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Title: Isospin Splittings of Doubly Heavy Baryons

Abstract

The SELEX Collaboration has reported a very large isospin splitting of doubly charmed baryons. We show that this effect would imply that the doubly charmed baryons are very compact. One intriguing possibility is that such baryons have a linear geometry Q-q-Q where the light quark q oscillates between the two heavy quarks Q, analogous to a linear molecule such as carbon dioxide. However, using conventional arguments, the size of a heavy-light hadron is expected to be around 0.5 fm, much larger than the size needed to explain the observed large isospin splitting. Assuming the distance between two heavy quarks is much smaller than that between the light quark and a heavy one, the doubly heavy baryons are related to the heavy mesons via heavy quark-diquark symmetry. Based on this symmetry, we predict the isospin splittings for doubly heavy baryons including {Xi}{sub cc}, {Xi}{sub bb} and {Xi}{sub bc}. The prediction for the {Xi}{sub cc} is much smaller than the SELEX value. On the other hand, the {Xi}{sub bb} baryons are predicted to have an isospin splitting as large as (6.3 {+-} 1.7) MeV. An experimental study of doubly bottomed baryons is therefore very important to better understand the structure of baryonsmore » with heavy quarks.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1022515
Report Number(s):
SLAC-PUB-14347
Journal ID: ISSN 0370-2693; arXiv:1101.1983; TRN: US1104254
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Phys.Lett.B698:251-255,2011
Additional Journal Information:
Journal Volume: 698; Journal Issue: 3; Journal ID: ISSN 0370-2693
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BARYONS; CARBON DIOXIDE; CHARMED BARYONS; FORECASTING; GEOMETRY; HADRONS; ISOSPIN; MESONS; QUARKS; SYMMETRY; Experiment-HEP, Lattice, Phenomenology-HEP,HEPPH, HEPTH

Citation Formats

Brodsky, Stanley J., /SLAC, Guo, Feng-Kun, /Bonn U., HISKP /Bonn U., Hanhart, Christoph, /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich, Meissner, Ulf-G., and /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich /Bonn U., HISKP /Bonn U. Isospin Splittings of Doubly Heavy Baryons. United States: N. p., 2011. Web. doi:10.1016/j.physletb.2011.03.014.
Brodsky, Stanley J., /SLAC, Guo, Feng-Kun, /Bonn U., HISKP /Bonn U., Hanhart, Christoph, /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich, Meissner, Ulf-G., & /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich /Bonn U., HISKP /Bonn U. Isospin Splittings of Doubly Heavy Baryons. United States. doi:10.1016/j.physletb.2011.03.014.
Brodsky, Stanley J., /SLAC, Guo, Feng-Kun, /Bonn U., HISKP /Bonn U., Hanhart, Christoph, /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich, Meissner, Ulf-G., and /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich /Bonn U., HISKP /Bonn U. Thu . "Isospin Splittings of Doubly Heavy Baryons". United States. doi:10.1016/j.physletb.2011.03.014. https://www.osti.gov/servlets/purl/1022515.
@article{osti_1022515,
title = {Isospin Splittings of Doubly Heavy Baryons},
author = {Brodsky, Stanley J. and /SLAC and Guo, Feng-Kun and /Bonn U., HISKP /Bonn U. and Hanhart, Christoph and /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich and Meissner, Ulf-G. and /Julich, Forschungszentrum /JCHP, Julich /IAS, Julich /Bonn U., HISKP /Bonn U.},
abstractNote = {The SELEX Collaboration has reported a very large isospin splitting of doubly charmed baryons. We show that this effect would imply that the doubly charmed baryons are very compact. One intriguing possibility is that such baryons have a linear geometry Q-q-Q where the light quark q oscillates between the two heavy quarks Q, analogous to a linear molecule such as carbon dioxide. However, using conventional arguments, the size of a heavy-light hadron is expected to be around 0.5 fm, much larger than the size needed to explain the observed large isospin splitting. Assuming the distance between two heavy quarks is much smaller than that between the light quark and a heavy one, the doubly heavy baryons are related to the heavy mesons via heavy quark-diquark symmetry. Based on this symmetry, we predict the isospin splittings for doubly heavy baryons including {Xi}{sub cc}, {Xi}{sub bb} and {Xi}{sub bc}. The prediction for the {Xi}{sub cc} is much smaller than the SELEX value. On the other hand, the {Xi}{sub bb} baryons are predicted to have an isospin splitting as large as (6.3 {+-} 1.7) MeV. An experimental study of doubly bottomed baryons is therefore very important to better understand the structure of baryons with heavy quarks.},
doi = {10.1016/j.physletb.2011.03.014},
journal = {Phys.Lett.B698:251-255,2011},
issn = {0370-2693},
number = 3,
volume = 698,
place = {United States},
year = {2011},
month = {8}
}