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Full-Text Articles in Physics
Decay Widths Of Lowest Massive Regge Excitations Of Open Strings, Luis A. Anchordoqui, Haim Goldberg, Tomasz R. Taylor
Decay Widths Of Lowest Massive Regge Excitations Of Open Strings, Luis A. Anchordoqui, Haim Goldberg, Tomasz R. Taylor
Haim Goldberg
With the advent of the LHC there is widespread interest in the discovery potential for physics beyond the standard model. In TeV-scale open string theory, the new physics can be manifest in the excitation and decay of new resonant structures, corresponding to Regge recurrences of standard model particles. An essential input for the prediction of invariant mass spectra of the decay products (which could serve to identify the resonance as a string excitation) are the partial and total widths of the decay products. We present a parameter-free calculation of these widths for the first Regge recurrence of the SU(3) gluon …
Black Holes From Cosmic Rays: Probes Of Extra Dimensions And New Limits On Tev-Scale Gravity, Luis Anchordoqui, Jonathan Feng, Haim Goldberg, Alfred Shapere
Black Holes From Cosmic Rays: Probes Of Extra Dimensions And New Limits On Tev-Scale Gravity, Luis Anchordoqui, Jonathan Feng, Haim Goldberg, Alfred Shapere
Haim Goldberg
If extra spacetime dimensions and low-scale gravity exist, black holes will be produced in observable collisions of elementary particles. For the next several years, ultra-high energy cosmic rays provide the most promising window on this phenomenon. In particular, cosmic neutrinos can produce black holes deep in the Earth’s atmosphere, leading to quasi-horizontal giant air showers. We determine the sensitivity of cosmic ray detectors to black hole production and compare the results to other probes of extra dimensions. With n ≥ 4 extra dimensions, current bounds on deeply penetrating showers from AGASA already provide the most stringent bound on low-scale gravity, …
Compact Lattice Qed And The Coulomb Potential, Y. N. Srivastava, A. Widom, M. H. Friedman, O. Panella
Compact Lattice Qed And The Coulomb Potential, Y. N. Srivastava, A. Widom, M. H. Friedman, O. Panella
Allan Widom
The potential energy of a static charge distribution on a lattice is rigorously computed in the standard compact quantum electrodynamic model. The method used follows closely that of Weyl for ordinary quantum electrodynamics in continuous space-time. The potential energy of the static charge distribution is independent of temperature and can be calculated from the lattice version of Poisson’s equation. It is the usual Coulomb potential.
Breakdown Of The Kln Theorem For Charged Particles In Condensed Matter, Y. N. Srivastava, A. Widom
Breakdown Of The Kln Theorem For Charged Particles In Condensed Matter, Y. N. Srivastava, A. Widom
Allan Widom
The Kinoshita-Lee-Nauenberg (KLN) theorem describes the fact that inclusive electromagnetic and weak production processes in the vacuum do not contain singularities in the ultra-relativistic limit of zero mass. When these production processes occur in condensed matter, the KLN theorem fails. One consequence of this failure is that precision lifetime determinations of stopped muons will depend on the nature of the surrounding material.
Coherent Betatron Oscillation And Induced Errors In The Experimental Determination Of The Muon G-2 Factor, Y. N. Srivastava, A. Widom
Coherent Betatron Oscillation And Induced Errors In The Experimental Determination Of The Muon G-2 Factor, Y. N. Srivastava, A. Widom
Allan Widom
Precision measurements of the anomalous magnetic moment of the muon depend on the correct collective mode assignment of the coherent betatron oscillations in the beam. Presently, there is a disagreement between experiment and theory for the horizontal betatron frequency. The discrepancy is here resolved by our computations of electrostatic beam focusing. The correct treatment of the betatron effects renders less likely the need for non-standard model corrections to the muon g-2.
Concerning The Differences Between Zero Mass Dirac And Zero Mass Majorana Neutrinos, Y. Srivastava, A. Widom
Concerning The Differences Between Zero Mass Dirac And Zero Mass Majorana Neutrinos, Y. Srivastava, A. Widom
Allan Widom
That a Majorana neutrino theory is different from a Dirac neutrino theory (even in the zero mass limit) is proved in two sentences.
