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In this talk, we report recent progress in understanding Roper resonances within the Skyrme framework. As a first step towards modelling Roper resonances, we focus on BPS Skyrmion solutions and their radial vibration spectra. The BPS Skyrme model allows for an axially symmetric ansatz leading to skyrmions with a radially symmetric energy density for arbitrary baryon number B. Hence, radial excitation modes may be studied for any B. In this project, we carry out both a linearised and full nonlinear analysis of radial oscillations and resonances (quasi-normal modes) of Skyrmions in the BPS Skyrme model. We find that the fundamental excitation compares reasonably well with the excitation energy of the Roper resonance. Furthermore, for a wide class of potentials higher resonances can appear which might be candidates for the description of higher Roper resonances.

We study possible baryon molecules in the non-strange heavy baryon spectrum. We include configurations with a heavy-meson and a light baryon. We find several structures, in particular we can understand the Λc(2940) as a D*N molecule with JP = 3/2− quantum numbers. We also find D(*)Δ candidates for the recently discovered Xc(3250) resonance.

By using the overlap-Dirac operator eigenmodes, we investigate spatial distribution of the chiral condensate around static color sources for both quark-antiquark and three quark systems. In the presence of color sources, a characteristic flux-tube structure appears among them, suggesting a linear confining potential. We show that the magnitude of the condensate is reduced inside the color flux, which indicates the partial restoration of chiral symmetry inside the "hadrons." Considering a periodic box containing a static baryon source, which mimics the "nuclear matter," we estimate the chiral symmetry restoration in the presence of finite baryon number density., 7 pages, 6 figures, presented at the 32nd International Symposium on Lattice Field Theory, 23-28 June, 2014, Columbia University New York, NY

We present an extension of the standard model to dark sector with an unbroken local dark $U(1)_X$ symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken $U(1)_X$ case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if $U(1)_X$ is spontaneously broken, because of a mixing with a new neutral scalar boson in the models., Comment: 10 pages, 3 figures, VII International Conference on Interconnections between Particle Physics and Cosmology (PPC2013)

Minimal SO(10) models which utilize a 126-plet of Higgs for breaking B - L symmetry are quite predictive for the neutrino oscillation parameters. These models have been known to predict sin2 2θ13 ≃ 0.09, which is consistent with recent measurements. It is shown that the same class of models generates naturally baryon number violating dimension seven operators leading to novel nucleon decay modes such as n → e−K+, e−π+ and p → νπ+ which violate B - L by two units. In two-step breaking schemes of non-supersymmetric SO(10), the partial lifetimes for these modes can be within reach of experiments. The interactions responsible for these decay modes also provide a new way to understand the origin of matter in the universe via the decays of colored scalar bosons with GUT scale masses. Their (B - L)-violating nature guarantees that the GUT scale induced baryon asymmetry is not washed out by the electroweak sphaleron interactions. In minimal SO(10) models this asymmetry is closely tied to the masses of quarks, lep...

A TeV scale extension of the standard model that incorporates the seesaw mechanism for neutrino masses along with quark-lepton unification is presented. It is shown that this model leads to the ΔB = 2 baryon number violating process of neutron-antineutron (n - n) oscillation. The model has all the ingredients to generate the observed baryon asymmetry of the universe using the B-violating decay of a scalar field involved in the seesaw mechanism. The B-violating decay arises from the exchange of color sextet scalars which have TeV scale masses. Baryogenesis occurs below the sphaleron decoupling temperature and has been termed post-sphaleron baryogenesis. Here we show that the constraints of TeV scale baryogenesis, when combined with the neutrino oscillation data and restrictions from flavor changing neutral currents mediated by the colored scalars imply an upper limit on the n - n oscillation time of 5 × 1010 sec. regardless of the quark-lepton unification scale. If this scale is relatively low, in the (2...

We present recent BABAR results on lepton universality in decays of the γ(2S) and γ(3S), and lepton-flavor violation and lepton-number violation in semileptonic charm hadron decays, and lepton-number and baryon-number conservation in B, and charm decays. No violations of these observed quantities are observed and improved or new upper limits are calculated on the respective branching fractions.

Minimal SO(10) models which utilize a 126–plet of Higgs for breaking B – L symmetry are predictive schemes for neutrino masses and mixings. These models have been known to predict sin22θ13≃0.09, which is consistent with recent measurements. It is shown that the same class of models generates naturally baryon number violating dimension seven operators leading to novel nucleon decay modes such as n→e−K+, e−π+ and p→νπ+ which violate B – L by two units. We find that in two–step breaking schemes of non-supersymmetric SO(10), the partial lifetimes for these modes can be within reach of experiments. The interactions responsible for these decay modes also provide a new way to understand the origin of matter in the universe via the decays of GUT scale colored scalar bosons. Their (B – L)–violating nature guarantees that the GUT scale induced baryon asymmetry is not washed out by the electroweak sphaleron interactions. In minimal SO(10) models this asymmetry is closely tied to the masses of quarks, leptons and the...

