Thu, 24 Jul 2008 23:18:55 BST CiteULike: Tag hep http://www.citeulike.org/tag/hep CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/simeon_warner/article/2689596 <i>(16 Apr 2008)</i><br /><br />Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally “early adopters” of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities. Information Resources in High-Energy Physics: Surveying the Present Landscape and Charting the Future Course Anne Gentil-Beccot Salvatore Mele Annette Holtkamp Heath O&#x27;connell Travis Brooks (16 Apr 2008) 2008-04-18T21:48:45-00:00 2008 hep http://www.citeulike.org/user/sash/article/1175885 <i>Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, No. 3. (1 July 2003), pp. 250-303.</i><br /><br />G4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. Geant4--a simulation toolkit S Agostinelli J Allison K Amako J Apostolakis H Araujo P Arce M Asai D Axen S Banerjee G Barrand F Behner L Bellagamba J Boudreau L Broglia A Brunengo H Burkhardt S Chauvie J Chuma R Chytracek G Cooperman G Cosmo P Degtyarenko A Dell'acqua G Depaola D Dietrich R Enami A Feliciello C Ferguson H Fesefeldt G Folger F Foppiano A Forti S Garelli S Giani R Giannitrapani D Gibin Gomez I Gonzalez Gracia G Greeniaus W Greiner V Grichine A Grossheim S Guatelli P Gumplinger R Hamatsu K Hashimoto H Hasui A Heikkinen A Howard V Ivanchenko A Johnson FW Jones J Kallenbach N Kanaya M Kawabata Y Kawabata M Kawaguti S Kelner P Kent A Kimura T Kodama R Kokoulin M Kossov H Kurashige E Lamanna T Lampen V Lara V Lefebure F Lei M Liendl W Lockman F Longo S Magni M Maire E Medernach K Minamimoto Mora Y Morita K Murakami M Nagamatu R Nartallo P Nieminen T Nishimura K Ohtsubo M Okamura S O'Neale Y Oohata K Paech J Perl A Pfeiffer MG Pia F Ranjard A Rybin S Sadilov E Di Salvo G Santin T Sasaki N Savvas Y Sawada S Scherer S Sei V Sirotenko D Smith N Starkov H Stoecker J Sulkimo M Takahata S Tanaka E Tcherniaev Safai M Tropeano P Truscott H Uno L Urban P Urban M Verderi A Walkden W Wander H Weber JP Wellisch T Wenaus DC Williams D Wright T Yamada H Yoshida D Zschiesche doi:10.1016/S0168-9002(03)01368-8 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, No. 3. (1 July 2003), pp. 250-303. 2007-03-19T13:08:03-00:00 2003 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 506 3 250 303 computing geant4 hep simulation http://www.citeulike.org/user/sash/article/1175876 <i>Nuclear Science, IEEE Transactions on, Vol. 52, No. 4. (2005), pp. 910-918.</i><br /><br />The Geant4 Simulation Toolkit provides an ample set of physics models describing electromagnetic interactions of particles with matter. This paper presents the results of a series of comparisons for the evaluation of Geant4 electromagnetic processes with respect to United States National Institute of Standards and Technologies (NIST) reference data. A statistical analysis was performed to estimate quantitatively the compatibility of Geant4 electromagnetic models with NIST data; the statistical analysis also highlighted the respective strengths of the different Geant4 models. Comparison of Geant4 Electromagnetic Physics Models Against the NIST Reference Data K Amako S Guatelli VN Ivanchenko M Maire B Mascialino K Murakami P Nieminen L Pandola S Parlati MG Pia M Piergentili T Sasaki L Urban Nuclear Science, IEEE Transactions on, Vol. 52, No. 4. (2005), pp. 910-918. 2007-03-19T12:52:53-00:00 2005 Nuclear Science, IEEE Transactions on 52 4 910 918 hep simulation http://www.citeulike.org/user/sash/article/1175874 <i>Nuclear Physics B - Proceedings Supplements, Vol. 150 (January 2006), pp. 44-49.</i><br /><br />Geant4 is an object-oriented toolkit for simulating the passage of particles through matter. At the very heart of Geant4 there is a wide set of complementary, and sometimes alternative, physics models which describe the basic interaction of particles with matter. After a review of the main characteristics of the toolkit and a status report of the current activities, the results of a series of detailed tests for the quantitative validation of the electromagnetic models of Geant4 are presented. Such precision tests demonstrate the reliability of the physics models provided in Geant4 and are hence particularly relevant for critical applications of simulation models. Geant4 and its validation K Amako S Guatelli V Ivanchencko M Maire B Mascialino K Murakami L Pandola S Parlati MG Pia M Piergentili T Sasaki L Urban doi:10.1016/j.nuclphysbps.2004.10.083 Nuclear Physics B - Proceedings Supplements, Vol. 150 (January 2006), pp. 44-49. 2007-03-19T12:51:26-00:00 2006 Nuclear Physics B - Proceedings Supplements 150 44 49 computing hep simulation http://www.citeulike.org/user/sash/article/1404869 <i>Physical Review D (Particles and Fields), Vol. 69, No. 3. (2004)</i><br /><br />Experimental results for the bremsstrahlung energy loss of 149, 207, and 287 GeV electrons in thin Ir, Ta, and Cu targets are presented. For each target and energy, a comparison between simulated values based on the Landau-Pomeranchuk-Migdal (LPM) suppression of incoherent bremsstrahlung is shown. For the electron energies investigated, the LPM effect enters the quantum regime where the recoil imposed on the electron by the emitted photon becomes important. Good agreement between simulations based on Migdal's theory and data from the experiment is found, indicating that the LPM suppression is well understood also in the quantum regime. Results from a comparison between simulations with the "threshold" energy ELPM as a free parameter and the data are shown. This analysis reproduces the expected trend as a function of nominal radiation length, but yields values that tend to be low compared to Migdal's theory. Landau-Pomeranchuk-Migdal effect for multihundred GeV electrons HD Hansen UI Uggerhoj C Biino S Ballestrero A Mangiarotti P Sona TJ Ketel ZZ Vilakazi doi:10.1103/PhysRevD.69.032001 Physical Review D (Particles and Fields), Vol. 69, No. 3. (2004) 2007-06-22T15:31:14-00:00 2004 Physical Review D (Particles and Fields) 69 3 APS hep lpm http://www.citeulike.org/user/sash/article/908572 <i>(24 Jun 2004)</i><br /><br />The cross section for coherent pair production by linearly polarised photons in the 20-170 GeV energy range was measured for photon aligned incidence on ultra-high quality diamond and germanium crystals. The theoretical description of coherent bremsstrahlung and coherent pair production phenomena is an area of active theoretical debate and development. However, under our experimental conditions, the theory predicted the combined cross section and polarisation experimental observables very well indeed. In macroscopic terms, our experiment measured a birefringence effect in pair production in a crystal. This study of this effect also constituted a measurement of the energy dependent linear polarisation of photons produced by coherent bremsstrahlung in aligned crystals. New technologies for manipulating high energy photon beams can be realised based on an improved understanding of QED phenomena at these energies. In particular, this experiment demonstrates an efficient new polarimetry technique. The pair production measurements were done using two independent methods simultaneously. The more complex method using a magnet spectrometer showed that the simpler method using a multiplicity detector was also viable. Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence Na59 Collaboration A Apyan RO Avakian B Badelek S Ballestrero C Biino I Birol P Cenci SH Connell S Eichblatt T Fonseca A Freund B Gorini R Groess K Ispirian TJ Ketel YV Kononets A Lopez A Mangiarotti B van Rens JPF Sellschop M Shieh P Sona V Strakhovenko E Uggerhoj UI Uggerhoj G Unel M Velasco ZZ Vilakazi O Wessely (24 Jun 2004) 2006-10-20T22:57:15-00:00 2004 channeling crystals hep na59 photons physics polarization http://www.citeulike.org/user/sash/article/908570 <i>(24 Jun 2004)</i><br /><br />We present new results regarding the features of high energy photon emission by an electron beam of 178 GeV penetrating a 1.5 cm thick single Si crystal aligned at the Strings-Of-Strings (SOS) orientation. This concerns a special case of coherent bremsstrahlung where the electron interacts with the strong fields of successive atomic strings in a plane and for which the largest enhancement of the highest energy photons is expected. The polarization of the resulting photon beam was measured by the asymmetry of electron-positron pair production in an aligned diamond crystal analyzer. By the selection of a single pair the energy and the polarization of individual photons could be measured in an the environment of multiple photons produced in the radiator crystal. Photons in the high energy region show less than 20% linear polarization at the 90% confidence level. Measurement of Coherent Emission and Linear Polarization of Photons by Electrons in the Strong Fields of Aligned Crystals Na59 Collaboration A Apyan RO Avakian B Badelek S Ballestrero C Biino I Birol P Cenci SH Connell S Eichblatt T Fonseca A Freund B Gorini R Groess K Ispirian TJ Ketel Yu A Lopez A Mangiarotti B van Rens JPF Sellschop M Shieh P Sona V Strakhovenko E Uggerhoj UI Uggerhoj G Unel M Velasco ZZ Vilakazi O Wessely (24 Jun 2004) 2006-10-20T22:57:12-00:00 2004 channeling crystals hep na59 photons physics polarization http://www.citeulike.org/user/sash/article/908549 <i>Physics Letters B, Vol. 459, No. 1-3. (22 July 1999), pp. 347-353.</i><br /><br />Presented are experimental results for the difference in pair production probability (the asymmetry) for 5-150 GeV photons polarized parallel and perpendicular to a (110) plane in a 1.5 mm thick diamond crystal. The photons are produced by interaction of 150 GeV electrons with an aligned diamond crystal of 0.5 mm thickness. A significant asymmetry is found over the whole energy range, which corresponds to a high degree of linear polarization of the photons as well as a difference in the refractive index. This proof-of-principle result gives the possibility of producing high energy photons with circular polarization by use of a crystal. This might open for several opportunities in high energy physics like for instance the investigation of the contribution of the gluons to the spin of the nucleon. Generation and detection of the polarization of multi-GeV photons by use of two diamond crystals K Kirsebom Yu Kononets U Mikkelsen SP Moller E Uggerhoj T Worm K Elsener C Biino S Ballestrero P Sona doi:10.1016/S0370-2693(99)00645-0 Physics Letters B, Vol. 459, No. 1-3. (22 July 1999), pp. 347-353. 2006-10-20T22:50:08-00:00 1999 Physics Letters B 459 1-3 347 353 channeling crystals hep na43 photons physics polarization http://www.citeulike.org/user/sash/article/908548 <i>Physics Letters B, Vol. 281, No. 1-2. (7 May 1992), pp. 153-158.</i><br /><br />For the first time very pronounced high-energy photon peaks have been measured in the radiation emission from 70, 150 and 240 GeV electrons incident at 0.1-1.0 mrad to the axis in diamond and Si crystals. The energy of the photons in the peaks is 0.7-0.8 times the particle energy with yields of 50 times the Bethe-Heitler one (in diamond). The peaks consist of single photons and are caused by the influence of strong crystalline fields on emission of coherent bremsstrahlung, emitted when the ultrarelativistic electrons cross the rows of atoms in a crystal plane. The effect should be envisaged as a source for nearly monoenergetic photons in the multihundred GeV-region. Experimental investigations of hard photon emission from strong crystalline fields R Medenwaldt SP Moller BN Jensen VM Strakhovenko E Uggerhoj T Worm K Elsener P Sona SH Connell JPF Sellschop RO Avakian AE Avetisian SP Taroian doi:10.1016/0370-2693(92)90290-K Physics Letters B, Vol. 281, No. 1-2. (7 May 1992), pp. 153-158. 2006-10-20T22:48:03-00:00 1992 Physics Letters B 281 1-2 153 158 channeling crystals hep na43 physics http://www.citeulike.org/user/sash/article/908547 <i>Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 145, No. 1-2. (2 October 1998), pp. 142-145.</i><br /><br />The spectral distributions and polarization of the radiation of electrons with longitudinal polarization when they move in parallel to crystallographic planes and axes are calculated in the constant field approximation. It is shown that the x=[omega]/[var epsilon]-dependence ([epsilon] and [omega] are the electron and photon energy) of the radiation circular polarization coincides with that for the bremsstrahlung in amorphous media and coherent bremsstrahlung in single crystals, and that the radiation under consideration may serve as a source of intense circularly polarized photons. Circularly polarized photon beams produced by channeled longitudinally polarized electrons AB Apyan RO Avakian PO Bosted SM Darbinian KA Ispirian doi:10.1016/S0168-583X(98)00257-2 Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 145, No. 1-2. (2 October 1998), pp. 142-145. 