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Beyond Standard Model Physics

Description: There are many recent results from searches for fundamental new physics using the TeVatron, the SLAC b-factory and HERA. This talk quickly reviewed searches for pair-produced stop, for gauge-mediated SUSY breaking, for Higgs bosons in the MSSM and NMSSM models, for leptoquarks, and v-hadrons. There is a SUSY model which accommodates the recent astrophysical experimental results that suggest that dark matter annihilation is occurring in the center of our galaxy, and a relevant experimental result. Finally, model-independent searches at D0, CDF, and H1 are discussed.
Date: November 1, 2009
Creator: Bellantoni, L.
Partner: UNT Libraries Government Documents Department

Inferred limits on lepton flavor violating decays of the Ks

Description: Strong model independent upper bounds on Br(K{sub s} {yields} {pi}{sup 0} e{mu}) may be inferred from recent experimental limits on Br(K{sub L} {yields} {pi}{sup 0} e{mu}) and Br(K{sup +} {yields} {pi}{sup +}e{sup +}{mu}{sup -}). From this result, upper bounds for Br(K{sub s} {yields} e{mu}) may be obtained for a broad class of models. Models outside of this class seem unlikely.
Date: October 1, 2005
Creator: Bellantoni, L.
Partner: UNT Libraries Government Documents Department

Recent results from KTEV

Description: The implications of the published KTeV K{sub L}{sup 0} {yields} {pi}{sup 0}{mu}{sup +}{mu}{sup -} result for interpreting recent {Sigma}{sup +} {yields} p{mu}{sup +} {mu}{sup -} results are discussed. The status of the KTeV {Xi}{sup 0} {yields} {Sigma}{sup +} {mu}{sup -}{nu} analysis is given. The KTeV |V{sub us}| result is also given.
Date: June 1, 2005
Creator: Bellantoni, L. & /Fermilab
Partner: UNT Libraries Government Documents Department

Calculation of asymptotic and RMS kicks due to higher order modes in the 3.9-GHz cavity

Description: FLASH plans to use a 'third harmonic' (3.9 GHz) superconducting cavity to compensate nonlinear distortions of the longitudinal phase space due to the sinusoidal curvature of the cavity voltage of the TESLA 1.3 GHz cavities. Higher order modes (HOMs) in the 3.9 GHz have a significant impact on the dynamics of the electron bunches in a long bunch train. Kicks due to dipole modes can be enhanced along the bunch train depending on the frequency and Q-value of the modes. The enhancement factor for a constant beam offset with respect to the cavity has been calculated. A simple Monte Carlo model of these effects, allowing for scatter in HOM frequencies due to manufacturing variances, has also been implemented and results for both FLASH and for an XFEL-like configuration are presented.
Date: March 1, 2008
Creator: Bellantoni, L.; Edwards, H. & Wanzenberg, R.
Partner: UNT Libraries Government Documents Department

Rare Decay Results from KTeV and ({rho}{sub CKM}, {eta}{sub CKM})

Description: Rare decay results from KTeV are reviewed, emphasizing modes that in principle provide information about the CKM matrix. The KTeV results shown here are from the 1997 data sample, which consists of about 2.7 x 10{sup 11} K{sub L}{sup 0} decay samples. KTeV also took data in 1999, giving a total data sample about 2.5 times what is presented here for three body decays and about 3.2 times what is presented here for four body decays. A summary of the KTeV detector is in the Appendix. Our recent results in lepton flavor violating modes are also presented.
Date: February 14, 2001
Creator: Bellantoni, L.
Partner: UNT Libraries Government Documents Department

Validation of Broadly Filtered Diagonalization Method for Extracting Frequencies and Modes from High-Performance Computations

