated with the BES detector, the process (Formula presented) is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the (Formula presented) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter (Formula presented) predicts that D wave pions should be present. We determine (Formula presented) based on the joint (Formula presented) distribution. The fraction of D wave amplitude as a function of (Formula presented) is found to decrease with increasing (Formula presented) in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. © 2000 The American Physical Society.

Published
2000

10. Direct measurement of [formula presented] and [formula presented]

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Huang, GS, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Schmid, B, and Schultz, J

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The first measurement of (Formula presented) and an upper limit for (Formula presented) are determined from 22.3 (Formula presented) of (Formula presented) annihilation data at a c.m. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from (Formula presented) reconstructed (Formula presented) (Formula presented) mesons. The branching fractions (Formula presented) and (Formula presented) are determined from 10 events with a reconstructed D and a recoiling (Formula presented) In addition, a 90% C.L. upper limit of (Formula presented) is determined from a search for semileptonic decays of the (Formula presented) © 2000 The American Physical Society.

Published
2000

11. Study of the hadronic decays of χc states

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, Shen, DL, Shen, H, Shen, XY, and Sheng, HY

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

Hadronic decays of the P-wave spin-triplet charmonium states (Formula presented) are studied using a sample of (Formula presented) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) and (Formula presented) are measured for the first time, and those for (Formula presented) (Formula presented) (Formula presented) and (Formula presented) are measured with improved precision. In addition, we determine the masses of the (Formula presented) and (Formula presented) to be (Formula presented) and (Formula presented) © 1999 The American Physical Society.

Published
1999

12. Charmonium Decays to Axial-Vector Plus Pseudoscalar Mesons

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, Shen, DL, Shen, H, Shen, XY, Sheng, HY, Shi, HZ, and Song, XF

Subjects
Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

A sample of 3.79 × 106ψ(2S) events is used to study the decays of charmonium to axial-vector plus pseudoscalar mesons. The branching fraction for the decay ψ(2S) → b±1(1235)π∓ agrees with expectations based on scaling the corresponding J/ψ branching fraction. Flavor-SU(3)-violating K1(1270)- K1(1400) asymmetries with opposite character for ψ(2S) and J/ψ decays are observed. This contrasting behavior cannot be accommodated by adjustments of the singlet-triplet mixing angle. © 1999 The American Physical Society.

Published
1999

13. Study of the hadronic decays of [formula presented] states

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, Shen, DL, Shen, H, Shen, XY, and Sheng, HY

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Hadronic decays of the P-wave spin-triplet charmonium states (Formula presented) are studied using a sample of (Formula presented) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays (Formula presented) (Formula presented) (Formula presented) (Formula presented) (Formula presented) and (Formula presented) are measured for the first time, and those for (Formula presented) (Formula presented) (Formula presented) and (Formula presented) are measured with improved precision. In addition, we determine the masses of the (Formula presented) and (Formula presented) to be (Formula presented) and (Formula presented) © 1999 The American Physical Society.

Published
1999

14. ψ(2S) Hadronic Decays to Vector-Tensor Final States

Author

Bai, JZ, Bian, JG, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Ding, LY, Dong, LY, Du, ZZ, Dunwoodie, W, Feng, S, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, PQ, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Lu, JY, Lu, LC, Luo, CH, M., A, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, and Shen, BW

Subjects
Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

The decays of the ψ(2S) into vector plus tensor meson final states have been studied for the first time using the BES detector. We determine upper limits on branching fractions for ψ(2S) decays into ωf2, ρa2, K*0K*02 + c.c., and φf'2(1525) that are, in each case, significantly smaller than the corresponding branching fractions for the J/ψ meson, scaled according to the expectations of perturbative QCD. © 1998 The American Physical Society.

Published
1998

15. Study of the P-Wave Charmonium State χcJ in ψ(2S) Decays

Author

Bai, JZ, Bian, JG, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Ding, LY, Dong, LY, Du, ZZ, Dunwoodie, W, Feng, S, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, PQ, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Lu, JY, Lu, LC, Luo, CH, M., A, C., E, M., J, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, and Shen, BW

Subjects
Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

The processes ψ(2S) → I π+ π−, γK+ K−, and γpp¯ have been studied using a sample of 3.79 × 106 ψ(2S) decays. We determine the total width of the χc0 to be γtotχc0 = 14.3 ± 2.0 ± 3.0 MeV. We present the first measurement of the branching fraction B(χc0 → pp¯) = (15.9 ± 4.3 ± 5.3) × 10−5, where the first error is statistical and the second one is systematic. Branching fractions of χc0, 2 → π+ π− and K+ K− are also reported. © 1998 American Physical Society.

