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Title: Search for {sigma}{sub 5}{sup 0},N{sub 5}{sup 0}, and {theta}{sup ++} pentaquark states

Abstract

A high-resolution ({sigma}{sub instr.}=1.5 MeV) search for narrow states ({gamma}<10 MeV) with masses of M{sub x}{approx_equal}1500-1850 MeV in ep{yields}e{sup '}K{sup +}X,e{sup '}K{sup -}X, and e{sup '}{pi}{sup +}X electroproduction at small angles and low Q{sup 2} was performed. These states would be candidate partner states of the reported {theta}{sup +}(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.8% and 4.9% of the {lambda}(1520) production cross section, depending on the channel and the assumed mass and width of the state.

Authors:
; ; ; ;  [1]; ;  [2]; ; ; ;  [3];  [4]; ; ; ; ;  [5]; ; ;  [6]
  1. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  2. University of Glasgow, Glasgow, Scotland (United Kingdom)
  3. Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  4. Nuclear Physics Institute, St. Petersburg RU-188300 (Russian Federation)
  5. Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States)
  6. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States) (and others)
Publication Date:
OSTI Identifier:
20995325
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.055208; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTROPRODUCTION; LAMBDA-1520 BARYONS; MASS; MEV RANGE; RESOLUTION

Citation Formats

Qiang, Y., Bertozzi, W., Gayou, O., Monaghan, P., Suleiman, R., Annand, J., Hamilton, D. J., Arrington, J., Reimer, P. E., Schulte, E., Zheng, X., Azimov, Ya. I., Cates, G., Lindgren, R., Liyanage, N., Nelyubin, V., Singh, J., Chen, J. P., Chudakov, E., and Jager, C. W. de. Search for {sigma}{sub 5}{sup 0},N{sub 5}{sup 0}, and {theta}{sup ++} pentaquark states. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.055208.
Qiang, Y., Bertozzi, W., Gayou, O., Monaghan, P., Suleiman, R., Annand, J., Hamilton, D. J., Arrington, J., Reimer, P. E., Schulte, E., Zheng, X., Azimov, Ya. I., Cates, G., Lindgren, R., Liyanage, N., Nelyubin, V., Singh, J., Chen, J. P., Chudakov, E., & Jager, C. W. de. Search for {sigma}{sub 5}{sup 0},N{sub 5}{sup 0}, and {theta}{sup ++} pentaquark states. United States. doi:10.1103/PHYSREVC.75.055208.
Qiang, Y., Bertozzi, W., Gayou, O., Monaghan, P., Suleiman, R., Annand, J., Hamilton, D. J., Arrington, J., Reimer, P. E., Schulte, E., Zheng, X., Azimov, Ya. I., Cates, G., Lindgren, R., Liyanage, N., Nelyubin, V., Singh, J., Chen, J. P., Chudakov, E., and Jager, C. W. de. Tue . "Search for {sigma}{sub 5}{sup 0},N{sub 5}{sup 0}, and {theta}{sup ++} pentaquark states". United States. doi:10.1103/PHYSREVC.75.055208.
@article{osti_20995325,
title = {Search for {sigma}{sub 5}{sup 0},N{sub 5}{sup 0}, and {theta}{sup ++} pentaquark states},
author = {Qiang, Y. and Bertozzi, W. and Gayou, O. and Monaghan, P. and Suleiman, R. and Annand, J. and Hamilton, D. J. and Arrington, J. and Reimer, P. E. and Schulte, E. and Zheng, X. and Azimov, Ya. I. and Cates, G. and Lindgren, R. and Liyanage, N. and Nelyubin, V. and Singh, J. and Chen, J. P. and Chudakov, E. and Jager, C. W. de},
abstractNote = {A high-resolution ({sigma}{sub instr.}=1.5 MeV) search for narrow states ({gamma}<10 MeV) with masses of M{sub x}{approx_equal}1500-1850 MeV in ep{yields}e{sup '}K{sup +}X,e{sup '}K{sup -}X, and e{sup '}{pi}{sup +}X electroproduction at small angles and low Q{sup 2} was performed. These states would be candidate partner states of the reported {theta}{sup +}(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.8% and 4.9% of the {lambda}(1520) production cross section, depending on the channel and the assumed mass and width of the state.},