We define a BPS Skyrme model, which is integrable, solvable and with solitons saturating a topological bound. When applied to nuclear physics, the model cures several serious problems appearing in the standard Skyrme model as well as in its typical generalizations. At the classical level, it qualitatively reproduces the main features of the liquid drop model of nuclei, providing proper relations between masses and radii of nuclei and the baryon number. In spite of its rather unusual form, the model also allows for the semiclassical quantization.

As a strangeness S = −1 and baryon number B = 2 system, the two‐body bound state of Λ* = Λ(1405) and a nucleon is studied. To solve the Λ*N system, we construct the Λ*N potential by extending the Julich model with couplings estimated in the chiral unitary approach. We have the Λ*N quasi‐bound state with the mass, MΛ*N∼2366 MeV which is shallowly bound with the binding energy B∼9 MeV in terms of the KNN system. Decay width of the fall apart process, where the Λ*N resonance decays to πΣN with a nucleon being as a spectator, is estimated to be ΓF.A∼49 MeV.

We calculate the leading relativistic correction to the rigid body approximation used by Adkins and Nappi (and Witten) for the collective coordinate quantization of a Skyrmion with baryon number one. We derive a field theory solution of a spinning Skyrmion, expanding the field configuration in powers of the angular velocity, and then obtain the relativistic corrections to the decay constant and various static properties of nucleons. which amount to 5% – 20%.

The structure of multi‐antikaonic nuclei (MKN) is investigated in a relativistic mean‐field theory coupled with the nonlinear K− field by the use of effective chiral Lagrangian. The effects of the Λ(1405) range terms on the structure of the MKN are taken into account. It is shown that baryon number density exceeds three times the normal saturation density in the central region of the MKN that a neutron skin structure becomes remarkable as the number of the embedded K− mesons increases. The similarity difference between the MKN kaon condensation in neutron stars are discussed.

We discuss the new exotic nuclei which contains charm and bottom flavors. We consider the possibility of exotic nuclei with D and B mesons. As simplest systems, we consider the systems of D and B bound with one nucleon and two nucleons. As an interaction between D (B) meson and nucleon, we regard the heavy quark symmetry as important. The potential between D (B) meson is supplied by one pion exchange potential as long range force based on heavy quark symmetry. We investigate possible DN (BN) bound state with several quantum numbers. We further discuss the possibility of the existence of DNN (BNN) as systems with baryon number two.

The origins of baryons and dark matter have been considered to be unrelated. We discuss the probability that both of the baryon number and dark matter arise from the same origin in the supersymmetric anomalous U(1) grand unified theory. We derive some conditions to make this scenario successful, and show they can be satisfied with appropriate model parameters.

The 1/NC expansion in baryons is discussed with two applications, namely baryon masses and partial decay widths. These applications provide the basic insights on the utility of the expansion.

The study of the universe's primordial plasma at high temperature plays an important role when tackling different questions in cosmology, such as the origin of the matter‐antimatter asymmetry. In the Minimal Standard Model (MSM) neither the amount of CP violation nor the strength of the phase transition are enough to produce and preserve baryon number during the Electroweak Phase Transition (EWPT), which are two of the three ingredients needed to develop baryon asymmetry. In this talk we present the first part of the analysis done within a scenario where it is viable to have improvements to the aforementioned situation: we work with the degrees of freedom in the broken symmetry phase of the MSM and analyze the development of the EWPT in the presence of a weak magnetic field. More specifically, we calculate the particle self‐energies that include the effects of the weak magnetic field, needed for the MSM effective potential up to ring diagrams.

The correlation between baryon number and strangeness, CBS = −3σBS/σS2, elucidates the nature of strongly interacting matter, such as that formed transiently in high‐energy nuclear collisions. This diagnostic can be extracted from lattice QCD calculations by means of its expression in terms of flavor susceptibilities, CBS = 1 + (χus + χds)/χss. The smallness of the mixed‐flavor susceptibitities severely limits the presence of qq bound states above the critical temperature, thus supporting a mean‐field picture of independent (quasi)quarks.

Our recent experiment (KEK-PS E471) has discovered a distinct peak structure in the proton semi-inclusive missing mass spectrum of the {sup 4}He(K{sub stop}{sup -}, pX{sup {+-}}) reaction. The state, denoted as strange tribaryon S0(3115), has a mass of 3117 MeV, baryon number B = 3, charge Z = 0, isospin T = 1 and strangeness S = - 1. For the further study, we carried out a new experiment, KEK-PS E549, by improving the experimental setup for better capability both on the proton and neutron spectroscopy. In this paper, the objectives of our new experiment are presented.

Physics of exotic hadrons is in the limelight these days. The models for these baryons are discussed as well as their production and decay processes and methods of their identification. The results of recent experiments in this field are presented, in which some unusual states are observed. These states are candidates for exotic hadrons.

