Branching ratio and CP asymmetry of B→πη<sup>(′)sup> decays in the perturbative QCD approach
- 作者：Huisheng Wang ; Xin Liu ; Zhenjun Xiao ; Libo Guoand Cai-Dian Lü
- 刊名：Nuclear Physics B
- 出版年：2006
- 期刊代码：45_05503213
- 类别：ph
- 出版时间：20 March 2006
- 卷：738
- 期：1-2
- 页码：243-268
- 文件大小：356 K
摘要
We calculate the branching ratios and CP-violating asymmetries for l28">style="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TVC-4J554PH-1&_mathId=mml28&_user=10&_cdi=5531&_rdoc=10&_handle=V-WA-A-W-AV-MsSAYVW-UUA-U-AAVCBVUVCY-AAVWEWAWCY-DBCWAUDCY-AV-U&_acct=C000050221&_version=1&_userid=10&md5=af4596acd9c47106556d7aeea3f15bfd" title="Click to view the MathML source">B<sup>0sup>→π<sup>0sup>η<sup>(′)sup> and l29">style="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TVC-4J554PH-1&_mathId=mml29&_user=10&_cdi=5531&_rdoc=10&_handle=V-WA-A-W-AV-MsSAYVW-UUA-U-AAVCBVUVCY-AAVWEWAWCY-DBCWAUDCY-AV-U&_acct=C000050221&_version=1&_userid=10&md5=9eaffc966d241868090521c3abc7b9b2" title="Click to view the MathML source">B<sup>+sup>→π<sup>+sup>η<sup>(′)sup> decays in the perturbative QCD (pQCD) factorization approach here. We not only calculate the usual factorizable contributions, but also evaluate the non-factorizable and annihilation type contributions. Besides the current–current operators, the contributions from the QCD and electroweak penguin operators are also taken into account. The pQCD results for the CP-averaged branching ratios are l30">style="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TVC-4J554PH-1&_mathId=mml30&_user=10&_cdi=5531&_rdoc=10&_handle=V-WA-A-W-AV-MsSAYVW-UUA-U-AAVCBVUVCY-AAVWEWAWCY-DBCWAUDCY-AV-U&_acct=C000050221&_version=1&_userid=10&md5=5eded847aee726dee640b6f2e1df5597" title="Click to view the MathML source">Br(B<sup>+sup>→π<sup>+sup>η)≈4.1×10<sup>−6sup>, l31">style="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TVC-4J554PH-1&_mathId=mml31&_user=10&_cdi=5531&_rdoc=10&_handle=V-WA-A-W-AV-MsSAYVW-UUA-U-AAVCBVUVCY-AAVWEWAWCY-DBCWAUDCY-AV-U&_acct=C000050221&_version=1&_userid=10&md5=749cc18704a593c6a37fbbd48f346611" title="Click to view the MathML source">Br(B<sup>+sup>→π<sup>+sup>η<sup>′sup>)≈2.4×10<sup>−6sup>, and l32">style="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TVC-4J554PH-1&_mathId=mml32&_user=10&_cdi=5531&_rdoc=10&_handle=V-WA-A-W-AV-MsSAYVW-UUA-U-AAVCBVUVCY-AAVWEWAWCY-DBCWAUDCY-AV-U&_acct=C000050221&_version=1&_userid=10&md5=aa6b60231f9f196691ad5fcd37eb8a61" title="Click to view the MathML source">Br(B<sup>0sup>→π<sup>0sup>η<sup>(′)sup>)≈0.2×10<sup>−6sup>, which agree very well with the measured values or currently available experimental upper limits. We also predict large CP-violating asymmetries in these decays: l33">, and l34">, but with large errors. The pQCD prediction for l35"> (l36">) has the same (opposite) sign with the primary measured values. Further improvements in both theory and experiments are needed to clarify this discrepancy.