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Title: Search for the H-dibaryon resonance in {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X)

Abstract

The H-dibaryon resonance was sought by a {lambda}{lambda} invariant mass spectrum that was obtained by the {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X) reactions. We observed a bump near the {lambda}{lambda} threshold, as reported by the previous experiment (KEK E224), with better statistics. Data were compared with results of a cascade model calculation including {lambda}{lambda} final state interactions consistent with the newly measured binding energy of {sub {lambda}}{sub {lambda}}{sup 6}He. No significant enhancements above levels of the model predictions were observed. The resulting upper limit for the production cross section of the H with a mass range between the {lambda}{lambda} and {xi}N threshold is found to be 2.1 {+-} 0.6 (stat.) {+-} 0.1 (syst.) {mu}b/sr at a 90% confidence level.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;  [1]; ;  [2];  [3]; ; ;  [4]
  1. Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
  2. Physics Department, Tokyo University of Science, Noda 278-8510 (Japan)
  3. High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan)
  4. Department of Physics, Osaka University, Osaka 558-8585 (Japan) (and others)
Publication Date:
OSTI Identifier:
20990998
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevC.75.022201; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BINDING ENERGY; CARBON 12; CROSS SECTIONS; DIBARYONS; FINAL-STATE INTERACTIONS; MASS SPECTRA; POTASSIUM IONS