Description: Recent developments have shown that one can get around the difficulties of finding the eigenvalues and eigenmodes of the large systems studied with high performance computation by using broadly filtered diagonalization [G. R. Werner and J. R. Cary, J. Compo Phys. 227, 5200 (2008)]. This method can be used in conjunction with any time-domain computation, in particular those that scale very well up to 10000s of processors and beyond. Here we present results that show that this method accurately obtains both modes and frequencies of electromagnetic cavities, even when frequencies are nearly degenerate. The application was to a well-characterized Kaon separator cavity, the A15. The computations are shown to have a precision to a few parts in 10{sup 5}. Because the computed frequency differed from the measured frequency by more than this amount, a careful validation study to determine all sources of difference was undertaken. Ultimately, more precise measurements of the cavity showed that the computations were correct, with remaining differences accounted for by uncertainties in cavity dimensions and atmospheric and thermal conditions. Thus, not only was the method validated, but it was shown to have the ability to predict differences in cavity dimensions from fabrication specifications.
Date: June 1, 2009
Creator: Austin, T.M.; Cary, J.R.; U., /Colorado; Werner, G.R.; U., /Colorado; Bellantoni, L. et al.
Partner: UNT Libraries Government Documents Department

Status of 3.9 GHz superconducting RF cavity technology at Fermilab

Description: Fermilab is involved in an effort to assemble 3.9 GHz superconducting RF cavities into a four cavity cryomodule for use at the DESY TTF/FLASH facility as a third harmonic structure. The design gradient of the cavities is 14 MV/m. This effort involves design, fabrication, intermediate testing, assembly, and eventual delivery of the cryomodule. We report on all facets of this enterprise from design through future plans. Included will be test results of single 9-cell cavities, lessons learned, and current status.
Date: June 1, 2007
Creator: Harms, E.; Arkan, T.; Bellantoni, L.; Carter, H.; Edwards, H.; Foley, M. et al.
Partner: UNT Libraries Government Documents Department

A copper 3.9 GHz TM110 cavity for emittance exchange

Description: An experiment is being developed at the FNAL Photoinjector Lab to demonstrate the exchange of longitudinal emittance with a transverse horizontal emittance. The longitudinal electric field of a TM{sub 110} cavity vanishes on axis and increases linearly with transverse displacement. This 'shearing' electric field is pivotal to the exchange. The design of this TM{sub 110} cavity is a variant of the Fermilab 3.9 GHz superconducting deflecting mode cavity; however, the cavity was constructed of OFHC copper. The authors report on the construction, field flatness, polarization and high power testing of a TM{sub 110} cavity.
Date: June 1, 2007
Creator: Koeth, T.W.; /Rutgers U., Piscataway; Fliller, R.P., III; Bellantoni, L.; Edwards, D.A.; Edwards, H.T. et al.
Partner: UNT Libraries Government Documents Department

Progress towards crab cavity solutions for the ILC

Description: In order to achieve acceptable luminosity for ILC crossing angles greater than 2 mrad, RF deflection cavities must be used to rotate electron and position bunches leading up to the IP. A bunch that passes through a deflection cavity at a phase where the deflection averages to zero, receives a crab kick leading to a finite rotation at the IP. For a beam energy of 500 GeV and a crossing angle of 20 mrad the required crab kick is about 11.4 MV at 1.3 GHz and 3.8 MV at 3.9 GHz. Cavities are needed on both beams and are likely to be positioned about 12 m before the IP. Any RF phase error between the bunch and the cavity leads to a deflection of the bunch in addition to a rotation of the bunch. Any differential phase error between the cavities leads to differing deflections and consequential loss in luminosity. An updated analysis of system requirements and phase tolerances with respect to original calculations [1] is given. Issues on cavity and frequency choice are discussed.
Date: June 1, 2006
Creator: Burt, G.; Dexter, A.; U., /Lancaster; Bellantoni, L.; /Fermilab; Beard, C. et al.
Partner: UNT Libraries Government Documents Department

Highly Accurate Frequency Calculations of Crab Cavities Using the VORPAL Computational Framework

