CP Violation

We show simple methods how to separate pure CP violating effect from matter effect in long baseline neutrino oscillation experiments with three generations of neutrinos. We give compact formulae for neutrino oscillation probabilities assuming one of the three neutrino masses (presumably ν τ mass) to be much larger than the other masses and the effective mass due to matter effect. Two methods are shown: One is to observe envelopes of the curves of oscillation probabilities as functions of neutrino energy; a merit of this method is that only a single detector is enough to determine the presence of CP violation. The other is to compare experiments with at least two different baseline lengths; this has a merit that it needs only narrow energy range of oscillation data.

The Belle Collaboration* Equal amounts of matter and antimatter are predicted to have been produced in the Big Bang, but our observable Universe is clearly matter-dominated. One of the prerequisites 1 for understanding this elimination of antimatter is the nonconservation of charge-parity (CP) symmetry. So far, two types of CP violation have been observed in the neutral K meson (K 0 ) and B meson (B 0 ) systems: CP violation involving the mixing 2 between K 0 and its antiparticle K K 0 (and likewise 3,4 for B 0 and B B 0 ), and direct CP violation in the decay of each meson 5-8 . The observed effects for both types of CP violation are substantially larger for the B 0 meson system. However, they are still consistent with the standard model of particle physics, which has a unique source 9 of CP violation that is known to be too small 10 to account for the matterdominated Universe. Here we report that the direct CP violation in charged B 6 RK 6 p 0 decay is different from that in the neutral B 0 counterpart. The direct CP-violating decay rate asymmetry, A K + p 0 (that is, the difference between the number of observed B 2 RK 2 p 0 event versus B 1 RK 1 p 0 events, normalized to the sum of these events) is measured to be about 17%, with an uncertainty that is reduced by a factor of 1.7 from a previous measurement 7 . However, the asymmetry A K + p + for B B 0 ?K { p z versus B 0 RK 1 p 2 is at the 210% level 7,8 . Although it is susceptible to strong interaction effects that need further clarification, this large deviation in direct CP violation between charged and neutral B meson decays could be an indication of new sources of CP violation-which would help to explain the dominance of matter in the Universe.

In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K, D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report is the result of the work of the physicists attending the 5 th CKM workshop, hosted by the University of Rome "La Sapienza", September 9-13, 2008. It summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field which has greatly improved in the past decade.

This review of CP violation focuses on the status of the subject and its likely future development through experiments in the Kaon system and with B-decays. Although present observations of CP violation are perfectly consistent with the CKM model, we discuss the theoretical and experimental difficulties which must be faced to establish this conclusively. In so doing, theoretical predictions and experimental prospects for detecting $\Delta S=1$ CP violation through measurements of $\epsilon^\prime/\epsilon$ and of rare K decays are reviewed. The crucial role that B CP-violating experiments will play in elucidating this issue is emphasized . The importance of looking for evidence for non-CKM CP-violating phases, through a search for a non-vanishing transverse muon polarization in $K_{\mu 3}$ decays, is also stressed.

Abstract: This physics book provides detailed discussions on important topics in $\tau$-charm physics that will be explored during the next few years at \bes3 . Both theoretical and experimental issues are covered, including extensive reviews of recent theoretical developments and ...

This report presents the results of studies that investigate the physics reach at a Super B factory, an asymmetric-energy e + e − collider with a design luminosity of 8 × 10 35 cm −2 s −1 , which is around 50 times as large as the peak luminosity achieved by the KEKB collider. The studies focus on flavor physics and CP violation measurements that could be carried out in the LHC era. The physics motivation, key observables, measurement methods and expected precisions are presented. 5.13.

Several topics on CP violation in the lepton sector are reviewed. A few theoretical aspects concerning neutrino masses, leptonic mixing, and CP violation will be covered, with special emphasis on seesaw models. A discussion is provided on observable effects which are manifest in the presence of CP violation, particularly, in neutrino oscillations and neutrinoless double beta decay processes, and their possible implications in collider experiments such as the LHC. The role that leptonic CP violation may have played in the generation of the baryon asymmetry of the Universe through the mechanism of leptogenesis is also discussed.

