اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدA comparative measurement of $phirightarrow K^+K^-$ and $phirightarrow mu^+mu^-$ in In-In collisions at the CERN SPS
57
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The NA60 experiment at the CERN SPS has studied $phi$ meson production in In-In collisions at 158A GeV via both the $K^+K^-$ and the $mu^+mu^-$ decay channels. The yields and inverse slope parameters of the $m_T$ spectra observed in the two channels are compatible within errors, different from the large discrepancies seen in Pb-Pb collisions between the hadronic (NA49) and dimuon (NA50) decay channels. Possible physics implications are discussed.
قيم البحث
اقرأ أيضاً
The first measurements of the forward-backward asymmetry of the dimuon pair ($A_{FB}$), the triple-product asymmetry ($A_{2phi}$), and the charge-parity-conjugation asymmetry ($A_{CP}$), in $D^0topi^+pi^-mu^+mu^-$ and $D^0to K^+K^-mu^+mu^-$ decays ar
e reported. They are performed using data from proton-proton collisions collected with the LHCb experiment from 2011 to 2016, corresponding to a total integrated luminosity of 5 fb$^{-1}$. The asymmetries are measured to be begin{align*} A_{FB}(D^0topi^+pi^-mu^+mu^-) &= (phantom{-}3.3pm3.7pm0.6)%, A_{2phi}(D^0topi^+pi^-mu^+mu^-)&= (-0.6pm3.7pm0.6)%, A_{CP}(D^0topi^+pi^-mu^+mu^-) &= (phantom{-}4.9pm3.8pm0.7)%, A_{FB}(D^0to K^+K^-mu^+mu^-) &= (0pm11pm2)%, A_{2phi}(D^0to K^+K^-mu^+mu^-)&= (9pm11pm1)%, A_{CP}(D^0to K^+K^-mu^+mu^-) &= (0pm11pm2)%, end{align*} where the first uncertainty is statistical and the second systematic. The asymmetries are also measured as a function of the dimuon invariant mass. The results are consistent with the Standard Model predictions.
The direct $C!P$ asymmetries of the decays $B^0 rightarrow K^{*0} mu^+ mu^-$ and $B^+ rightarrow K^{+} mu^+ mu^-$ are measured using $pp$ collision data corresponding to an integrated luminosity of 3.0$mbox{fb}^{-1}$ collected with the LHCb detector.
The respective control modes $B^0 rightarrow J/psi K^{*0}$ and $B^+ rightarrow J/psi K^{+}$ are used to account for detection and production asymmetries. The measurements are made in several intervals of $mu^+ mu^-$ invariant mass squared, with the $phi(1020)$ and charmonium resonance regions excluded. Under the hypothesis of zero $C!P$ asymmetry in the control modes, the average values of the asymmetries are begin{align} {cal A}_{C!P}(B^0 rightarrow K^{*0} mu^+ mu^-) &= -0.035 pm 0.024 pm 0.003, cr {cal A}_{C!P}(B^+ rightarrow K^{+} mu^+ mu^-) &= phantom{-}0.012 pm 0.017 pm 0.001, end{align} where the first uncertainties are statistical and the second are due to systematic effects. Both measurements are consistent with the Standard Model prediction of small $C!P$ asymmetry in these decays.
A measurement of the CP asymmetry in B0 -> K*0 mu+ mu- decays is presented, based on 1.0fb-1 of pp collision data recorded by the LHCb experiment during 2011. The measurement is performed in six bins of invariant mass squared of the mu+ mu- pair, exc
luding the J/psi and psi(2S) resonance regions. Production and detection asymmetries are removed using the B0 -> J/Psi K*0 decay as a control mode. The integrated CP asymmetry is found to be -0.072 +- 0.040 (stat.) +- 0.005 (syst.), consistent with the Standard Model.
A measurement of the $CP$ asymmetry in $B^+ rightarrow K^+ mu^+ mu^-$ decays is presented using $pp$ collision data, corresponding to an integrated luminosity of 1.0${,fb}^{-1}$, recorded by the LHCb experiment during 2011 at a centre-of-mass energy
of 7 TeV. The measurement is performed in seven bins of $mu^+ mu^-$ invariant mass squared in the range ${0.05<q^{2}<22.00{mathrm{GeV^2/}c^4}}$, excluding the ${J/psi}$ and $psi{(2S)}$ resonance regions. Production and detection asymmetries are corrected for using the $B^+ rightarrow J/psi K^+$ decay as a control mode. Averaged over all the bins, the $CP$ asymmetry is found to be ${{cal A}_{CP} = 0.000pm 0.033{(stat.)} pm0.005 {(syst.)} pm 0.007{}(J/psi K^+)}$, where the third uncertainty is due to the $CP$ asymmetry of the control mode. This is consistent with the Standard Model prediction.
The isospin asymmetries of $B to K^{(*)}mu^+mu^-$ decays and the partial branching fractions of $B^0 to K^0mu^+mu^-$ and $B^+ to K^{*+}mu^+mu^-$ are measured as a function of the di-muon mass squared $q^2$ using an integrated luminosity of 1.0 fb$^{-
1}$ collected with the LHCb detector. The $B to Kmu^+mu^-$ isospin asymmetry integrated over $q^2$ is negative, deviating from zero with over 4 $sigma$ significance. The $B to K^{*}mu^+mu^-$ decay measurements are consistent with the Standard Model prediction of negligible isospin asymmetry. The observation of the decay $B^0 to K^0_{rmscriptscriptstyle S}mu^+mu^-$ is reported with 5.7 $sigma$ significance. Assuming that the branching fraction of $B^0 to K^0mu^+mu^-$ is twice that of $B^0 to K^0_{rmscriptscriptstyle S}mu^+mu^-$, the branching fractions of $B^0 to K^0mu^+mu^-$ and $B to K^{*+}mu^+mu^-$ are found to be ($0.31^{+0.07}_{-0.06}) times 10^{-6}$ and ($1.16pm0.19) times 10^{-6}$, respectively.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
