arXiv subjects

I. I. Bigi

Publications and source records attributed to I. I. Bigi.

At least 19 recordsLinked to original sources

arXiv2022

Probing violation of CP & T invariance in the transitions of τ leptons

The SM predicts zero value for {\bf CP} \& {\bf T} violation in the decays of $τ$ leptons -- except $τ^- \to νK_S [π^-/π^-π^0 ...]$. Our community could establish impact of New Dynamics (ND) in a {\bf CP} asymmetry in a semi-hadronic $τ$ transition and later in a second one. To be `practical', I suggest to our experimental colleagues to probe $τ^- \to ν\bar K^0 [π^-/π^-π^0/π^-η]$and $τ^- \to νK^-[π^0/π^+π^-/η]$. While I had mostly given comments about {\bf CP} violation in $τ$ transitions, some theorists have shown how ND models could produce {\bf CP} asymmetries; I will discuss these ones, although sometimes I am not a true theorist, but as a phenomenalist here. I can hardly `dream' that {\bf CP} asymmetry in $τ$ decays could connected with our huge asymmetry in `our' matter vs. anti-matter.

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arXiv2020

2019/20 Lessons from $τ(Ω_c^0)$ \& $τ(Ξ_c^0)$ and {\bf CP} asymmetry in charm decays

Our 2003 "Cicerone" had discussed charm dynamics with different directions and levels \cite{CICERONE}. Here we focus on two items, where the `landscape' has changed sizably. (A) The lifetimes \& semi-leptonic decays of charm hadrons show the impact of non-perturbative QCD and to which degree one can apply Heavy Quark Expansion (HQE) for charm hadrons. It is more complex as we have learnt from 2019/20 data. (B) {\bf CP} asymmetry has been established in 2019 \cite{LHCbGuy}: $ΔA_{\bf CP} \equiv A_{\bf CP}(D^0 \to K^+K^-) - A_{\bf CP}(D^0 \to π^+π^-) $=$\, -\, (1.54 \pm 0.29 ) \cdot 10^{-3}$ is quite an achievement by the LHCb collaboration! Our community is at the beginning of a long travel for fundamental dynamics. Can the SM account for these? We discuss the assumptions that were made up to 2018 data and new conclusions from 2019/20 ones. We need more data; however, one has to discuss correlations between different transitions. We give an {\bf Appendix} what we have learnt for large {\bf CP} asymmetry in $K_L \to π^+π^-e^+e^-$.

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arXiv2019

The Belle II Physics Book

We present the physics program of the Belle II experiment, located on the intensity frontier SuperKEKB $e^+e^-$ collider. Belle II collected its first collisions in 2018, and is expected to operate for the next decade. It is anticipated to collect 50/ab of collision data over its lifetime. This book is the outcome of a joint effort of Belle II collaborators and theorists through the Belle II theory interface platform (B2TiP), an effort that commenced in 2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II program, which includes a wide scope of physics topics: B physics, charm, tau, quarkonium, electroweak precision measurements and dark sector searches. It is composed of nine working groups (WGs), which are coordinated by teams of theorist and experimentalists conveners: Semileptonic and leptonic B decays, Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm, Quarkonium(like), tau and low-multiplicity processes, new physics and global fit analyses. This book highlights "golden- and silver-channels", i.e. those that would have the highest potential impact in the field. Theorists scrutinised the role of those measurements and estimated the respective theoretical uncertainties, achievable now as well as prospects for the future. Experimentalists investigated the expected improvements with the large dataset expected from Belle II, taking into account improved performance from the upgraded detector.