Citation Formats

Yoon, C. J., Akikawa, H., Aoki, K., Fukao, Y., Funahashi, H., Hayata, M., Imai, K., Miwa, K., Okada, H., Saito, N., Sato, H. D., Shoji, K., Takahashi, H., Taketani, K., Asai, J., Kurosawa, M., Ieiri, M., Hayakawa, T., Kishimoto, T., and Sato, A. Search for the H-dibaryon resonance in {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X). United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.022201.
Yoon, C. J., Akikawa, H., Aoki, K., Fukao, Y., Funahashi, H., Hayata, M., Imai, K., Miwa, K., Okada, H., Saito, N., Sato, H. D., Shoji, K., Takahashi, H., Taketani, K., Asai, J., Kurosawa, M., Ieiri, M., Hayakawa, T., Kishimoto, T., & Sato, A. Search for the H-dibaryon resonance in {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X). United States. doi:10.1103/PHYSREVC.75.022201.
Yoon, C. J., Akikawa, H., Aoki, K., Fukao, Y., Funahashi, H., Hayata, M., Imai, K., Miwa, K., Okada, H., Saito, N., Sato, H. D., Shoji, K., Takahashi, H., Taketani, K., Asai, J., Kurosawa, M., Ieiri, M., Hayakawa, T., Kishimoto, T., and Sato, A. Thu . "Search for the H-dibaryon resonance in {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X)". United States. doi:10.1103/PHYSREVC.75.022201.
@article{osti_20990998,
title = {Search for the H-dibaryon resonance in {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X)},
author = {Yoon, C. J. and Akikawa, H. and Aoki, K. and Fukao, Y. and Funahashi, H. and Hayata, M. and Imai, K. and Miwa, K. and Okada, H. and Saito, N. and Sato, H. D. and Shoji, K. and Takahashi, H. and Taketani, K. and Asai, J. and Kurosawa, M. and Ieiri, M. and Hayakawa, T. and Kishimoto, T. and Sato, A.},
abstractNote = {The H-dibaryon resonance was sought by a {lambda}{lambda} invariant mass spectrum that was obtained by the {sup 12}C (K{sup -},K{sup +}{lambda}{lambda}X) reactions. We observed a bump near the {lambda}{lambda} threshold, as reported by the previous experiment (KEK E224), with better statistics. Data were compared with results of a cascade model calculation including {lambda}{lambda} final state interactions consistent with the newly measured binding energy of {sub {lambda}}{sub {lambda}}{sup 6}He. No significant enhancements above levels of the model predictions were observed. The resulting upper limit for the production cross section of the H with a mass range between the {lambda}{lambda} and {xi}N threshold is found to be 2.1 {+-} 0.6 (stat.) {+-} 0.1 (syst.) {mu}b/sr at a 90% confidence level.},
doi = {10.1103/PHYSREVC.75.022201},
journal = {Physical Review. C, Nuclear Physics},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • Hypernuclear mass spectra of {sub {Lambda}}{sup 10}B, {sub {Lambda}}{sup 12}C, {sub {Lambda}}{sup 28}Si, {sub {Lambda}}{sup 89}Y, {sub {Lambda}}{sup 139}La, and {sub {Lambda}}{sup 208}Pb were measured by the ({pi}{sup +},{ital K}{sup +}) reaction with an energy resolution of 2 MeV (FWHM). The experiment was carried out with a 1.06 GeV/{ital c} {pi}{sup +} beam from the KEK 12-GeV PS and with the superconducting kaon spectrometer (SKS). For light hypernuclei, core-excited states were resolved for the first time. For heavy hypernuclei, peak structure reflecting {Lambda} shell structure was observed. {copyright} {ital 1996 The American Physical Society.}
  • A high-sensitivity search for the strangeness S=-2 H dibaryon (uuddss) was conducted at the Brookhaven Alternating Gradient Synchrotron (AGS) using the reaction {sup 3}He(K{sup -},K{sup +})Hn at P{sub K{sup -}}=1.8GeV/ c. The sensitivity was independent of H lifetime and decay modes. No evidence for H production was observed. In a mass range extending from about 50 to 380MeV/c{sup 2} below the {Lambda}{Lambda} threshold of 2.231GeV/c{sup 2}, the resulting upper limits on the H-production cross section are in the range of 0.058 to 0.021{mu}b/sr, approximately 1 order of magnitude below a theoretical calculation. {copyright} {ital 1997} {ital The American Physical Society}
  • We have studied ({ital K}{sup {minus}},{ital K}{sup +}) reactions from an emulsion target. The {ital S}={minus}2 {ital H} dibaryon has been searched for by the analysis of the {ital K}{sup +} momentum spectrum together with emulsion data. No evidence of {ital H} production was observed in the mass range of 1.90--2.16 GeV/{ital c}{sup 2}. Upper limits for the production cross section of the {ital H} are (0.2--0.6)% of that for the quasifree {Xi}{sup {minus}} production at the 90% confidence level.
  • Measurement of the energy of neutrons in coincidence with the production of free {xi}{sup -} hyperons can be used to determine the masses of {sub {lambda}}{sub {lambda}}{sup 12}B hypernuclear states and branching ratios of their formation from ({xi}{sup -},{sup 12}C){sub atom}{yields}{sub {lambda}}{sub {lambda}}{sup 12}B+n. The E885 Collaboration utilized the Alternating Gradient Synchrotron 1.8 GeV/c K{sup -} beam incident on a diamond target to accumulate the largest-to-date data sample of (K{sup -},K{sup +}) events. A total of about 3x10{sup 5} (K{sup -},K{sup +}) events have been collected and analyzed. The neutron spectrum shows no apparent peaks from the neutron-emission channel ofmore » double-{lambda} hypernuclear formation from ({xi}{sup -},{sup 12}C){sub atom} decay. The upper limit on the branching ratio of the above process has been set to be at or below 4% in the region of expected neutron energies. (c) 2000 The American Physical Society.« less
  • The angular dependence of the tensor A{sub yy} and vector A{sub y} analyzing powers in the inelastic scattering of deuterons with a momentum of 9.0 GeV/c on hydrogen and carbon has been measured. The range of measurements corresponds to the baryonic resonance excitation with masses of {approx}2.2-2.6 GeV/c{sup 2}. The A{sub yy} data, being in good agreement with the previous results, demonstrate an approximate t scaling up to -1.5 (GeV/c){sup 2}. The large values of A{sub y} show a significant role of the spin-dependent part of the elementary amplitude of the NN {sup {yields}} NN* reaction. The results of themore » experiment are compared with model predictions of the plane-wave impulse approximation.« less