Nuclear-Matter Modification of Decay Widths in the {phi}{yields}e{sup +}e{sup -} and {phi}{yields}K{sup +}K{sup -} Channels
- Department of Physics, Kyoto University, Kitashirakawa Sakyo-ku, Kyoto 606-8502 (Japan)
- Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)
- RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
The invariant mass spectra of {phi}{yields}K{sup +}K{sup -} are measured in 12 GeV p+A reactions in order to search for the in-medium modification of {phi} mesons. The observed K{sup +}K{sup -} spectra are well reproduced by the relativistic Breit-Wigner function with a combinatorial background shape in three {beta}{gamma} regions between 1.0 and 3.5. The nuclear mass number dependence of the yields of the K{sup +}K{sup -} decay channel is compared to the simultaneously measured e{sup +}e{sup -} decay channel for carbon and copper targets. We parameterize the production yields as {sigma}(A)={sigma}{sub 0}A{sup {alpha}} and obtain {alpha}{sub {phi}}{sub {yields}}{sub K{sup +}}{sub K{sup -}}-{alpha}{sub {phi}}{sub {yields}}{sub e{sup +}}{sub e{sup -}} to be 0.14{+-}0.12. Limits are obtained for the partial decay widths of the {phi} mesons in nuclear matter.
- OSTI ID:
- 20951232
- Journal Information:
- Physical Review Letters, Vol. 98, Issue 15; Other Information: DOI: 10.1103/PhysRevLett.98.152302; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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