Search

Primordial black holes are studied in the Bose-Einstein condensate description of space-time. The question of baryon-number conservation is investigated with emphasis on the possible formation of bound states of the system's remaining captured baryons. This leads to distinct predictions both for the formation time, which for the naively natural assumptions is shown to lie between 10-12 s and 1012 s after the big bang, and for the remnant's mass, yielding approximately 3 x 1023 kg in the same scheme. The consequences for astrophysically formed black holes are also considered. [ABSTRACT FROM AUTHOR]

We present a search for ten baryon number violating decay modes of Λ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state (Λ→ml) and conserve either the sum or the difference of baryon and lepton number (B±L). The tenth decay mode (Λ→p¯π+) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range (4-200)×10-7 at the 90% confidence level. [ABSTRACT FROM AUTHOR]

We propose an extension of the Standard Model in which baryon number is promoted to be part of a non-Abelian gauge symmetry at high energies. Specifically, we consider the gauge group SU(4) x SU(2)L x U(1)X, where the SU(4) unifies baryon number and color. This symmetry is spontaneously broken down to the Standard Model gauge group at a scale which can be as low as a few TeV. The SU(4) stmcture implies that each SM quark comes along with an uncolored quark partner, the lightest of which is stabilized by the generalized baryon number symmetry and can play the role of dark matter. We explore circumstances under which one can realize a model of asymmetric dark matter whose relic abundance is connected to the observed baryon asymmetry, and discuss unique signatures that can be searched for at the LHC. [ABSTRACT FROM AUTHOR]

The article presents a study which promotes the use of baryon number in non-Abelian gauge symmetry, and mentions topics including the mechanism of baryogenesis, the properties of dark matter, and proton decay.

The article discusses the study which shows the possibility that pentaquark candidates within baryons' topological soliton picture could be accounted for quantum number and masses.

We initiate a study of cosmological implications of sphaleron-mediated CP-violation arising from the electroweak vacuum angle under the reasonable assumption that the semiclassical suppression is lifted at finite temperature. In this article, we explore the implications for existing scenarios of baryogenesis. Many compelling models of baryogenesis rely on electroweak sphalerons to relax a (B + L) charge asymmetry. Depending on the sign of the CP-violating parameter, it is shown that the erasure of positive (B + L) will proceed more or less quickly than the relaxation of negative (B + L). This is a higher order effect in the kinetic equation for baryon number, which we derive here through order n2B+L. Its impact on known baryogenesis models therefore seems minor, since phenomenologically nB+L is much smaller than the entropy density. However, there remains an intriguing unexplored possibility that baryogenesis could be achieved with the vacuum angle alone providing the required CP-violation. [ABSTRACT FROM AUTHOR]

We present a mechanism where a particle asymmetry in one sector is used to generate an asymmetry in another sector. The two sectors are not coupled through particle number violating interactions and are not required to be in thermal contact with each other. When this mechanism is applied to baryogenesis in asymmetric dark matter models, we find that the dark matter particles can be extremely light, e.g. much lighter than an eV, and that in some cases there is no need to annihilate away the symmetric component of dark matter. We discuss a concrete realization of the mechanism with signals in direct detection, at the LHC, at B-factories, or in future beam dump experiments. [ABSTRACT FROM AUTHOR]

We develop a one-parameter family of static baby Skyrme models that do not require a potential term to admit topological solitons. This is a novel property as the standard baby Skyrme model must contain a potential term in order to have stable soliton solutions, though the Skyrme model does not require this. Our new models satisfy an energy bound that is linear in terms of the topological charge and can be saturated in an extreme limit. They also satisfy a virial theorem that is shared by the Skyrme model. We calculate the solitons of our new models numerically and observe that their form depends significantly on the choice of parameter. In one extreme, we find compactons while at the other there is a scale invariant model in which solitons can be obtained exactly as solutions to a Bogomolny equation. We provide an initial investigation into these solitons and compare them with the baby Skyrmions of other models. [ABSTRACT FROM AUTHOR]