Published
1998

16. Evidence for the leptonic decay D → μνμ

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Liu, HM, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Luo, S, Luo, Y, Ma, AM, Ma, EC, Ma, JM, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, and Quigley, J

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Astronomical and Space Sciences, Mathematical Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Purely leptonic decays of the charged D meson have been studied using the reaction e+e- → D*+D- at a center of mass energy of 4.03 GeV. A search was performed for D → μνμ recoiling against a D0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e+e- → D*+D-, where D*+ → π+D0 with the D0 → K-π+, and the recoiling D- decaying via D- → μ-ν̄μ. This yields a branching fraction value B(D → μνμ) = 0.08+0.16+0.05-0.05-0.02%, and a corresponding value of the pseudoscalar decay constant fD = 300+180+80-150-40 MeV. © 1998 Elsevier Science B.V. All rights reserved.

Published
1998

17. Evidence for the leptonic decay D→μνμ

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Liu, HM, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Luo, S, Luo, Y, Ma, AM, Ma, EC, Ma, JM, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, and Quigley, J

Subjects
Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

Purely leptonic decays of the charged D meson have been studied using the reaction e+e- → D*+D- at a center of mass energy of 4.03 GeV. A search was performed for D → μνμ recoiling against a D0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e+e- → D*+D-, where D*+ → π+D0 with the D0 → K-π+, and the recoiling D- decaying via D- → μ-ν̄μ. This yields a branching fraction value B(D → μνμ) = 0.08+0.16+0.05-0.05-0.02%, and a corresponding value of the pseudoscalar decay constant fD = 300+180+80-150-40 MeV. © 1998 Elsevier Science B.V. All rights reserved.

Published
1998

18. Search for ψ(2S) production in e+e- annihilations at 4.03 GeV

Author

Bai, JZ, Bian, JG, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Ding, LY, Dong, LY, Du, ZZ, Dunwoodie, W, Feng, S, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, PQ, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Lu, JY, Lu, LC, Luo, CH, M., A, C., E, M., J, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, and Schmid, B

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

A search is performed for the production of the (Formula presented) in (Formula presented) annihilation at a center-of-mass energy of 4.03 GeV using the BES detector operated at the Beijing Electron Positron Collider (BEPC). The kinematic features of the reconstructed (Formula presented) signal are consistent with its being produced only in association with an energetic photon resulting from initial state radiation (ISR). Limits are placed on (Formula presented) production from the decay of unknown charmonia or metastable hybrids that might be produced in (Formula presented) annihilations at 4.03 GeV. Under the assumption that the observed cross section for (Formula presented) production is due entirely to ISR, the partial width (Formula presented) of the (Formula presented) is measured to be (Formula presented). © 1998 The American Physical Society.

Published
1998

19. Direct measurement of B(Ds+→φX+)

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Lu, JY, Luo, S, Luo, Y, M., A, C., E, M., J, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, Rong, G, and Schernau, M

Subjects
Intellectual and Developmental Disabilities (IDD), Brain Disorders, Down Syndrome, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

The absolute inclusive branching fraction of (Formula presented) has been measured from data collected by the BES detector at a center-of-mass energy of 4.03 GeV, corresponding to an integrated luminosity of 22.3 pb(Formula presented). At this energy, direct pair production (Formula presented) has been observed. We have selected (Formula presented) candidate events by reconstructing five hadronic decay modes (Formula presented), (Formula presented), (Formula presented), (Formula presented) and (Formula presented) and have searched for inclusive (Formula presented)’s in the recoiling (Formula presented). We observed three recoiling (Formula presented)’s in the 166.4 (Formula presented) 31.8 (Formula presented) candidate events, which leads to the absolute branching fraction (Formula presented) and (Formula presented). © 1998 The American Physical Society.

