Department

Physics

Document Type

Article

Publication Date

3-2018

Embargo Period

7-3-2018

Abstract

We report the first observation of the Ξc(2930)0" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Ξc(2930)0Ξc(2930)0 charmed-strange baryon with a significance greater than 5σ" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">σσ. The Ξc(2930)0" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Ξc(2930)0Ξc(2930)0 is found in its decay to K−Λc+" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">K−Λ+cK−Λc+ in B−→K−Λc+Λ¯c−" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">B−→K−Λ+cΛ¯−cB−→K−Λc+Λ¯c− decays. The measured mass and width are [2928.9±3.0(stat.)−12.0+0.9(syst.)]" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">[2928.9±3.0(stat.)+0.9−12.0(syst.)][2928.9±3.0(stat.)−12.0+0.9(syst.)] MeV/c2" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">c2c2 and [19.5±8.4(stat.)−7.9+5.9(syst.)]" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">[19.5±8.4(stat.)+5.9−7.9(syst.)][19.5±8.4(stat.)−7.9+5.9(syst.)] MeV, respectively, and the product branching fraction is B(B−→Ξc(2930)0Λ¯c−)B(Ξc(2930)0→K−Λc+)=[1.73±0.45(stat.)±0.21(syst.)]×10−4" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">(B−→Ξc(2930)0Λ¯−c)(Ξc(2930)0→K−Λ+c)=[1.73±0.45(stat.)±0.21(syst.)]×10−4B(B−→Ξc(2930)0Λ¯c−)B(Ξc(2930)0→K−Λc+)=[1.73±0.45(stat.)±0.21(syst.)]×10−4. We also measure B(B−→K−Λc+Λ¯c−)=[4.80±0.43(stat.)±0.60(syst.)]×10−4" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">(B−→K−Λ+cΛ¯−c)=[4.80±0.43(stat.)±0.60(syst.)]×10−4B(B−→K−Λc+Λ¯c−)=[4.80±0.43(stat.)±0.60(syst.)]×10−4 with improved precision, and search for the charmonium-like state Y(4660) and its spin partner, Yη" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">YηYη, in the Λc+Λ¯c−" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Λ+cΛ¯−cΛc+Λ¯c− invariant mass spectrum. No clear signals of the Y(4660) nor its spin partner are observed and the 90% credibility level (C.L.) upper limits on their production rates are determined. These measurements are obtained from a sample of (772±11)×106BB¯" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">(772±11)×106BB¯(772±11)×106BB¯ pairs collected at the Υ(4S)" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Υ(4S)Υ(4S) resonance by the Belle detector at the KEKB asymmetric energy electron–positron collider.

Journal

European Physical Journal C

Journal ISSN

1434-6044

Volume

28

First Page

251

Digital Object Identifier (DOI)

10.1140/epjc/s10052-018-5720-5

Comments

© The Author(s) 2018

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

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