2006-10-20T22:46:54-00:00 1998 Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 145 1-2 142 145 channeling crystals hep physics polarization http://www.citeulike.org/user/sash/article/908525 <i>(7 Dec 2005)</i><br /><br />The processes of coherent bremsstrahlung (CB) and coherent pair production (CPP) based on aligned crystal targets have been studied in the energy range 20-170 GeV. The experimental arrangement allowed these phenomena as well as their polarization dependence to be evaluated under conditions where single-photon cross-sections could be measured. This proved very important as the theoretical description of CB and CPP is an area of active theoretical debate and development. The theoretical approach used in this paper predicts both the cross sections and polarization observables very well for the experimental conditions investigated, indicating that the understanding of CB and CPP is reliable up to energies of 170 GeV. A birefringence effect in CPP was studied and it was demonstrated this enabled new technologies for high energy photon beam optics, such as polarimeters (for both linear and circular polarization) and phase plates. We also present new results regarding the features of coherent high energy photon emission for the Strings-Of-Strings (SOS) orientation, where the coherent enhancement of hard photon radiation is larger than for the CB case. The photon polarization in this case has been controversial. Our measurements commented on this situation as well. Coherent Bremsstrahlung, Coherent Pair Production, Birefringence and Polarimetry in the 20-170 GeV energy range using aligned crystals Na59 Collaboration A Apyan RO Avakian B Badelek S Ballestrero C Biino I Birol P Cenci SH Connell S Eichblatt T Fonseca A Freund B Gorini R Groess K Ispirian TJ Ketel Yu Kononets A Lopez A Mangiarotti B van Rens JPF Sellschop M Shieh P Sona V Strakhovenko E Uggerhoj UI Uggerhoj G Unel M Velasco ZZ Vilakazi O Wessely (7 Dec 2005) 2006-10-20T22:13:49-00:00 2005 channeling crystals hep na59 photons physics polarization http://www.citeulike.org/user/sash/article/908524 <i>(22 Jun 2005)</i><br /><br />The CERN-NA-59 experiment examined a wide range of electromagnetic processes for multi-GeV electrons and photons interacting with oriented single crystals. The various types of crystals and their orientations were used for producing photon beams and for converting and measuring their polarisation. <br />The radiation emitted by 178 GeV unpolarised electrons incident on a 1.5 cm thick Si crystal oriented in the Coherent Bremsstrahlung (CB) and the String-of-Strings (SOS) modes was used to obtain multi-GeV linearly polarised photon beams. <br />A new crystal polarimetry technique was established for measuring the linear polarisation of the photon beam. The polarimeter is based on the dependence of the Coherent Pair Production (CPP) cross section in oriented single crystals on the direction of the photon polarisation with respect to the crystal plane. Both a 1 mm thick single crystal of Germanium and a 4 mm thick multi-tile set of synthetic Diamond crystals were used as analyzers of the linear polarisation. <br />A birefringence phenomenon, the conversion of the linear polarisation of the photon beam into circular polarisation, was observed. This was achieved by letting the linearly polarised photon beam pass through a 10 cm thick Silicon single crystal that acted as a "quarter wave plate" (QWP) as suggested by N. Cabibbo et al. Results on the Coherent Interaction of High Energy Electrons and Photons in Oriented Single Crystals Na59 Collaboration A Apyan RO Avakian B Badelek S Ballestrero C Biino I Birol P Cenci SH Connell S Eichblatt T Fonseca A Freund B Gorini R Groess K Ispirian TJ Ketel YV Kononets A Lopez A Mangiarotti B van Rens JPF Sellschop M Shieh P Sona V Strakhovenko E Uggerhoj UI Uggerhoj G Unel M Velasco ZZ Vilakazi O Wessely (22 Jun 2005) 2006-10-20T22:07:06-00:00 2005 channeling crystals hep na59 photons physics polarization http://www.citeulike.org/user/sash/article/908522 <i>(24 Jun 2004)</i><br /><br />We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linearly polarised photon beam. The linearly polarised photon beam is produced from coherent bremsstrahlung radiation by 178 GeV unpolarised electrons incident on an aligned Si crystal, acting as a radiator. The linear polarisation of the photon beam is characterised by measuring the asymmetry in electron-positron pair production in a Ge crystal, for different crystal orientations. The Ge crystal therefore acts as an analyser. The birefringence phenomenon, which converts the linear polarisation to circular polarisation, is observed by letting the linearly polarised photons beam pass through a thick Si quarter wave plate crystal, and then measuring the asymmetry in electron-positron pair production again for a selection of relative angles between the crystallographic planes of the radiator, analyser and quarter wave plate. The systematics of the difference between the measured asymmetries with and without the quarter wave plate are predicted by theory to reveal an evolution in the Stokes parameters from which the appearance of a circularly polarised component in the photon beam can be demonstrated. The measured magnitude of the circularly polarised component was consistent with the theoretical predictions, and therefore is in indication of the existence of the birefringence effect. Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons Na59 Collaboration A Apyan RO Avakian B Badelek S Ballestrero C Biino I Birol P Cenci SH Connell S Eichblatt T Fonseca A Freund B Gorini R Groess K Ispirian TJ Ketel YV Kononets A Lopez A Mangiarotti B van Rens JPF Sellschop M Shieh P Sona V Strakhovenko E Uggerhoj UI Uggerhoj G Unel M Velasco ZZ Vilakazi O Wessely (24 Jun 2004) 2006-10-20T21:55:45-00:00 2004 channeling crystals hep na59 photons physics polarization http://www.citeulike.org/user/RMT/article/2904108 <i>(9 Jun 2008)</i><br /><br />We study n-point boundary correlation functions in Timelike Boundary Liouville theory, relevant for open string multi-production by a decaying unstable D-brane. We give an exact result for the one-point function and show that it is consistent with a previously proposed relation to a conserved charge in string theory. Using a straightforward perturbative expansion, we find an explicit expression for a n-point amplitude for all n, however the result is still a toy model. The calculation uses a new asymptotic approximation for Toeplitz determinants, derived by relating the system to a Dyson gas at finite temperature. N-point functions in rolling tachyon background Niko Jokela Matti Jarvinen Esko Keski-Vakkuri (9 Jun 2008) 2008-06-18T03:32:55-00:00 2008 correlation_functions cue hep rmt_applications http://www.citeulike.org/user/rbmoura/article/2620722 <i>Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 537, No. 1-2. (21 January 2005), pp. 101-104.</i><br /><br />Scintillation crystals of lead tungstate PbWO4 with increased light yield are described. The scintillation with maximum emission at 420 nm is rather fast and 97% of light are emitted within an integration gate of 100 ns width at operating temperatures in the range of 310-250 K. The light yield of samples of 1 cm3 volume increases from 41 to 66 phe/MeV in the temperature range 296-258 K. More than 10.000 full size scintillation crystals of such quality are considered for the construction of the electromagnetic calorimeter of the PANDA detector proposed for experiments at the antiproton storage ring of the future accelerator facility at GSI, Darmstadt. Lead tungstate scintillation crystal with increased light yield for the PANDA electromagnetic calorimeter A Borisevich A Fedorov A Hofstaetter M Korzhik BK Meyer O Missevitch R Novotny doi:10.1016/j.nima.2004.07.244 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 537, No. 1-2. (21 January 2005), pp. 101-104. 