We study a Skyrme-type model with a quadratic potential for a field with S² vacua. We consider two flavors of the model, the first is the Skyrme model and the second has a sixth-order derivative term instead of the Skyrme term; both with the added quadratic potential. The model contains molecules of half Skyrmions, each of them is a global (anti)monopole with baryon number 1/2. We numerically construct solutions with baryon numbers one through six, and find stable solutions which look like beads on rings. We also construct a molecule with fractional Skyrmions having the baryon numbers 1 / 3 + 2/3, by adding a linear potential term. [ABSTRACT FROM AUTHOR]

A search for neutron-antineutron (n-n) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or 2.45 × 1034 neutron-year exposure data. This process violates both baryon and baryon minus lepton numbers by an absolute value of two units and is predicted by a large class of hypothetical models where the seesaw mechanism is incorporated to explain the observed tiny neutrino masses and the matter-antimatter asymmetry in the Universe. No evidence for n-n oscillation was found; the lower limit of the lifetime for neutrons bound in 16O, in an analysis that included all of the significant sources of experimental uncertainties, was determined to be 1.9 × 1032 years at the 90% confidence level. The corresponding lower limit for the oscillation time of free neutrons was calculated to be 2.7 × 108 using a theoretical value of the nuclear suppression factor of 0.517 × 1023 s-1 and its uncertainty. [ABSTRACT FROM AUTHOR]

The spin-charge-family theory [1-13], in which spinors, besides the Dirac spin, also carry the second kind of Clifford object--no charges--is a type of Kaluza-Klein theory [14]. The Dirac spinors of one Weyl representation in d = (13 + 1) manifest [1,3,4,10,13,15] in d = (3 + 1) at low energies all of the properties of quarks and leptons assumed by the standard model. The second kind of spin explains the origin of families. Spinors interact with the vielbeins and the two kinds of spin connection fields, the gauge fields of the two kinds of Clifford objects, which, besides the gravity and known gauge vector fields, manifest in d = (3 + 1) also several scalar gauge fields. Scalars with the space index s ∈ (7,8) carry the weak charge and the hypercharge (∓ 12, ± 12, respectively), thereby explaining the origin of the Higgs and Yukawa couplings. It is demonstrated in this paper that the scalar fields with the space index t ∈ (9,10,...,14) carry the triplet color charges, causing transitions of antileptons and antiquarks into quarks and back, thus enabling the appearance and the decay of baryons. These scalar fields show themselves in the presence of the right-handed neutrino condensate, which breaks the CP symmetry, the answer to the question about matter-antimatter asymmetry. [ABSTRACT FROM AUTHOR]

We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model: the first is the Skyrme model, and the second has a sixth-order derivative term instead of the Skyrme term, both with the added BEC motivated potential. The model contains toroidally shaped Skyrmions, and they are characterized by two integers P and Q, representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B = PQ. We find stable Skyrmion solutions for P = 1,2,3,4,5 with 0 = 1, while for P = 6 and Q = 1, it is only metastable. We further find that configurations with higher Q > 1 are all unstable and split into Q configurations with Q = 1. Finally we discover a phase transition, possibly of first order, in the mass parameter of the potential under study. [ABSTRACT FROM AUTHOR]

A novel cosmological scenario, capable of generating the observed baryon number at the electroweak scale for very small charge parity violating angles, is presented. The proposed mechanism can be applied in conventional Friedmann-Robertson-Walker cosmology, but becomes extremely efficient due to accretion in the context of early cosmic expansion with high-energy modifications. Assuming that our Universe is a Randall-Sundrum brane, baryon asymmetry can easily be produced by Hawking radiation of very small primordial black holes. The Hawking radiation reheats a spherical region around every black hole to a high temperature and the electroweak symmetry is restored there. A domain wall is formed separating the region with the symmetric vacuum from the asymmetric region where electroweak baryogenesis takes place. First order phase transition is not needed. The black hole's lifetime is prolonged due to accretion, resulting in strong efficiency of the baryon producing mechanism. The black hole mass range allowed by the mechanism includes masses that are energetically favored to be produced from interactions around the higher dimensional Planck scale. [ABSTRACT FROM AUTHOR]

We show that the discovery of baryon number violation in two processes, with at least one obeying the selection rule Δ(B - L) = ±2, can determine the Majorana character of neutrinos. Thus, observing p → e+ π0 and n e- π+ decays, or p → e+ π0 and n-n oscillations, or n → e-jπ+ and n-n oscillations would establish that neutrinos are Majorana particles. We discuss this in a model-independent effective operator approach. [ABSTRACT FROM AUTHOR]

Since the baryon-number susceptibilities are correlated with the cumulant of baryon-number fluctuations in experiments, we do calculations of the susceptibilities and compare them with the experimental fluctuation data under the framework of the Dyson-Schwinger equations (DSEs) approach. We compare our results with lattice QCD and experimental data at RHIC. The fitness of the results indicates that under the framework of DSEs, we can deal with the problems of heavy ion collisions properly. [ABSTRACT FROM AUTHOR]

We consider two-color QCD with two flavors of quarks as a possible theory of composite dark matter and use lattice field theory methods to investigate nuclear spectroscopy in the spin 7 = 0 and J = 1 multibaryon sectors. We find compelling evidence that J = 1 systems with baryon number B = 2,3 (and their mixed meson-baryon counterparts) are bound states--the analogues of nuclei in this theory. In addition, we estimate the cr-terms of the J = 0 and J = 1 single baryon states which are important for the coupling of the theory to scalar currents that may mediate interactions with the visible sector. [ABSTRACT FROM AUTHOR]

We investigate whether the baryon asymmetry of the Universe is explained in the framework of the supersymmetric extension of the Standard Model with R-parity violating interactions. It is shown that the Affleck-Dine mechanism naturally works via a trilinear interaction LLEc, LQDc, or Uc Dc Dc, if the magnitude of the coupling corresponding to the operator λ, λ', or λ" is sufficiently small. The formation of Q-balls and their subsequent evolution are also discussed. The present baryon asymmetry can be explained in the parameter region where R-parity is mildly violated 10-9≲ λ,λ',λ" ≲ 10 -6 and the mass of the gravitino is relatively heavy m3/2 104 GeV. On the other hand, it is difficult to explain the present baryon asymmetry for larger values of R-parity violating couplings λ,λ',λ" ≳ 10-5, since Q-balls are likely to be destructed in the thermal environment and the primordial baryon number is washed away. [ABSTRACT FROM AUTHOR]

Generic extensions of the Standard Model that respect baryon and lepton numbers have accidentally stable particles. Typical examples are the lightest exotic neutral fermion, or "neutralino," and fields with nontrivial lepton and baryon charges. In this paper we identify the accidentally stable neutralino with the dark matter, and discuss its phenomenology in the framework of warped extra dimensions. We find that annihilation into other Kaluza-Klein resonances is often allowed and very efficient. The observed dark matter abundance may then be obtained with couplings of order unity and a compactification scale above the TeV. Light dark matter is also possible in the presence of unsuppressed couplings to the Higgs boson. In this latter case dark matter direct detection experiments will soon be able to probe a significant portion of the parameter space. This analysis suggests that dark matter is a natural feature of realistic models with warped extra dimensions. [ABSTRACT FROM AUTHOR]

The geometrical construction of rational maps using a cubic grid has led to many new Skyrmion solutions, with baryon numbers up to 108. Energy spectra of some of the new Skyrmions are calculated here by semiclassical quantization. Quantization of the B = 20 Td-symmetric Skyrmion, which is one of the newly found Skyrmions, is considered, and this leads to the development of a new approach to solving Finkelstein- Rubinstein constraints. Matrix equations are simplified by introducing a Cartesian version of angular momentum basis states, and the computations are easier. The quantum states of all Td-symmetric Skyrmions, constructed from the cubic grid, are classified into three classes, depending on the contribution of vertex points of the cubic grid to the rational maps. The analysis is extended to the larger symmetry group Oh. Quantum states of Oh-symmetric Skyrmions, constructed from the cubic grid, form a subset of the Td-symmetric quantum states. [ABSTRACT FROM AUTHOR]

Is it possible to detect a new weakly coupled force at the QCD scale that interacts primarily with quarks? This work investigates experimental signatures of a new MeV-GeV gauge boson that couples to the baryon number, with attention to the 100 MeV-GeV mass range that is the regime of nonperturbative QCD. Such a state can be searched for in rare radiative decays of light mesons (η, η', φ, ω) as a π0γ resonance, which is its leading decay mode from 140 to 620 MeV. This is a new discovery window for forces beyond the Standard Model that is not covered by existing dark photon searches. [ABSTRACT FROM AUTHOR]