Published
1998

20. Direct measurement of [Formula presented]

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Lu, JY, Luo, S, Luo, Y, Ma, AM, Ma, EC, Ma, JM, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, Rong, G, and Schernau, M

Subjects
Down Syndrome, Brain Disorders, Intellectual and Developmental Disabilities (IDD), Intellectual and Developmental Disabilities, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The absolute inclusive branching fraction of (Formula presented) has been measured from data collected by the BES detector at a center-of-mass energy of 4.03 GeV, corresponding to an integrated luminosity of 22.3 pb(Formula presented). At this energy, direct pair production (Formula presented) has been observed. We have selected (Formula presented) candidate events by reconstructing five hadronic decay modes (Formula presented), (Formula presented), (Formula presented), (Formula presented) and (Formula presented) and have searched for inclusive (Formula presented)’s in the recoiling (Formula presented). We observed three recoiling (Formula presented)’s in the 166.4 (Formula presented) 31.8 (Formula presented) candidate events, which leads to the absolute branching fraction (Formula presented) and (Formula presented). © 1998 The American Physical Society.

Published
1998

21. Search for [Formula presented] production in [Formula presented] annihilations at 4.03 GeV

Author

Bai, JZ, Bian, JG, Blum, I, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Ding, LY, Dong, LY, Du, ZZ, Dunwoodie, W, Feng, S, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, JD, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, PQ, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, JH, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Lu, JY, Lu, LC, Luo, CH, Ma, AM, Ma, EC, Ma, JM, Malchow, R, Mandelkern, M, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, and Schmid, B

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

A search is performed for the production of the (Formula presented) in (Formula presented) annihilation at a center-of-mass energy of 4.03 GeV using the BES detector operated at the Beijing Electron Positron Collider (BEPC). The kinematic features of the reconstructed (Formula presented) signal are consistent with its being produced only in association with an energetic photon resulting from initial state radiation (ISR). Limits are placed on (Formula presented) production from the decay of unknown charmonia or metastable hybrids that might be produced in (Formula presented) annihilations at 4.03 GeV. Under the assumption that the observed cross section for (Formula presented) production is due entirely to ISR, the partial width (Formula presented) of the (Formula presented) is measured to be (Formula presented). © 1998 The American Physical Society.

Published
1998

22. Measurement of the branching fraction of Ds inclusive semileptonic decay Ds+→e+X

Author

Bai, JZ, Bardon, O, Bian, JG, Blum, I, Breakstone, A, Burnett, T, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, XP, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Lu, F, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Lu, JY, Luo, SQ, Luo, Y, M., A, C., E, M., J, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, and Pan, LJ

Subjects
Down Syndrome, Brain Disorders, Intellectual and Developmental Disabilities (IDD), Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

The absolute inclusive semileptonic branching fraction of the [Formula presented] meson has been measured based on [Formula presented] of [Formula presented] collision data collected with the Beijing Spectrometer at [Formula presented] At this energy, the [Formula presented] are produced in pairs: [Formula presented] We reconstructed [Formula presented] [Formula presented] events in five hadronic decay modes. In the recoil system of these events, several [Formula presented] inclusive semileptonic decays were observed and the branching fraction is estimated to be [Formula presented] © 1997 The American Physical Society.

Published
1997

23. Measurement of the branching fraction of [Formula presented] inclusive semileptonic decay [Formula presented]

Author

Bai, JZ, Bardon, O, Bian, JG, Blum, I, Breakstone, A, Burnett, T, Chai, ZW, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, M, Hitlin, DG, Hu, GY, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, XP, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Lu, F, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Lu, JY, Luo, SQ, Luo, Y, Ma, AM, Ma, EC, Ma, JM, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, and Pan, LJ

Subjects
Down Syndrome, Brain Disorders, Intellectual and Developmental Disabilities (IDD), Intellectual and Developmental Disabilities, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The absolute inclusive semileptonic branching fraction of the [Formula presented] meson has been measured based on [Formula presented] of [Formula presented] collision data collected with the Beijing Spectrometer at [Formula presented] At this energy, the [Formula presented] are produced in pairs: [Formula presented] We reconstructed [Formula presented] [Formula presented] events in five hadronic decay modes. In the recoil system of these events, several [Formula presented] inclusive semileptonic decays were observed and the branching fraction is estimated to be [Formula presented] © 1997 The American Physical Society.

Published
1997

24. Search for a vector glueball by a scan of the Jψ resonance

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Lin, SZ, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, Luo, SQ, Luo, Y, M., A, C., E, M., J, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, and Quigley, J

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

The cross section for e+e-→ρπ has been measured by the BES detector at BEPC at center-of-mass energies covering a 40 MeV interval spanning the J/ψresonance. The data are used to search for the vector gluonium state hypothesized by Brodsky, Lepage, and Tuan as an explanation of the ρπ puzzle in charmonium physics. The shape of the ρπ cross section is compatible with that of the total hadronic cross section. No distortions indicating the presence of a vector glueball are seen. © 1996 The American Physical Society.

