Heavy quark spectroscopy and matrix elements: A lattice study using the static approximation

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.54.3526· OSTI ID:383404

Ewing, A K; Flynn, J M; Sachrajda, C T; Stella, N; Wittig, H ^[1]; Bowler, K C; Kenway, R D; Mehegan, J; Richards, D G ^[2]; Michael, C ^[3]

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1. Physics Department, The University, Southampton SO17 1BJ (United Kingdom)
2. Department of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ (Scotland)
3. DAMTP, University of Liverpool, Liverpool L69 3BX, United Kingdom (UKQCD Collaboration)

We present results of a lattice analysis of the {ital B} parameter {ital B}{sub {ital B}}, the decay constant {ital f}{sub {ital B}}, and several mass splittings using the static approximation. Results were obtained for 60 quenched gauge configurations computed at {beta}=6.2 on a lattice size of 24{sup 3}{times}48. Light quark propagators were calculated using the {ital O}({ital a})-improved Sheikholeslami-Wohlert action. We find {ital B}{sub {ital B}}{sup static}({ital m}{sub {ital b}})=0.69{sub {minus}4}{sup +3}(stat){sub {minus}1}{sup +2} (syst), corresponding to {ital B}{sub {ital B}}{sup static}=1.02{sub {minus}6 {minus}2}{sup +5 +3}, {ital f}{sub {ital B}}{sup static}=266{sub {minus}20 {minus}27}{sup +18 +28} MeV, and {ital f}{sub {ital B}}{sub {ital s}}{sup 2}{ital B}{sub {ital B}}{sub {ital s}}/{ital f}{sub {ital B}}{ital i}{sup 2}{ital B}{sub {ital B}}=1.34{sub {minus}8 {minus}3}{sup +9 +5}, where a variational fitting technique was used to extract {ital f}{sup 2}{sub {ital B{sub s}}}{ital B}{sub {ital B{sub {ital s}}}}{sub B{sup static}}. For the mass splittings we obtain {ital M}{sub {ital B{sub {ital s}}}}{minus}{ital M}{sub {ital B{sub {ital d}}}}=87{sub {minus}12 {minus}12}{sup +15 +6} MeV, {ital M}{sub {Lambda}{sub {ital b}}}{minus}{ital M}{sub {ital B}}{sub {ital d}}=420{sub {minus}90 {minus}30}{sup +100 +30} MeV, and {ital M}{sub {ital B}{asterisk}}{sup 2}{minus}{ital M}{sup 2}{sub {ital B}}=0.281{sub {minus}16 {minus}37}{sup +15 +40} GeV{sup 2}. We compare different smearing techniques intended to improve the signal/noise ratio. From a detailed assessment of systematic effects, we conclude that the main systematic uncertainties are associated with the renormalization constants relating a lattice matrix element to its continuum counterpart. The dependence of our findings on lattice artifacts is to be investigated in the future. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 383404
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 5 Vol. 54; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
B MESONS
B QUARKS
BEAUTY BARYONS
LATTICE FIELD THEORY
MASS
MATRIX ELEMENTS
RENORMALIZATION
SPECTROSCOPY