ترغب بنشر مسار تعليمي؟ اضغط هنا

$|V_{ub}|$ determination by $B to D_s pi$

291   0   0.0 ( 0 )
 نشر من قبل Takeshi Kurimoto
 تاريخ النشر 2002
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We investigate $ovar{B^0} to D_s^- pi^+$ decay in perturbative QCD approach which has recently been applied to $B$ meson decays. $ovar{B^0} to D_s^- pi^+$ decay (and its charge conjugated mode) can be one of the hopeful modes to determine $|V_{ub}|$ since it occurs through $b to u$ transition only. We estimate both factorizable and non-factorizable contribution, and show that the non-factorizable contribution is much less than the factorizable one. Our calculation gives ${BR}(ovar{B^0} to D_s^- pi^+) = (50 sim 70) times f_{Ds}^2|{V_{ub}}{V_{cs}}|^2$.



قيم البحث

اقرأ أيضاً

The 2012 PDG reports a tension at the level of $3 sigma$ between two exclusive determinations of $|V_{ub}|$. They are obtained by combining the experimental branching ratios of $B to tau u$ and $B to pi l u$ (respectively) with a theoretical comput ation of the hadronic matrix elements $fB$ and the $B to pi$ form factor $f_+(q^2)$. To understand the tension, improved precision and a careful analysis of the systematics involved are necessary. We report the results of the ALPHA collaboration for $fB$ from the lattice with 2 flavors of $O(a)$ improved Wilson fermions. We employ HQET, including $1/m_b$ corrections, with pion masses ranging down to $approx$ 190 MeV. Renormalization and matching were performed non-perturbatively, and three lattice spacings reaching $a^{-1}approx 4.1$ GeV are used in the continuum extrapolation. We also present progress towards a computation of $f_+(q^2)$, to directly compare two independent exclusive determinations of $|V_{ub}|$ with each other and with inclusive determinations. Additionally, we report on preliminary results for $fBq{s}$, needed for the analysis of $B_s to mu^+mu^-$.}
We employ the $Btopi$ form factors obtained from QCD light-cone sum rules and calculate the $Bto pi ell u_l$ width ($ell=e,mu$) in units of $1/|V_{ub}|^2$, integrated over the region of accessible momentum transfers, $0leq q^2leq 12.0 ~GeV^2$. Using the most recent BABAR-collaboration measurements we extract $|V_{ub}|=(3.50^{+0.38}_{-0.33}big|_{th.}pm 0.11 big|_{exp.})times 10^{-3}$. The sum rule results for the form factors, taken as an input for a $z$-series parameterization, yield the $q^2$-shape in the whole semileptonic region of $Bto piell u_ell$. We also present the charged lepton energy spectrum in this decay. Furthermore, the current situation with $Bto tau u_tau$ is discussed from the QCD point of view. We suggest to use the ratio of the $Bto pi tau u_tau$ and $Bto piell u_l ~(ell =mu,e) $ widths as an additional test of Standard Model. The sensitivity of this observable to new physics is illustrated by including a charged Higgs-boson contribution in the semileptonic decay amplitude.
114 - W.Y. Wang , Y.L. Wu 2001
B --> rho l nu decay is analyzed in the effective theory of heavy quark with infinite mass limit. The matrix element relevant to the heavy to light vector meson semileptonic decays is parametrized by a set of four heavy flavor-spin independent univer sal wave functions at the leading order of effective theory. The form factors are calculated at the leading 1/m_Q order using the light cone sum rule method in the framework of effective theory. |V_{ub}| is then extracted via B --> rho l nu decay mode.
201 - H. Ha , E. Won , I. Adachi 2010
We present a measurement of the charmless semileptonic decay $B^0topi^-ell^+ u$ using a data sample containing 657$times 10^6$ $Bbar{B}$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider operating near the $Upsi lon(4S)$ resonance. We determine the total branching fraction of the decay, $mathcal{B}(B^0topi^-ell^+ u)=(1.49pm 0.04{(mathrm{stat})}pm 0.07{(mathrm{syst})})times 10^{-4}$. We also report a new precise measurement of the differential decay rate, and extract the Cabibbo-Kobayashi-Maskawa matrix element $|V_{ub}|$ using model-independent and -dependent approaches. From a simultaneous fit to the measured differential decay rate and lattice QCD results, we obtain $|V_{ub}|=(3.43pm 0.33)times 10^{-3}$, where the error includes both statistical and systematic uncertainties.
199 - W. Y. Wang , Y. L. Wu , M. Zhong 2005
In the heavy quark effective field theory of QCD, we analyze the order 1/m_Q contributions to heavy to light vector decays. Light cone sum rule method is applied with including the effects of 1/m_Q order corrections. We then extract |V_{ub}| from B -> rho l nu decay up to order of 1/m_Q corrections.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا