The decay Bs0 → η' Xss̄ is searched for at Belle, using Belle’s 121.4/fb integrated luminosity data sample, taken at Υ(5S) resonance. A semi-inclusive reconstruction method whereby the Xss̄ is ...reconstructed as a system of two kaons and up to four pions, with at most one neutral pion, is used. Using the η' sub-decay mode η'→ η (→ γγ ) π+ π− and examining the Xss̄ mass range M( Xss̄ ) ≤ 2.4 GeV/c2 , an upper limit at90% confidence level is set. This mode had been previously unstudied and this analysis partially hopes to motivate future theoretical studies as well as future analyses at the Belle II experiment.
The Time-Of-Propagation detector is a Cherenkov particle identification detector based on quartz radiator bars for the Belle II experiment at the SuperKEKB e+e−− collider. The purpose of the detector ...is to identify the type of charged hadrons produced in e+e−− collisions, and requires a single photon timing resolution below 100 picoseconds. A novel front-end electronic system was designed, built, and integrated to acquire data from the 8192 microchannel plate photomultiplier tube channels in the detector. Waveform sampling of these analog signals is done by switched-capacitor array application-specific integrated circuits. The processes of triggering, digitization of windows of interest, readout, and data transfer to the Belle II data acquisition system are managed by Xilinx Zynq-7000 programmable system on a chip devices.
The Time-Of-Propagation detector is a Cherenkov particle identification detector based on quartz radiator bars for the Belle II experiment at the SuperKEKB e+e- collider. The focus of the detector is ...to identify the type of charged hadrons produced in e+e- collisions, and requires a single photon timing resolution below 100 picoseconds. A novel front-end electronic system was created, built, and integrated to acquire data from the 8192 microchannel plate photomultiplier tube channels in the detector. Waveform sampling of these analog signals is done by switched-capacitor array application-specific integrated circuits. The processes of triggering, digitization of windows of interest, readout, and data transfer to the Belle II data acquisition system are managed by Xilinx Zynq-7000 programmable system on a chip devices.
The study of quantum mechanics has greatly broadened since its inception in the early twentieth century. Recent research has focused on the emergence of thermalization in quantum many-body systems. ...In this thesis I will demonstrate the approach to typicalitythe notion that for specific sets of objects, most of the objects share a common property-in a single, many-body spins chain of spin half particles. This notion of typicality is new. But it serves as a good explanation for the emergence of thermalization.
Approach to typicality in many-body quantum systems Dubey, Shawn; Silvestri, Luciano; Finn, Justin ...
Physical review. E, Statistical, nonlinear, and soft matter physics
85, Issue:
1 Pt 1
Journal Article
Open access
The recent discovery that for large Hilbert spaces, almost all (that is, typical) Hamiltonians have eigenstates that place small subsystems in thermal equilibrium, has shed much light on the origins ...of irreversibility and thermalization. Here we give numerical evidence that many-body lattice systems generically approach typicality as the number of subsystems is increased, and thus provide further support for the eigenstate thermalization hypothesis. Our results indicate that the deviation of many-body systems from typicality decreases exponentially with the number of systems. Further, by averaging over a number of randomly selected nearest-neighbor interactions, we obtain a powerlaw for the atypicality as a function of the Hilbert space dimension, distinct from the power law possessed by random Hamiltonians.
Recent experimental results in $B$ physics from Belle, BaBar and LHCb suggest
new physics (NP) in the weak $b\to c$ charged-current and the $b\to s$
neutral-current processes. Here we focus on the ...charged-current case and
specifically on the decay modes $\bar{B}^0\to D^{*+}\ell^- \bar{\nu}$ with
$\ell = e$ and $\mu$. The world averages of the ratios $R_D$ and $R_D^{*}$
currently differ from the Standard Model (SM) predictions by $3.4\sigma$ while
recently a new anomaly has been observed in the forward-backward asymmetry
measurement, $A_{FB}$, in $ \bar{B}^0\to D^{*+}\mu^- \bar{\nu}$ decay. It is
found that $\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e
\nu)$ is around $4.1\sigma$ away from the SM prediction in an analysis of 2019
Belle data. In this work we explore possible solutions to the $\Delta A_{FB}$
anomaly and point out correlated NP signals in other angular observables. These
correlations between angular observables must be present in the case of beyond
the Standard Model physics. We stress the importance of $\Delta$ type
observables that are obtained by taking the difference of the observable for
the muon and the electron mode. These quantities cancel form factor
uncertainties in the SM and allow for clean tests of NP. These intriguing
results also suggest an urgent need for improved simulation and analysis
techniques in $\bar{B}^0\to D^{*+}\ell^- \bar{\nu}$ decays. Here we also
describe a new Monte Carlo Event-generator tool based on EVTGEN that we
developed to allow simulation of the NP signatures in $\bar{B}^0\to
D^{*+}\ell^- \nu$, which arise due to the interference between the SM and NP
amplitudes. We then discuss prospects for improved observables sensitive to NP
couplings with 1, 5, 50, and 250 ab$^{-1}$ of Belle II data, which seem to be
ideally suited for this class of measurements.
