Measuring Slepton Masses and Mixings at the LHC (2009)
Feng, Jonathan L., French, Sky T., Galon, Iftah, Lester, Christopher G., Nir, Yosef, Shadmi, Yael, ...
Flavor physics may help us understand theories beyond the standard model. In the context of supersymmetry, if we can measure the masses and mixings of sleptons and squarks, we may learn something...
BMSSM Implications for Cosmology (2009)
Bernal, Nicolas, Blum, Kfir, Losada, Marta, Nir, Yosef
The addition of non-renormalizable terms involving the Higgs fields to the MSSM (BMSSM) ameliorates the little hierarchy problem of the MSSM. We analyze in detail the two main cosmological issues...
The Shifted Peak: Resolving Nearly Degenerate Particles at the LHC (2009)
Feng, Jonathan L., French, Sky T., Lester, Christopher G., Nir, Yosef, Shadmi, Yael
We propose a method for determining the mass difference between two particles, \slep_1 and \slep_2, that are nearly degenerate, with \Delta{m}, defined as m_2-m_1, being much less than m_1. This...
Lessons from Recent Measurements of D-\bar D Mixing (2009)
Gedalia, Oram, Grossman, Yuval, Nir, Yosef, Perez, Gilad
An impressive progress in measurements of the D-\bar D mixing parameters has been made in recent years. We explore the implications of these measurements to models of new physics, especially in view...
Future prospects of B physics (2009)
Grossman, Yuval, Ligeti, Zoltan, Nir, Yosef
In recent years, the CKM picture of flavor and CP violation has been confirmed, mainly due to B decay data. Yet, it is likely that there are small corrections to this picture. We expect to find new...
Testing New Indirect CP Violation (2009)
Grossman, Yuval, Nir, Yosef, Perez, Gilad
If new CP violating physics contributes to neutral meson mixing, but its contribution to CP violation in decay amplitudes is negligible, then there is a model independent relation between four...
Blum, Kfir, Grossman, Yuval, Nir, Yosef, Perez, Gilad
New physics at high energy scale often contributes to K-\bar K and D-\bar D mixings in an approximately SU(2)_L invariant way. In such a case, the combination of measurements in these two systems is...
Flavor Changing Processes in Supersymmetric Models with Hybrid Gauge- and Gravity-Mediation (2008)
Hiller, Gudrun, Hochberg, Yonit, Nir, Yosef
We consider supersymmetric models where gauge mediation provides the dominant contributions to the soft supersymmetry breaking terms while gravity mediation provides sub-dominant yet non-negligible...
Beyond MSSM Baryogenesis (2008)
Taking the MSSM as an effective low-energy theory, with a cut-off scale of a few TeV, can make significant modifications to the predictions concerning the Higgs and stop sectors. We investigate the...
Davidson, Sacha, Nardi, Enrico, Nir, Yosef
Leptogenesis is a class of scenarios where the baryon asymmetry of the Universe is produced from a lepton asymmetry generated in the decays of a heavy sterile neutrino. We explain the motivation for...
Measuring Flavor Mixing with Minimal Flavor Violation at the LHC (2008)
The mixing between third and second (or first) generation squarks is very small in supersymmetric models with minimal flavor violation such as gauge-, anomaly- or gaugino-mediation. An opportunity to...
The Standard Model and Supersymmetric Flavor Puzzles at the Large Hadron Collider (2007)
Feng, Jonathan L., Lester, Christopher G., Nir, Yosef, Shadmi, Yael
Can the Large Hadron Collider explain the masses and mixings of the known fermions? A promising possibility is that these masses and mixings are determined by flavor symmetries that also govern new...
Probing new physics with flavor physics (and probing flavor physics with new physics) (2007)
This is a written version of a series of lectures aimed at graduate students and postdoctoral fellows in particle theory/string theory/particle experiment familiar with the basics of the Standard...
Probing CP violation in neutrino oscillations with neutrino telescopes (2007)
Blum, Kfir, Nir, Yosef, Waxman, Eli
Measurements of flavor ratios of astrophysical neutrino fluxes are sensitive to the two yet unknown mixing parameters $\theta_{13}$ and $\delta$ through the combination $\sin\theta_{13}\cos\delta$....
