The $$\chi_\mathrm{b1}$$(3P) and $$\chi_\mathrm{b2}$$(3P) states are observed through their $$\Upsilon$$(3S) $$\gamma$$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$$^{-1}$$. The $$\Upsilon$$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$$e$$^-$ pairs in the silicon tracker, leading to a $$\chi_\mathrm{b}$$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$$\,$$513.42 $$\pm$$ 0.41 (stat) $$\pm$$ 0.18 (syst) MeV and 10$$\,$$524.02 $$\pm$$ 0.57 (stat) $$\pm$$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $$\Upsilon$$(3S) mass, which has an uncertainty of 0.5 MeV. As a result, the mass splitting is measured to be 10.60 $$\pm$$ 0.64 (stat) $$\pm$$ 0.17 (syst) MeV.
Sirunyan, A. M., et al. "Observation of the <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>2</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and Measurement of their Masses." Physical Review Letters, vol. 121, no. 9, Aug. 2018. https://doi.org/10.1103/PhysRevLett.121.092002
Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Dragicevic, M., Erö, J., Escalante Del Valle, A., Flechl, M., Frühwirth, R., Ghete, V. M., Hrubec, J., Jeitler, M., Krammer, N., Krätschmer, I., Liko, D., ... Woods, N. (2018). Observation of the <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>2</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and Measurement of their Masses. Physical Review Letters, 121(9). https://doi.org/10.1103/PhysRevLett.121.092002
Sirunyan, A. M., Tumasyan, A., Adam, W., et al., "Observation of the <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>2</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and Measurement of their Masses," Physical Review Letters 121, no. 9 (2018), https://doi.org/10.1103/PhysRevLett.121.092002
@article{osti_1452827,
author = {Sirunyan, A. M. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Asilar, E. and Bergauer, T. and Brandstetter, J. and Dragicevic, M. and Erö, J. and Escalante Del Valle, A. and others},
title = {Observation of the <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>1</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and <math display='inline'><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>b</mi><mn>2</mn></mrow></msub><mo stretchy='false'>(</mo><mn>3</mn><mi>P</mi><mo stretchy='false'>)</mo></mrow></math> and Measurement of their Masses},
annote = {The $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) states are observed through their $\Upsilon$(3S) $\gamma$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$^{-1}$. The $\Upsilon$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $\chi_\mathrm{b}$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$\,$513.42 $\pm$ 0.41 (stat) $\pm$ 0.18 (syst) MeV and 10$\,$524.02 $\pm$ 0.57 (stat) $\pm$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $\Upsilon$(3S) mass, which has an uncertainty of 0.5 MeV. As a result, the mass splitting is measured to be 10.60 $\pm$ 0.64 (stat) $\pm$ 0.17 (syst) MeV.},
doi = {10.1103/PhysRevLett.121.092002},
url = {https://www.osti.gov/biblio/1452827},
journal = {Physical Review Letters},
issn = {ISSN PRLTAO},
number = {9},
volume = {121},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2018},
month = {08}}
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 462, Issue 1-2https://doi.org/10.1016/S0168-9002(01)00089-4
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3https://doi.org/10.1016/S0168-9002(03)01368-8