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541 results on '"Blum, I."'

1. Numeric modeling of synchronous laser pulsing and voltage pulsing field evaporation

Author

Zhao, L., Normand, A., Houard, J., Blum, I., Delaroche, F., and Vurpillot, F.

Subjects
Physics - Instrumentation and Detectors, Physics - Optics
Abstract

We have recently proposed an atom probe design based on a femtosecond time-resolved pump-probe setup. This setup unlocks the limitation of voltage pulsed mode atom probe thanks to the occurrence of local photoconductive switching effect . In this paper, we have used a numerical model to simulate the field evaporation process triggered by the synchronous two pulses. The model takes into account the local photoconductive effect and the temperature rise caused by the laser application and the voltage pulse distortion due to the RC effect., Comment: This paper provides the supplemental modeling information for the paper:Nanoscale photoconductive switching effect applied to atom probe tomography

Published
2016

2. THz vs NIR laser-assisted atom probe tomography of LaB6 samples.

Author

Karam, M., Houard, J., Bhorade, O., Blum, I., and Vella, A.

Subjects
ATOM-probe tomography, ELECTRON emission, PHOTON emission, ION emission, FEMTOSECOND lasers, SUBMILLIMETER waves, TERAHERTZ spectroscopy
Abstract

Terahertz (THz) radiation with low-energy photons (meV) is used in a wide range of applications, such as microscopy, sensing, and spectroscopy. However, recently, high amplitude THz pulses of MV/cm have been generated and used for electron emission and ion evaporation from field emitters, opening up the possibility of using high amplitude THz pulses for material imaging by THz-assisted atom probe tomography (APT). In this work, we compare the APT analyses of lanthanum hexaboride (LaB6) samples using a femtosecond near-infrared laser with those obtained using high-amplitude single-cycle THz pulses. The atomic-scale characterization of stoichiometric LaB6 is challenging in laser-assisted APT due to the detection losses of boron ions. Here, we show that the THz radiation reduces the emission of molecular ions and multiple detection events, and it increases the charge state of the emitted ions. All these effects result in an improvement in boron detection. Furthermore, the emission dynamics of boron and lanthanum ions differ in their evaporation times when using THz radiation. This work emphasizes the ability of high-amplitude, single-cycle THz pulses to well control material analysis in APT, leading to better results on chemical composition. It also paves the way for the use of this radiation for material manipulation. [ABSTRACT FROM AUTHOR]

Published
2024
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5. 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

6. 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

7. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. [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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. 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

29. Isotopic Correction of Compositional Inaccuracies in the Atom Probe Analysis of LaB6

Author

Ndiaye, S., Bhorade, O., Blum, I., Klaes, B., Bacchi, C., Houard, J., Vella, A., Vurpillot, F., and Rigutti, L.

Abstract

The atomic-scale characteristics of stoichiometric lanthanum hexaboride (LaB6) material are investigated in this work using atom probe tomography (APT). The presence of a higher background level in the mass spectrum is attributed to continuous boron evaporation, causing preferential boron loss and affecting composition measurements. The measured composition in LaB6exhibits inaccuracies influenced by the experimental conditions, particularly showing an excess of lanthanum (La). This enrichment is consistently linked to boron’s tendency for continuous evaporation, leading to a higher fraction of multiple evaporation and detection events. Consequently, the susceptibility of boron to measurement errors is increased due to detector limitations. To address this issue, we propose a method of compositional correction based on pseudomultiple events and an abundance of isotopic pairs, which has been successfully applied to elements with two isotopes and has the potential for elements with multiple isotopes.

Published
2024
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30. 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

31. 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

32. 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

34. 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

36. Temporal Bounds for TTA : Validation

Author

Godary, K., Augé-Blum, I., Mignotte, A., Kleinjohann, Bernd, editor, Gao, Guang R., editor, Kopetz, Hermann, editor, Kleinjohann, Lisa, editor, and Rettberg, Achim, editor

Published
2004
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42. Contributors

Author

Blavette, D., primary, Blum, I., additional, Cuvilly, F., additional, Da Costa, G., additional, Danoix, F., additional, Houard, J., additional, Lefebvre-Ulrikson, W., additional, Pareige, C., additional, Rigutti, L., additional, Sauvage, X., additional, Vella, A., additional, and Vurpillot, F., additional

Published
2016
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43. Data Mining

Author

Lefebvre-Ulrikson, W., primary, Da Costa, G., additional, Rigutti, L., additional, and Blum, I., additional

Published
2016
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45. Compositional accuracy in atom probe tomography analyses performed on III-N light emitting diodes.