Recent experimental results in $B$ physics from Belle, BaBar and LHCb suggest
new physics (NP) in the weak $b\to c$ charged-current and the $b\to s$
neutral-current processes. Here we focus on the ...charged-current case and
specifically on the decay modes $B\to D^{*+}\ell^- \bar{\nu}$ with $\ell = e,
\mu,$ and $\tau$. The world averages of the ratios $R_D$ and $R_D^{*}$
currently differ from the Standard Model (SM) by $3.4\sigma$ while $\Delta
A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e \nu)$ is found to be
$4.1\sigma$ away from the SM prediction in an analysis of 2019 Belle data.
These intriguing results suggest an urgent need for improved simulation and
analysis techniques in $B\to D^{*+}\ell^- \bar{\nu}$ decays. Here we describe a
Monte Carlo Event-generator tool based on EVTGEN developed to allow simulation
of the NP signatures in $B\to D^*\ell^- \nu$, which arise due to the
interference between the SM and NP amplitudes. As a demonstration of the
proposed approach, we exhibit some examples of NP couplings that are consistent
with current data and could explain the $\Delta A_{FB}$ anomaly in $B\to
D^*\ell^- \nu$ while remaining consistent with other constraints. We show that
the $\Delta$-type observables such as $\Delta A_{FB}$ and $\Delta S_5$
eliminate most QCD uncertainties from form factors and allow for clean
measurements of NP. We introduce correlated observables that improve the
sensitivity to NP. We discuss prospects for improved observables sensitive to
NP couplings with the expected 50 ab$^{-1}$ of Belle II data, which seems to be
ideally suited for this class of measurements.
Recent experimental results in \(B\) physics from Belle, BaBar and LHCb suggest new physics (NP) in the weak \(b\to c\) charged-current and the \(b\to s\) neutral-current processes. Here we focus on ...the charged-current case and specifically on the decay modes \(\bar{B}^0\to D^{*+}\ell^- \bar{\nu}\) with \(\ell = e\) and \(\mu\). The world averages of the ratios \(R_D\) and \(R_D^{*}\) currently differ from the Standard Model (SM) predictions by \(3.4\sigma\) while recently a new anomaly has been observed in the forward-backward asymmetry measurement, \(A_{FB}\), in \( \bar{B}^0\to D^{*+}\mu^- \bar{\nu}\) decay. It is found that \(\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e \nu)\) is around \(4.1\sigma\) away from the SM prediction in an analysis of 2019 Belle data. In this work we explore possible solutions to the \(\Delta A_{FB}\) anomaly and point out correlated NP signals in other angular observables. These correlations between angular observables must be present in the case of beyond the Standard Model physics. We stress the importance of \(\Delta\) type observables that are obtained by taking the difference of the observable for the muon and the electron mode. These quantities cancel form factor uncertainties in the SM and allow for clean tests of NP. These intriguing results also suggest an urgent need for improved simulation and analysis techniques in \(\bar{B}^0\to D^{*+}\ell^- \bar{\nu}\) decays. Here we also describe a new Monte Carlo Event-generator tool based on EVTGEN that we developed to allow simulation of the NP signatures in \(\bar{B}^0\to D^{*+}\ell^- \nu\), which arise due to the interference between the SM and NP amplitudes. We then discuss prospects for improved observables sensitive to NP couplings with 1, 5, 50, and 250 ab\(^{-1}\) of Belle II data, which seem to be ideally suited for this class of measurements.
Recent experimental results in \(B\) physics from Belle, BaBar and LHCb suggest new physics (NP) in the weak \(b\to c\) charged-current and the \(b\to s\) neutral-current processes. Here we focus on ...the charged-current case and specifically on the decay modes \(B\to D^{*+}\ell^- \bar{\nu}\) with \(\ell = e, \mu,\) and \(\tau\). The world averages of the ratios \(R_D\) and \(R_D^{*}\) currently differ from the Standard Model (SM) by \(3.4\sigma\) while \(\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e \nu)\) is found to be \(4.1\sigma\) away from the SM prediction in an analysis of 2019 Belle data. These intriguing results suggest an urgent need for improved simulation and analysis techniques in \(B\to D^{*+}\ell^- \bar{\nu}\) decays. Here we describe a Monte Carlo Event-generator tool based on EVTGEN developed to allow simulation of the NP signatures in \(B\to D^*\ell^- \nu\), which arise due to the interference between the SM and NP amplitudes. As a demonstration of the proposed approach, we exhibit some examples of NP couplings that are consistent with current data and could explain the \(\Delta A_{FB}\) anomaly in \(B\to D^*\ell^- \nu\) while remaining consistent with other constraints. We show that the \(\Delta\)-type observables such as \(\Delta A_{FB}\) and \(\Delta S_5\) eliminate most QCD uncertainties from form factors and allow for clean measurements of NP. We introduce correlated observables that improve the sensitivity to NP. We discuss prospects for improved observables sensitive to NP couplings with the expected 50 ab\(^{-1}\) of Belle II data, which seems to be ideally suited for this class of measurements.
The Time-Of-Propagation detector is a Cherenkov particle identification detector based on quartz radiator bars for the Belle II experiment at the SuperKEKB electron-positron collider. The purpose of ...the detector is to identify the type of charged hadrons produced in electron-positron collisions, and requires a single photon timing resolution below 100 picoseconds. A novel front-end electronic system was designed, built, and integrated to acquire data from the 8192 microchannel plate photomultiplier tube channels in the detector. Waveform sampling of these analog signals is done by switched-capacitor array application-specific integrated circuits. The processes of triggering, digitization of windows of interest, readout, and data transfer to the Belle II data acquisition system are managed by Xilinx Zynq-7000 programmable system on a chip devices.
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