A generation of neutrino experiments have established that neutrinos mix and probably have mass. The mixing phenomenon points to processes beyond those of the Standard Model, possibly at the Grand Unification energy scale. A extensive sequence of of experiments will be required to measure precisely all the parameters of the neutrino mixing matrix, culminating with the discovery and study of leptonic CP violation. As a first step, extensions of conventional pion/kaon decay beams, such as off-axis beams or low-energy super-beams, have been considered. These could yield first observations of ν µ → ν e transitions at the atmospheric frequency, which have not yet been observed, and a first measurement of θ 13 . Experiments with much better flux control can be envisaged if the neutrinos are obtained from the decays of stored particles. One such possibility is the concept of beta beams provided by the decays of radioactive nuclei, that has been developed within the context of these studies. These would provide a pure (anti-)electron-neutrino beam of a few hundred MeV, and beautiful complementarity with a high-intensity, low-energy conventional beam, enabling experimental probes of T violation as well as CP violation. Ultimately, a definitive and complete set of measurements would offered by a Neutrino Factory based on a muon storage ring. This powerful machine offers the largest reach for CP violation, even for very small values of θ 13 .

I review oscillation solutions to the neutrino anomalies and discuss how to account for the required pattern of neutrino masses and mixings from first principles. Unification and low-energy bottom-up approaches are discussed, the latter open up the possibility of testing neutrino mixing at high energy colliders, such as the LHC. Large νe mixing is consistent with Supernova (SN) astrophysics and may serve to probe galactic SN parameters at Cherenkov detectors. I discuss the robustness of the atmospheric neutrino oscillation hypothesis against the presence of Flavor Changing (FC) Non-Standard neutrino Interactions (NSI), generally expected in models of neutrino mass. Atmospheric data strongly constrain FC-NSI in the νµ -ντ channel, while solar data can be explained by FC-NSI in the νe -ντ channel, or, alternatively, by spin flavor precession. I illustrate how a neutrino factory offers a unique way to probe for FC-NSI and argue that a near-site detector is necessary in order to probe for leptonic mixing and CP violation.

The Large Hadron Collider presents an unprecedented opportunity to probe the realm of new physics in the TeV region and shed light on some of the core unresolved issues of particle physics. These include the nature of electroweak symmetry breaking, the origin of mass, the possible constituent of cold dark matter, new sources of CP violation needed to explain the baryon excess in the universe, the possible existence of extra gauge groups and extra matter, and importantly the path Nature chooses to resolve the hierarchy problem -is it supersymmetry or extra dimensions. Many models of new physics beyond the standard model contain a hidden sector which can be probed at the LHC. Additionally, the LHC will be a top factory and accurate measurements of the properties of the top and its rare decays will provide a window to new physics. Further, the LHC could shed light on the origin of neutralino masses if the new physics associated with their generation lies in the TeV region. Finally, the LHC is also a laboratory to test the hypothesis of TeV scale strings and D brane models. An overview of these possibilities is presented in the spirit that it will serve as a companion to the Technical Design Reports (TDRs) by the particle detector groups ATLAS and CMS to facilitate the test of the new theoretical ideas at the LHC. Which of these ideas stands the test of the LHC data will govern the course of particle physics in the subsequent decades.

This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

In supersymmetric grand-unified models, the lepton mixing matrix can possibly affect flavor-changing transitions in the quark sector. We present a detailed analysis of a model proposed by Chang, Masiero and Murayama, in which the near-maximal atmospheric neutrino mixing angle governs large new b → s transitions. Relating the supersymmetric low-energy parameters to seven new parameters of this SO(10) GUT model, we perform a correlated study of several flavor-changing neutral current (FCNC) processes. We find the current bound on B(τ → µγ) more constraining than B(B → X s γ). The LEP limit on the lightest Higgs boson mass implies an important lower bound on tan β, which in turn limits the size of the new FCNC transitions. Remarkably, the combined analysis does not rule out large effects in B s −B s mixing and we can easily accomodate the large CP phase in the B s −B s system which has recently been inferred from a global analysis of CDF and DØ data. The model predicts a particle spectrum which is different from the popular Constrained Minimal Supersymmetric Standard Model (CMSSM). B(τ → µγ) enforces heavy masses, typically above 1 TeV, for the sfermions of the degenerate first two generations. However, the ratio of the third-generation and first-generation sfermion masses is smaller than in the CMSSM and a (dominantly right-handed) stop with mass below 500 GeV is possible.