2008-04-01T18:14:24-00:00 2005 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 537 1-2 101 104 ecal hep properties pwo scintillator http://www.citeulike.org/user/rbmoura/article/2620709 <i>Nuclear Science Symposium Conference Record, 2004 IEEE, Vol. 1 (2004), pp. 117-125 Vol. 1.</i><br /><br />Because of high stopping power and fast bright scintillation, cerium doped silicate based heavy crystal scintillators, such as GSO, LSO and LYSO, have been developed for medical instruments. Their application in high energy and nuclear physics, however, is limited by lacking high quality crystals in large size. The optical and scintillation properties, including the transmittance, emission and excitation spectra and the light output, decay kinetics and light response uniformity as well as their degradation under irradiation, were measured for large size LYSO samples from different vendors, and were compared to a BGO sample of the same size. Possible applications for crystal calorimetry in future high energy and nuclear physics experiments are discussed. Large size LYSO crystals for future high energy physics experiments Jiaming Chen Liyuan Zhang Ren-Yuan Zhu doi:10.1109/NSSMIC.2004.1462080 Nuclear Science Symposium Conference Record, 2004 IEEE, Vol. 1 (2004), pp. 117-125 Vol. 1. 2008-04-01T18:06:27-00:00 2004 Nuclear Science Symposium Conference Record, 2004 IEEE 1 117 125 Vol. 1 characterization cms hep lyso properties scintillator http://www.citeulike.org/user/rbmoura/article/2620785 <i>Nuclear Physics B - Proceedings Supplements, Vol. 150 (January 2006), pp. 366-371.</i><br /><br />Scintillating crystals are the state of the art for electromagnetic calorimeters and are exploited in many different applications. The paper presents some recent developments and results in different fields of application. Scintillating crystals for calorimetry and other applications Egidio Longo doi:10.1016/j.nuclphysbps.2004.08.046 Nuclear Physics B - Proceedings Supplements, Vol. 150 (January 2006), pp. 366-371. 2008-04-01T18:52:05-00:00 2006 Nuclear Physics B - Proceedings Supplements 150 366 371 application ecal hep medical scintillator http://www.citeulike.org/user/rbmoura/article/1468643 <i>Nuclear Science, IEEE Transactions on, Vol. 52, No. 6. (2005), pp. 3133-3140.</i><br /><br />Because of their high stopping power and fast bright scintillation, cerium doped silicate based heavy crystal scintillators, such as GSO, LSO, and LYSO, have been developed for medical instruments. Their applications in high energy and nuclear physics, however, are limited by lacking high quality crystals in sufficiently large size. The optical and scintillation properties, including the transmittance, emission and excitation spectra and the light output, decay kinetics and light response uniformity, as well as their degradation under /spl gamma/-ray irradiation were measured for two long (2.5/spl times/2.5/spl times/20 cm) LYSO samples from CPI and Saint-Gobain, and were compared to a BGO sample of the same size from SIC. Possible applications for crystal calorimetry in future high energy and nuclear physics experiments are discussed. Large size LYSO crystals for future high energy physics experiments Jianming Chen Liyuan Zhang Ren-Yuan Zhu Nuclear Science, IEEE Transactions on, Vol. 52, No. 6. (2005), pp. 3133-3140. 2007-07-20T10:36:16-00:00 2005 Nuclear Science, IEEE Transactions on 52 6 3133 3140 characterization crystals hep lyso properties http://www.citeulike.org/user/rbmoura/article/2620756 <i>Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE, Vol. 1 (1998), pp. 46-51 vol.1.</i><br /><br />The development of a new scintillator with tight specifications for light yield, decay time and radiation damage, poses challenging problems to be solved by experts working in different fields of material science. This requires a multidisciplinary approach, with a good coordination of efforts and a well organized support. If, in addition, a large production of several cubic meters has to be made in a few years only, additional problems have to be solved, related to production infrastructure, reproducibility of parameters, production yields and cost effectiveness. The example of the development in Russia of lead tungstate crystals for the CMS electromagnetic calorimeter at CERN, Geneva, will be chosen to illustrate this challenging enterprise Lead tungstate scintillator for high energy physics applications AN Annekov M Korzhik P Lecoq doi:10.1109/NSSMIC.1998.774806 Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE, Vol. 1 (1998), pp. 46-51 vol.1. 2008-04-01T18:35:52-00:00 1998 Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE 1 46 51 vol.1 hep pwo scintillator http://www.citeulike.org/user/quianominorleo/article/2894477 <i>(02 November 1993)</i><br /><br />If you've read any of Richard Feynman's wonderful autobiographies you may think that a _biography_ of Feynman would be a waste of your time. Wrong! Gleick's _Genius_ is a masterpiece of scientific biography--and an inspiration to anyone in pursuit of their own fulfillment as a person of genius. Deservedly nominated for a National Book Award, underservedly passed over by the committee in the face of tough competition, and very deservedly a book that you must read. Genius: The Life and Science of Richard Feynman James Gleick (02 November 1993) 2008-06-14T10:18:09-00:00 1993 Vintage 1993 biographies books hep physics http://www.citeulike.org/user/quianominorleo/article/2894470 <i>(01 July 1998)</i><br /><br />Richard Feynman was something of a rarity: a science superstar. Like another superstar who preceded him, Albert Einstein, Feynman's science was ahead of his time, but it was his qualities as a human being that caught the imaginations of ordinary people. A whole body of legend has grown up around the man--much of it promulgated by Feynman himself--and nearly 10 years after his death he remains a popular subject of memoirs, biographies, and even films. In _Richard Feynman_, respected science writers John and Mary Gribbins combine biography with popular science in this absorbing look at the great man's life and work. Though there's little new information about Feynman's personal life and interests here--everything from his passion for bongo drums to his fascination with the country of Tuva has been documented many times and in many places before now--the Gribbons do an exemplary job of explaining just why Feyman was such a giant among physicists. Quanatum theory is the kind of subject that could give the average reader a raging headache, yet the Gribbons explain it so well that by the end of _Richard Feynman_ even the most non-scientific among us will be able to appreciate just what a singular contribution to our world this science superstar made. Richard Feynman: A Life in Science John Gribbin Mary Gribbin (01 July 1998) 2008-06-14T10:12:38-00:00 1998 Plume 1998 biographies books hep physics http://www.citeulike.org/user/quianominor/article/1428851 <i>American Journal of Physics, Vol. 63, No. 5. (1995), pp. 398-410.