ترغب بنشر مسار تعليمي؟ اضغط هنا

A Search for Nucleon Decay via $n rightarrow bar{ u} pi^{0}$ and $p rightarrow bar{ u} pi^{+}$ in Super-Kamiokande

293   0   0.0 ( 0 )
 نشر من قبل Jennifer Raaf
 تاريخ النشر 2013
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We present the results of searches for nucleon decay via bound neutron to antineutrino plus pizero and proton to antineutrino plus piplus using data from a combined 172.8 kiloton-years exposure of Super-Kamiokande-I, -II, and -III. We set lower limits on the partial lifetime for each of these modes. For antineutrino pizero, the partial lifetime is >1.1x10^{33} years; for antineutrino piplus, the partial lifetime is >3.9x10^{32} years at 90% confidence level.



قيم البحث

اقرأ أيضاً

184 - V. Takhistov , K. Abe , Y. Haga 2014
The trilepton nucleon decay modes $p rightarrow e^+ u u$ and $p rightarrow mu^+ u u$ violate $|Delta (B - L)|$ by two units. Using data from a 273.4 kiloton year exposure of Super-Kamiokande a search for these decays yields a fit consistent with no signal. Accordingly, lower limits on the partial lifetimes of $tau_{p rightarrow e^+ u u} > 1.7 times 10^{32}$ years and $tau_{p rightarrow mu^+ u u} > 2.2 times 10^{32}$ years at a $90 % $ confidence level are obtained. These limits can constrain Grand Unified Theories which allow for such processes.
We have searched for proton decay via $p rightarrow u K^{+}$ using Super-Kamiokande data from April 1996 to February 2013, 260 kiloton$cdot$year exposure in total. No evidence for this proton decay mode is found. A lower limit of the proton lifetime is set to $5.9 times 10^{33}$ years at 90% confidence level.
69 - E787 Collaboration 2004
We report the results of a search for the decay $K^+ to pi^+ u bar u$ in the kinematic region with $pi^+$ momentum $140 < P < 195$ MeV/c using the data collected by the E787 experiment at BNL. No events were observed. When combined with our previou s search in this region, one candidate event with an expected background of $1.22 pm 0.24$ events results in a 90% C.L. upper limit of $2.2 times 10^{-9}$ on the branching ratio of $K^+ to pi^+ u bar u$. We also report improved limits on the rates of $K^+ to pi^+ X^0$ and $K^+ to pi^+ X^1 X^2$ where $X^0, X^1, X^2$ are hypothetical, massless, long-lived neutral particles.
We report a measurement of ratio ${cal R}(D^*) = {cal B}(bar{B}^0 rightarrow D^{*+} tau^- bar{ u}_{tau})/{cal B}(bar{B}^0 rightarrow D^{*+} ell^- bar{ u}_{ell})$, where $ell$ denotes an electron or a muon. The results are based on a data sample conta ining $772times10^6$ $Bbar{B}$ pairs recorded at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+ e^-$ collider. We select a sample of $B^0 bar{B}^0$ pairs by reconstructing both $B$ mesons in semileptonic decays to $D^{*mp} ell^{pm}$. We measure ${cal R}(D^*)= 0.302 pm 0.030({rm stat)} pm 0.011({rm syst)}$, which is within $1.6 sigma$ of the Standard Model theoretical expectation, where $sigma$ is the standard deviation including systematic uncertainties.
375 - Y. Sato , T. Iijima , K. Adamczyk 2016
We report a measurement of the ratio ${cal R}(D^*) = {cal B}(bar{B}^0 rightarrow D^{*+} tau^- bar{ u}_{tau})/{cal B}(bar{B}^0 rightarrow D^{*+} ell^- bar{ u}_{ell})$, where $ell$ denotes an electron or a muon. The results are based on a data sample c ontaining $772times10^6$ $Bbar{B}$ pairs recorded at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+ e^-$ collider. We select a sample of $B^0 bar{B}^0$ pairs by reconstructing both $B$ mesons in semileptonic decays to $D^{*mp} ell^{pm}$. We measure ${cal R}(D^*)= 0.302 pm 0.030({rm stat)} pm 0.011({rm syst)}$, which is within $1.6 sigma$ of the Standard Model theoretical expectation, where the standard deviation $sigma$ includes systematic uncertainties. We use this measurement to constrain several scenarios of new physics in a model-independent approach.
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