Search

We present preliminary results of a partial-wave analysis of $\tau^-\to\pi^-\pi^-\pi^+\nu_\tau$ using data from the Belle experiment at the KEKB $\mathrm{e}^+\mathrm{e}^-$ collider. We validate our analysis with a model-independent one. We see an $\mathrm{a}_1(1420)$ resonance and a G-parity violating $1^-[\omega(782)\pi]_\mathrm{P}]$ wave in tauon decays. Our results will improve models used in simulation studies necessary for measuring the tauon electric and magnetic dipole moments and Michel parameters., Comment: 4 pages, 2 figures, on behalf of the Belle collaboration, submitted to SciPost Physics Proceedings, 17th International Workshop on Tau Lepton Physics (TAU2023). arXiv admin note: text overlap with arXiv:2310.09155

We present preliminary results of a partial-wave analysis of $\tau^-\to\pi^-\pi^-\pi^+\nu_\tau$ in data from the Belle experiment at the KEKB $\mathrm{e}^+\mathrm{e}^-$ collider. We demonstrate the presence of the $\mathrm{a}_1(1420)$ and $\mathrm{a}_1(1640)$ resonances in tauon decays and measure their masses and widths. We also present validation of our findings using a model-independent approach. Our results can improve modeling in simulation studies necessary for measuring the tauon electric and magnetic dipole moments and Michel parameters., Comment: 4 pages, 2 figures, The 20th International Conference on Hadron Spectroscopy and Structure (HADRON 2023)

Belle II is an experiment operating at the intensity frontier. Over the next decades, it will record the decay of billions of bottom mesons, charm hadrons, and tau leptons produced in 10 GeV electron-positron collisions at the SuperKEKB high-luminosity collider at KEK. These data, collected in low-background and kinematically known conditions, will allow us to measure hundreds of parameters that test the standard model (SM) and probe for the existence of new particles, at mass scales orders of magnitudes higher than those studied at the energy frontier. We project our sensitivities for measurements that are of primary relevance and where Belle II will be unique or world leading for data corresponding to 1 to 50 ab-1. Belle II will uniquely probe non-SM contributions in sensitive b -> qqbar s decays and charmless b -> qqbar d(u) decays, semileptonic b -> s nu nubar and s tau+ \tau- decays, fully leptonic b -> ell nu decays, and select c -> u processes. Belle II will lead exploration of non-SM physics in b -> c tau nu and b -> s gamma decays and will most precisely determine the quark-mixing parameters |Vub| and |Vcb|. Belle II will measure many parameters in tau physics to precisions that will be world leading for the foreseeable future, including the electric and magnetic dipole moments, branching fractions for charged-lepton-flavor-violating decays, and quantities that test lepton-flavor universality. Belle II will perform unique searches for dark-sector particles with masses in the MeV--GeV range. We will also pursue a broad spectroscopy program for conventional and multiquark c cbar and b bbar states and provide essential inputs to sharpen the interpretation of muon magnetic-anomaly results. Our exploration of uncharted regions of non-SM parameter space with high precision will reveal non-SM particles or set stringent constraints on their existence, guiding future endeavors., Comment: 48 pages, 15 figures. The document has been confidentially distributed to Snowmass conveners since March 2022, but only now is distributed on arxiv due to Belle II collaboration authorship restrictions following the Ukraine situation

We present simulation studies in preparation for analyzing $\tau^-\to\pi^-\pi^+\pi^-\nu_\tau$ in data from the Belle experiment at the KEK $\mathrm{e}^+\mathrm{e}^-$ collider. Analyzing this decay can shed light on the $\mathrm{a}_1(1260)$ and $\mathrm{a}_1(1420)$ resonances and yield results that improve measurement of the $\tau$ electric and magnetic dipole moments. We show that we can achieve a higher signal efficiency than previous analyses of the same decay. We also demonstrate that neural networks can model our complicated six-dimensional background distributions and that quasi-model-independent partial-wave analysis can extract resonance masses, widths, and production amplitudes and phases., Comment: submitted to Proceedings of Science, ICHE2022 poster session, 4 pages, 2 figures

Belle II is an experiment operating at the intensity frontier. Over the next decades, it will record the decay of billions of bottom mesons, charm hadrons, and tau leptons produced in 10 GeV electron-positron collisions at the SuperKEKB high-luminosity collider at KEK. These data, collected in low-background and kinematically known conditions, will allow us to measure hundreds of parameters that test the standard model (SM) and probe for the existence of new particles, at mass scales orders of magnitudes higher than those studied at the energy frontier. We project our sensitivities for measurements that are of primary relevance and where Belle II will be unique or world leading for data corresponding to 1 to 50 ab$^{-1}$. Belle II will uniquely probe non-SM contributions in sensitive $b \to q\bar q s$ decays and charmless $b \to q\bar q d(u)$ decays, semileptonic $b \to s \nu \bar\nu$ and $s \tau^+ \tau^-$ decays, fully leptonic $b \to \ell \nu$ decays, and select $c \to u$ processes. Belle II will lead exploration of non-SM physics in $b \to c \tau \nu$ and $b \to s \gamma$ decays and will most precisely determine the quark-mixing parameters $|V_{ub}|$ and $|V_{cb}|$. Belle II will measure many parameters in $\tau$ physics to precisions that will be world leading for the foreseeable future, including the electric and magnetic dipole moments, branching fractions for charged-lepton-flavor-violating decays, and quantities that test lepton-flavor universality. Belle II will perform unique searches for dark-sector particles with masses in the MeV-GeV range. We will also pursue a broad spectroscopy program for conventional and multiquark $c \bar c$ and $b \bar b$ states and provide essential inputs to sharpen the interpretation of muon magnetic-anomaly results. Our exploration of uncharted regions of non-SM parameter space with high precision will reveal non-SM particles or set stringent constraints on their existence, guiding future endeavors., Comment: 49 pages, 15 figures. Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)