Published
1996

25. Measurement of the mass of the τ lepton

Author

Bai, JZ, Bardon, O, Becker-Szendy, RA, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, HC, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Gao, CS, Gao, ML, Gao, SQ, Gao, WX, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, KR, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jiang, ZZ, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, XH, Li, XN, Li, YS, Lin, SZ, Liu, HM, Liu, J, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, Y, M., A, H., D, C., E, M., J, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Marsiske, H, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, and Paluselli, D

Subjects
Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

A data-driven energy scan in the immediate vicinity of the τ pair production threshold has been performed using the Beijing Spectrometer at the Beijing Electron-Positron Collider. Approximately 5pb-1 of data, distributed over 12 scan points, have been collected. A previous mass value for the τ lepton, obtained using only the eµ final state, has been published. In this paper, the final BES result on the mass measurement is presented. The analysis is based on the combined data from the ee, eµ, eh, µµ, µh, and hh final states, where h denotes a charged Π or K. A maximum likelihood fit to the τ pair production cross section data yields the value mT=1776.96-0.21 -0.17+0.18+0.25. © 1995 The American Physical Society.

Published
1996

26. Measurement of the mass of the tau lepton.

Author

Bai, JZ, Bardon, O, Becker-Szendy, RA, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, HC, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Gao, CS, Gao, ML, Gao, SQ, Gao, WX, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, KR, He, M, Hitlin, DG, Hu, GY, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jiang, ZZ, Jin, S, Jin, Y, Jones, L, Kang, SH, Ke, ZJ, Kelsey, MH, Kim, BK, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, and Li, PQ

Subjects
Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

A data-driven energy scan in the immediate vicinity of the τ pair production threshold has been performed using the Beijing Spectrometer at the Beijing Electron-Positron Collider. Approximately 5pb-1 of data, distributed over 12 scan points, have been collected. A previous mass value for the τ lepton, obtained using only the eµ final state, has been published. In this paper, the final BES result on the mass measurement is presented. The analysis is based on the combined data from the ee, eµ, eh, µµ, µh, and hh final states, where h denotes a charged Π or K. A maximum likelihood fit to the τ pair production cross section data yields the value mT=1776.96-0.21 -0.17+0.18+0.25. © 1995 The American Physical Society.

Published
1996

27. Direct Measurement of the Pseudoscalar Decay Constant, fDs

Author

Bai, JZ, Bardon, O, Blum, I, Breakstone, A, Burnett, T, Chen, GP, Chen, HF, Chen, J, Chen, SJ, Chen, SM, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cowan, RF, Cui, HC, Cui, XZ, Ding, HL, Du, ZZ, Dunwoodie, W, Fan, XL, Fang, J, Fero, M, Gao, CS, Gao, ML, Gao, SQ, Gao, WX, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, Hatanaka, M, He, J, He, KR, He, M, Hitlin, DG, Hu, GY, Hu, HB, Hu, T, Hu, XQ, Huang, DQ, Huang, YZ, Izen, JM, Jia, QP, Jiang, CH, Jin, Y, Jones, L, Kang, SH, Kelsey, MH, Kim, BK, Lai, YF, Lan, HB, Lang, PF, Lankford, A, Li, F, Li, J, Li, PQ, Li, Q, Li, RB, Li, W, Li, WD, Li, WG, Li, X, Li, XN, Lin, SZ, Liu, HM, Liu, JH, Liu, Q, Liu, RG, Liu, Y, Liu, ZA, Lou, XC, Lowery, B, Lu, JG, M., A, C., E, M., J, Mao, HS, Mao, ZP, Malchow, R, Mandelkern, M, Meng, XC, Ni, HL, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Prabhakar, E, Qi, ND, Que, YK, Quigley, J, and Rong, G

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, Intellectual and Developmental Disabilities (IDD), Down Syndrome, Brain Disorders, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The Beijing Spectrometer (BES) experiment has observed purely leptonic decays of the Ds meson in the reaction e+e-→Ds+Ds- at a c.m. energy of 4.03 GeV. Three events are observed in which one Ds decays hadronically to φπ, K̄*0K, or K̄0K, and the other decays leptonically to μνμ or τντ. With the assumption of μ-τ universality, values of the branching fraction, B(Ds→μνμ)=(1.5-0.6-0.2+1.3+0.3)%, and the Ds pseudoscalar decay constant, fDs=(4.3-1.3-0.4+1.5+0.4)×102 MeV, are obtained. © 1995 The American Physical Society.