We investigate that the two types of the Q-balls explain the baryon asymmetry and the dark matter of the Universe in the gauge-mediated supersymmetry breaking. The gauge-mediation type Q-balls of one flat direction produce baryon asymmetry, while the new type Q-balls of another flat direction become the dark matter. We show that the dark matter new type Q-balls are free from the neutron star constraint. The n = 5 gauge mediation type and n = 6 new type Q-balls are displayed as an example, where the potential is lifted by the superpotential Fn. These dark matter Q-balls may be detected by future observations, such as in advanced IceCube-like observations. [ABSTRACT FROM AUTHOR]

We construct a spherical domain wall which has baryon charge distributed on a sphere of finite radius in a Skyrme model with a sixth order derivative term and a modified mass term. Its distribution of energy density likewise takes the form of a sphere. In order to localize the domain wall at a finite radius we need a negative coefficient in front of the Skyrme term and a positive coefficient of the sixth order derivative term to stabilize the soliton. Increasing the pion mass pronounces the shell-like structure of the configuration. [ABSTRACT FROM AUTHOR]

Hadronic matrix elements of proton decays are essential ingredients for bridging the grand unification theory to low-energy observables like the proton lifetime. In this paper we nonperturbatively calculate the matrix elements, relevant for the process of a nucleon decaying into a pseudoscalar meson and an antilepton through generic baryon-number-violating four-fermi operators. Lattice QCD with 2 + 1 flavor dynamical domain-wall fermions with the direct method--which is the direct measurement of the matrix elements from the three-point function without using chiral perturbation theory--is used for this study in order to have good control over the errors due to lattice discretization effects, operator renormalization, and chiral extrapolation. The relevant form factors for possible transition processes from an initial proton or neutron to a final pion or kaon induced by all types of three-quark operators are obtained through three-point functions of the (nucleon)-(three-quark operator)-(meson) with physical kinematics. In this study all the relevant systematic uncertainties of the form factors are taken into account for the first time, and the total error is found to be in the range 30% 10% for the n and 20% Of 0% for the K final states. [ABSTRACT FROM AUTHOR]

A simple theoretical framework for the spontaneous breaking of parity, and baryon and lepton numbers is proposed. In this context, the baryon and lepton numbers are independent local gauge symmetries, while parity is defined making use of the left-right symmetry. We show that in the minimal model the new leptoquark fields needed to define an anomaly-free theory also generate neutrino masses through the type III seesaw mechanism. The spectrum of neutrinos and some phenomenological aspects are discussed. This theory predicts the possible existence of two light sterile neutrinos. [ABSTRACT FROM AUTHOR]

Effects of an external magnetic field on the fluctuations of quark number, fluctuations, and correlations of conserved charges, including baryon number, electric charge, and strangeness, are studied in the 2+1 flavor Polyakov-Nambu-Jona-Lasinio model. We find that a magnetic field increases fluctuations and correlations in the regime of chiral crossover. It makes the transition of quadratic fluctuations more abrupt, and the peak structure of quartic fluctuations more pronounced. Our calculations indicate that ?4B/?2B, ?4Q/?2Q, and ?11BQ are very sensitive to the external magnetic field and can possibly be used for probes for the strong magnetic field produced in the early stage of noncentral collisions. [ABSTRACT FROM AUTHOR]

The Skyrme crystal is built up of repeating units similar to the cubic Skyrmion of baryon number 4. Using this as a guide, we construct new Skyrmion solutions in the massive-pion case, with various baryon numbers up to 108. Most of our solutions resemble chunks of the Skyrme crystal. They are constructed using a multilayer version of the rational map ansatz to create initial configurations, which are then relaxed numerically to find the energy minima. The coefficients of the rational maps are found by a geometrical construction related to the Skyrme crystal structure. We find some further solutions by numerical relaxation of clusters composed of baryon number 4 Skyrmions. [ABSTRACT FROM AUTHOR]

