کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10724413 | 1033988 | 2009 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Power corrections to αs(MÏ), |Vus| and m¯s
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک هسته ای و انرژی بالا
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چکیده انگلیسی
We re-examine recent determinations of power corrections from Ï-decay and confront the results with the existing ones from QCD spectral sum rules (QSSR). We conclude that contrary to the QSSR analysis, which lead to ãαsG2ã=(6.8±1.3)10â2GeV4, Ï-decay is not a good place for extracting the gluon condensate due to its extra αs2 coefficient which suppresses its contribution in this process. Results from e+eâ sum rules and Ï-decay: Ïαsãu¯uã2=(4.5±0.3)10â4GeV6, where Ï=3.0±0.2 confirm the deviation from the vacuum saturation estimate of the four-quark condensate. “Non-standard” power corrections (direct instantons, duality violation and tachyonic gluon mass) beyond the SVZ-expansion, partially cancel out in the V+A hadronic Ï-decay channel, which gives at order αs4: αs(MÏ)=0.3249(29)ex(75)th leading to αs(MZ)|Ï=0.1192(4)ex(9)th, in remarkable agreement with (but more accurate than) αs(MZ)|Z=0.1191(27) obtained at the same αs4 order from the Z-width and the global fit of electroweak data. Finally, the rôle of the tachyonic gluon mass in the determinations of |Vus| from Ï-decay and of m¯s from Ï decay, e+eâ and (pseudo)scalar channels is emphasized.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics Letters B - Volume 673, Issue 1, 9 March 2009, Pages 30-36
Journal: Physics Letters B - Volume 673, Issue 1, 9 March 2009, Pages 30-36
نویسندگان
Stephan Narison,