Published
1995

28. First measurement of the branching fraction of the decay ψ(2S)→τ+ τ

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, AD, Chen, HF, Chen, HS, Chen, J, Chen, JC, Chen, XD, Chen, Y, Chen, YB, Cheng, BS, Chi, SP, Chu, YP, Choi, JB, Cui, XZ, Dai, YS, Dong, LY, Du, ZZ, Dunwoodie, W, Fu, HY, Fu, LP, Gao, CS, Gratton, P, Gu, SD, Gu, YF, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, He, X, Hong, T, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, QH, Hu, T, Huang, GS, Huang, XP, Huang, YZ, Izen, JM, Ji, XB, Jiang, CH, Jin, Y, Jones, BD, Kang, JS, Ke, ZJ, Kelsey, MH, Kim, BK, Kim, HJ, Kim, SK, Kim, TY, Kong, D, Lai, YF, Lankford, A, Li, D, Li, HB, Li, HH, Li, J, Li, JC, Li, PQ, Li, QJ, Li, RY, Li, W, Li, WG, Li, XN, Li, XQ, Liu, B, Liu, F, Liu, HM, Liu, J, Liu, JP, Liu, TR, Liu, RG, Liu, Y, Liu, ZX, Lou, XC, Lowery, B, Lu, GR, Lu, F, Lu, JG, Lu, ZJ, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, and Nie, J

Subjects
High Energy Physics::Experiment
Abstract

The branching fraction of the ψ(2S) decay into τ+τ - has been measured for the first time using the BES detector at the Beijing Electron-Positron Collider. The result is Bττ=(2.710. 43±0.55)× 10-3, where the first error is statistical and the second is systematic. This value, along with those for the branching fractions into e+e- and μ+ μ- of this resonance, satisfy well the relation predicted by the sequential lepton hypothesis. Combining all these values with the leptonic width of the resonance, the total width of the ψ(25) is determined to be (252±37) keV. ©2002 The American Physical Society.

Published
2002
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29. ψ(2S)→π+π- J/ψ decay distributions

Author

Bai, J. Z., Ban, Y., Bian, J. G., Blum, I., Chen, G. P., Chen, H. F., Chen, J., Chen, J. C., Chen, Y., Chen, Y. B., Chen, Y. Q., Cheng, B. S., Cui, X. Z., Ding, H. L., Dong, L. Y., Du, Z. Z., Dunwoodie, W., Gao, C. S., Gao, M. L., Gao, S. Q., Gratton, P., Gu, J. H., Gu, S. D., Gu, W. X., Gu, Y. F., Guo, Z. J., Guo, Y. N., Han, S. W., Han, Y., Harris, F. A., He, J., He, J. T., He, K. L., He, M., Heng, Y. K., Hitlin, D. G., Hu, G. Y., Hu, H. M., Hu, J. L., Hu, Q. H., Hu, T., Hu, X. Q., Huang, G. S., Huang, Y. Z., Joseph Izen, Jiana, C. H., Jin, Y., Jones, B. D., Ju, X., Ke, Z. J., Kelsey, M. H., Kim, B. K., Kong, D., Lai, Y. F., Lang, P. F., Lankford, A., Li, C. G., Li, D., Li, H. B., Li, J., Li, J. C., Li, P. Q., Li, R. B., Li, W., Li, W. G., Li, X. H., Li, X. N., Liu, H. M., Liu, J., Liu, R. G., Liu, Y., Lou, X. C., Lowery, B., Lu, F., Lu, J. G., Luo, X. L., Ma, E. C., Ma, J. M., Malchow, R., Mao, H. S., Mao, Z. P., Meng, X. C., Nie, J., Olsen, S. L., Oyang, J., Paluselli, D., Pan, L. J., Panetta, J., Porter, F., Qi, N. D., Qi, X. R., Qian, C. D., Qiu, J. F., Qu, Y. H., Que, Y. K., Rong, G., Schernau, M., Shao, Y. Y., Shen, B. W., and Shen, D. L.