</i><br /><br />Physicists embarking on seemingly routine error analyses are finding themselves grappling with major conceptual issues which have divided the statistics community for years. While the philosophical aspects of the debate may be endless, a practicing experimenter must choose a way to report results. The results can depend on which of the two major frameworks, classical or Bayesian, one adopts. This article reviews reasons why most data analysis in particle physics has traditionally been carried out within the classical framework, and why this will probably continue to be the case. However, Bayesian reasoning has recently made significant inroads in some published work in this field, and many other particle physicists may frequently think in a Bayesian manner without realizing it. I illustrate the issues involved with a few simple, commonly encountered examples which reveal how each framework can sometimes lead to unsatisfying results. ©1995 American Association of Physics Teachers. Why isn't every physicist a Bayesian? Robert Cousins doi:10.1119/1.17901 American Journal of Physics, Vol. 63, No. 5. (1995), pp. 398-410. 2007-07-02T14:24:14-00:00 1995 American Journal of Physics 63 5 398 410 AAPT bayesian hep physics http://www.citeulike.org/user/NitinCR/article/2371207 <i>(24 April 2000)</i><br /><br />This highly regarded textbook for advanced undergraduates provides a comprehensive introduction to modern particle physics. Coverage emphasizes the balance between experiment and theory. It places stress on the phenomenological approach and basic theoretical concepts rather than rigorous mathematical detail. Donald Perkins also details recent developments in elementary particle physics, as well as its connections with cosmology and astrophysics. A number of key experiments are also identified along with a description of how they have influenced the field. Perkins presents most of the material in the context of the Standard Model of quarks and leptons. He also fully explores the shortcomings of this model and new physics beyond its compass (such as supersymmetry, neutrino mass and oscillations, GUTs and superstrings). The text includes many problems and a detailed and annotated further reading list. The volume will also provide a solid foundation for graduate study. Introduction to High Energy Physics Donald Perkins (24 April 2000) 2008-02-13T18:37:13-00:00 2000 Cambridge University Press hep http://www.citeulike.org/group/2734/article/1188313 <i>(24 Mar 2007)</i><br /><br />I discuss some simple aspects of the low-energy physics of a nontrivial scale invariant sector of an effective field theory. I argue that the unparticle stuff described by such a theory might actually exist in our world. I suggest a scenario in which some details of the production of unparticle stuff can be calculated. I find that unparticle stuff with scale dimension $d_\mathcalU$ looks like a non-integral number $d_\mathcalU$ of invisible particles. Thus evidence for a nontrivial scale invariant sector could show up experimentally in missing energy distributions. Unparticle Physics Howard Georgi (24 Mar 2007) 2007-03-26T17:27:43-00:00 2007 bsm hep lhc physics unparticle http://www.citeulike.org/group/2734/article/832290 <i>(31 Aug 2006)</i><br /><br />We present a new Fortran Monte Carlo generator to simulate black hole events at CERN's Large Hadron Collider. The generator interfaces to the PYTHIA Monte Carlo fragmentation code. The physics of the BH generator includes, but not limited to, inelasticity effects, exact field emissivities, corrections to semiclassical black hole evaporation and gravitational energy loss at formation. These features are essential to realistically reconstruct the detector response and test different models of black hole formation and decay at the LHC. Catfish: A Monte Carlo simulator for black holes at the LHC M Cavaglia R Godang L Cremaldi D Summers (31 Aug 2006) 2006-09-06T11:29:43-00:00 2006 blackhole fpythia generator gr hep lhc montecarlo physics http://www.citeulike.org/group/2734/article/684588 <i>(1 Jun 2006)</i><br /><br />We describe a statistical hypothesis test for the presence of a signal based on the likelihood ratio statistic. We derive the test for several cases of interest and also show that for those cases the test works very well, even far out in the tails of the distribution. We also study extensions of the test to cases where there are multiple channels. A Test for the Presence of a Signal Wolfgang Rolke Angel Lopez (1 Jun 2006) 2006-06-05T16:30:27-00:00 2006 analysis data hep statistics http://www.citeulike.org/group/2734/article/2507935 <i>(11 Feb 2008)</i><br /><br />Building on earlier work, the dipole subtraction formalism for photonic corrections is extended to various photon--fermion splittings where the resulting collinear singularities lead to corrections that are enhanced by logarithms of small fermion masses. The difference to the earlier treatment of photon radiation is that now no cancellation of final-state singularities is assumed, i.e. we allow for non-collinear-safe final-state radiation. Moreover, we consider collinear fermion production from incoming photons, forward-scattering of incoming fermions, and collinearly produced fermion-antifermion pairs. For all cases we also provide the corresponding formulas for the phase-space slicing approach, and particle polarization is supported for all relevant situations. A comparison of numerical results obtained with the proposed subtraction procedure and the slicing method is explicitly performed for the sample process e- gamma -> e- mu- mu+. Polarized QED splittings of massive fermions and dipole subtraction for non-collinear-safe observables Stefan Dittmaier Alois Kabelschacht Tobias Kasprzik (11 Feb 2008) 2008-03-11T12:45:48-00:00 2008 dipole hep qed subtraction http://www.citeulike.org/group/2734/article/681336 <i>(1 Jun 2006)</i><br /><br />I provide a pedagogical introduction to supersymmetry. The level of discussion is aimed at readers who are familiar with the Standard Model and quantum field theory, but who have had little or no prior exposure to supersymmetry. Topics covered include: motivations for supersymmetry, the construction of supersymmetric Lagrangians, supersymmetry-breaking interactions, the Minimal Supersymmetric Standard Model (MSSM), R-parity and its consequences, the origins of supersymmetry breaking, the mass spectrum of the MSSM, decays of supersymmetric particles, experimental