Although ordinary matter and what is called ‘anti-matter’ maybe considered being mathematically equivalent, there are subtle differences that distinguish both, resulting in a  perceivable asymmetry. This difference, as described by the ‘Sakharov conditions’, has resulted in the dominance of matter over its counterpart- the ‘anti-matter’. An attempt to describe the same would essentially put into perspective, the fundamental reason for our very existence. The most prominent of these conditions, is that of CP violation, which is a combined breaking of the two fundamental symmetries of nature, the Charge conjugation symmetry and the Parity inversion symmetry. It is interesting to note that the combination of these discrete symmetries is a mathematical operation that transforms a particle into an antiparticle.
This very discussion has been the subject of rigorous study, both in the theoretical and experimental fronts, for the past several decades. Despite constant efforts from all around the globe, several essential details pertaining to the minutest descriptions of the subject have not been addressed at sufficient lengths at a single platform. The underlying connections between the physics and the mathematics, describing the phenomenon, have not been much emphasised and has not yet reached the level of understanding of an average reader. This very same deterrent is attempted to be addressed here.

This report provides a first design for H2+ accelerators as the DAEdALUS neutrino sources. A description of all aspects of the system, from the ion source to the extracted beam, is provided. The analysis provides a first proof of principle of a full cyclotron system which can provide the necessary beam power for the CP violation search proposed by the DAEdALUS Collaboration.

The most dramatic implication of L-violating interactions from R-parity violations is the automatic generation of neutrino masses and mixings. The possibility that the results of atmospheric and solar neutrino experiments be explained by neutrino masses and mixings originating from R-parity-violating interactions has motivated a large number of studies and models. R-parity violation in the lepton sector also leads to many new phenomena related to neutrino and sneutrino physics. These aspects of neutrino physics related to L-violating interactions are reviewed in chapter 5.

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between multiple Higgs bosons or other new scalar bosons. Alternatively, the Higgs may be a composite state, or there may even be no Higgs at all. These non-standard Higgs scenarios have important implications for collider physics as well as for cosmology, and understanding their phenomenology is essential for a full comprehension of electroweak symmetry breaking. This report discusses the most relevant theories which go beyond the Standard Model and its minimal, CP-conserving supersymmetric extension: two-Higgs-doublet models and minimal supersymmetric models with CP violation, supersymmetric models with an extra singlet, models with extra gauge groups or Higgs triplets, Little Higgs models, models in extra dimensions, and models with technicolour or other new strong dynamics. For each of these scenarios, this report presents an introduction to the phenomenology, followed by contributions on more detailed theoretical aspects and studies of possible experimental signatures at the LHC and other colliders.

An introductory overview of the Standard Model description of flavour is presented. The main emphasis is put on present tests of the quark-mixing matrix structure and the phenomenological determination of its parameters. Special attention is given to the experimental evidences of CP violation and their important role in our understanding of flavour dynamics.

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between multiple Higgs bosons or other new scalar bosons. Alternatively, the Higgs may be a composite state, or there may even be no Higgs at all. These non-standard Higgs scenarios have important implications for collider physics as well as for cosmology, and understanding their phenomenology is essential for a full comprehension of electroweak symmetry breaking. This report discusses the most relevant theories which go beyond the Standard Model and its minimal, CP-conserving supersymmetric extension: two-Higgs-doublet models and minimal supersymmetric models with CP violation, supersymmetric models with an extra singlet, models with extra gauge groups or Higgs triplets, Little Higgs models, models in extra dimensions, and models with technicolour or other new strong dynamics. For each of these scenarios, this report presents an introduction to the phenomenology, followed by contributions on more detailed theoretical aspects and studies of possible experimental signatures at the LHC and other colliders.