Probing Minimal Flavor Violation at the LHC (2007)
Grossman, Yuval, Nir, Yosef, Thaler, Jesse, Volansky, Tomer, Zupan, Jure
If the LHC experiments discover new particles that couple to the Standard Model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate...
Lessons from BaBar and Belle measurements of D-Dbar mixing parameters (2007)
The BaBar and Belle experiments have recently presented evidence for D-Dbar mixing. We explain the following points: (i) The measurements imply width difference $y \sim 0.01$. In the limit of small...
Introduction to leptogenesis (2007)
The discovery of neutrino masses makes leptogenesis a very attractive scenario for explaining the puzzle of the baryon asymmetry of the Universe. We present the basic ingredients of leptogenesis,...
Relating leptogenesis parameters to light neutrino masses (2007)
Engelhard, Guy, Grossman, Yuval, Nir, Yosef
We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries $\epsilon_{N_\alpha}$, the washout parameters $\tilde...
The importance of N2 leptogenesis (2006)
Engelhard, Guy, Grossman, Yuval, Nardi, Enrico, Nir, Yosef
We argue that fast interactions of the lightest singlet neutrino $N_1$ would project part of a preexisting lepton asymmetry $L_p$ onto a direction that is protected from $N_1$ washout effects, thus...
New Physics and CP Violation in Singly Cabibbo Suppressed D Decays (2006)
Grossman, Yuval, Kagan, Alexander L., Nir, Yosef
We analyze various theoretical aspects of CP violation in singly Cabibbo suppressed (SCS) D-meson decays, such as $D \to K K,\pi \pi$. In particular, we explore the possibility that CP asymmetries...
Constraining the Phase of B_s - \bar{B}_s Mixing (2006)
Grossman, Yuval, Nir, Yosef, Raz, Guy
New physics contributions to B_s-\bar{B}_s mixing can be parametrized by the size (r_s^2) and the phase (2\theta_s) of the total mixing amplitude relative to the Standard Model amplitude. The phase...
The importance of flavor in leptogenesis (2006)
Nardi, Enrico, Nir, Yosef, Roulet, Esteban, Racker, Juan
We study leptogenesis from the out-of-equilibrium decays of the lightest heavy neutrino $N_1$ in the medium (low) temperature regime, $T\lsim 10^{12}$ GeV ($10^{10}$ GeV), where the rates of...
Solving Flavor Puzzles with Quiver Gauge Theories (2005)
Antebi, Yaron E., Nir, Yosef, Volansky, Tomer
We consider a large class of models where the SU(5) gauge symmetry and a Froggatt-Nielsen (FN) Abelian flavor symmetry arise from a U(5)\times U(5) quiver gauge theory. An intriguing feature of these...
On Higgs and sphaleron effects during the leptogenesis era (2005)
Nardi, Enrico, Nir, Yosef, Racker, Juan, Roulet, Esteban
We discuss the effects of various processes that can be active during the leptogenesis era, and present the Boltzmann equations that take them into account appropriately. A non-vanishing Higgs number...
CP violation in meson decays (2005)
This is a written version of a series of lectures aimed at graduate students in the field of (theoretical and experimental) high energy physics. The main topics covered are: (i) The flavor sector of...
SU(3) Relations and the CP Asymmetry in $B \to K_S K_S K_S$ (2005)
Engelhard, Guy, Nir, Yosef, Raz, Guy
The CP asymmetry in the $B \to K_S K_S K_S$ decay is being measured by the two B factories. A large deviation of the CP asymmetry $S_{K_S K_S K_S}$ from $-S_{\psi K_S}$ and/or of $C_{K_S K_S K_S}$...
The Pattern of CP Asymmetries in $b\to s$ Transitions (2005)
Buchalla, Gerhard, Hiller, Gudrun, Nir, Yosef, Raz, Guy
New CP violating physics in $b\to s$ transitions will modify the CP asymmetries in B decays into final CP eigenstates ($\phi K_S$, $\eta^\prime K_S$, $\pi^0 K_S$, $\omega K_S$, $\rho^0 K_S$ and $\eta...