Abstract: Thermal generation of baryon number asymmetry in the Universe is studied in a radiative neutrino mass model with an inert doublet scalar. We show that the sufficient baryon number asymmetry can be produced through resonant leptogenesis under rather mild degeneracy between right-handed neutrinos compared with the ordinary TeV-scale seesaw scenario. [Copyright &y& Elsevier]

We enumerate the simplest models that have baryon number violation at the classical level but do not give rise to proton decay. These models have scalar fields in two representations of SU(3)×SU(2)×U(1) and violate baryon number by two units. Some of the models give rise to nn̅ (neutron-antineutron) oscillations, while some also violate lepton number by two units. We discuss the range of scalar masses for which nn̅ oscillations are measurable in the next generation of experiments. We give a brief overview of the phenomenology of these models and then focus on one of them for a more quantitative discussion of nn̅ oscillations, the generation of the cosmological baryon number, the electric dipole moment of the neutron, and K0-K̅0 mixing. [ABSTRACT FROM AUTHOR]

Abstract: After a brief discussion of baryon and lepton number nonconservation, we review the status of thermal leptogenesis with GUT scale neutrino masses, as well as low scale alternatives with keV neutrinos as dark matter and heavy neutrino masses within the reach of the LHC. Recent progress towards a full quantum mechnical description of leptogenesis is described with resonant leptogenesis as an application. Finally, cosmological B-L breaking after inflation is considered as origin of the hot early universe, generating entropy, baryon asymmetry and dark matter. [Copyright &y& Elsevier]

The contribution of the R-parity violating minimal supersymmetric standard model to the neutron beta decay at the one-loop level is investigated. It is found that the baryon number and R-parity violating interactions contribute to the D correlation through one-loop corrections, while the tree-level prediction is vanishing. The Fierz interference term is also investigated at the one-loop level by considering the lepton number and R-parity violating interactions. We show that future experimental progress can provide us with better constraints on some of the combinations of R-parity violating couplings. [ABSTRACT FROM AUTHOR]

The quark gluon plasma (QGP) at zero temperature and high baryon number is a system that may be present inside compact stars. It is quite possible that this cold QGP shares some relevant features with the hot QGP observed in heavy ion collisions, being also a strongly interacting system. In a previous work we have derived from the QCD Lagrangian an equation of state (EOS) for the cold QGP, which can be considered an improved version of the MIT bag-model EOS. Compared to the latter, our EOS reaches higher values of the pressure at comparable baryon densities. This feature is due to perturbative corrections and also to nonperturbative effects. Here we apply this EOS to the study of neutron stars, discussing the absolute stability of quark matter and computing the mass-radius relation for self-bound (strange) stars. The maximum masses of the sequences exceed two solar masses, in agreement with the recently measured values of the mass of the pulsar PSR J1614-2230, and the corresponding radii of around 10-11 km. [ABSTRACT FROM AUTHOR]

We list all scalar and vector leptoquark states that contribute to the b → sℓ+ℓ- effective Hamiltonian. There are altogether three scalar and four vector leptoquarks that are relevant. For contribution of each state we infer the correlations between effective operators and find that only two baryon number-violating vector leptoquarks give rise to scalar and pseudoscalar four-fermion operators, whereas the scalar states can contribute to those operators only when two states with same charge are present. We bound the resulting Wilson coefficients by imposing experimental constraints coming from branching fractions of B → Kℓ+ℓ-, Bs μ+μ-, and B → Xsμ+μ- decays. [ABSTRACT FROM AUTHOR]

The radiative neutrino mass model with an inert doublet scalar has been considered as a promising candidate which can explain neutrino masses, dark matter abundance and baryon number asymmetry if dark matter is identified with the lightest neutral component of the inert doublet. We reexamine these properties by imposing all the data of the neutrino oscillation, which are recently suggested by the reactor experiments. We find that the sufficient baryon number asymmetry seems not to be easily generated in a consistent way with all the data of the neutrino masses and mixing as long as the right-handed neutrinos are kept in TeV regions. Two possible modifications of the model are examined. [ABSTRACT FROM AUTHOR]