We present a supersymmetric extension of the Standard Model in which only one electroweak doublet acquires a vacuum expectation value and gives mass to Standard Model fermions. As well as the novel accommodation of a Standard Model Higgs within a supersymmetric framework, this leads to a very predictive model, with some advantages over the MSSM. In particular, problems with proton decay, flavour changing neutral currents and large CP violation are ameliorated, primarily due to the presence of an anomalyfree R-symmetry. Since supersymmetry must be broken at a low scale, gravity-mediated effects which break the R-symmetry are naturally small. The R-symmetry requires the presence of adjoint chiral superfields, to give Dirac masses to the gauginos; these adjoints are the only non-MSSM fields in the visible sector. The LSP is a very light neutralino, which is mostly bino. Such a light neutralino is not in conflict with experiment, and is a striking prediction of the minimal model. Additional scenarios to raise the mass of this neutralino to the weak scale are also outlined. Prospects for discovery at the LHC are briefly discussed, along with viable scenarios for achieving gauge-coupling unification.

The working groups also held additional interim meetings to report on their progress and plan further work. The resulting physics studies can be found in Chapters 6-9. The other chapters in this report provide theoretical background on B decays (Chapter 1), common experimental issues (Chapter 2), and brief descriptions of the CDF, DØ, and BTeV detectors (Chapters 3-5). Flavor physics and CP violation will be a major focus of experimental high-energy physics in the coming decade. The preceding decade verified at a high precision the gauge sector of the Standard Model through a wide range of experimental tests. While many extensions of the Standard Model contain new sources of flavor and CP violation, these sectors of the theory are poorly tested at present. Precise tests of the flavor sector of the Standard Model and the origin of CP violation will come from sometimes competitive and sometimes complementary measurements at the Tevatron and at the e + e − B factories. Chapter 10 summarizes the results of the workshops for the most interesting processes. This report represents the status of the field around the Summer of 2001. Both the state of the theory and the experimental possibilities continue to advance. The results presented here are thus not a final view of what the experiments can achieve. This report concentrates on aspects of B physics accessible mainly to hadron colliders, and it is hoped that it will prove a ready and complete reference and aid new collaboration members and maybe others interested in the field as well. These workshops could not have been organized without the help of many people. The organizers would like to especially thank the support of Mike Witherell and the Fermilab Directorate; the help of Cynthia Sazama and Patti Poole of the Fermilab Conference Office with the general meetings' organization; and Lois Deringer and Laura Sedlacek in the Fermilab Theory Group for taking care of so many things. iii Workshop Structure The workshop formed four semi-autonomous working groups. Each was led by two theory conveners and a convener from each experiment.

The decays B → P P , where P denotes a pseudoscalar meson, are analyzed, with emphasis on charmless final states. Numerous triangle relations for amplitudes hold within SU(3) symmetry, relating (for example) the decays B + → π + π 0 , π 0 K + , and π + K 0 . Such relations can improve the possibilities for early detection of CP -violating asymmetries. Within the context of a graphical analysis of decays, relations are analyzed among SU(3) amplitudes which hold if some graphs are neglected. One application is that measurements of the rates for the above three B + decays and their charge-conjugates can be used to determine a weak CKM phase. With measurements of the remaining rates for B decays to ππ, πK, and KK, one can obtain two CKM phases and several differences of strong phase shifts. 1

P and CP violation in cosmology can be manifested as large-scale helical velocity flows in the ambient plasma and as primordial helical magnetic fields. We show that kinetic helicity at last scattering leads to temperature-polarization correlations ($C_l^{TB}$ and $C_l^{EB}$) in the cosmic microwave background radiation (CMBR) and calculate the magnitude of the effect. Helical primordial magnetic fields, expected from cosmic events such as electroweak baryogenesis, can lead to helical velocity flows and hence to non-vanishing correlations of the temperature and B-type polarization. However we show that the magnitude of the induced helical flow is unobservably small because the helical component of a magnetic field is almost force-free. We discuss an alternate scheme for extracting the helicity of a stochastically homogeneous and isotropic primordial magnetic field using observations of the CMBR. The scheme involves constructing Faraday rotation measure maps of the CMBR and thus determining the sum of the helical and non-helical components of the primordial magnetic field. The power spectrum of B-type polarization fluctuations, on the other hand, are sensitive only to the non-helical component of the primordial magnetic field. The primordial magnetic helicity can then be derived by combining these two sets of observations.