Cp Violation From Standard Model To Strings, Tarek Ibrahim, Pran Nath
Cp Violation From Standard Model To Strings, Tarek Ibrahim, Pran Nath
Pran Nath
A review of CP violation from the Standard Model to strings is given which includes a broad landscape of particle physics models, encompassing the non-supersymmetric 4D extensions of the standard model, and models based on supersymmetry, on extra dimensions, on strings and on branes. The supersymmetric models discussed include complex mSUGRA and its extensions, while the models based on extra dimensions include 5D models including models based on warped geometry. CP violation beyond the standard model is central to achieving the desired amount of baryon asymmetry in the universe via baryogenesis and leptogenesis. They also affect a variety of particle …
Detecting Physics At The Post-Gut And String Scales By Linear Colliders, R. Arnowitt, Pran Nath
Detecting Physics At The Post-Gut And String Scales By Linear Colliders, R. Arnowitt, Pran Nath
Pran Nath
The ability of linear colliders to test physics at the post-GUT scale is investigated. Using current estimates of measurements available at such accelerators, it is seen that soft breaking masses can be measured with errors of about (1-20)%. Three classes of models in the post-GUT region are examined: models with universal soft breaking masses at the string scale, models with horizontal symmetry, and string models with Calabi-Yau compactifications. In each case, linear colliders would be able to test directly theoretical assumptions made at energies beyond the GUT scale to a good accuracy, distinguish between different models, and measure parameters that …
Aspects Of The Stueckelberg Extension, Boris Körs, Pran Nath
Aspects Of The Stueckelberg Extension, Boris Körs, Pran Nath
Pran Nath
A detailed analysis of a Stueckelberg extension of the electro-weak gauge group with an extra abelian U(1)ₓ factor is presented for the Standard Model as well as for the MSSM. The extra gauge boson gets massive through a Stueckelberg type coupling to a pseudo-scalar, instead of a Higgs effect. This new massive neutral gauge boson Z′ has vector and axial vector couplings uniquely different from those of conventional extra abelian gauge bosons, such as appear e.g. in GUT models. The extended MSSM furthermore contains two extra neutralinos and one extra neutral CP-even scalar, the latter with a mass larger than …
Cp Violation And The Muon Anomaly In N=1 Supergravity, Tarek Ibrahim, Pran Nath
Cp Violation And The Muon Anomaly In N=1 Supergravity, Tarek Ibrahim, Pran Nath
Pran Nath
The one loop supersymmetric electro-weak correction to the anomalous magnetic moment of the muon is derived in the minimal N = 1 supergravity unification with two CP violating phases. A numerical analysis of the CP violating effects on gμ−2 is carried out with the cancellation mechanism to guarantee the satisfaction of the experimental limits on the electric dipole moments of the electron and on the neutron. It is found that the effects of the CP phases can significantly affect the supersymmetric electro-weak correction to gμ−2, and that the numerical size of such a correction can be as large or larger …
Constraints On The Minimal Supergravity Model From The B→Sγ Decay, Jizhi Wu, Richard Arnowitt, Pran Nath
Constraints On The Minimal Supergravity Model From The B→Sγ Decay, Jizhi Wu, Richard Arnowitt, Pran Nath
Pran Nath
The constraints on the minimal supergravity model from the b → sγ decay are studied. A large domain in the parameter space for the model satisfies the CLEO bound, BR(b → sγ) < 5.4 × 10−4. However, the allowed domain is expected to diminish significantly with an improved bound on this decay. The dependence of the b → sγ branching ratio on various parameters is studied in detail. It is found that, for At < 0 and the top quark mass within the vicinity of the center of the CDF value, mtpole = 174±17 GeV, there exists only a small allowed domain because the light stop is tachyonic for most of the parameter space. A similar phenomenon exists for a lighter top and At negative when the GUT coupling constant is slightly reduced. For At > 0, however, the branching ratio is much less sensitive to small changes in mt, and αG.)
Cp Violation In Susy, Strings And Branes, Tarek Ibrahim, Pran Nath
Cp Violation In Susy, Strings And Branes, Tarek Ibrahim, Pran Nath
Pran Nath
A review is given of CP violation in a broad class of models based on supersymmetry, superstrings and brane models. Such models contain typically large CP violating phases which affect a variety of supersymmetric phenomenon at low energies and affect search for supersymmetry at colliders and in dark matter experiments. We focus here on few such phenomena, specifically the mixing of the CP even and the CP odd Higgs bosons which can be induced by loop corrections and on CP violation in the muon sector. Possible signals for the observation of CP violation are also discussed.
