Equivalence of model space techniques and the renormalization group for a separable model problem

Lee-Suzuki similarity transformations and Krencigowa-Kuo folded diagrams are two common methods used to derive energy independent model space effective interactions for nuclear many-body systems. We demonstrate that these methods are equivalent to a Renormalization Group (RG) analysis of a separable potential model. The effective low-momentum potentials V_{eff} are shown to give the same scaling equation that RG arguments predict. We find the new result that the different model space techniques considered in this paper yield a unique low-momentum V_{eff} when applied to the toy model problem.Comment: 10 pages. Minor content and stylistic change

CP violation in 5D Split Fermions Scenario

We give a new configuration of split fermion positions in one extra dimension with two different Yukawa coupling strengths for up-type, $h_u$, and down-type, $h_d$, quarks at $\frac{h_u}{h_d}=36.0$. The new configurations can give enough CP violating (CPV) phase for accommodating all currently observed CPV processes. Therefore, a 5D standard model with split fermions is viable. In addition to the standard CKM phase, new CPV sources involving Kaluza-Klein(KK) gauge bosons coupling which arise from the fact that unitary rotation which transforms weak eigenstates into their mass eigenstates only holds for the zero modes which are the SM fields and not for the KK excitations. We have examined the physics of kaon, neutron, and $B/D$ mesons and found the most stringent bound on the size $R$ of the extra dimension comes from $|\epsilon_K|$. Moreover, it depends sensitively on the width, $\sigma$, of the Gaussian wavefunction in the extra dimension used to describe of the fermions. When $\sigma/R \ll 1$, the constraint will be lifted due to GIM suppression on the flavor changing neutral current(FCNC) and CPV couplings.Comment: 24 pages, 8 figure

Towards a Model-Independent Low Momentum Nucleon-Nucleon Interaction

We provide evidence for a high precision model-independent low momentum nucleon-nucleon interaction. Performing a momentum-space renormalization group decimation, we find that the effective interactions constructed from various high precision nucleon-nucleon interaction models, such as the Paris, Bonn, Nijmegen, Argonne, CD Bonn and Idaho potentials, are identical. This model-independent low momentum interaction, called V_{low k}, reproduces the same phase shifts and deuteron pole as the input potential models, without ambiguous assumptions on the high momentum components, which are not constrained by low energy data and lead to model-dependent results in many-body applications. V_{low k} is energy-independent and does not necessitate the calculation of the Brueckner G matrix.Comment: 12 pages, 5 figures, minor changes and additions, to appear in Phys. Lett.

Model-independent low momentum nucleon interaction from phase shift equivalence

We present detailed results for the model-independent low momentum nucleon-nucleon interaction V_{low k}. By introducing a cutoff in momentum space, we separate the Hilbert space into a low momentum and a high momentum part. The renormalization group is used to construct the effective interaction V_{low k} in the low momentum space, starting from various high precision potential models commonly used in nuclear many-body calculations. With a cutoff in the range of $\Lambda ~ 2.1 fm^{-1}$, the new potential V_{low k} is independent of the input model, and reproduces the experimental phase shift data for corresponding laboratory energies below $E_{lab} ~ 350 MeV$, as well as the deuteron binding energy with similar accuracy as the realistic input potentials. The model independence of V_{low k} demonstrates that the physics of nucleons interacting at low momenta does not depend on details of the high momentum dynamics assumed in conventional potential models. V_{low k} does not have momentum components larger than the cutoff, and as a consequence is considerably softer than the high precision potentials. Therefore, when V_{low k} is used as microscopic input in the many-body problem, the high momentum effects in the particle-particle channel do not have to be addressed by performing a Brueckner ladder resummation or short-range correlation methods. By varying the cutoff, we study how the model independence of V_{low k} is reached in different partial waves. This provides numerical evidence for the separation of scales in the nuclear problem, and physical insight into the nature of the low momentum interaction.Comment: 32 pages, 19 figure

Sub-millimeter Tests of the Gravitational Inverse-square Law

Motivated by a variety of theories that predict new effects, we tested the gravitational 1/r^2 law at separations between 10.77 mm and 137 microns using two different 10-fold azimuthally symmetric torsion pendulums and rotating 10-fold symmetric attractors. Our work improves upon other experiments by up to a factor of about 100. We found no deviation from Newtonian physics at the 95% confidence level and interpret these results as constraints on extensions of the Standard Model that predict Yukawa or power-law forces. We set a constraint on the largest single extra dimension (assuming toroidal compactification and that one extra dimension is significantly larger than all the others) of R <= 160 microns, and on two equal-sized large extra dimensions of R <= 130 microns. Yukawa interactions with |alpha| >= 1 are ruled out at 95% confidence for lambda >= 197 microns. Extra-dimensions scenarios stabilized by radions are restricted to unification masses M >= 3.0 TeV/c^2, regardless of the number of large extra dimensions. We also provide new constraints on power-law potentials V(r)\propto r^{-k} with k between 2 and 5 and on the gamma_5 couplings of pseudoscalars with m <= 10 meV/c^2.Comment: 34 pages, 38 figure