In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K, D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model.

The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum with the apparatus at ambient temperature. In the first phase, R&D towards the upgrade of the RAL/ Sussex/ILL apparatus is being performed at the Institut Laue-Langevin (ILL). In the second phase the apparatus, moved from ILL to PSI, will allow an improvement in experimental sensitivity by a factor of 5. In the third phase, a new spectrometer should gain another order of magnitude in sensitivity. The improvements will be mainly due to (1) much higher UCN intensity, (2) improved magnetometry and magnetic field control, and (3) a double chamber configuration with opposite electric field directions.

In a framework of the renormalizable theory of weak interaction, problems of CP-violation are studied. It is concluded that no realistic models of CP-violation exist in the quartet scheme without introducing any other new fields. Some possible models of CP-violation are also discussed.

This chapter of the report of the "Flavor in the era of the LHC" Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector and in flavor conserving CPviolating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

Using the entire sample of 467 million Υ (4S) → BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, we perform an analysis of B ± → DK ± decays, using decay modes in which the neutral D meson decays to either CP -eigenstates or non-CP -eigenstates. We measure the partial decay rate charge asymmetries for CP -even and CP -odd D final states to be ACP+ = 0.25 ± 0.06 ± 0.02 and ACP− = −0.09 ± 0.07 ± 0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter ACP+ is different from zero with a significance of 3.6 standard deviations, constituting evidence for direct CP violation. We also measure the ratios of the charged-averaged B partial decay rates in CP and non-CP decays, RCP+ = 1.18 ± 0.09 ± 0.05 and RCP− = 1.07 ± 0.08 ± 0.04. We infer frequentist confidence intervals for the angle γ of the unitarity triangle, for the strong phase difference δB, and for the amplitude ratio rB, which are related to the B − → DK − decay amplitude by

Recently, the CDF and D0 collaborations measured indirect CP violation in B 0 s → J/ψφ and found a hint of a signal. If taken at face value, this can be interpreted as a nonzero phase of B 0 s -B 0 s mixing (β s ), in disagreement with the standard model, which predicts that β s ≃ 0. In this paper, we argue that this analysis may be incomplete. In particular, there can be new physics (NP) in theb →scc decay. If so, the value of β s is different than for the case in which NP is assumed to be present only in the mixing. We have examined several models of NP and found that, indeed, there can be significant contributions to the decay. These effects are consistent with measurements in B → J/ψK * and B 0 d → J/ψK S . Due to the NP in the decay, polarization-dependent indirect CP asymmetries and triple-product asymmetries are predicted in B 0 s → J/ψφ.

A new mechanism for baryogenesis is proposed in the context of an extended Brans-Dicke (BD) theory. We generalize the BD scalar to complex field with CP violating coupling to curvature and show that the charged BD current can be enhanced during inflationary epoch. After inflation the current decays (via tree level interactions) into the standard model particles. When the BD scalar is charged under baryon and/or lepton number, the decay produces a net baryon number. Rather generically a sufficiently large scalar current can be produced during inflation to account for the observed baryon asymmetry of the Universe. Our baryogensis scenario can in an elegant way be incorporated into a model of extended inflation.

The standard model of hot big bang cosmology requires initial conditions which are problematic in two ways: (1) the early universe is assumed to be highly homogeneous, in spite of the fact that separated regions were causally disconnected (horizon problem); and (2) the initial value of the Hubble constant must be fine tuned to extraordinary accuracy to produce a universe as flat (i.e., near critical mass density) as'the one we see today (flatness problem). These problems would disappear if, in its early history, the universe supercooled to temperatures 28 or more orders of magnitude below the critical temperature for some phase transition. A huge expansion factor would then result from a period of exponential growth, and the entropy of the universe would be multiplied by a huge factor when the latent heat is released. Such a scenario is completely natural in the context of grand unified models of elementary particle interactions. In such models, the supercooling is also relevant to the problem of monopole suppression. Unfortunately, the scenario seems to lead to some unacceptable consequences, so modifications must be sought.