We list scalar leptoquarks which mediate proton decay via renormalizable couplings to the standard model fermions. We employ a general basis of baryon number violating operators to parametrize contributions of each leptoquark towards proton decay. This then sets the stage for investigation of bounds on the leptoquark couplings to fermions with respect to the most current Super Kamiokande results on proton stability. We quantify if, and when, it is necessary to have leptoquark masses close to a scale of grand unification in the realistic SU(5) and flipped SU(5) frameworks. The most and the least conservative lower bounds on the leptoquark masses are then presented. We furthermore single out a leptoquark without phenomenologically dangerous tree-level exchanges which might explain discrepancy of the forward-backward asymmetries in tt production observed at Tevatron, if relatively light. The same state could also play a significant role in explaining muon anomalous magnetic moment. We identify contributions of this leptoquark to dimension-six operators, mediated through a box diagram, and tree-level dimension-nine operators, which would destabilize the proton if sizable leptoquark and diquark couplings were to be simultaneously present. [ABSTRACT FROM AUTHOR]

The relation between the baryon number in QCD at nonzero chemical potential and the spectral density of the baryon number Dirac operator, &ggr;0{D + m), is examined. We show that extreme oscillations of the spectral density, caused by the QCD sign problem, are essential for the formation of the average baryon number when &mgr; > m_/2. We compute the oscillating region of the spectral density using chiral perturbation theory. The extreme oscillations have a microscopic period and are resolved using random matrix theory. [ABSTRACT FROM AUTHOR]

Baryon number violating interactions could modify the signatures of supersymmetric models at the Large Hadron Collider. In this article we investigate the predictions for the Higgs mass and the Higgs decays in a simple extension of the minimal supersymmetric standard model where the local baryon and lepton numbers are spontaneously broken at the TeV scale. This theory predicts baryon number violation at the low scale that can change the current LHC bounds on the supersymmetric spectrum. Using the ATLAS and CMS bounds on the Higgs mass we show the constraints on the sfermion masses and show the subsequent predictions for the radiative Higgs decays. We found that the Higgs decay into two photons is suppressed due to the existence of new light leptons. In this theory the stops can be very light in agreement with all experimental bounds, and we make a brief discussion of the possible signals at the LHC. [ABSTRACT FROM AUTHOR]

The relatively small binding energy in nuclei suggests that they may be well represented by near-BPS Skyrmions since their mass is roughly proportional to the baryon number A. For that purpose, we propose a generalization of the Skyrme model with terms up to order six in derivatives of the pion fields and treat the nonlinear &sgr; and Skyrme terms as small perturbations. For our special choice of mass term (or potential) V, we obtain well-behaved analytical BPS-type solutions with nonshell configurations for the baryon density, as opposed to the more complex shell-like configurations found in most extensions of the Skyrme model. Along with static and (iso)rotational energies, we add to the mass of the nuclei the often neglected Coulomb energy and isospin breaking term. Fitting the four model parameters, we find a remarkable agreement for the binding energy per nucleon Β/A with respect to experimental data. These results support the idea that nuclei could be near-BPS Skyrmions. [ABSTRACT FROM AUTHOR]

Massive Z′-gauge bosons act as excellent harbingers for string compactifications with a low string scale. In D-brane models they are associated to i/(l) gauge symmetries that are either anomalous in four dimensions or exhibit a hidden higher-dimensional anomaly. We discuss the possible signals of massive Z′-gauge bosons at hadron collider machines (Tevatron, LHC) in a minimal D-brane model consisting out of four stacks of D-branes. In this construction, there are two massive gauge bosons, which can be naturally associated with baryon number B and B -- L (L being lepton number). Here baryon number is always anomalous in four dimensions, whereas the presence of a four-dimensional B -- L anomaly depends on the t/(l)-charges of the right-handed neutrinos. In case B -- L is anomaly-free, a mass hierarchy between the two associated Z′-gauge bosons can be explained. In our phenomenological discussion about the possible discovery of massive Z′-gauge bosons, we take as a benchmark scenario the dijet plus W signal, recently observed by the CDF Collaboration at Tevatron. It reveals an excess in the dijet-mass range 150 GeV/c2, 4.1σ beyond standard modelexpectations. We show that in the context of low-mass string theory this excess can be associated with the production and decay of a leptophobic Z′, a singlet partner of SU(3) gluons coupled primarily to baryon number. Even if the CDF signal disappears, as indicated by the more recent DO results, our analysis can still serve as the basis for future experimental search for massive Z′-gauge bosons in low string scale models. We provide the relevant cross sections for the production of Z′-gauge bosons in the TeV region, leading to predictions that are within reach of the present or the next LHC run. [ABSTRACT FROM AUTHOR]