New Ways to Soft Leptogenesis (2004)
Grossman, Yuval, Kashti, Tamar, Nir, Yosef, Roulet, Esteban
Soft supersymmetry breaking terms involving heavy singlet sneutrinos provide new sources of lepton number violation and of CP violation. In addition to the CP violation in mixing, investigated...
The Importance of Being Majorana: Neutrinos versus Charged Fermions in Flavor Models (2004)
We argue that neutrino flavor parameters may exhibit features that are very different from those of quarks and charged leptons. Specifically, within the Froggatt-Nielsen (FN) framework, charged...
The $D^0 - \bar D^0$ mass difference from a dispersion relation (2004)
Falk, Adam F., Grossman, Yuval, Ligeti, Zoltan, Nir, Yosef, Petrov, Alexey A.
We study the Standard Model prediction for the mass difference between the two neutral D meson mass eigenstates, $\Delta m$. We derive a dispersion relation based on heavy quark effective theory that...
Baryogenesis from the Kobayashi-Maskawa Phase (2004)
Berkooz, Micha, Nir, Yosef, Volansky, Tomer
The Standard Model fulfills the three Sakharov conditions for baryogenesis. The smallness of quark masses suppresses, however, the CP violation from the Kobayashi-Maskawa phase to a level that is...
The Standard Model predicts that the neutrinos are massless and do not mix. Generic extensions of the Standard Model predict that neutrinos are massive (but, very likely, much lighter than the...
Comment on extracting alpha from B -> rho rho (2003)
Falk, Adam F., Ligeti, Zoltan, Nir, Yosef, Quinn, Helen
Recent experimental results on $B\to\rho\rho$ decays indicate that the CP asymmetry $S_{\rho^+\rho^-}$ will give an interesting determination of $\alpha=\arg[-(V_{td}V_{tb}^*)/(V_{ud}V_{ub}^*)]$. In...
Leptogenesis from Supersymmetry Breaking (2003)
Grossman, Yuval, Kashti, Tamar, Nir, Yosef, Roulet, Esteban
We show that soft supersymmetry breaking terms involving the heavy sneutrinos can lead to sneutrino-antisneutrino mixing and to new sources of CP violation, which are present even if a single...
Grossman, Yuval, Ligeti, Zoltan, Nir, Yosef, Quinn, Helen
We consider CP asymmetries in neutral $B$ meson decays to $\eta' K_S$, $\phi K_S$, and $K^+ K^- K_S$. We use SU(3) relations to estimate or bound the contributions to these amplitudes proportional to...
Time Variations in the Scale of Grand Unification (2002)
Dine, Michael, Nir, Yosef, Raz, Guy, Volansky, Tomer
We study the consequences of time variations in the scale of grand unification, $M_U$, when the Planck scale and the value of the unified coupling at the Planck scale are held fixed. We show that the...
CP Violation: The CKM Matrix and New Physics (2002)
Recent measurements of CP violating asymmetries have led to a significant progress in our understanding of CP violation. The implications of the experimental results for the Kobayashi-Maskawa...
Product Groups, Discrete Symmetries, and Grand Unification (2002)
Dine, Michael, Nir, Yosef, Shadmi, Yael
We study grand unified theories based on an SU(5)xSU(5) gauge group in which the GUT scale, M_{GUT}, is the VEV of an exact or approximate modulus, and in which fast proton decay is avoided through a...
Quark-Squark Alignment Revisited (2002)
We re-examine the possibility that the solution to the supersymmetric flavor problem is related to small mixing angles in gaugino couplings induced by approximate horizontal Abelian symmetries. We...
New Physics and Future B Factories (2002)
Further experimental and theoretical studies of the physics of flavor and CP violation are well motivated. Within the supersymmetric framework, higher precision measurements will allow to explore...
Developments in Neutrino Physics (2002)
González-Garciá, M Concepción, Nir, Yosef
Measurements of various features of the fluxes of atmospheric and solar neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. We review the...