Description: We have applied the Werner-Cary method [J. Comp. Phys. 227, 5200-5214 (2008)] for extracting modes and mode frequencies from time-domain simulations of crab cavities, as are needed for the ILC and the beam delivery system of the LHC. This method for frequency extraction relies on a small number of simulations, and post-processing using the SVD algorithm with Tikhonov regularization. The time-domain simulations were carried out using the VORPAL computational framework, which is based on the eminently scalable finite-difference time-domain algorithm. A validation study was performed on an aluminum model of the 3.9 GHz RF separators built originally at Fermi National Accelerator Laboratory in the US. Comparisons with measurements of the A15 cavity show that this method can provide accuracy to within 0.01% of experimental results after accounting for manufacturing imperfections. To capture the near degeneracies two simulations, requiring in total a few hours on 600 processors were employed. This method has applications across many areas including obtaining MHD spectra from time-domain simulations.
Date: May 1, 2009
Creator: Austin, T.M.; /Tech-X, Boulder; Cary, J.R.; /Tech-X, Boulder /Colorado U.; Bellantoni, L. & /Argonne
Partner: UNT Libraries Government Documents Department

Copper Prototype Measurements of the HOM, LOM and SOM Couplers for the ILC Crab Cavity

Description: The ILC Crab Cavity is positioned close to the IP and delivered luminosity is very sensitive to the wakefields induced in it by the beam. A set of couplers were designed to couple to and damp the spurious modes of the crab cavity. As the crab cavity operates using a dipole mode, it has different damping requirements from an accelerating cavity. A separate coupler is required for the monopole modes below the operating frequency of 3.9 GHz (known as the LOMs), the opposite polarization of the operating mode (the SOM), and the modes above the operating frequency (the HOMs). Prototypes of each of these couplers have been manufactured out of copper and measured attached to an aluminum nine cell prototype of the cavity and their external Q factors were measured. The results were found to agree well with numerical simulations.
Date: June 23, 2008
Creator: Burt, G.; Ambattu, P.K.; Dexter, A.C.; U., /Lancaster; Bellantoni, L.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Copper Prototype Measurements of the HOM, LOM And SOM Couplers for the ILC Crab Cavity

Description: The ILC Crab Cavity is positioned close to the IP and delivered luminosity is very sensitive to the wakefields induced in it by the beam. A set of couplers were designed to couple to and damp the spurious modes of the crab cavity. As the crab cavity operates using a dipole mode, it has different damping requirements from an accelerating cavity. A separate coupler is required for the monopole modes below the operating frequency of 3.9 GHz (known as the LOMs), the opposite polarization of the operating mode (the SOM), and the modes above the operating frequency (the HOMs). Prototypes of each of these couplers have been manufactured out of copper and measured attached to an aluminum nine cell prototype of the cavity and their external Q factors were measured. The results were found to agree well with numerical simulations.
Date: November 4, 2011
Creator: Burt, G.; Ambattu, P.K.; Dexter, A.C.; U., /Lancaster; Bellantoni, L.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

First results of testing 3.9 GHz TM(010) superconducting cavity

Description: Fermilab is developing third harmonic 3.9 GHz superconducting cavity to improve performances of A0 and TTF photoinjectors. In frame of this project we have built and tested two nine-cell copper models and one 3-cell niobium cavity. Properties of the high order modes were carefully studied in a chain of two copper cavities at room temperature. In paper we discuss results of cold tests of the 3-cell cavity before and after BCP.
Date: October 1, 2004
Creator: Solyak, N. A.; Bellantoni, L.; Berenc, T. G.; Edwards, H. T.; Gonin, I. V.; Khabiboulline, T. N. et al.
Partner: UNT Libraries Government Documents Department

Status of the ILC Crab Cavity Development

Description: The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, ...
Date: October 20, 2011
Creator: Burt, G.; Dexter, A.; Tech., /Cockcroft Inst. Accel. Sci.; Beard, C.; Goudket, P.; McIntosh, P. et al.
Partner: UNT Libraries Government Documents Department