Shared appreciation mortgages (SAMs) feature mortgage payments that adjust with house prices. They are designed to stave off borrower default by providing payment relief when house prices fall. Some argue that SAMs may help prevent the next foreclosure crisis. However, home owners' gains from payment relief are mortgage lenders' losses. A general equilibrium model in which financial intermediaries channel savings from saver to borrower households shows that indexation of mortgage payments to aggregate house prices increases financial fragility, reduces risk‐sharing, and leads to expensive financial sector bailouts. In contrast, indexation to local house prices reduces financial fragility and improves risk‐sharing.

Shared appreciation mortgages (SAMs) feature mortgage payments that adjust with house prices. They are designed to stave off borrower default by providing payment relief when house prices fall. Some argue that SAMs may help prevent the next foreclosure crisis. However, home owners' gains from payment relief are mortgage lenders' losses. A general equilibrium model in which financial intermediaries channel savings from saver to borrower households shows that indexation of mortgage payments to aggregate house prices increases financial fragility, reduces risk‐sharing, and leads to expensive financial sector bailouts. In contrast, indexation to local house prices reduces financial fragility and improves risk‐sharing.

Plastic scintillators are widely used in high-energy and medical physics, often for measuring the energy of ionizing radiation. Their main disadvantage is their non-linear response to highly ionizing radiation, called ionization quenching. This nonlinearity must be modeled and corrected for in applications where an accurate energy measurement is required. We present a new experimental technique to granularly measure the dependence of quenching on energy-deposition density. Based on this method, we determine the parameters for four commonly used quenching models for two commonly used plastic scintillators using protons with energies of 30 MeV to 100 MeV; and compare the models using a Bayesian approach. We also report the first model-independent measurement of the dependence of ionization quenching on energy-deposition density, providing a purely empirical view into quenching., Comment: Accepted manuscript

This document contains a summary of the LHCb workshop on multi-body decays of D and B mesons, held at CBPF, Rio de Janeiro, in July 2015. The workshop was focused on issues related to amplitude analysis of three- and four-body hadronic decays. In addition to selected LHCb results, contributions from guest theorists are included.

This document contains a summary of the LHCb workshop on multi-body decays of D and B mesons, held at CBPF, Rio de Janeiro, in July 2015. The workshop was focused on issues related to amplitude analysis of three- and four-body hadronic decays. In addition to selected LHCb results, contributions from guest theorists are included.

The upgrades of the Belle experiment and the KEKB accelerator aim to increase the data set of the experiment by the factor 50. This will be achieved by increasing the luminosity of the accelerator which requires a significant upgrade of the detector. A new pixel detector based on DEPFET technology will be installed to handle the increased reaction rate and provide better vertex resolution. One of the features of the DEPFET detector is a long integration time of 20 {\mu}s, which increases detector occupancy up to 3 %. The detector will generate about 2 GB/s of data. An FPGA-based two-level read-out system, the Data Handling Hybrid, was developed for the Belle 2 pixel detector. The system consists of 40 read-out and 8 controller modules. All modules are built in {\mu}TCA form factor using Xilinx Virtex-6 FPGA and can utilize up to 4 GB DDR3 RAM. The system was successfully tested in the beam test at DESY in January 2014. The functionality and the architecture of the Belle 2 Data Handling Hybrid system as well as the performance of the system during the beam test are presented in the paper., Comment: Transactions on Nuclear Science, Proceedings of the 19th Real Time Conference, Preprint

A muon collider combines the advantages of proton-proton and electron-positron colliders, sidestepping many of their disadvantages, and has the potential to make discoveries and precision measurements at high energies. However, muons bring their own technical challenges, largely relating to their instability. We present a summary of the motivations and R&D efforts for a muon collider. We detail a scheme for preparing high-luminosity muon beams on timescales shorter than the muon lifetime, and an experiment to demonstrate aspects of this scheme at the Max Planck Institute for Physics. We also investigate the potentials to discover physics beyond the standard model at a muon collider., Ein Myon-Collider vereint die Vorteile eines Proton-Proton- und Elektron-Positron-Colliders und umgeht deren wesentliche Nachteile. Er hat das Potenzial, neue Erkenntnisse auf dem Gebiet der Teilchenphysik zu ermöglichen und erlaubt Präzisionsmessungen bei hohen Energien. Allerdings birgt die Arbeit mit Myonen ihre eigenen technischen Herausforderungen, vor allem aufgrund der Instabilität der Myonen. Im Folgenden werden die Konzepte eines Myon-Colliders sowie die dafür notwendige Forschungs- und Entwicklungsarbeit zusammengefasst. Wir beschreiben detailliert ein System, das auf kleineren Zeitskalen als der Myonlebensdauer zur Gewinnung von Myonenstrahlen mit hoher Luminosität verwendet wird. Wir besprechen ein Experiment, das Aspekte dieses Systems am Max-Planck-Institut für Physik demonstrieren kann. Wir diskutieren auch die Möglichkeiten, Physik jenseits des Standardmodells an einem Myon-Collider zu entdecken.