Implications of the CP asymmetry in semileptonic B decay (2002)
Laplace, Sandrine, Ligeti, Zoltan, Nir, Yosef, Perez, Gilad
Recent experimental searches for $A_{SL}$, the CP asymmetry in semileptonic B decay, have reached an accuracy of order one percent. Consequently, they give meaningful constraints on new physics. We...
CP Violation - A New Era (2001)
We give a pedagogical review of the theory of CP violation with emphasis on the implications of recent experimental results. The review includes: (i) A detailed description of how CP violation arises...
New CP Violation in Neutrino Oscillations (2001)
González-Garciá, M Concepción, Grossman, Y, Gusso, A, Nir, Yosef
Measurements of CP-violating observables in neutrino oscillation experiments have been studied in the literature as a way to determine the CP-violating phase in the mixing matrix for leptons. Here we...
CP Violation and the Scale of Supersymmetry Breaking (2001)
Dine, Michael, Kramer, Erik, Nir, Yosef, Shadmi, Yael
Supersymmetric models with a high supersymmetry breaking scale give, in general, large contributions to epsilon_K and/or to various electric dipole moments, even when contributions to CP conserving,...
Lessons from Recent Measurements of CP Violation (2000)
We review various implications of recent experimental results concerning CP violation and mixing in $K\to\pi\pi$, $B\to\psi K_S$, $D\to K\pi$ and $D\to KK$ decays.
Implications of a Small CP Asymmetry in B->\psi K_S (2000)
Eyal, Galit, Nir, Yosef, Perez, Gilad
New measurements of the CP asymmetry in B->\psi K_S, a_{\psi K_S}, by the BABAR and BELLE collaborations are consistent with the Standard Model prediction for sin2\beta. These measurements, however,...
Lessons from CLEO and FOCUS Measurements of D0-anti-D0 Mixing Parameters (2000)
Bergmann, Sven, Grossman, Yuval, Ligeti, Zoltan, Nir, Yosef, Petrov, Alexey A.
If the true values of the D0-anti-D0 mixing parameters lie within the one sigma ranges of recent measurements, then there is strong evidence for a large width difference, y > 0.01, and large SU(3)...
Pseudo-Dirac Solar Neutrinos (2000)
Three of the viable solutions of the solar neutrino problem are consistent with close to maximal leptonic mixing: $\sin^2\theta_{12}={1\over2}(1-\epsilon_{12})$ with $|\epsilon_{12}|\ll1$. Flavor...
Strong phases and D0-anti-D0 mixing parameters (1999)
Falk, Adam F., Nir, Yosef, Petrov, Alexey A.
We argue that there could be large, SU(3) violating resonance contributions to D -> K pi decays which would affect the extraction of the D0-anti-D0 mixing parameters from experiment. Such...
Neutrino Parameters, Abelian Flavor Symmetries, and Charged Lepton Flavor Violation (1999)
Feng, Jonathan L., Nir, Yosef, Shadmi, Yael
Neutrino masses and mixings have important implications for models of fermion masses, and, most directly, for the charged lepton sector. We consider supersymmetric Abelian flavor models, where...
CP Violation In and Beyond the Standard Model (1999)
The special features of CP violation in the Standard Model are presented. The significance of measuring CP violation in B, K and D decays is explained. The predictions of the Standard Model for CP...
New Physics Effects in Doubly Cabibbo Suppressed D Decays (1999)
The most sensitive experimental searches for $D-\bar D$ mixing use $D^0 \to K^+ \pi^-$ decays. It is often assumed that effects of New Physics and, in particular, CP violation, can appear through the...
Constraining Extensions of the Quark Sector with the CP Asymmetry in $B\to \psi K_{S}$ (1999)
Models with extended quark sector affect the CP asymmetry in the $B\to \psi K_{S}$ decay, $a_{\psi K_{S}}$, in two ways: First, the top-mediated box diagram is not necessarily the only important...
