Search for double-Lambda hypernuclei and the H-dibaryon in the (K-, K+) reaction on C-12

Yamamoto, K Alburger, DE Barnes, PD Bassalleck, B Berdoz, AR Biglan, A Burger, T Carman, DS Chrien, RE Davis, CA Fischer, H Franklin, GB Franz, J Gan, L Ichikawa, A Iijima, T Imai, K Khaustov, P Kondo, Y Koran, P Landry, M Lee, L Lowe, J Magahiz, R May, M McCrady, R Merrill, F Meyer, CA Page, SA Paschke, K Pile, PH Quinn, BP Ramsay, WD Rusek, A Sawafta, R Schmitt, H Schumacher, RA Stotzer, RW Sutter, R Takeutchi, F van Oers, WTH Yosoi, M Zeps, VJ

K. Yamamoto et al., Search for double-Lambda hypernuclei and the H-dibaryon in the (K-, K+) reaction on C-12, PHYS LETT B, 478(4), 2000, pp. 401-407

29

INGLESE

Article

Physics

PHYSICS LETTERS B

0370-2693 → ACNP

478

4

2000

401 - 407

ISI

0370-2693(20000413)478:4<401:SFDHAT>2.0.ZU;2-9

A search for double-Lambda hypernuclei (Be-12(Lambda Lambda)) and H-dibaryo ns using the C-12(K-,K+) reaction was perlormeu at the BNL-AGS using a high -intensity 1.8 GeV/c K- beam. A missing-mass analysis below the end point o f the quasi-free Xi(-) was used to investigate these S = -2 systems, The up per limit obtained for the forward-angle cross section of (12)(Lambda Lambd a) Be production is 6 to 10 nb/sr. This is the first search for the direct production of double-Lambda hypernuclei to reach the sensitivity required t o observe the signal predicted by theoretical calculations. For the H-produ ction cross section, we have obtained an upper limit in the range of a few nb/sr to 10 nb/sr for the H mass below 2100 MeV/c(2.) This upper limit is t he most sensitive H search result to date for a tightly bound H. (C) 2000 P ublished by Elsevier Science B.V. All rights reserved.