Search for the Rare Decay K(L) ---> pi0 pi0 gamma

Description: The KTeV E799 experiment has conducted a search for the rare decay K{sub L} {yields} {pi}{sup 0}{sup 0}{gamma} via the topology K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{sub D}{gamma} (where {pi}{sup 0}{sub D} {yields} {gamma}e{sup +}e{sup -}). Due to Bose statistics of the {pi}{sup 0} pair and the real nature of the photon, the K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{gamma} decay is restricted to proceed at lowest order by the CP conserving direct emission (DE) of an E2 electric quadrupole photon. The rate of this decay is interesting theoretically since chiral perturbation theory predicts that this process vanishes at level O(p{sup 4}). Therefore, this mode probes chiral perturbation theory at O(p{sup 6}). In this paper we report a determination of an upper limit of 2.43 x 10{sup -7} (90% CL) for K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{gamma}. This is approximately a factor of 20 lower than previous results.
Date: August 1, 2007
Creator: Abouzaid, E.; Arenton, M.; Barker, A. R.; Bellantoni, L.; Blucher, E.; Bock, G. J. et al.
Partner: UNT Libraries Government Documents Department

Xi0 and anti-Xi0 Polarization Measurements at 800-GeV/c

Description: The polarization of {Xi}{sup 0} and {bar {Xi}}{sup 0} hyperons produced by 800 GeV/c protons on a BeO target at a fixed targeting angle of 4.8 mrad is measured by the KTeV experiment at Fermilab. The result of 9.7% for {Xi}{sup 0} polarization shows no significant energy dependence when compared to a result obtained at 400 GeV/c production energy and at twice the targeting angle. The polarization of the {Xi}{sup 0} is measured for the first time and found to be consistent with zero. They also examine the dependence of polarization on production p{sub t}.
Date: August 1, 2006
Creator: Abouzaid, E.; Alavi-Harati, A.; Alexopoulos, T.; Arenton, M.; Barker, A. R.; Bellantoni, L. et al.
Partner: UNT Libraries Government Documents Department

Development of the superconducting 3.9-GHz accelerating cavity at Fermilab

Description: A superconducting third harmonic 3.9 GHz accelerating cavity was proposed to improve the beam quality in the TTF-like photoinjector [1]. Fermilab has developed, built and tested several prototypes, including two copper 9-cell cavities, one niobium 3-cell cavity, and one 9-cell cavity. The helium vessel and frequency tuner for the 9-cell cavity was built and tested as well. In cold tests, we achieved a peak surface magnetic field of {approx}100mT, well above the 70mT specification. The accelerating gradient was likely limited by thermal breakdown. Studies of the higher order modes in the cavity revealed that the existing cavity design with two HOM couplers will provide sufficient damping of these modes. In this paper we discuss the cavity design, results of the studies and plans for further development.
Date: May 1, 2005
Creator: Arkan, T.; Bauer, P.; Bellantoni, L.; Boffo, C.; Borissov, E.; Carter, H. et al.
Partner: UNT Libraries Government Documents Department

Final Results from the KTeV Experiment on the Decay K(L) ---> pi0 gamma gamma

Description: The authors report on a new measurement of the branching ratio B(K{sub L} {yields} {pi}{sup 0}{gamma}{gamma}) using the KTeV detector. They reconstruct 1982 events with an estimated background of 608, that results in B(K{sub L} {yields} {pi}{sup 0}{Gamma}{gamma}) = (1.29 {+-} 0.03{sub stat} {+-} 0.05{sub syst}) x 10{sup -6}. They also measure the parameter, a{sub V}, which characterizes the strength of vector meson exchange terms in this decay. They find a{sub V} = -0.31 {+-} 0.05{sub stat} {+-} 0.07{sub syst}. These results utilize the full KTeV data set collected from 1997 to 2000 and supersede earlier KTeV measurements of the branching ratio and a{sub V}.
Date: May 1, 2008
Creator: Abouzaid, E.; /Illinois U., Chicago; Arenton, M.; U., /Virginia; Barker, A.R.; U., /Colorado et al.
Partner: UNT Libraries Government Documents Department