Cosmological Constraints And Su(5) Supergravity Grand Unification, R. Arnowitt, Pran Nath
Cosmological Constraints And Su(5) Supergravity Grand Unification, R. Arnowitt, Pran Nath
Pran Nath
The predictions of SU(5) supergravity models with radiative breaking constrained by experimental proton decay bounds are discussed. It is shown that cosmological constraints further restrict the parameter space but can be satisfied for a wide range of parameters. It is also shown that no serious fine tuning problems (either at MSUSY or MGUT) exist.
Annual Modulation Signature For The Direct Detection Of Milky Way Wimps And Supergravity Models, R. Arnowitt, Pran Nath
Annual Modulation Signature For The Direct Detection Of Milky Way Wimps And Supergravity Models, R. Arnowitt, Pran Nath
Pran Nath
An analysis is given of the annual modulation signal for the direct detection of relic neutralinos within the framework of supergravity unified models. It is shown that both the minimal and the non-minimal SUGRA models can generate neutralinoproton cross-sections at the level compatible with the signals reported in the DAMA experiment at the Gran Sasso National Laboratory. Effects of proton stability on the analysis of the DAMA data in the minimal and the non-minimal SUGRA models are also discussed.
B−Τ Unification, Gμ−2, The B→S+Γ Constraint, And Nonuniversalities, Utpal Chattopadhyay, Pran Nath
B−Τ Unification, Gμ−2, The B→S+Γ Constraint, And Nonuniversalities, Utpal Chattopadhyay, Pran Nath
Pran Nath
An analysis is given of the b−τ Yukawa coupling unification in view of the recent result from Brookhaven on gμ−2 and under the constraint of b→s+γ. We explore b−τ unification under the above constraints for nonuniversal boundary conditions for the soft SUSY breaking parameters. We find new regions of the parameter space where significant negative supersymmetric contribution to the b quark mass can arise and b−τ unification within SU(5) framework can occur with nonuniversal gaugino masses. Specifically we find that for the case where the gaugino mass matrix transforms like a 24 plet one finds a negative contribution to the …
Baryon Instability In Susy Models, Pran Nath, R. Arnowitt
Baryon Instability In Susy Models, Pran Nath, R. Arnowitt
Pran Nath
A review is given of nucleon instability in SUSY models. The minimal SU(5) model is discussed in detail.
Connecting The Direct Detection Of Dark Matter With Observation Of Sparticles At The Lhc, Daniel Feldman, Zuowei Liu, Pran Nath
Connecting The Direct Detection Of Dark Matter With Observation Of Sparticles At The Lhc, Daniel Feldman, Zuowei Liu, Pran Nath
Pran Nath
An analysis is given connecting event rates for the direct detection of neutralino dark matter with the possible signatures of supersymmetry at the LHC. It is shown that if an effect is seen in the direct detection experiments at a level of O(10⁻⁴⁴) cm² for the neutralino-proton cross section, then within the mSUGRA model the next heavier particle above the neutralino is either a stau, a chargino, or a CP odd/CP even (A/H) Higgs boson. Further, the collider analysis shows that models with a neutralino-proton cross section at the level of (1 − 5) × 10⁻⁴⁴ cm² could be probed …
Corrections To The Higgs Boson Masses And Mixings From Chargino, W, And Charged Higgs Exchange Loops And Large Cp Phases, Tarek Ibrahim, Pran Nath
Corrections To The Higgs Boson Masses And Mixings From Chargino, W, And Charged Higgs Exchange Loops And Large Cp Phases, Tarek Ibrahim, Pran Nath
Pran Nath
One loop contributions to the Higgs boson masses and mixings from the chargino sector consisting of the chargino, the W, and the charged Higgs boson (χ⁺ − W − H⁺) exchanges and including the effects of large CP violating phases are computed. It is found that the chargino sector makes a large contribution to the mixings of the CP even and the CP odd Higgs sectors through the induced one loop effects and may even dominate the mixing generated by the stop and the sbottom sectors. Effects of the chargino sector contribution to the Higgs boson masses are also computed. …