signals for supersymmetry, and some extensions of the minimal framework. A Supersymmetry Primer Stephen Martin (1 Jun 2006) 2006-06-02T10:49:25-00:00 2006 hep mssm physics susy http://www.citeulike.org/group/2734/article/665649 <i>(19 May 2006)</i><br /><br />The black hole information paradox apparently indicates the need for a fundamentally new ingredient in physics. The leading contender is nonlocality. Possible mechanisms for the nonlocality needed to restore unitarity to black hole evolution are investigated. Suggestions that such dynamics arises from ultra-planckian modes in Hawking's derivation are investigated and found not to be relevant, in a picture using smooth slices spanning the exterior and interior of the horizon. However, no simultaneous description of modes that have fallen into the black hole and outgoing Hawking modes can be given without appearance of a large kinematic invariant, or other dependence on ultra-planckian physics; a reliable argument for information loss thus has not been constructed. This suggests that strong gravitational dynamics is important. Such dynamics has been argued to be fundamentally nonlocal in extreme situations, such as those required to investigate the fate of information. Black hole information, unitarity, and nonlocality Steven Giddings (19 May 2006) 2006-05-22T15:39:31-00:00 2006 blackhole gr hep http://www.citeulike.org/group/2734/article/591875 <i>(19 Apr 2006)</i><br /><br />We calculate the likelihood map in the full 7 dimensional parameter space of the minimal supersymmetric standard model (MSSM) assuming universal boundary conditions on the supersymmetry breaking terms. Simultaneous variations of m_0, A_0, M_1/2, tan beta, m_t, m_b and alpha_s(M_Z) are applied using a Markov chain Monte Carlo algorithm. We use measurements of b -> s gamma, (g-2)_mu and Omega_DM h^2 in order to constrain the model. We present likelihood distributions for some of the sparticle masses, for the branching ratio of B_s^0 -> mu^+ mu^- and for m_stau-m_chi_1^0. An upper limit of 2.10^-8 on this branching ratio might be achieved at the Tevatron, and would rule out 29% of the currently allowed likelihood. If one allows for non thermal-neutralino components of dark matter, this fraction becomes 35%. The mass ordering allows the important cascade decay squark_L -> chi_2^0 -> slepton_R -> chi_1^0 with a likelihood of 24+/-4%. The stop coannihilation region is highly disfavoured, whereas the light Higgs region is marginally disfavoured. Multi-Dimensional mSUGRA Likelihood Maps BC Allanach CG Lester (19 Apr 2006) 2006-04-20T12:55:31-00:00 2006 bayesian hep lhc markovchain msugra sampling statistics susy http://www.citeulike.org/group/2734/article/2507925 <i>(10 Mar 2008)</i><br /><br />I present the two-loop QCD corrections to the production of a massive quark-anti-quark pair in the massless quark-anti-quark annihilation channel. The result is obtained as a combination of a deep expansion in the mass around the high energy limit and of a numerical integration of a system of differential equations. The primary application of the outcome and developed methods is top quark pair production at the Large Hadron Collider. Tops from Light Quarks: Full Mass Dependence at Two-Loops in QCD M Czakon (10 Mar 2008) 2008-03-11T12:44:58-00:00 2008 hep qcd top twoloop http://www.citeulike.org/group/2734/article/586429 <i>(13 Apr 2006)</i><br /><br />This Report summarises the activities of the "SM and Higgs" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. On the one hand, we performed a variety of experimental and theoretical studies on standard candles (such as W, Z, and ttbar production), treating them either as proper signals of known physics, or as backgrounds to unknown physics; we also addressed issues relevant to those non-perturbative or semi-perturbative ingredients, such as Parton Density Functions and Underlying Events, whose understanding will be crucial for a proper simulation of the actual events taking place in the detectors. On the other hand, several channels for the production of the Higgs, or involving the Higgs, have been considered in some detail. The report is structured into four main parts. The first one deals with Standard Model physics, except the Higgs. A variety of arguments are treated here, from full simulation of processes constituting a background to Higgs production, to studies of uncertainties due to PDFs and to extrapolations of models for underlying events, from small-$x$ issues to electroweak corrections which may play a role in vector boson physics. The second part of the report treats Higgs physics from the point of view of the signal. In the third part, reviews are presented on the current status of multi-leg, next-to-leading order and of next-to-next-to-leading order QCD computations. Finally, the fourth part deals with the use of Monte Carlos for simulation of LHC physics. Les Houches Physics at TeV Colliders 2005, Standard Model and Higgs working group: Summary report C Buttar S Dittmaier V Drollinger S Frixione A Nikitenko Willenbrock E Accomando D Acosta A Arbuzov RD Ball A Ballestrero P Bartalini U Baur A Belhouari S Belov A Belyaev D Benedetti T Binoth S Bolognesi S Bondarenko EE Boos F Boudjema A Bredenstein VE Bunichev C Buttar JM Campbell Carloni S Catani R Cavanaugh M Ciccolini J Collins AM Cooper-Sarkar G Corcella S Cucciarelli G Davatz V Delduca A Denner J D'Hondt S Dittmaier V Drollinger A Drozdetskiy LV Dudko M Duehrssen R Frazier S Frixione J Fujimoto S Gascon-Shotkin T Gehrmann Gehrmann-De A Giammanco -S EWN Glover RM Godbole A Grau M Grazzini -Ph A Gusev R Harlander R Hegde G Heinrich J Heyninck J Huston T Ishikawa (13 Apr 2006) 2006-04-14T14:30:55-00:00 2006 hep leshouches physics qcd standardmodel http://www.citeulike.org/group/2734/article/2911263 <i>(19 Jun 2008)</i><br /><br />We develop techniques to determine the mass scale of invisible particles pair-produced at hadron colliders. We employ the constrained mass variable m_2C, which provides an event-by-event lower-bound to the mass scale given a mass difference. We complement this variable with a new variable m_2C,UB which provides an additional upper bound to the mass scale, and demonstrate its utility with a realistic case study of a supersymmetry model. These variables together effectively quantify the `kink' in the function Max m_T2 which has been proposed as a mass-determination technique for collider-produced dark matter. An important advantage of the m_2C method is that it does not rely simply on the position at the endpoint, but it uses the additional information contained in events which lie far from the endpoint. We found the mass by comparing the HERWIG generated m_2C distribution to ideal distributions for different masses. We find that for the case studied, with 100 fb^-1 of integrated luminosity (about 400 signal