We study the implications of the simultaneous existence of a texture zero and a vanishing minor in the neutrino mass matrix. There are thirty six possible texture structures of this type, twenty one of which reduce to two texture zero cases which have, already, been extensively studied. Of the remaining fifteen textures only six are allowed by the current data. We examine the phenomenological implications of the allowed texture structures for Majorana type CP-violating phases, 1-3 mixing angle and Dirac type CP-violating phase. All these possible textures can be generated through the seesaw mechanism and realized in the framework of discrete abelian flavor symmetry. We present the symmetry realization of these texture structures. * Electronic address: dev5703@yahoo.com †

We perform an extensive study of FCNC and CP Violation within Supersymmetric (SUSY) theories with particular emphasis put on processes governed by b → s transitions and of their correlations with processes governed by b → d transitions, s → d transitions, D 0 −D 0 oscillations, lepton flavour violating decays, electric dipole moments and (g − 2) µ . We first perform a comprehensive model-independent analysis of ∆F = 2 observables and we emphasize the usefulness of the R b − γ plane in exhibiting transparently various tensions in the present UT analyses. Secondly, we consider a number of SUSY models: the general MSSM, a flavour blind MSSM, the MSSM with Minimal Flavour Violation as well as SUSY flavour models based on abelian and non-abelian flavour symmetries that show representative flavour structures in the soft SUSY breaking terms. We show how the characteristic patterns of correlations among the considered flavour observables allow to distinguish between these different SUSY scenarios. Of particular importance are the correlations between the CP asymmetry S ψφ and B s → µ + µ − , between the anomalies in S φK S and S ψφ , between S φK S and d e , between S ψφ and (g − 2) µ and also those involving lepton flavour violating decays. In our analysis, the presence of right-handed currents and of the double Higgs penguin contributions to B s mixing plays a very important role. We propose a "DNA-Flavour Test" of NP models including Supersymmetry, the Littlest Higgs model with T-parity and the Randall-Sundrum model with custodial protection, with the aim of showing a tool to distinguish between these NP scenarios, once additional data on flavour changing processes become available. As a byproduct, we present the SM prediction for BR(B + → τ + ν) = (0.80 ± 0.12) × 10 −4 that follows solely from an analytical formula for this branching ratio in terms of ∆M s,d and S ψK S asymmetry and which does not involve V ub and F B uncertainties. arXiv:0909.1333v2 [hep-ph]

This chapter of the report of the "Flavor in the era of the LHC" Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector and in flavor conserving CPviolating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

We review CP violation in various extensions of the electroweak sector of the Standard Model. A particular emphasis is put on supersymmetric models. We describe the two CP problems of supersymmetry, concerning $d_N$ and $\epsilon_K$. We critically review the various mechanisms that have been suggested to solve these problems: exact universality, approximate CP symmetry, alignment, approximate universality and heavy squarks.

We study the physics capabilities of the NuMI beamline with an off-axis highly-segmented iron scintillator detector and with the inclusion of the currently under study proton driver upgrade. We focus on the prospects for the experimental determination of the remaining neutrino oscillation parameters, assuming different outcomes for experiments under way or in preparation. An optimization of the beam conditions and

The long-term prospects for fully exploring three-flavor mixing in the neutrino sector depend upon an ongoing and increased investment in the appropriate accelerator R&D. Two new concepts have been proposed that would revolutionize neutrino experiments, namely the Neutrino Factory and the Beta Beam facility. These new facilities would dramatically improve our ability to test the three-flavor mixing framework, measure CP violation in the lepton sector, and perhaps determine the neutrino mass hierarchy, and, if necessary, probe extremely small values of the mixing angle θ 13 . The stunning sensitivity that could be achieved with a Neutrino Factory is described, together with our present understanding of the corresponding sensitivity that might be achieved with a Beta Beam facility. In the Beta Beam case, additional study is required to better understand the optimum Beta Beam energy, and the achievable sensitivity. Neither a Neutrino Factory nor a Beta Beam facility could be built without significant R&D. An impressive Neutrino Factory R&D effort has been ongoing in the U.S. and elsewhere over the last few years and significant progress has been made towards optimizing the design, developing and testing the required accelerator components, and significantly reducing the cost. The recent progress is described here. There has been no corresponding activity in the U.S. on Beta Beam facility design and, given the very limited resources, there is little prospect of starting a significant U.S. Beta Beam R&D effort in the near future. However, the Beta Beam concept is interesting, and progress on its development in Europe should be followed. The Neutrino Factory R&D program has reached a critical stage in which support is required for two crucial international experiments and a third-generation international design study. If this support is forthcoming, a Neutrino Factory could be added to the Neutrino Community's road map in about a decade.