Author

Di Russo, E., Cherkashin, N., Korytov, M., Nikolaev, A. E., Sakharov, A. V., Tsatsulnikov, A. F., Bonef, B., Blum, I., Houard, J., Da Costa, G., Blavette, D., and Rigutti, L.

Subjects
ATOM-probe tomography, LIGHT emitting diodes, INDIUM gallium nitride, ELECTRON holography, LASER pulses
Abstract

Laser-assisted atom probe tomography (APT) and high-resolution dark-field electron holography (HR-DFEH) were performed to investigate the composition of a polar [0001] GaN/AlxGa1 − xN/InyGa1 − yN light emitting diode. In particular, the III-site fraction of both AlxGa1 − xN and InyGa1 − yN alloys was studied adopting a comparative approach. HR-DFEH allows mapping the projected strain with a subnanometer spatial resolution which is used for the calculation of the two-dimensional alloy composition distribution. APT provides three-dimensional alloys composition distribution with a nanometer spatial resolution. However, here we reveal that important inaccuracies affect local composition measurements. A Ga-poor composition is obtained in high DC-electric field regions. Moreover, such inaccuracies may be locally enhanced where the [0001] pole intersects the surface of the analyzed specimen, leading to a lower fraction of Ga measured. III-site fractions closer to the nominal values were measured at low field conditions. Ga loss is thought to be due to preferential DC field induced evaporation of Ga ions between laser pulses. This is explained in terms of formation of a metallic layer on the tip surface during APT analysis, where weak Ga-Ga bonds are formed, promoting the loss of Ga at high field conditions. [ABSTRACT FROM AUTHOR]

Published
2019
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46. Effect of laser illumination on the electrical conductivity of single-crystal diamond needles.

Author

Arnoldi, L., Borz, M., Blum, I., Kleshch, V., Obraztsov, A., and Vella, A.

Subjects
ELECTRIC conductivity, DIAMOND thin films, INDUSTRIAL diamonds, CHEMICAL vapor deposition, DIAMOND films, ELECTRIC properties, DIAMOND anvil cell
Abstract

Herein, we present the results of electrical conductivity studies of single-crystal diamond needles. Pyramid-shaped needles of about hundreds of micrometers in length and about tens of micrometers in thickness were produced by oxidation of polycrystalline diamond films fabricated by chemical vapor deposition. The electrical conductivity of the needles was characterized via current measurements using a field ion microscope in the dark and under laser illumination. Considering the effects of laser intensity and wavelength on the measured current, we determine that the observed conduction regime corresponds to competing Ohmic and Poole-Frenkel conduction mechanisms. The measured values are in good agreement with the values reported previously for bulk and thin film diamond. The model that is proposed explains the electric conduction properties as well as light absorption and subsequent sample heating, with the presence of structural defects and impurities in diamond. [ABSTRACT FROM AUTHOR]

Published
2019
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49. Dissociation of GaN2+ and AlN2+ in APT: Analysis of experimental measurements.

Author

Zanuttini, D., Blum, I., di Russo, E., Rigutti, L., Vurpillot, F., Douady, J., Jacquet, E., Anglade, P.-M., and Gervais, B.

Subjects
*GALLIUM nitride, *ALUMINUM nitride, *ATOM-probe tomography, *DISSOCIATION (Chemistry), *MOLECULAR probes
Abstract

The use of a tip-shaped sample for the atom probe tomography technique offers the unique opportunity to analyze the dynamics of molecular ions in strong DC fields. We investigate here the stability of AlN2+ and GaN2+ dications emitted from an Al0.25Ga0.75N sample in a joint theoretical and experimental study. Despite the strong chemical resemblance of these two molecules, we observe only stable AlN2+, while GaN2+ can only be observed as a transient species. We simulate the emission dynamics of these ions on field-perturbed potential energy surfaces obtained from quantum chemical calculations. We show that the dissociation is governed by two independent processes. For all bound states, a mechanical dissociation is induced by the distortion of the potential energy surface in the close vicinity of the emitting tip. In the specific case of GaN2+, the relatively small electric dipole of the dication in its ground 13Σ− and excited 11Δ states induces a weak coupling with the electric field so that the mechanical dissociation into Ga+ + N+ lasts for sufficient time to be observed. By contrast, the AlN2+ mechanical dissociation leads to Al2+ + N which cannot be observed as a correlated event. For some deeply bound singlet excited states, the spin-orbit coupling with lower energy triplet states gives another chance of dissociation by system inter-system crossing with specific patterns observed experimentally in a correlated time of flight map. [ABSTRACT FROM AUTHOR]

Published
2018
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