events), the invisible particle's mass can be measured to a precision of 4.1 GeV. We conclude that this technique's precision and accuracy is as good as, if not better than, the best known techniques for invisible-particle mass-determination at hadron colliders. The Precision Determination of Invisible-Particle Masses at the LHC Alan Barr Graham Ross Mario Serna (19 Jun 2008) 2008-06-20T18:12:28-00:00 2008 darkmatter hep lhc physics susy http://www.citeulike.org/group/2734/article/2773583 <i>(7 May 2008)</i><br /><br />In this thesis we investigate proposed duals to QCD. Duals to QCD fall into two categories: `top-down' and `bottom-up'. We take inspiration from both by truncating a consistent solution to the type IIB supergravity equations of motion (top-down). This model demonstrates dynamical chiral symmetry breaking, has a running coupling and contains a holographic description of the vector meson sector. By artificially extending the existing U(1) symmetry to SU(2) (bottom-up) we then obtain a holographic description of the axial vector sector. We show that this model reproduces the masses and decay constants of the lightest mesons to the 10% level. By regulating the UV with a sharp cut-off we can reproduce the rho meson masses to within 2%. Finally we demonstrate that this model can be used to reproduce a very good agreement with hadronization data for particle production over a range of four orders of magnitude. Holographic Descriptions Of QCD Andrew Tedder (7 May 2008) 2008-05-08T21:06:29-00:00 2008 duality hep holography physics qcd strings http://www.citeulike.org/group/2734/article/1610715 <i>(3 May 2007)</i><br /><br />An easy-to-implement form of the Metropolis Algorithm is described which, unlike most standard techniques, is well suited to sampling from multi-modal distributions on spaces with moderate numbers of dimensions (order ten) in environments typical of investigations into current constraints on Beyond-the-Standard-Model physics. The sampling technique makes use of pre-existing information (which can safely be of low or uncertain quality) relating to the distribution from which it is desired to sample. This information should come in the form of a “bank” or “cache” of space points of which at least some may be expected to be near regions of interest in the desired distribution. In practical circumstances such “banks of clues” are easy to assemble from earlier work, aborted runs, discarded burn-in samples from failed sampling attempts, or from prior scouting investigations. The technique equilibrates between disconnected parts of the distribution without user input. The algorithm is not lead astray by “bad” clues, but there is no free lunch: performance gains will only be seen where clues are helpful. Sampling using a `bank' of clues Benjamin Allanach Christopher Lester (3 May 2007) 2007-08-31T12:45:51-00:00 2007 hep sampling statistics http://www.citeulike.org/group/2734/article/1610713 <i>(5 Jul 2007)</i><br /><br />Previous LHC forecasts for the constrained minimal supersymmetric standard model (CMSSM), based on current astrophysical and laboratory measurements, have used priors that are flat in the parameter tan beta, while being constrained to postdict the central experimental value of MZ. We construct a different, new and more natural prior with a measure in mu and B (the more fundamental MSSM parameters from which tan beta and MZ are actually derived). We find that as a consequence this choice leads to a well defined fine-tuning measure in the parameter space. We investigate the effect of such on global CMSSM fits to indirect constraints, providing posterior probability distributions for Large Hadron Collider (LHC) sparticle production cross sections. The change in priors has a significant effect, strongly suppressing the pseudoscalar Higgs boson dark matter annihilation region, and diminishing the probable values of sparticle masses. We also show how to interpret fit information from a Markov Chain Monte Carlo in a frequentist fashion; namely by using the profile likelihood. Bayesian and frequentist interpretations of CMSSM fits are compared and contrasted. Natural Priors, CMSSM Fits and LHC Weather Forecasts Ben Allanach Kyle Cranmer Christopher Lester Arne Weber (5 Jul 2007) 2007-08-31T12:45:06-00:00 2007 hep lhc markovchain sampling statistics http://www.citeulike.org/group/2734/article/1610709 <i>(29 Aug 2007)</i><br /><br />The spectroscopy of light and heavy mesons is reviewed with emphasis on glueballs, hybrids, and tetraquarks. Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts Eberhard Klempt Alexander Zaitsev (29 Aug 2007) 2007-08-31T12:43:32-00:00 2007 hep hybrids multiquarks qcd qlueballs http://www.citeulike.org/group/2734/article/1610708 <i>(30 Aug 2007)</i><br /><br />We consider the role of the perturbative Pomeron-to-parton splitting in the formation of the diffractive parton distributions. Diffractive parton distributions: the role of the perturbative Pomeron G Watt AD Martin MG Ryskin (30 Aug 2007) 2007-08-31T12:42:56-00:00 2007 diffraction hep parton pdf pomeron qcd http://www.citeulike.org/group/2734/article/1605762 <i>(28 Aug 2007)</i><br /><br />We review recent work on the Hawking radiation of rotating brane black holes, as may be produced at the LHC. We outline the methodology for calculating the fluxes of particles, energy and angular momentum by spin-0, spin-1/2 and spin-1 quantum fields on the brane. We briefly review some of the key features of the emission, in particular the changes in the spectra as the number of extra dimensions or the angular velocity of the black hole increases. These quantities will be useful for accurate simulations of black hole events at the LHC. Hawking radiation from rotating brane black holes Elizabeth Winstanley (28 Aug 2007) 2007-08-29T17:18:31-00:00 2007 blackhole hawking hep lhc physics http://www.citeulike.org/group/2734/article/1448175 <i>(7 Jul 2007)</i><br /><br />Results from the Fermilab Tevatron pbar-p collider on diffractive and total cross sections are reviewed with emphasis on physics significance and properties pointing to expectations at the LHC. Diffractive and Total Cross Sections at Tevatron and LHC Konstantin Goulianos (7 Jul 2007) 2007-07-11T11:20:30-00:00 2007 diffraction hep lhc physics qcd tevatron http://www.citeulike.org/group/2734/article/1447048 <i>(23 Jun 2007)</i><br /><br />The experimental charged particles multiplicity distributions in $e^+e^-$ annihilation to hadrons are compared with the distributions obtained by PYTHIA. The ratio $χ^2$/degrees of freedom is calculated for 6 energies at $\sqrts$ 14 -- 206.2 GeV. The necessity of more subtle tuning of PYTHIA at the energy of $Z^0$ peak is discussed. About agreement of PYTHIA and the experimental results in $e^+e^-$ annihilation to hadrons NV Radchenko (23 Jun 2007) 2007-07-10T17:04:21-00:00 2007 