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arXiv2019

Impact of Non-perturbative QCD on CP Violation in Many-Body Final States of Flavor Transitions

The title of my talk pointed out central statements: the impact of non-perturbative QCD on {\bf CP} asymmetries in many-body FS in charm \& beauty hadrons. For practical reasons one measures first {\bf CP} violation in two-body final states of heavy flavor hadrons. However, those are small parts of charm hadrons and tiny ones for beauty hadrons; therefore one has to probe {\bf CP} asymmetries in three- \& four-body final states. Thus the transitions to the many-body FS basically give information about the underlying dynamics. The impact of non-perturbative QCD on {\bf CP} asymmetries in many-body FS shows that -- in principle; it is a true challenge even in a semi-quantitative way. One needs correlations with other transitions. That is my strategy; however, I have to discuss the tactics on the same level like using consistent parameterization of the CKM matrix. Our community has entered a novel era: direct {\bf CP} violation has been found in $D^0 \to h^+h^-$ decays \cite{CHARM}. Finally I give short comments about the possible impact of New Dynamics on direct {\bf CP} violation in $K_L \to 2 π$ and probe {\bf CP} asymmetry in $J/ψ\to \bar ΛΛ$ transitions.

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arXiv2018

The Dynamics of Beauty & Charm Hadrons and top quarks in the Era of the LHCb & Belle II and ATLAS/CMS, Motto: Non-perturbative QCD \& Many-body Final States

Our community has to apply {\em non}-perturbative QCD on different levels of flavor dynamics in strange, charm \& beauty hadrons and even for top quarks. We need {\em consistent} parameterization of the CKM matrix and describe weak decays of beauty hadrons with {\em many-body} final states. It is crucial to use the {\em Wilsonian} OPE as much as possible and discuss "duality" in the worlds of quarks and hadrons. The pole mass of heavy quarks is {\em not} well-defined on the {\em non}-perturbative level -- i.e., it is {\em not} Borel summable in total QCD. We need a novel team to combine the strengths of our tools from MEP and HEP.

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arXiv2017

CP Asymmetries in Strange Baryon Decays

While indirect & direct CP violations (CPV) had been established in the decays of strange & beauty mesons, none have been done for baryons. There are different "roads" for finding CP asymmetries in the decays of strange baryons; they are highly non-trivial ones. The HyperCP Collaboration had probed CPV in the decays of single $Ξ$ & $Λ$ [Phys.Rev.Lett 93 (2004) 262001]. We talk about future lessons from $e^+e^-$ collisions at BESIII/BEPCII: probing decays of pairs of strange baryons, namely $Λ$, $Σ$ & $Ξ$. Realistic goals are to learn about non-perturbative QCD. One can hope to find CPV in the decays of strange baryons; one can also dream to find impact of New Dynamics (ND). We point out that a new important era starts with the BESIII/BEPCII data accumulated by the end of 2018.

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arXiv2017

"The school of Athens" or "Bridge between MEP and HEP"

This century the situation has changed: neutrino oscillations have shown that the SM is incomplete. On the other hand, we have not found signs of SUSY, which is seen as the best candidate for New Dynamics (ND). We should search for ND indirectly with accuracy in regions that are above what LHC can find it directly. General comments: (a) QCD is the only local quantum field theory to describe strong forces. We have to apply non-perturbative QCD on different levels to flavor dynamics in strange, charm \& beauty hadrons and even for top quarks. We need consistent parameterization of the CKM matrix and apply to weak decays of beauty hadrons with many-body final states. (b) It is crucial to use the Wilsonian OPE as much as possible and discuss "duality" in the worlds of quarks and hadrons. The pole mass of heavy quarks is {\em not} well-defined on the non-perturbative level -- i.e., it is {\em not} Borel summable in total QCD. (c) We need a novel team to combine the strengths of our tools from MEP and HEP.

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arXiv2016

Bridge between Hadrodynamics & HEP: Regional CP Violation in Beauty & Charm Decays

