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Title: Evidence for a bottom baryon resonance $$\Lambda^{*)}_b$$ in CDF data

Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
Report Number(s):
arXiv eprint number arXiv:1309.6269
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: 2013 Meeting of the APS Division of Particles and Fields. Santa Cruz, California, USA, 13-17 Aug 2013.
Country of Publication:
United States

Citation Formats

Palni, Prabhakar. Evidence for a bottom baryon resonance $\Lambda^{*)}_b$ in CDF data. United States: N. p., 2013. Web.
Palni, Prabhakar. Evidence for a bottom baryon resonance $\Lambda^{*)}_b$ in CDF data. United States.
Palni, Prabhakar. Tue . "Evidence for a bottom baryon resonance $\Lambda^{*)}_b$ in CDF data". United States. doi:.
title = {Evidence for a bottom baryon resonance $\Lambda^{*)}_b$ in CDF data},
author = {Palni, Prabhakar},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Sep 24 00:00:00 EDT 2013},
month = {Tue Sep 24 00:00:00 EDT 2013}

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  • We present the latest results on the search for bottom baryon states {Sigma}{sub b} using {approx} 1 fb{sup -1} of CDF data. The study is performed with the world's largest sample of fully reconstructed {Lambda}{sub b}{sup 0} decays collected by CDF II detector at {radical}s = 1.96TeV in the hadronic trigger path. We observe 4 new states consistent with {Sigma}{sub b}{sup (*){+-}} bottom baryons.
  • The {Lambda}{sub b} baryon has been observed recently by UA1 through its decay {Lambda}{sub b} {yields} J/{psi}{Lambda}{degrees}. Although CDF finds twice as many J/{psi} and observes {Lambda}{degrees} decays, no evidence for an {Lambda}{sub b} signal is seen. The UA1 data supports a lower than expected production P{sub T} for the {Lambda}{sub b}, and therefore, a lower pion P{sub T}, below the observation threshold of CDF. This result suggests that UA1 and CDF are probably not inconsistent, but also that the production models are not quite right.
  • We have searched for new gauge bosons (W{prime}{yields} lv, Z{prime} {yields} ll) and b baryons ({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0}) in p{bar p} collisions at {radical}s = 1.8 TeV from the 1988--1989 run of the Collider Detector at Fermilab (CDF). We present 95% confidence level (C.L.) limits on the W{prime} and Z{prime} production cross section in leptonic decay modes. The nonobservation of these processes leads to limits of M{sub w{prime}} > 520 GeV/c{sub 2} and M{sub z{prime}} > 412 GeV/c{sub 2} (95% C.L.), assuming Standard Model coupling strengths. We see no evidence for the signal ({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0})more » in our {psi} sample ({psi} {yields} {mu}{mu}) around the {Lambda}{sub b} mass region of 5600 MeV. We set an upper limit on F({Lambda}{sub b})Br({Lambda}{sub b} {yields} {psi}{Lambda}{sup 0}) of 0.55 {times} 10{sup {minus}3} (90% C.L.), assuming that b baryons and mesons are produced in the fragmentation process in similar ways. The CDF Ai, search is also reported in the QCD session of this conference. This paper summarizes our result briefly; the details can be found in the other talk.« less