标题： 在HERA-B中搜索Theta^+和Xi^{--}_{3/2}五夸克 显示英文标题

标题： Search for Theta^+ and Xi^{--}_{3/2} pentaquarks in HERA-B

摘要： 在sqrt(s) = 41.6 GeV下，对质子诱导反应在C、Ti和W靶中产生的Theta^+(1540)和Xi^{--}_{3/2}(1862)五夸克候选粒子进行了搜索，研究了pK_s、Xi^-pi^-和Xi^-pi^+（以及电荷共轭）的衰变通道，在中间快速度范围内进行。 灵敏度为(Br)x(dsigma/dx_F) < 5至25微靶/核子，我们在任何研究的末态中都没有发现窄五夸克峰的证据。 初步值为在中间快速度范围内的相对产率比上限为(Theta^+(1540)) / (Lambda(1520)) < 0.02，(Br)x(Xi^{--}_{3/2}(1862)) / (Xi(1530)^0) < 0.077，以及(Br)x(Xi_bar^{++}_{3/2}(1862)) / (Xi_bar(1530)^0) < 0.058，在95%置信水平下。 显示英文摘要

摘要： A search for Theta^+(1540) and Xi^{--}_{3/2}(1862) pentaquark candidates has been performed in proton-induced reactions on C, Ti and W targets at sqrt(s) = 41.6 GeV studying the pK_s resp. Xi^-pi^- and Xi^-pi^+ (and charge conjugated) decay channels at mid-rapidity. With sensitivities of (Br)x(dsigma/dx_F) < 5 to 25 microbarn/nucleon, we find no evidence for narrow pentaquark peaks in any of the studied final states. Preliminary values for the upper limit of relative yield ratios at mid-rapidity are (Theta^+(1540)) / (Lambda(1520)) < 0.02, (Br)x(Xi^{--}_{3/2}(1862)) / (Xi(1530)^0) < 0.077, and (Br)x(Xi_bar^{++}_{3/2}(1862)) / (Xi_bar(1530)^0) < 0.058 at 95% CL.