Constraining New Physics with the CDF Measurement of CP Violation in $B \to \psi K_S$ (1999)
Barenboim, Gabriela, Eyal, Galit, Nir, Yosef
Recently, the CDF collaboration has reported a measurement of the CP asymmetry in the $B\to\psi K_S$ decay: $a_{\psi K_S}=0.79^{+0.41}_{-0.44}$. We analyze the constraints that follow from this...
Lepton Parity in Supersymmetric Flavor Models (1999)
We investigate supersymmetric models where neither R-parity nor lepton number nor baryon number is imposed. The full high energy theory has an exact horizontal U(1) symmetry that is spontaneously...
CP Violation in B Decays (1999)
In the near future, we will have the first significant experimental measurements of CP violation in B decays. These measurements will easily test crucial questions such as whether the Standard Model...
Neutrino Masses and Mixing with Non-Anomalous Abelian Flavor Symmetries (1999)
The experimental data on atmospheric and solar neutrinos are used to test the framework of non-anomalous Abelian horizontal gauge symmetries with only three light active neutrinos. We assume that the...
Probing Supersymmetric Flavor Models with $\epsilon'/\epsilon$ (1999)
Eyal, Galit, Masiero, Antonio, Nir, Yosef, Silvestrini, Luca
Flavor Physics and CP Violation (1998)
This is a written version of a series of three lectures aimed at graduate students in the field of experimental high energy physics. The emphasis is on physics that is relevant to $B$-factories. The...
Naturally Light Sterile Neutrinos in Gauge Mediated Supersymmetry Breaking (1998)
Moduli are generic in string (M) theory. In a large class of gauge-mediated Supersymmetry breaking models, the fermionic components of such fields have very light masses, around the eV scale, and...
Large Mixing and Large Hierarchy Between Neutrinos with Abelian Flavor Symmetries (1998)
Grossman, Yuval, Nir, Yosef, Shadmi, Yael
The experimental data on atmospheric and solar neutrinos suggest that there is near-maximal mixing between \nu_\mu and \nu_\tau but that their masses are hierarchically separated. In models of...
Approximate CP in Supersymmetric Models (1998)
We construct phenomenologically viable supersymmetric models where CP is an approximate symmetry. The full high energy theory has exact CP and horizontal symmetries that are spontaneously broken with...
Final State Interactions and New Physics in B -> pi K Decays (1997)
Falk, Adam F., Kagan, Alexander L., Nir, Yosef, Petrov, Alexey A.
Within the Standard Model, and if one assumes that soft rescattering effects are negligible, the CP asymmetry A^dir_CP (B^\pm -> \pi^\pm K) is predicted to be very small and the ratio R = BR(B_d ->...
Probing the Flavor and CP Structure of Supersymmetric Models with K --> pi nu nubar Decays (1997)
We study the implications of various supersymmetric models on the rare $K^+ \to \pi^+ \nu \bar\nu$ and $K_L \to \pi^0 \nu \bar\nu$ decays. Although large effects are possible in generic...
Recent Developments in Theory of CP Violation (1997)
Four topics in theory of CP violation are reviewed. (a) CP violation in $B$ decays: We describe a new clean way of constraining the angle $\gamma$ of the unitarity triangle and how new CP violation...
Implications of the Fleischer-Mannel Bound (1997)
Grossman, Yuval, Nir, Yosef, Plaszczynski, Stephane, Schune, Marie-Helene
Fleischer and Mannel (FM) have shown that it may become possible to constrain the angle $\gamma$ of the unitarity triangle from measurements of various $B\to\pi K$ decays. This constraint is...
The Role of the Vacuum Insertion Approximation in Calculating CP Asymmetries in B Decays (1997)
Grossman, Yuval, Kayser, Boris, Nir, Yosef
CP asymmetries in $B$ decays into final CP eigenstates are in many cases theoretically clean. In particular, they do not depend on the values of hadronic parameters. The sign of the asymmetries,...
A Model Independent Construction of the Unitarity Triangle (1997)
Grossman, Yuval, Nir, Yosef, Worah, Mihir P.
In a large class of models, the only significant new physics effect on the CP asymmetries in $B \to \psi K_S$ and $B \to \pi\pi$ decays is a new contribution to the $B-\bar B$ mixing amplitude. This...