We consider an extension of the radiative neutrino mass model at TeV regions so as to give the origin for inflation of the Universe. This extension also gives a consistent explanation for both the origin of baryon number asymmetry and dark matter. A small scalar coupling which plays a crucial role in the neutrino mass generation in the original model may be related to parameters which control inflation. [ABSTRACT FROM AUTHOR]

Subject to strong experimental constraints at low energies, baryon number violation is nonetheless well motivated from a theoretical point of view. We examine the possibility of observing baryon-number-violating top-quark production or decay at hadron colliders. We adopt a model-independent effective approach and focus on operators with minimal mass dimension. Corresponding effective coefficients could be directly probed at the Large Hadron Collider (LHC) already with an integrated luminosity of 1 fb-1 at 7 TeV, and further constrained with 30(100) fb-1 at 7 (14) TeV. [ABSTRACT FROM AUTHOR]

Baryon number violating (BNV) processes are heavily constrained by experiments searching lor nucleon decay and neutron-antineutron oscillations. If the baryon number violation occurs via the third generation quarks, however, we may be able to avoid the nucleon stability constraints, thus making such BNV interactions accessible at the LHC. In this paper we study a specific class of BNV extensions of the standard model involving diquark and leptoquark scalars. After an introduction to these models we study one promising extension in detail, being interested in particles with mass of O(TeV). We calculate limits on the masses and couplings from neutron-antineutron oscillations and dineutron decay for couplings to first and third generation quarks. We explore the possible consequences of such a model on the matter- antimatter asymmetry. We shall see that for models which break the global baryon minus lepton number symmetry (B - L), the most stringent constraints come from the need to preserve a matter-antimatter asymmetry. That is, the BNV interaction cannot be introduced if it would remove the matter-antimatter asymmetry independent of baryogenesis mechanism and temperature. Finally, we examine the phenome- nology of such models at colliders such as the LHC. [ABSTRACT FROM AUTHOR]

We investigate the large baryon number sector of the Einstein-Skyrme model as a possible model for baryon stars and construct low energy configurations that resemble neutron stars. Previous studies have shown that gravitating Skyrmions produced by using rational maps can achieve spherically symmetric, multibaryon-bound states at large baryon numbers, but these configurations were hollow shells. In this paper, we improve on the previous work by constructing configurations corresponding to solid spheres with a radius-dependent baryon density. [ABSTRACT FROM AUTHOR]

Motivated by recent attempts to reconcile hints of direct dark matter detection by the CoGeNT and DAMA experiments, we construct simple particle physics models that can accommodate the constraints. We point out challenges for building reasonable models and identify the most promising scenarios for getting isospin violation and inelasticity, as indicated by some phenomenological studies. If inelastic scattering is demanded, we need two new light gauge bosons, one of which kinetically mixes with the standard model hypercharge and has mass <2 GeV, and another which couples to baryon number and has mass Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. GeV. Their interference gives the desired amount of isospin violation. The dark matter is nearly Dirac, but with small Majorana masses induced by spontaneous symmetry breaking, so that the gauge boson couplings become exactly off-diagonal in the mass basis, and the small mass splitting needed for inelasticity is simultaneously produced. If only elastic scattering is demanded, then an alternative model, with interference between the kinetically mixed gauge boson and a hidden sector scalar Higgs, is adequate to give the required isospin violation. In both cases, the light kinetically mixed gauge boson is in the range of interest for currently running fixed target experiments. [ABSTRACT FROM AUTHOR]