fpythia generator hep lep multiplicity physics z http://www.citeulike.org/group/2734/article/1447046 <i>(19 Jun 2007)</i><br /><br />We introduce the concept of the area of a jet, and show how it can be used to perform the subtraction of even a large amount of diffuse noise from hard jets. Jet Areas, and What They are Good For Matteo Cacciari (19 Jun 2007) 2007-07-10T17:02:59-00:00 2007 eventshapes hep jets partonshower physics qcd http://www.citeulike.org/group/2734/article/1438970 <i>(28 Nov 1995)</i><br /><br />Event shape and charged particle inclusive distributions determined from 750 000 hadronic Z events measured with the DELPHI detector at LEP are presented. The statistical and systematic precision of this data allows for a decisive confrontation with Monte Carlo models of the hadronization process and a better understanding of the structure of the Z hadronic final state. Improved tunings of the JETSET, ARIADNE and HERWIG parton shower models and the JETSET matrix element model are obtained by fitting the models to identified particle distributions from all LEP experiments and the DELPHI data presented. The description of the data distributions by the models is critically reviewed with special importance attributed to identified particles. The Next Round of Hadronic Generator Tuning Heavily Based on Identified Particle Data K Hamacher M Weierstall (28 Nov 1995) 2007-07-06T09:13:03-00:00 1995 generator hadrons hep lep montecarlo physics qcd tuning http://www.citeulike.org/group/2734/article/1428715 <i>(27 Jul 2006)</i><br /><br />A procedure is developed for using Soft Collinear Effective Theory (SCET) to generate fully exclusive events, which can then be compared to data from collider experiments. We show that SCET smoothly interpolates between QCD for hard emissions, and the parton shower for soft emissions, while resumming all large logarithms. In SCET, logarithms are resummed using the renormalization group, instead of classical Sudakov factors, so subleading logarithms can be resummed as well. In addition, all loop effects of QCD can be reproduced in SCET, which allows the effective theory to incorporate next-to-leading and higher-order effects. We also show through SCET that in the soft/collinear limit, successive branchings factorize, a fact which is essential to parton showers, and that the splitting functions of QCD are reproduced. Finally, combining these results, we present a example of an algorithm that incorporates the SCET results into an event generator which is systematically improvable. Event Generation from Effective Field Theory Christian Bauer Matthew Schwartz (27 Jul 2006) 2007-07-02T13:37:04-00:00 2006 eft generator hep montecarlo physics qcd standardmodel http://www.citeulike.org/group/2734/article/1423792 <i>(28 Jun 2007)</i><br /><br />If new physics is called upon to explain away fine tunings, like the hierarchy problem, then, we argue, the principle of Minimal Flavor Violation is inescapable. We review the principle and recent extensions to the lepton sector and to Grand-Unified theories. Minimal Flavor Violation Benjamin Grinstein (28 Jun 2007) 2007-06-29T22:59:42-00:00 2007 bsm flavourviolation hep hierarchy physics http://www.citeulike.org/group/2734/article/1423791 <i>(28 Jun 2007)</i><br /><br />The properties and behaviour of the solutions of the recently obtained $k_t$-dependent evolution equations are investigated. When used to reproduce transverse momentum spectra of hadrons in Semi-Inclusive DIS, an encouraging agreement with data is found. The present analysis also supports at the phenomenological level the factorization properties of the Semi-Inclusive DIS cross-sections in terms of $k_t$-dependent distributions. Further improvements and possible developments of the proposed evolution equations are envisaged. An application of transverse-momentum-dependent evolution equations in QCD Federico Ceccopieri Luca Trentadue (28 Jun 2007) 2007-06-29T22:58:44-00:00 2007 dis hep kt partonshower physics qcd standardmodel http://www.citeulike.org/group/2734/article/1423789 <i>(28 Jun 2007)</i><br /><br />This review describes the conformality approach to extending the standard model of particle phenomenology using an assumption of no conformal anomaly at high energy. Topics include quiver gauge theory, the conformality approach to phenomenology, strong-electroweak unification at 4 TeV, cancellation of quadratic divergences, cancellation of U(1) anomalies, and a dark matter candidate. Quiver Gauge Theory and Conformality at the Large Hadron Collider Paul Frampton Thomas Kephart (28 Jun 2007) 2007-06-29T22:57:53-00:00 2007 conformal fieldtheory hep lhc maths physics quiver http://www.citeulike.org/group/2734/article/1415537 <i>(26 Jun 2007)</i><br /><br />We report an observation of new bottom baryons produced in proton-antiproton collisions at the Tevatron. Using 1.1 fb^-1 of data collected by the CDF II detector, we observe four Λ_b^0π^± resonances in the fully reconstructed decay mode Λ_b^0 \to Λ_c^+ π^-, where Λ_c^+ \to p K^- π^+. We interpret these states as the Σ_b^(*)± baryons and measure their masses to be: m_Σ_b^+ = 5807.8^+2.0_-2.2 (stat.) ± 1.7 (syst.) MeV/c^2 m_Σ_b^- = 5815.2 ± 1.0 (stat.) ± 1.7 (syst.) MeV/c^2 m_Σ_b^*+ = 5829.0^+1.6_-1.8 (stat.) ^+1.7_-1.8 (syst.) MeV/c^2 m_Σ_b^*- = 5836.4 ± 2.0 (stat.) ^+1.8_-1.7 (syst.) MeV/c^2 First Observation of Heavy Baryons Σ_b and Σ_b^* CDF Collaboration T Aaltonen (26 Jun 2007) 2007-06-27T09:57:45-00:00 2007 baryons experiment hadrons hep physics qcd standardmodel tevatron http://www.citeulike.org/group/2734/article/1413370 <i>(22 Jun 2007)</i><br /><br />The charged particles multiplicity distribution in the KNO form is discussed in processes of $e^+e^-$ annihilation at energies $\sqrts$ 14 -- 206.2 GeV. The experimental data are compared to data, obtained with Monte Carlo simulation in PYTHIA in the Lund quark string model. It is shown, that both experimental and simulated data are described by the same distribution function in the KNO form. It is shown, that the KNO scaling is consequence of quark string hadronization dynamics in the Lund string model. KNO scaling in processes of electron-positron annihilation to hadrons VA Abramovsky NV Radchenko (22 Jun 2007) 2007-06-26T12:54:03-00:00 2007 fpythia hep jets physics standardmodel http://www.citeulike.org/group/2734/article/1413366 <i>(27 Apr 2005)</i><br /><br />These six lectures, given at the XI Mexican School of Particles and Fields held at Xalapa in August 2004, are on the subject of strong coupling QCD. How this colours and shapes the hadron world in terms of (i) the hadron spectrum, (ii) chiral symmetry breaking, (iii) dynamical mass generation and (iv) confinement, are the topics discussed. Swimming with Quarks MR Pennington (27 Apr 2005) 2007-06-26T12:53:06-00:00 2005 hadrons hep nonperturbative physics qcd standardmodel