$K_L \to \pi^0 \nu \bar \nu$ Beyond the Standard Model (1997)
We analyze the decay $K_L \to \pi^0 \nu \bar \nu$ in a model independent way. If lepton flavor is conserved the final state is (to a good approximation) purely CP even. In that case this decay mode...
CP Violation Beyond the Standard Model (1997)
Grossman, Y, Nir, Yosef, Rattazzi, Riccardo
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,...
CP Violation Beyond the Standard Model (1997)
Grossman, Yuval, Nir, Yosef, Rattazzi, Riccardo
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,...
On Supersymmetric CP Violation (1996)
We discuss the discovery potential for New Physics of various measurements of CP violation. If nature is supersymmetric, then the flavor problem is even more mysterious than in the standard model. We...
Variations on Minimal Gauge Mediated Supersymmetry Breaking (1996)
Dine, Michael, Nir, Yosef, Shirman, Yuri
We study various modifications to the minimal models of gauge mediated supersymmetry breaking. We argue that, under reasonable assumptions, the structure of the messenger sector is rather restricted....
Neutrino Masses and Mixing in Supersymmetric Models without $R$ Parity (1996)
Borzumati, Francesca M., Grossman, Yuval, Nardi, Enrico, Nir, Yosef
We study neutrino masses and mixing in Supersymmetric Models without $R$ parity and with generic soft Supersymmetry breaking terms. Neutrinos acquire mass from various sources: tree level...
Solving the Supersymmetric CP Problem with Abelian Horizontal Symmetries (1996)
Nir, Yosef, Rattazzi, Riccardo
Models that combine Abelian horizontal symmetries and spontaneous CP violation can (i) explain the smallness and hierarchy in quark parameters; (ii) satisfactorily suppress supersymmetric...
New Tools for Low Energy Dynamical Supersymmetry Breaking (1995)
Dine, Michael, Nelson, Ann E., Nir, Yosef, Shirman, Yuri
We report the construction of large new classes of models which break supersymmetry dynamically. We then turn to model building. Two of the principal obstacles to constructing simple models of...
Exploring New Physics with CP Violation in Neutral D and B Decays (1995)
If New Physics contributes significantly to neutral meson mixing, then it is quite likely that it does so in a CP violating manner. In $D^0-\bar D^0$ mixing measured through $D^0\rightarrow...
QCD corrections to charged Higgs-mediated b --> c$\tau\nu$decay (1995)
Grossman, Y, Haber, Howard E, Nir, Yosef
We calculate the O(\alpha_s) corrections to the charged Higgs mediated inclusive semi-tauonic B decay. By working in the Landau gauge, we demonstrate how to obtain the charged Higgs contributions...
QCD corrections to charged Higgs-mediated $b \to c \tau \nu$ decay (1995)
Grossman, Yuval, Haber, Howard E., Nir, Yosef
We calculate the $O(\alpha_s)$ corrections to the charged Higgs mediated inclusive semi-tauonic $B$ decay. By working in the Landau gauge, we demonstrate how to obtain the charged Higgs contributions...
Supersymmetry without R-Parity and without Lepton Number (1995)
Banks, Tom, Grossman, Yuval, Nardi, Enrico, Nir, Yosef
We investigate Supersymmetric models where neither R parity nor lepton number is imposed. Neutrino masses can be kept highly suppressed compared to the electroweak scale if the $\mu$-terms in the...
Gauge Unification, Yukawa Hierarchy and the $\mu$ Problem (1995)
The hierarchy in the Yukawa couplings may be the result of a gauged horizontal $U(1)_H$ symmetry. If the mixed anomalies of the Standard Model gauge group with $U(1)_H$ are cancelled by a...
Lepton Mass Matrix Models (1995)
The smallness and hierarchy in fermion parameters could be the result of selection rules due to an Abelian horizontal symmetry broken by a small parameter. When applied to the lepton sector, then for...
Some Phenomenological Implications of String Loop Effects (1994)
We investigate low energy implications of string loop corrections to supergravity couplings which break a possible flavor universality of the tree level. If Supersymmetry is broken by the dilaton...
