292 research outputs found
Fully differential NLO predictions for the radiative decay of muons and taus
We present a general purpose Monte Carlo program for the calculation of the
radiative muon decay and the radiative decays
and at
next-to-leading order in the Fermi theory. The full dependence on the lepton
masses and polarization of the initial-sate lepton are kept. We study the
branching ratios for these processes and show that fully-differential
next-to-leading order corrections are important for addressing a tension
between BaBar's recent measurement of the branching ratio and the Standard Model prediction. In addition, we
study various distributions of the process and
obtain precise predictions for the irreducible background to
searches, tailored to the geometry of the MEG detector.Comment: 14 pages, 5 figures, published versio
Tree Level Unitarity Bounds for the Minimal B-L Model
We have derived the unitarity bounds in the high energy limit for the minimal
B-L extension of the Standard Model by analysing the full class of Higgs and
would-be Goldstone boson two-to-two scatterings at tree level. Moreover, we
have investigated how these limits could vary at some lower critical value of
the energy.Comment: 20 pages, 4 figures, 2 tables; 1d figure modified, typos corrected,
bibliography augmented; published in PRD after minor adjustmen
The Z' boson of the minimal B-L model at future Linear Colliders in e+e- --> mu+mu-
We study the capabilities of future electron-positron Linear Colliders, with
centre-of-mass energy at the TeV scale, in accessing the parameter space of a
boson within the minimal model. We carry out a detailed comparison
between the discovery regions mapped over a two-dimensional configuration space
( mass and coupling) at the Large Hadron Collider and possible future
Linear Colliders for the case of di-muon production. As known in the literature
for other models, we confirm that leptonic machines, as compared to the
CERN hadronic accelerator, display an additional potential in discovering a
boson as well as in allowing one to study its properties at a level of
precision well beyond that of any of the existing colliders.Comment: 5 pages, proceeding of LC09 (Perugia), published by the Italian
Physical Society in the Nuovo Cimento C (Colloquia
Production of Z' and W' via Drell-Yan processes in the 4D Composite Higgs Model at the LHC
We present an analysis of both the Neutral Current (NC) and Charged Current
(CC) Drell-Yan processes at the LHC within a 4 Dimensional realization of a
Composite Higgs model studying the cross sections and taking into account the
possible impact of the extra fermions present in the spectrum.Comment: Conference proceeding, XII IFAE Edition, 3-5 April 2013, Cagliari. 2
pages, 2 figures; v2 typo correcte
Phenomenology of the minimal B-L extension of the Standard Model
We present the Large Hadron Collider (LHC) discovery potential in the
and heavy neutrino sectors of a enlarged Standard Model also
encompassing three heavy Majorana neutrinos. This model exhibits novel
signatures at the LHC, the most interesting arising from a decay chain
involving heavy neutrinos, eventually decaying into leptons and jets. In
particular, this signature allows one to measure the and heavy neutrino
masses involved. In addition, over a large region of parameter space, the heavy
neutrinos are rather long-lived particles producing distinctive displaced
vertices that can be seen in the detectors. Lastly, the simultaneous
measurement of both the heavy neutrino mass and decay length enables an
estimate of the absolute mass of the parent light neutrino. For completeness,
we will also compare the LHC and a future Linear Collider (LC) discovery
potentials.Comment: 4 pages, no figures. LaTeX. Talk given at "The 2009 Europhysics
Conference on High Energy Physics", Krakow, Poland, July 16-22, 200
Influence of synthesis conditions on properties of green-reduced graphene oxide