Measurement of direct photon emission in the K(L) ---> pi+ pi- gamma decay mode

Description: In this paper the KTeV collaboration reports the analysis of 112.1 x 10{sup 3} candidate K{sub L} {yields} {pi}{sup +}{pi}{sup -}{gamma} decays including a background of 671 {+-} 41 events with the objective of determining the photon production mechanisms intrinsic to the decay process. These decays have been analyzed to extract the relative contributions of the Cp violating bremsstrahlung process and the CP conserving M1 and CP violating E1 direct photon emission processes. The M1 direct photon emission amplitude and its associated vector form factor parameterized as |{bar g}{sub M1}|(1 + a{sub 1}/a{sub 2}/(M{sub {rho}}{sup 2}-M{sub K}{sup 2}) + 2M{sub K}E{sub {gamma}}) have been measured to be |{bar g}{sub M1}| = 1.198 {+-} 0.035(stat) {+-} 0.086(syst) and a{sub 1}/a{sub 2} = =0.738 {+-} 0.007(stat) {+-} 0.018(syst) GeV{sup 2}/c{sup 2} respectively. An upper limit for the CP violating E1 direct emission amplitude |g{sub E1}| {le} 0.1 (90%CL) has been found. The overall ratio of direct photon emission (DE) to total photon emission including the bremsstrahlung process (IB) has been determined to be DE/(DE + IB) = 0.689 {+-} 0.021 for E{sub {gamma}} {ge} 20 MeV.
Date: April 1, 2006
Creator: Abouzaid, E.; /Chicago U., EFI; Arenton, M.; U., /Virginia; Barker, A.R.; U., /Colorado et al.
Partner: UNT Libraries Government Documents Department

Determination of the Parity of the Neutral Pion via the Four-Electron Decay

Description: We present a new determination of the parity of the neutral pion via the double Dalitz decay {pi}{sup 0} {yields} e{sup +}e{sup -}e{sup +}e{sup -}. Our sample, which consists of 30 511 candidate decays, was collected from K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative {pi}{sup 0} parity, and place a limit on scalar contributions to the {pi}{sup 0} {yields} e{sup +}e{sup -}e{sup +}e{sup -} decay amplitude of less than 3.3% assuming CPT conservation. The {pi}{sup 0}{gamma}*{gamma}* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase space distribution. Additionally, we have measured the branching ratio of this mode to be B({pi}{sup 0} {yields} e{sup +}e{sup -}e{sup +}e{sup -}) = (3.26 {+-} 0.18) x 10{sup -5}.
Date: February 1, 2008
Creator: Abouzaid, E.; U., /Chicago; Arenton, M.; U., /Virginia; Barker, A.R.; U., /Colorado et al.
Partner: UNT Libraries Government Documents Department

Design and Optimization of Large Accelerator Systems through High-Fidelity Electromagnetic Simulations

Description: SciDAC1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' (AST) project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC CETs/Institutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider (ILC) and the Large Hadron Collider (LHC) in High Energy Physics (HEP), the JLab 12-GeV Upgrade in Nuclear Physics (NP), as well as the Spallation Neutron Source (SNS) and the Linac Coherent Light Source (LCLS) in Basic Energy Sciences (BES).
Date: August 1, 2008
Creator: Ng, Cho; Akcelik, Volkan; Candel, Arno; Chen, Sheng; Ge, Lixin; Kabel, Andreas et al.
Partner: UNT Libraries Government Documents Department

Design of the ILC Crab Cavity System

Description: The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.
Date: August 15, 2007
Creator: Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B. et al.
Partner: UNT Libraries Government Documents Department