Implications of Horizontal Symmetries on Baryon Number Violation in Supersymmetric Models (1994)
The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection...
Missing (up) Mass, Accidental Anomalous Symmetries, and the Strong CP Problem (1994)
Banks, Tom, Nir, Yosef, Seiberg, Nathan
We reconsider the massless up quark solution of the strong CP problem. We show that an anomaly free horizontal symmetry can naturally lead to a massless up quark and to a corresponding accidental...
Within the Standard Model, $x_s$ (the mixing parameter in the $B_s-\bar B_s$ system) is constrained to the range $7 \leq x_s\leq 40$. We point out that if New Physics contributes significantly to...
Phenomenological Constraints on $\bar\Lambda$ and $\lambda_1$ (1994)
Combining the experimental data on the inclusive decays $D\to X\,e\,\nu$, $B\to X\,e\,\nu$ and $B\to X\,\tau\,\nu$, we find severe constraints on the $\bar\Lambda$ and $\lambda_1$ parameters of the...
Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X (1994)
Falk, A F, Ligeti, Z, Neubert, M, Nir, Yosef
We calculate the differential decay rate for inclusive $\bar B\to\tau\ \bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show...
Heavy Quark Expansion for the Inclusive Decay $\bar B\to\tau\,\bar\nu\,X$ (1994)
Falk, Adam F., Ligeti, Zoltan, Neubert, Matthias, Nir, Yosef
We calculate the differential decay rate for inclusive $\bar B\to\tau\,\bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show...
Mass Matrix Models: The Sequel (1993)
Leurer, Miriam, Nir, Yosef, Seiberg, Nathan
The smallness of the quark sector parameters and the hierarchy between them could be the result of a horizontal symmetry broken by a small parameter. Such an explicitly broken symmetry can arise from...
New Physics Effects on CP Violation in $B$ Decays (1993)
We review new physics effects on CP violation in B decays. We describe the Standard Model predictions for the various types of CP asymmetries and discuss the theoretical cleanliness of these...
The Decay $B\to\pi\ell\nu$ in Heavy Quark Effective Theory (1993)
Burdman, Gustavo, Ligeti, Zoltan, Neubert, Matthias, Nir, Yosef
We present a systematic analysis of the $B^{(*)}\to\pi\,\ell\,\nu$ weak decay form factors to order $1/m_b$ in the heavy quark effective theory, including a discussion of renormalization group...
Constraints on Extended Technicolor Models from B -> mu+ mu- X (1993)
Grinstein, Benjamin, Nir, Yosef, Soares, Joao M.
A recent study by Randall and Sundrum shows that models of Extended Technicolor (ETC) have interesting implications on rare B decays. We extend their study to the decay B -> mu+ mu- X. ETC models...
Implications of $b\rightarrow s\gamma$ for CP Violation in Charged Scalar Exchange (1993)
In models of three or more scalar doublets, new CP violating phases appear in charged scalar exchange. These phases affect CP asymmetries in neutral $B$ decays, even if Natural Flavor Conservation...
Should Squarks Be Degenerate? (1993)
For generic squark masses, box diagrams with squarks and gluinos give unacceptably large contributions to neutral meson ($K$, $B$ and $D$) mixing. The standard solution to this problem is to assume...
Z\rightarrow A^0 A^0\nu\bar\nu$ and $e^+e^-\rightarrow A^0 A^0 Z$ in Two Higgs Doublet Models (1993)
In LEP searches for the neutral CP-odd scalar $A^0$ of a multi-Higgs doublet model, experimenters have searched for $Z\rightarrow h^0 A^0$ (where $h^0$ is the lightest CP-even scalar). No...
Leurer, Miriam, Nir, Yosef, Seiberg, Nathan
It is possible that the hierarchy in the masses and mixing of quarks is a result of a horizontal symmetry. The smallness of various parameters is related to their suppression by high powers of a...
The values of $\sin (2 \alpha)$ and $\sin (2 \beta)$, where $\alpha$ and $\beta$ are angles of the unitarity triangle, will be readily measured in a B factory (and maybe also in hadron colliders). We...