There is a long way from `accuracy' to `precision' about {\bf CP} asymmetries in the decays of beauty \& charm hadrons. (a) We have to apply consistent parametrization of the CKM matrix. (b) Probing many-body final states (FS) is {\em not} a back-up for understanding the underlying forces; to be realistic we can hardly go beyond four-body FS. (c) Broken U-spin symmetry is a good tools to describe spectroscopy of hadrons.However the landscape is very different for weak transitions; the connection of U- \& V-spin symmetries are important. We have to understand the differences between Penguin {\em operators} vs. Penguin {\em diagrams}. (d) Collaborations of experimenters \& theorists are crucial with {\em judgment}. There is a `hot' news from the conference ICHEP2016: LHCb data show evidence of {\bf CP} asymmetries in the {\bf T}-odd moment from $Λ_b^0 \to p π^-π^+π^-$. LHCb will follow this `road' with $Λ_b^0 \to p π^-K^+K^-$, $Λ_b^0 \to p K^- π^+π^-$ \& $Λ_b^0 \to p K^-K^+K^-$ in run-1. With much more data it is crucial to probe its features in {\em regional} asymmetries. \\ A quote from Marinus, who was a $\sim$ 468 AD student of Proklos, a well-known Neoplatonic philosopher: "Only {\em being} good is one thing -- but good {\em doing} it is the other one!"

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arXiv2016

CP Asymmetries (\& T Violation) in Known Matter -- and beyond

Finding \cp~violation (\CPV ) in 1964 produced a real revolution in the fundamental dynamics, although the community did not understand it right away. The paper by Kobayashi \& Maskawa \cite{KM} appeared in 1973 to describe \CPV~in classes of three (or more) families of quarks, non-minimal Higgs' dynamics and/or charged right-handed currents. The Standard Model is defined now with three families of quarks. It can describe the measured \cp~ \& \ot~violation in kaon and $B$ mesons at least as the leading source. None has been found in baryons, charm mesons, top quarks and EDMs -- except from `hot' news from LHCb data about {\bf T}-odd moment in $Λ_b^0 \to p π^-π^+π^-$ \cite{LHCbtalk}. We have failed the explain our matter vs. anti-matter huge asymmetry. Even when there is no obvious connections with that asymmetry, it makes sense to probe \CPV~for the signs of New Dynamics \& their features. Furthermore we have to measure regional \CPV~in many-body final states with accuracy. I discuss EDMs, axion's impact on cosmology \& its connection with Dark Matter; finally I talk about \CPV~in leptonic dynamics.

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arXiv2015

CP Asymmetries in Many-Body Final States in Beauty & Charm Transitions

Our community has focused on two-body final states in $B$ & $D$ decays. The SM produces at least the leading source of CP violation in $B$ transitions, none has been established yet in charm decays. It is crucial to measure three- and four-body FS with accuracy and to compare with predictions based on refined theoretical tools. Correlations between different final states (FS) based on CPT invariance are often not obvious, how to apply them and where. We have to probe regional asymmetries and use refined parametrization of the CKM matrix. One uses (broken) U- & V-spin symmetries for spectroscopy. The situations with weak decays of hadrons are much more complex. The impact of strong re-scattering is large, and it connects U- \& V-spin symmetries. Drawing diagrams often does not mean we understand the underlying dynamics. We have to probe the decays of beauty \& charm baryons. I discuss the `strategies' more than the `tactics'.

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arXiv2015

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C. Please note that version 3 on the archive is the auxiliary version of the Physics of the B Factories book. This uses the notation alpha, beta, gamma for the angles of the Unitarity Triangle. The nominal version uses the notation phi_1, phi_2 and phi_3. Please cite this work as Eur. Phys. J. C74 (2014) 3026.

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arXiv2015

Working with Kolya Uraltsev for twenty-five years about Fundamental Dynamics & Symmetries and for the future -- like CP Violation & EDMs

Working with Kolya Uraltsev was a real `marvel' for me about CP & T violation, QCD & its impact on transitions in heavy flavor hadrons, EDMs. The goal was -- and still is -- to define fundamental parameters dynamics, how to measure them and compare SM forces with New Dynamics using the best theoretical tools including our brains. The correlations of them with accurate data were crucial for Kolya. Here is a review of CP asymmetries in $B$ & $D$ mesons and $τ$ decays, the impact of perturbative and non-perturbative QCD, about EDMs till 2013 -- and for the future.