doi = {10.1103/PHYSREVC.75.055208},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • A high-resolution ({sigma}{sub instr.} = 1.5 MeV) search for narrow states ({Lambda} < 10 MeV) with masses of M{sub x} {approx} 1500-1850 MeV in ep {yields} e{prime}K{sup +}X,e{prime}K{sup -}X, and e{prime}{pi}{sup +}X electroproduction at small angles and low Q{sup 2} was performed. These states would be candidate partner states of the reported {Theta}{sup +}(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.8% and 4.9% of the {Lambda}(1520) production cross section, depending on the channel and the assumed mass and width of themore » state.« less
  • The exclusive reactions {gamma}p{yields}K{sup 0}K{sup +}n and {gamma}p{yields}K{sup 0}K{sup 0}p have been studied in the photon energy range 1.6-3.8 GeV, searching for evidence of the exotic baryon {theta}{sup +}(1540) in the decays {theta}{sup +}{yields}nK{sup +} and {theta}{sup +}{yields}pK{sup 0}. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70 pb{sup -1}. The reactions have been isolated by detecting the K{sup +} and proton directly, the neutral kaon via its decay to K{sub S}{yields}{pi}{sup +}{pi}{sup -} and the neutron or neutral kaon via the missing mass technique. The mass and widthmore » of known hyperons such as {sigma}{sup +}, {sigma}{sup -} and {lambda}(1116) were used as a check of the mass determination accuracy and experimental resolution. Approximately 100 000 {lambda}*(1520)'s and 150 000 {phi}'s were observed in the K{sup 0}K{sup +}n and K{sup 0}K{sup 0}p final state, respectively. No evidence for the {theta}{sup +} pentaquark was found in the nK{sup +} or pK{sub S} invariant mass spectra. Upper limits were set on the production cross section of the reaction {gamma}p{yields}K{sup 0}{theta}{sup +} as functions of center-of-mass angle, nK{sup +} and pK{sub S} masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the {theta}{sup +} width, {gamma}{sub {theta}{sup +}}, ranging between 0.01 and 7 MeV.« less
  • A high-resolution ({sigma}{sub instr.} = 1.5 MeV) search for narrow states ({Lambda} < 10 MeV) with masses of M{sub x} {approx} 1500-1850 MeV in ep {yields} e' K{sup +} X, e' K{sup -} X and e' {pi}{sup +} X electroproduction at small angles and low Q{sup 2} was performed. These states would be candidate partner states of the reported {Theta}{sup +}(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.7% and 4.2% of the {Lambda}(1520) production cross section, depending on the channel andmore » the assumed mass and width of the state.« less
  • The exclusive reaction {gamma}p{yields}K{sup 0}K{sup +}n was studied in the photon energy range between 1.6 and 3.8 GeV searching for evidence of the exotic baryon {theta}{sup +}(1540){yields}nK{sup +}. The decay to nK{sup +} requires the assignment of strangeness S=+1 to any observed resonance. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility corresponding to an integrated luminosity of 70 pb{sup -1}. No evidence for the {theta}{sup +} pentaquark was found. Upper limits were set on the production cross section as function of center-of-mass angle and nK{sup +} mass. The 95% C.L. upper limit on themore » total cross section for a narrow resonance at 1540 MeV was found to be 0.8 nb.« less
  • We search for the charmed pentaquark candidate reported by the H1 collaboration, the {theta}{sub c}(3100){sup 0}, in e{sup +}e{sup -} interactions at a center-of-mass (c.m.) energy of 10.58 GeV, using 124 fb{sup -1} of data recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} facility at SLAC. We find no evidence for such a state in the same pD*{sup -} decay mode reported by H1, and we set limits on its production cross section times branching fraction into pD*{sup -} as a function of c.m. momentum. The corresponding limit on its total rate per e{sup +}e{sup -}{yields}qq event,more » times branching fraction, is about 3 orders of magnitude lower than rates measured for the charmed {lambda}{sub c} and {sigma}{sub c} baryons in such events.« less