Neutrino Oscillations and Collider Test of the R-parity Violating Minimal Supergravity Model

We study the R-parity violating minimal supergravity models accounting for the observed neutrino masses and mixing, which can be tested in future collider experiments. The bi-large mixing can be explained by allowing five dominant tri-linear couplings $\lambda'_{1,2,3}$ and $\lambda_{1,2}$. The desired ratio of the atmospheric and solar neutrino mass-squared differences can be obtained in a very limited parameter space where the tree-level contribution is tuned to be suppressed. In this allowed region, we quantify the correlation between the three neutrino mixing angles and the tri-linear R-parity violating couplings. Qualitatively, the relations $| \lambda'_1 | < | \lambda'_2| \sim | \lambda'_3|$, and $|\lambda_1| \sim |\lambda_2|$ are required by the large atmospheric neutrino mixing angle $\theta_{23}$ and the small angle $\theta_{13}$, and the large solar neutrino mixing angle $\theta_{12}$, respectively. Such a prediction on the couplings can be tested in the next linear colliders by observing the branching ratios of the lightest supersymmetric particle (LSP). For the stau or the neutralino LSP, the ratio $|\lambda_1|^2: |\lambda_2|^2: |\lambda_1|^2 + |\lambda_2|^2$ can be measured by establishing $Br(e\nu): Br(\mu\nu) : Br(\tau\nu)$ or $Br(\nu e^\pm \tau^\mp ): Br(\nu\mu^\pm\tau^\mp) : Br(\nu\tau^\pm\tau^\mp)$, respectively. The information on the couplings $\lambda'_i$ can be drawn by measuring $Br(l_i t \bar{b}) \propto |\lambda'_i|^2$ if the neutralino LSP is heavier than the top quark.Comment: RevTex, 25 pages, 8 eps figure

Local realizations of contact interactions in two- and three-body problems

Mathematically rigorous theory of the two-body contact interaction in three dimension is reviewed. Local potential realizations of this proper contact interaction are given in terms of Poschl-Teller, exponential and square-well potentials. Three body calculation is carried out for the halo nucleus 11Li using adequately represented contact interaction.Comment: submitted to Phys. Rev.

θ13\theta_{13}, δ\delta and the neutrino mass hierarchy at a γ=350\gamma=350 double baseline Li/B β\beta-Beam

We consider a $\beta$-Beam facility where $^8$Li and $^8$B ions are accelerated at $\gamma = 350$, accumulated in a 10 Km storage ring and let decay, so as to produce intense $\bar \nu_e$ and $\nu_e$ beams. These beams illuminate two iron detectors located at $L \simeq 2000$ Km and $L \simeq 7000$ Km, respectively. The physics potential of this setup is analysed in full detail as a function of the flux. We find that, for the highest flux ($10 \times 10^{18}$ ion decays per year per baseline), the sensitivity to $\theta_{13}$ reaches $\sin^2 2 \theta_{13} \geq 2 \times10^{-4}$; the sign of the atmospheric mass difference can be identified, regardless of the true hierarchy, for $\sin^2 2 \theta_{13} \geq 4\times10^{-4}$; and, CP-violation can be discovered in 70% of the $\delta$-parameter space for $\sin^2 2 \theta_{13} \geq 10^{-3}$, having some sensitivity to CP-violation down to $\sin^2 2 \theta_{13} \geq 10^{-4}$ for $|\delta| \sim 90^\circ$.Comment: 35 pages, 20 figures. Minor changes, matches the published versio

U(2)-like Flavor Symmetries and Approximate Bimaximal Neutrino Mixing

Models involving a U(2) flavor symmetry, or any of a number of its non-Abelian discrete subgroups, can explain the observed hierarchy of charged fermion masses and CKM angles. It is known that a large neutrino mixing angle connecting second and third generation fields may arise via the seesaw mechanism in these models, without a fine tuning of parameters. Here we show that it is possible to obtain approximate bimaximal mixing in a class of models with U(2)-like Yukawa textures. We find a minimal form for Dirac and Majorana neutrino mass matrices that leads to two large mixing angles, and show that our result can quantitatively explain atmospheric neutrino oscillations while accommodating the favored, large angle MSW solution to the solar neutrino problem. We demonstrate that these textures can arise in models by presenting a number of explicit examples.Comment: 20 pages RevTex4, 2 figure

Probing Sub-Micron Forces by Interferometry of Bose-Einstein Condensed Atoms

We propose a technique, using interferometry of Bose-Einstein condensed alkali atoms, for the detection of sub-micron-range forces. It may extend present searches at 1 micron by 6 to 9 orders of magnitude, deep into the theoretically interesting regime of 1000 times gravity. We give several examples of both four-dimensional particles (moduli), as well as higher-dimensional particles -- vectors and scalars in a large bulk-- that could mediate forces accessible by this technique.Comment: 32 pages, 5 figures, RevTeX4, expanded discussion of interactions, references added, to appear in PR