We present a complete study of ∆S = 2 and ∆B = 2 processes in a warped extra dimensional model with a custodial protection of Zb LbL , including ε K , ∆M K , ∆M s , ∆M d , A q SL , ∆Γ q , A CP (B d → ψK S ) and A CP (B s → ψφ). These processes are affected by tree level contributions from Kaluza-Klein gluons, the heavy KK photon, new heavy electroweak gauge bosons Z H and Z ′ , and in principle by tree level Z contributions. We confirm recent findings that the fully anarchic approach where all the hierarchies in quark masses and weak mixing angles are geometrically explained seems implausible and we confirm that the KK mass scale M KK generically has to be at least ∼ 20 TeV to satisfy the ε K constraint. We point out, however, that there exist regions in parameter space with only modest fine-tuning in the 5D Yukawa couplings which satisfy all existing ∆F = 2 and electroweak precision constraints for scales M KK ≃ 3 TeV in reach of the LHC. Simultaneously we find that A CP (B s → ψφ) and A s SL can be much larger than in the SM as indicated by recent results from CDF and DØ data. We point out that for B d,s physics ∆F = 2 observables the complex (Z H , Z ′ ) can compete with KK gluons, while the tree level Z and KK photon contributions are very small. In particular we point out that the Zd i Ld j L couplings are protected by the custodial symmetry. As a by-product we show the relation of the RS flavour model to the Froggatt-Nielsen mechanism and we provide analytic formulae for the effective flavour mixing matrices in terms of the fundamental 5D parameters. RS models. The lower bound on the KK gluon mass obtained in originates from the excessive contribution of Q LR to ε K . One of our strategies will be to find regions of parameter space consistent with EW precision observables for which Q LR is sufficiently suppressed even if the 5D Yukawa couplings are mostly anarchic.

I review the interpretation of solar and atmospheric neutrino data in terms neutrino oscillations and describe some ways to account for the required neutrino masses and mixing angles from first principles, both within topdown and bottom-up approaches. I also discuss non-oscillation phenomena such as ββ0ν which may probe the absolute scale of neutrino mass, and also reveal its Majorana nature. I note that leptonic CP violation induced by "Majorana" phases drop from oscillations but play a role in the leptogenesis scenario for the baryon asymmetry of the Universe. Direct tests of leptonic CP violation in oscillation experiments, such as neutrino factories, will be a tough challenge, due to the hierarchical neutrino mass splittings and the smallness of θ13 indicated by reactors. The large solar mixing angle θ12 offers a way to probe otherwise inaccessible features of supernova physics. Finally, I note that in low-scale models of neutrino mass, one may probe all mixing angles, including the atmospheric θ23, at high energy accelerator experiments such as the LHC or NLC. A neat example is supersymmetry with bilinear breaking of R parity, where the LSP decay branching ratios are directly correlated to the neutrino mixing angles. I also discuss non-oscillation solutions to the solar neutrino problem in terms of spin-flavor precession and non-standard neutrino interactions, which will be crucially tested at KamLAND.