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arXiv2014

CP Asymmetries in Three-Body Final States in Charged $D$ Decays & CPT Invariance

The study of local \cp \ asymmetry in Dalitz plots of charm (& beauty) decays gives us more information about the underlying dynamics than the ratio between total rates. In this paper we explore the consequences of the constraint from \cpt \ symmetry with emphasis on three-body $D$ decays. We show simulations of $D^{\pm} \to π^{\pm}K^+K^-$ and discuss correlations with measured $D^{\pm} \to π^{\pm}π^+ π^-$. There are important comments about analysies of recent LHCb data in \cp\ asymmetries for $B^{\pm}$ decays to three-body final states.

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arXiv2013

3- and 4-Body Final States in B, D and tau Decays about Features of New Dynamics with CPT Invariance or "Achaeans outside Troy"

The 'landscape' of fundamental dynamics has changed even for the 'known' matter. The Standard Model has produced at least the leading source of CP violation (CPV) in B decays; the data have not shown CP asymmetries in $D$ transitions. It needs more data and better technologies to understand the underlying forces. Probing three- and four-body final states in $B$ & $D$ & $τ$ decays with better accuracy is crucial about the existence and the features of New Dynamics. Theoretical tools produced about MEP will show even more about HEP in the future. We have to work on the {\em correlations} between different final states on several CKM levels and the connection between known matter and Dark Matter in indirect ways. CPT invariance is usable in $D$ and $τ$ decays.

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arXiv2013

Memorial Contribution about Kolya Uraltsev's Talk at 2012 Workshop $B\to D**$

Uraltev has given us a deeper understanding of the forces underlying the data from beauty and charm hadrons for the last 35 years and neutron EDM in the future -- in particular about non-perturbative QCD. At the Workshop in the November 2012 before his death he has focused mostly on the data about semi-leptonic B decays beyond $B \to l νD/D^*$. Here is a very short review of his talk at this Workshop. Next year colleagues will produce a `Memorial Book' about Kolya Uraltsev's excellent contributions to fundamental dynamics.

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arXiv2013

Implications of LHCb measurements and future prospects

During 2011 the LHCb experiment at CERN collected 1.0 fb-1 of sqrt{s} = 7 TeV pp collisions. Due to the large heavy quark production cross-sections, these data provide unprecedented samples of heavy flavoured hadrons. The first results from LHCb have made a significant impact on the flavour physics landscape and have definitively proved the concept of a dedicated experiment in the forward region at a hadron collider. This document discusses the implications of these first measurements on classes of extensions to the Standard Model, bearing in mind the interplay with the results of searches for on-shell production of new particles at ATLAS and CMS. The physics potential of an upgrade to the LHCb detector, which would allow an order of magnitude more data to be collected, is emphasised.

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arXiv2012

CP Violation in $τ$ Decays at SuperB \& Super-Belle Experiments -- like Finding Signs of Dark Matter

BaBar has found $A_{\rm CP}(τ^- \to νK_Sπ^- [\geq π^0]) = (-0.36 \pm 0.23 \pm 0.11)%$ with 2.8 $σ$ difference with SM prediction $A_{\rm CP}(τ^- \to νK_Sπ^-) = (0.36 \pm 0.01)%$ based on $K^0 - \bar K^0$ oscillation. Four central points: (i) to establish both the `existence' of New Dynamics (ND) and its `features' in local CP asymmetries; (ii) to increase the number of final states to be probed; (iii) to emphasize correlations of CP violations between different final states; (iv) likewise for the correlations with $D^{\pm}$ final states. These measurements should be possible at SuperB & Belle II experiments.

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arXiv2012

Probing CP Asymmetries in Charm Baryons Decays

With the first evidence of direct CP violation in $D^0 \to K^+K^-/π^+π^-$ there is a strong reason to probe CP asymmetries in charm baryons in three-body final states $Λ_c \to pπ^+π^-/pK^+K^-$ & $Λ_c \to pK^+π^-$ with $Λ_c \to pK^-π^+$ to calibrate them. Analyzing the Dalitz plots carefully allows to find the 'existence' of New Dynamics (ND) and its `features'. One can test different methods to probe CP asymmetries. Final data from CDF and D0 experiments have advantage by comparing $Λ_c $ with $\bar Λ_c $ directly from $p \bar p $ collisions. LHCb will need more data with $\bar Λ_c$ transitions.

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