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Charm Effects in the MS Bottom Quark Mass from Υ Mesons
| Content Provider | Semantic Scholar |
|---|---|
| Author | Hoang, André H. Manohar, Aneesh V. |
| Copyright Year | 1999 |
| Abstract | We study the shift in the Υ mass due to a non-zero charm quark mass. This shift affects the value of the MS b-quark mass extracted from the Υ system by about −20 MeV, due to an incomplete cancellation of terms that are nonanalytic in the charm quark mass. The precise size of the shift depends on unknown higher order corrections, and might have a considerable uncertainty if they are large. Typeset using REVTEX 1 The bottom quark mass is an important parameter for the theoretical description of B meson decays and b jet production cross sections in collider experiments. In continuum QCD, the most precise determinations of the bottom quark mass parameter have been obtained from data on the spectrum and the electronic partial widths of the Υ mesons. Recently, a number of MS bottom quark determinations have been carried out, which were based on Υ meson sum rules at next-to-next-to-leading order (NNLO) in the non-relativistic expansion, and which consistently eliminated all linear sensitivity to small momenta [1– 3]. The latter is mandatory to reduce the systematic uncertainty in the bottom quark mass below the typical hadronization scale ΛQCD [4, 5]. The analyses mentioned above, however, treated all quarks other than the b quark as massless. This treatment is justified for light quarks that have masses much smaller than the inverse Bohr radius 1/〈r〉 of the non-relativistic bottom–antibottom system i.e. for up, down and strange quarks, because in this case the theoretical expressions describing the bottom–antibottom dynamics and the conversion to the MS bottom mass definition can be expanded in the light quark masses. Like the contributions that are linearly sensitive to small momenta, the terms linear (and non-analytic) in these light quark masses cancel out in the analysis. At NLO in the nonrelativistic expansion this can be seen explicitly by considering the effects of a light virtual quark to the static energy of a bottom–antibottom quark pair with spatial distance r, Estat = 2Mb + Vstat(r) , (1) where Mb is the bottom quark pole mass and Vstat the potential energy of the non-relativistic bottom–antibottom quark system. At order α s the correction coming from the finite mass of a light quark q to the pole mass contribution reads [6] δM q b = 4 3 α s π2 Mb ∆ (mq Mb ) , (2) ∆(r) = π 8 r − 3 4 r + π 8 r − ( 4 ln r − 13 24 ln r + π 24 + 151 288 ) r − ∞ |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://arxiv.org/pdf/hep-ph/9911461v1.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Adjudication Arabic numeral 0 Cross section (geometry) Experiment Extraction Lattice QCD Mandatory - HL7DefinedRoseProperty Mesons Partial Population Parameter Reading (activity) Rule (guideline) Small Triune continuum paradigm |
| Content Type | Text |
| Resource Type | Article |