A muon collider combines the advantages of proton-proton and electron-positron colliders, sidestepping many of their disadvantages, and has the potential to make discoveries and precision measurements at high energies. However, muons bring their own technical challenges, largely relating to their instability. We present a summary of the motivations and R&D efforts for a muon collider. We detail a scheme for preparing high-luminosity muon beams on timescales shorter than the muon lifetime, and an experiment to demonstrate aspects of this scheme at the Max Planck Institute for Physics. We also investigate the potentials to discover physics beyond the standard model at a muon collider., Ein Myon-Collider vereint die Vorteile eines Proton-Proton- und Elektron-Positron-Colliders und umgeht deren wesentliche Nachteile. Er hat das Potenzial, neue Erkenntnisse auf dem Gebiet der Teilchenphysik zu ermöglichen und erlaubt Präzisionsmessungen bei hohen Energien. Allerdings birgt die Arbeit mit Myonen ihre eigenen technischen Herausforderungen, vor allem aufgrund der Instabilität der Myonen. Im Folgenden werden die Konzepte eines Myon-Colliders sowie die dafür notwendige Forschungs- und Entwicklungsarbeit zusammengefasst. Wir beschreiben detailliert ein System, das auf kleineren Zeitskalen als der Myonlebensdauer zur Gewinnung von Myonenstrahlen mit hoher Luminosität verwendet wird. Wir besprechen ein Experiment, das Aspekte dieses Systems am Max-Planck-Institut für Physik demonstrieren kann. Wir diskutieren auch die Möglichkeiten, Physik jenseits des Standardmodells an einem Myon-Collider zu entdecken.

One of the focuses of research and development towards the construction of a muon collider is muon beam preparation. Simulation of frictional cooling shows that it can achieve the desired emittance reduction to produce high-luminosity muon beams. We show that for positively charged particles, charge exchange interactions necessitate significant changes to schemes previously developed for negatively charged particles. We also demonstrate that foil-based schemes are not viable for positive particles., Comment: 15 pages, 6 figures

A muon collider would open new frontiers of investigation in high energy particle physics, allowing precision measurements to be made at the TeV energy frontier. One of the greatest challenges to constructing a muon collider is the preparation of a beam of muons on a timescale comparable to the lifetime of the muon. Frictional cooling is a potential solution to this problem. In this paper, we briefly describe frictional cooling and detail the Frictional Cooling Demonstration (FCD) experiment at the Max Planck Institute for Physics, Munich. The FCD experiment, which aims to verify the working principles behind frictional cooling, is at the end of the commissioning phase and will soon begin data taking., Comment: 27 pages, 25 figures

Low-energy muon beams are useful for a range of physics experiments. We consider the production of low-energy muon beams with small energy spreads using frictional cooling. As the input beam, we take a surface muon source such as that at the Paul Scherrer Institute. Simulations show that the efficiency of low energy muon production can potentially be raised to 1%, which is significantly higher than that of current schemes.

Two theoretical camps have existed regarding the relationship between suicide and violence. One perspective held that suicide and violence were inversely related, while the second purported that risk for one might indicate risk for the other. The purpose of this study was twofold: (a) to examine the relationship between risk for violence and risk for suicide in a patient population--alcoholics--known to be at risk for these behaviors, and (b) to investigate potential predictors/mediators of suicide risk alone, violence risk alone, and combined aggressive risk (risk for suicide and violence). Suicide and violence risk were considered dependent variables. The independent variables/mediators selected for study were a set of 8 defense mechanisms and a set of 13 disordered personality styles. Maladaptive personality styles and defenses have been linked in the literature to aggressive risk. Seventy-four male alcoholics were administered: (a) the Suicide Risk Scale, (b) the Past Feelings and Acts of Violence scale, (c) the Life Style Index, a measure of defenses, and (d) the Millon Clinical Multiaxial Inventory-II, a personality measure. Suicide and violence risk were significantly non-inversely associated. Nevertheless, the results indicated that few of the hypothesized relations between aggressive risk, defense mechanisms, and personality styles were borne out. This may have been due to notable disparities between the score distribution shapes of the comparison variables which lowered their degree of association. Although the study variables did not align in their expected directions, a group of independent variables related to violence risk alone (antisocial personality style was the best predictor in this group), one related to suicide risk alone (here borderline personality style best predicted suicide risk alone), and a third related to risk for suicide and violence were located (the defense of displacement and alcohol and drug use). An attempt was made to explain th