Subjects
High Energy Physics::Experiment
Abstract

Using a sample of 3.8 M ψ(2S) events accumulated with the BES detector, the process ψ(2S) → π+π- J/ψ is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the J/ψ-(π+π-) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter κ, predicts that D wave pions should be present. We determine κ=0.183 ±0.002±0.003 based on the joint mππ-cos θ*π distribution. The fraction of D wave amplitude as a function of mππ is found to decrease with increasing mππ, in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. ©2000 The American Physical Society.

Published
2000

30. Measurement of the mass and full width of the ηcmeson

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, AD, Chen, GP, Chen, HF, Chen, HS, Chen, J, Chen, JC, Chen, XD, Chen, Y, Chen, YB, Cheng, BS, Choi, JB, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Guo, YN, Guo, ZJ, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Heng, YK, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Huang, GS, Huang, XP, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Kang, JS, Ke, ZJ, Kelsey, MH, Kim, BK, Kim, HJ, Kim, SK, Kim, TY, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, W, Li, WG, Li, XH, Li, XN, Li, XQ, Li, ZC, Liu, B, Liu, F, Liu, HM, Liu, J, Liu, JP, Liu, RG, Liu, Y, Liu, ZX, Lou, XC, Lowery, B, Lu, GR, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Mo, XH, Nie, J, Olsen, SL, Oyang, J, and Paluselli, D

Abstract

In a sample of 7.8 million J/ψ decays collected in the Beijing Spectrometer, the process J/ψ→γηcis observed for five different ηcdecay channels: K+K-π+π-, π+π-π+π-, K±KS0π∓ (with KS0→π+π-), φφ (with φ→K+K-) and K+K-π0. From these signals, we determine the mass of ηcto be 2976.6±2.9 ±1.3 MeV. Combining this result with a previously reported result from a similar study using ψ(2S)→γηcdetected in the same spectrometer gives mηc=2976.3±2.3±1.2 MeV. For the combined samples, we obtain Γηc=11.0±8.1±4.1 MeV. ©2000 The American Physical Society.

Published
2000

31. Study of the hadronic decays of χcstates

Author

Bai, JZ, Ban, Y, Bian, JG, Blum, I, Chen, GP, Chen, HF, Chen, J, Chen, JC, Chen, Y, Chen, YB, Chen, YQ, Cheng, BS, Cui, XZ, Ding, HL, Dong, LY, Du, ZZ, Dunwoodie, W, Gao, CS, Gao, ML, Gao, SQ, Gratton, P, Gu, JH, Gu, SD, Gu, WX, Gu, YF, Guo, YN, Han, SW, Han, Y, Harris, FA, He, J, He, JT, He, KL, He, M, Hitlin, DG, Hu, GY, Hu, HM, Hu, JL, Hu, QH, Hu, T, Hu, XQ, Huang, YZ, Izen, JM, Jiang, CH, Jin, Y, Jones, BD, Ju, X, Ke, ZJ, Kelsey, MH, Kim, BK, Kong, D, Lai, YF, Lang, PF, Lankford, A, Li, CG, Li, D, Li, HB, Li, J, Li, JC, Li, PQ, Li, RB, Li, W, Li, WG, Li, XH, Li, XN, Liu, HM, Liu, J, Liu, RG, Liu, Y, Lou, XC, Lowery, B, Lu, F, Lu, JG, Luo, XL, Ma, EC, Ma, JM, Malchow, R, Mao, HS, Mao, ZP, Meng, XC, Nie, J, Olsen, SL, Oyang, J, Paluselli, D, Pan, LJ, Panetta, J, Porter, F, Qi, ND, Qi, XR, Qian, CD, Qiu, JF, Qu, YH, Que, YK, Rong, G, Schernau, M, Shao, YY, Shen, BW, Shen, DL, Shen, H, Shen, XY, and Sheng, HY

Abstract

Hadronic decays of the P-wave spin-triplet charmonium states χcJ(J=0,1,2) are studied using a sample of ψ(2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays χc1→Ks0K+π-+c.c., χc0→Ks0Ks0, χc2→Ks0Ks0, χc0→φφ, χc2→φφ and χcJ→K+K-K+K-are measured for the first time, and those for χcJ→π+π-π+π-, χcJ→π+π-K+K-, χcJ→π+π-pp̄ and χcJ→3(π+π-) are measured with improved precision. In addition, we determine the masses of the χc0and ηcto be Mχc0=3414.1±0.6(stat)±0.8(syst) MeV and Mηc=2975.8±3.9(stat)±1.2(syst) MeV. ©1999 The American Physical Society.

Published
1999

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