The structure of high density nuclear matter is studied in the framework of a new approach, a mean‐field description of non‐overlapping neutron and proton bags with soft surfaces bound by the self‐consistent exchange of the σ, ω and ρ meson fields. We consider in this formulation each bag with an internal region, where quarks are free, a finite surface region, where the quark wave functions are gradually suppressed, and an exterior region, where the quark wave functions vanish. The finite surface region with a typical scale of about half a Fermi models the smooth transition region between the perturbative and non‐perturbative vacua, as expected from a gradual outside‐inside restoration of chiral symmetry. As an application we determine the structure of the equation of state for neutron stars. We then consistently include in the formulation lepton degrees of freedom, the chemical equilibrium conditions for neutron stars and baryon number and electric charge conservation. We investigate properties of both n...

We developed the new mass formula to obtain the exotic baryon mass spectrum which was observed by Tatischeff et al.

During the last year there has been mounting experimental evidence of the existence of a new type of baryon which cannot be made of three quarks but necessarily contains four quarks and one antiquark. It has been named Θ+ and its minimal quark content is uudds. Its mass is about 1540MeV and width less than about 10MeV. This baryon has been predicted in 1997 with the correct mass and narrow width from the chiral soliton model of baryons. In this contribution, we briefly summarize the main predictions of the soliton picture of baryons for exotic anti‐decuplet.

We study two distinct phases of nuclear matter, a baryon‐meson phase and a quark‐gluon phase (QGP). For the baryon‐meson phase we develop an equation of state (EoS) using a quark‐meson formulation based on a new version of the fuzzy bag model with scalar‐isoscalar, vector‐isoscalar and vector‐isovector meson‐quark couplings and leptonic degrees of freedom as well as the constraints of chemical equilibrium, baryon number and electric charge conservation. For the QGP phase we model an EoS for asymptotically free massless quarks and gluons using the MIT approach and a temperature and baryon chemical potential dependent bag constant, B(T,μ), which allows an isentropic equilibrium phase transition from a QGP to a hadron gas. Our main results indicate the EoS and static global properties of neutron stars and protoneutron stars at low and moderate values of temperature are slightly modified in comparison to the predictions based on the MIT bag model with a constant B.

We investigate in detail the compression modulus of nuclear matter as a function of the effective nucleon mass. We include consistently in our modelling chemical equilibrium as well as baryon number and electric charge conservation and investigate properties of neutron stars. Among other predictions, we focus on the dependence of the maximum mass of a sequence of neutron stars as a function of the compression modulus and the nucleon effective mass.

Recently it has been speculated by several authors that quark matter at large density and low temperature can become a color superconductor. This prediction relies on the asymptotically free character of the strong interaction, QCD, and on the general property of fermionic systems, for which the Fermi surface is unstable with respect to an attractive interaction among the fermions, however weak. In our work we have studied the effects of finite size on the two flavor colour superconducting state, by taking into account three different aspects: the boundary conditions felt by the quark fields, which are now constrained in a finite volume, the exact projection of the BCS state over a definite baryon number and the projection of the BCS state over a color singlet. These effects have been evaluated numerically.

Primordial magnetic fields, independently of their origin, could have had a significant influence over several physical processes that took place during the evolution of the early universe, in particular baryogenesis. Recall that for temperatures above the electroweak phase transition (T > 100 GeV), the symmetry of the standard model corresponded to the U(1)y hypercharge group, instead of the U(1)em electromagnetic group and are therefore properly called hypermagnetic fields. In this work, we show that during a first order electroweak phase transition, the presence of hypermagnetic fields produces an axial charge segregation in the reflection and transmission of fermions off the true vacuum bubbles. We also comment on the possible consequences that these processes have for the generation of baryon number during the phase transition.

We present a new interpretation for the low‐lying states recently observed by Tatischeff et al. based on the assumption of the polarization of the baryon number.

We comprehensively investigate a chaotic inflation model proposed recently in the framework of supergravity. In this model, the form of K\"ahler potential is determined by a symmetry, that is, the Nambu-Goldstone-like shift symmetry, which guarantees the absence of the exponential factor in the potential for the inflaton field. Though we need the introduction of small parameters, the smallness of the parameters is justified also by symmetries. That is, the zero limit of the small parameters recovers symmetries, which is natural in the 't Hooft's sense. The leptogenesis scenario via the inflaton decay in this chaotic inflation model is also discussed. We find that the lepton asymmetry enough to explain the present baryon number density is produced for low reheating temperatures avoiding the overproduction of gravitinos., Comment: 16 pages. To appear in Phys. Rev. D

The characteristic feature of the ground state configuration of the Skyrme model description of nuclei is the absence of recognizable individual nucleons. The classical skyrmion with baryon number 2 is axially symmetric, and can be approximated by a simple rational map anzats. Quantized version of biskyrmion then can be identified with dibarion if one employs three collective rotational coordinates. Three independent parameters, however, are not sufficient to identify biskyrmion with deuteron which has different values of spin and isospin. We show that modification of collective coordinate quantization approach by introducing additional three parameters allows us to identify quantized biskyrmion with the deuteron.