We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T matrix for meson-baryon scattering in the s wave. The building blocks of the scheme are the π and N octets, the ρ nonet and the Δ decuplet. We identify poles in this unitary T matrix and interpret them as resonances. We study here the nonexotic sectors with strangeness S = 0, -1, -2, -3 and spin J = 1/2,1/3 and 5/2. Many of the poles generated can be associated with known N, Δ, Σ, Λ, Ξ and Ω resonances with negative parity. We show that most of the low-lying three and four star odd-parity baryon resonances with spin 1/2 and 3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This study allows us to predict the spin-parity of the Ξ(1620), Ξ(1690), Ξ(1950), Ξ(2250), Ω(2250) and Ω(2380) resonances, which have not been determined experimentally yet. [ABSTRACT FROM AUTHOR]

We study the QCD phase diagram at finite temperature and baryon chemical potential by relating the behavior of the light-quark condensate to the threshold energy for the onset of perturbative QCD. These parameters are connected to the chiral symmetry restoration and the deconfinement phase transition, respectively. This relation is obtained in the framework of finite energy QCD sum rules at finite temperature and density, with input from Schwinger-Dyson methods to determine the light-quark condensate. Results indicate that both critical temperatures are basically the same within some 3% accuracy. We also obtain bounds for the position of the critical end point, μBc ≳ 300 MeV and Tc ≲ 185 MeV. [ABSTRACT FROM AUTHOR]

We investigate the spontaneous breaking of the Baryon (B) and Lepton (L) number at the TeV scale in supersymmetric models. A simple extension of the minimal supersymmetric standard model where B and L are spontaneously broken local gauge symmetries is proposed. The B and L symmetry breaking scales are defined by the supersymmetry breaking scale. By gauging B and L, we understand the absence of the baryon and lepton number violating interactions of dimension four and five in the minimal supersymmetric standard model. Furthermore, we show that even though these symmetries are spontaneously broken there are no dangerous operators mediating proton decay. We discuss the main properties of the spectrum, the possible baryon number violating decays and the implications for the dark matter candidates. In this model, one can have lepton number violating signals from the decays of the right-banded neutrinos and baryon number violating signals from the decays of squarks and gauginos without conflict with the bounds coming from proton decay, n - n̄ oscillations and dinucleon decays. [ABSTRACT FROM AUTHOR]

This paper considers unitarity and CPT constraints on asymmetric freeze-in, the use of freeze-in to store baryon number in a dark sector. In this scenario, Sakharov's out-of-equilibrium condition is satisfied by placing the visible and hidden sectors at different temperatures while a net visible baryon number is produced by storing negative baryon number in a dark sector. It is shown that unitarity and CPT lead to unexpected cancellations. In particular, the transfer of baryon number cancels completely at leading order. [ABSTRACT FROM AUTHOR]

We discuss the role of cumulants of net baryon number fluctuations in the analysis of critical behavior in QCD and the study of freeze-out conditions in heavy ion experiments. Through the comparison of the current set of measurements of higher order cumulants of net baryon number fluctuations with lattice QCD calculations and results from hadron resonance gas model we can learn to what extent freeze-out as, determined by such cumulants, occurs close to the QCD transition temperature and thus can probe critical behavior at small values of the baryon chemical potential. However, we provide indications that a recently performed comparison of lattice QCD results on cumulants with data from heavy ion experiments suffer from systematic as well as statistical uncertainties in the lattice QCD calculations, which makes such comparison at present not useful. [ABSTRACT FROM AUTHOR]

At large baryon number density, it is likely that the ground state of QCD is a color-flavor-locked phase with a K0 condensate. The CFL + K0 phase is known to support superconducting vortex strings, and it has been previously suggested that it may also support vortons, which are superconducting vortex rings. We reexamine the question of the stability of vortons, taking into account electromagnetic effects, which make leading-order contributions to vorton dynamics but were not investigated in previous work. We find that current-carrying and electrically charged vortons can be stabilized either by their angular momentum, by Coulomb repulsion, or by a combination of both effects. [ABSTRACT FROM AUTHOR]

We develop an analytical technique to evaluate the magnetic helicity in the debris from sphaleron decay. We show that baryon number production leads to left-handed magnetic fields, and that the magnetic helicity is conserved at late times. Our analysis explicitly demonstrates the connection between sphaleron-mediated cosmic baryogenesis and cosmic magnetogenesis. [ABSTRACT FROM AUTHOR]