اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSearch for the lepton-flavour violating decays $B^0_s rightarrow e^{pm}mu^{mp}$ and $B^0 rightarrow e^{pm} mu^{mp}$
187
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
A search for the lepton-flavour violating decays $B^0_s to e^{pm} mu^{mp}$ and $B^0 to e^{pm} mu^{mp}$ is performed with a data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$ of $pp$ collisions at $sqrt{s} = 7$ TeV, collected by the LHCb experiment. The observed number of $B^0_s to e^{pm} mu^{mp}$ and $B^0 to e^{pm} mu^{mp}$ candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be $BR(B^0_s to e^{pm} mu^{mp}) < 1.1 ,(1.4) times 10^{-8}$ and $BR (B^0 to e^{pm} mu^{mp}) < 2.8 ,(3.7) times 10^{-9}$ at 90% (95%) confidence level (C.L.). These limits are a factor of twenty lower than those set by previous experiments. Lower bounds on the Pati-Salam leptoquark masses are also calculated, $M_{rm LQ} (B^0_s to e^{pm} mu^{mp}) > 107$ TeV/c$^2$ and $M_{rm LQ} (B^0 to e^{pm} mu^{mp}) > 126$ TeV/c$^2$ at 95% C.L., and are a factor of two higher than the previous bounds.
قيم البحث
اقرأ أيضاً
A search for the lepton-flavour violating decays $B^0_s rightarrow e^pm mu^mp$ and $B^0 rightarrow e^pm mu^mp$ is performed based on a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb$^{-1}$, collected with the
LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yields are consistent with the background-only hypothesis. Upper limits on the branching fractions are determined to be $mathcal{B}(B^0_s rightarrow e^pm mu^mp) < 5.4,(6.3) times 10^{-9}$ and $mathcal{B}(B^0 rightarrow e^pm mu^mp) < 1.0,(1.3) times 10^{-9}$ at $90%,(95%)$ confidence level, which are the strongest limits on these decays to date.
A search for $B^{0}_{s}totau^{pm}mu^{mp}$ and $B^{0}totau^{pm}mu^{mp}$ decays is performed using data corresponding to an integrated luminosity of 3 fb$^{-1}$ of proton-proton collisions, recorded with the LHCb detector in 2011 and 2012. For this sea
rch, the $tau$ lepton is reconstructed in the $tau^{-}topi^{-}pi^{+}pi^{-} u_{tau}$ channel. No significant signal is observed. Assuming no contribution from $B^{0}totau^{pm}mu^{mp}$ decays, an upper limit is set on the $B^{0}_{s}totau^{pm}mu^{mp}$ branching fraction of $mathcal{B}left( B^{0}_{s}totau^{pm}mu^{mp}right) < 4.2times 10^{-5}$ at $95%$ confidence level. If instead no contribution from $B^{0}_{s}totau^{pm}mu^{mp}$ decays is assumed, a limit of $mathcal{B}left( B^{0}totau^{pm}mu^{mp}right) < 1.4times 10^{-5}$ is obtained at $95%$ confidence level. These are the first limit on $mathcal{B}left( B^{0}_{s}totau^{pm}mu^{mp}right)$ and the worlds best limit on $mathcal{B}left( B^{0}totau^{pm}mu^{mp}right)$.
We present a search for seven lepton-flavor-violating neutral charm decays of the type $D^{0}rightarrow X^{0} e^{pm} mu^{mp}$, where $X^{0}$ represents a $pi^{0}$, $K^{0}_{rm S}$, $bar{K^{*0}}$, $rho^{0}$, $phi$, $omega$, or $eta$ meson. The analysis
is based on $468$ fb$^{-1}$ of $e^+e^-$ annihilation data collected at or close to the $Upsilon(4S)$ resonance with the BaBar detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90% confidence level upper limits on the branching fractions in the range $(5.0 - 22.5)times 10^{-7}$. The limits are between one and two orders of magnitude more stringent than previous measurements.
A search for the lepton-flavour violating decays $B^+ to K^+ {mu}^{pm} e^{mp}$ is performed using a sample of proton-proton collision data, collected with the LHCb experiment at centre-of-mass energies of $7$ and $8~{rm TeV}$ and corresponding to an
integrated luminosity of 3$rm~fb^{-1}$. No significant signal is observed, and upper limits on the branching fractions are set as $mathcal{B}(B^+ to K^+ {mu}^- e^+) < 7.0~(9.5) times 10^{-9}$ and $mathcal{B}(B^+ to K^+ {mu}^+ e^-) < 6.4~(8.8) times 10^{-9}$ at 90 (95) % confidence level. The results improve the current best limits on these decays by more than one order of magnitude.
We have searched for the lepton-flavor-violating decay $B^{0}to K^{ast 0} mu^{pm} e^{mp}$ using a data sample of 711 $fb^{-1}$ that contains $772 times 10^{6}$ $Bbar{B}$ pairs. The data were collected near the $Upsilon (4S)$ resonance with the Belle
detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. No signals were observed, and we set 90% confidence level upper limits on the branching fractions of ${cal B}(B^{0}to K^{ast 0} mu^{+} e^{-})< 1.2times 10^{-7}$, ${cal B}(B^{0}to K^{ast 0} mu^{-} e^{+})< 1.6times 10^{-7}$, and, for both decays combined, ${cal B}(B^{0}to K^{ast 0} mu^{pm} e^{mp}) < 1.8times 10^{-7}$. These are the most stringent limits on these decays to date.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