Neutrino oscillation data strongly support mu-tau symmetry as a good approximate flavor symmetry of the neutrino sector, which has to appear in any viable theory for neutrino mass-generation. The mu-tau breaking is not only small, but also the source of Dirac CP-violation. We conjecture that both discrete mu-tau and CP symmetries are fundamental symmetries of the seesaw Lagrangian (respected by interaction terms), and they are only softly broken, arising from a common origin via a unique dimension-3 Majorana mass-term of the heavy right-handed neutrinos. From this conceptually attractive and simple construction, we can predict the soft mu-tau breaking at low energies, leading to quantitative correlations between the apparently two small deviations \theta_{23} - 45^o and \theta_{13} - 0^o. This nontrivially connects the on-going measurements of mixing angle \theta_{23} with the upcoming experimental probes of \theta_{13}. We find that any deviation of \theta_{23} - 45^o must put a lower limit on \theta_{13}. Furthermore, we deduce the low energy Dirac and Majorana CP violations from a common soft-breaking phase associated with mu-tau breaking in the neutrino seesaw. Finally, from the soft CP breaking in neutrino seesaw we derive the cosmological CP violation for the baryon asymmetry via leptogenesis. We fully reconstruct the leptogenesis CP-asymmetry from the low energy Dirac CP phase and establish a direct link between the cosmological CP-violation and the low energy Jarlskog invariant. We predict new lower and upper bounds on the \theta_{13} mixing angle, 1^o < \theta_{13} < 6^o. In addition, we reveal a new hidden symmetry that dictates the solar mixing angle \theta_12 by its group-parameter, and includes the conventional tri-bimaximal mixing as a special case, allowing deviations from it.

Conceptual Developments of 20th Century Field Theories Tian Yu Cao This volume provides a broad synthesis of conceptual developments of twentieth century field theories, from the general theory of relativity to quantum field theory and gauge theory. The book traces the foundations and evolution of these theories within a historio-critical context. Theoretical physicists and students of theoretical physics will find this a valuable account of the foundational problems of their discipline that will help them understand the internal logic and dynamics of theoretical physics. It will also provide professional historians and philosophers of science, particularly philosophers of physics, with a conceptual basis for further historical, cultural and sociological analysis of the theories discussed. Finally, the scientifically qualified general reader will find in this book a deeper analysis of contemporary conceptions of the physical world than can be found in popular accounts of the subject. Download Conceptual Developments of 20th Century Field Theo ...pdf Read Online Conceptual Developments of 20th Century Field Th ...pdf

A systematic approach is followed in order to identify realistic D-brane models at toric del Pezzo singularities. Requiring quark and lepton spectrum and Yukawas from D3 branes and massless hypercharge, we are led to Pati-Salam extensions of the Standard Model. Hierarchies of masses, flavour mixings and control of couplings select higher order del Pezzo singularities, minimising the Higgs sector prefers toric del Pezzos with dP 3 providing the most successful compromise. Then a supersymmetric local string model is presented with the following properties at low energies: (i) the MSSM spectrum plus a local B − L gauge field or additional Higgs fields depending on the breaking pattern, (ii) a realistic hierarchy of quark and lepton masses and (iii) realistic flavour mixing between quark and lepton families with computable CKM and PMNS matrices, and CP violation consistent with observations. In this construction, kinetic terms are diagonal and under calculational control suppressing standard FCNC contributions. Proton decay operators of dimension 4, 5, 6 are suppressed, and gauge couplings can unify depending on the breaking scales from string scales at energies in the range 10 12 − 10 16 GeV, consistent with TeV soft-masses from moduli mediated supersymmetry breaking. The GUT scale model corresponds to D3 branes at dP 3 with two copies of the Pati-Salam gauge symmetry SU (4)×SU (2) R ×SU (2) L . D−brane instantons generate a non-vanishing µ−term. Right handed sneutrinos can break the B − L symmetry and induce a see-saw mechanism of neutrino masses and R-parity violating operators with observable low-energy implications.

In the context of the minimal supersymmetric seesaw model, the CP-violating neutrino Yukawa couplings might induce an electron EDM. The same interactions may also be responsible for the generation of the observed baryon asymmetry of the Universe via leptogenesis. We identify in a model-independent way those patterns within the seesaw models which predict an electron EDM at a level probed by planned laboratory experiments and show that negative searches on τ → eγ decay may provide the strongest upper bound on the electron EDM. We also conclude that a possible future detection of the electron EDM is incompatible with thermal leptogenesis, even when flavour effects are accounted for. *