[EN] Green reduction of graphene oxide (GO) was performed using ascorbic acid (AA) in the presence of poly(sodium 4-styrenesulfonate), which resulted in reduced graphene oxide (PSS-rGO) with excellent solubility and stability in water. Large rGO sheets of 4 mu m(2) area and 1.1-nm thickness were obtained. The measurements showed that noncovalent functionalization with PSS molecules prevented rGO from aggregation. The parameters of graphite oxidation process and AA: GO w/w ratio were evaluated, and the obtained results showed that the properties of the reduced material (PSS-rGO) can be tailored by proper selection and adjustment of these parameters.The authors thank the European Commission for their financial support through the project no. NMP3-SL-2010-246073.Pruna, A.; Pullini, D.; Busquets, D. (2013). Influence of synthesis conditions on properties of green-reduced graphene oxide. Journal of Nanoparticle Research. 15(5):1-11. https://doi.org/10.1007/s11051-013-1605-6S111155Acik M, Lee G, Mattevi C et al (2011) The role of oxygen during thermal reduction of graphene oxide studied by infrared absorption spectroscopy. J Phys Chem C 115:1981â19761Akhavan O, Ghaderi E (2012) Escherichia coli bacteria reduce graphene oxide to bactericidal graphene in a self-limiting manner. Carbon 50:1853â1860Akhavan O, Ghaderi E, Esfandiar A (2011) Wrapping bacteria by graphene nanosheets for isolation from environment, reactivation by sonication, and inactivation by near-infrared irradiation. J Phys Chem B 115:6279â6288Akhavan O, Ghaderi E, Aghayee S, Fereydooni Y, Talebi A (2012) The use of a glucose-reduced graphene oxide suspension for photothermal cancer therapy. J Mater Chem 22:13773â13781Bae S, Kim H, Lee Y et al (2010) Roll to- roll production of 30-inch graphene films for transparent electrodes. Nat Nanotechnol 5:574â578Bai H, Xu Y, Zhao L, Li C, Shi G (2009) Non-covalent functionalization of graphene sheets by sulfonated polyaniline. Chem Commun 13:1667â1669Boehm HP (1994) Some aspects of the surface chemistry of carbon blacks and other carbons. Carbon 32:759â769Boukhvalov DW, Katsnelson MI (2008) Modeling of graphite oxide. J Am Chem Soc 130:10697â10701Buchsteiner A, Lerf A, Pieper J (2006) Water dynamics in graphite oxide investigated with neutron scattering. J Phys Chem B 110:22328Choi BG, Park H, Park TJ et al (2010) Solution chemistry of self-assembled graphene nanohybrids for high-performance flexible biosensors. ACS Nano 4:2910â2918Cote LJ, Silva RC, Huang J (2009) Flash reduction and patterning of graphite oxide and its polymer composite. J Am Chem Soc 131:11027â11032Dai B, Fu L, Liao L et al (2011) High-quality single-layer graphene via reparative reduction of graphene oxide. Nano Res 4:434â439Davies MB, Austin J, Partridge DA (1991) Vitamin C: its chemistry and biochemistry. Royal Society of Chemistry, CambridgeElias DC, Nair RR, Mohiuddin TMG, Morozov SV, Blake P, Halsall MP et al (2009) Control of grapheneâs properties by reversible hydrogenation: evidence for graphene. Science 23:610â613Fan FRF, Park S, Zhu Y, Ruoff RS, Bard AJ (2009) Electrogenerated chemiluminescence of partially oxidized highly oriented pyrolytic graphite surfaces and of graphene oxide nanoparticles. J Am Chem Soc 131:937â939Fernandez-Merino MJ, Guardia L, Paredes JI, Villar-Rodil S et al (2010) Vitamin C is an ideal substitute for hydrazine in the reduction of graphene oxide suspensions. J Phys Chem C 114:6426â6432Ferrari AC, Meyer JC, Scardaci V, Casiraghi C, Lazzeri M, Mauri F, Piscanec S, Jiang D, Novoselov KS, Roth S, Geim AK (2006) Raman spectrum of graphene and graphene layers. Phys Rev Lett 97:187401â187405Ganguly A, Sharma S, Papakonstantinou P, Hamilton J (2011) Probing the thermal deoxygenation of graphene oxide using high-resolution in situ X-ray-based spectroscopies. J Phys Chem C 115:17009â17019Hancock RD, Viola R (2005) Biosynthesis and catabolism of l-ascorbic acid in plants. Crit Rev Plant Sci 24:167â188Hernandez Y, Nicolosi V, Lotya M et al (2008) High-yield production of graphene by liquid-phase exfoliation of graphite. Nat Nanotechnol 3:563â568Hontoria-Lucas C, Lopez-Peinado AJ, Loepz-Gonzalez JDD et al (1995) Study of oxygen-containing groups in a series of graphite oxides: physical and chemical characterization. Carbon 33:1585â1592Jeong HK, Lee YP, Lahaye RJWE et al (2008) Evidence of graphitic AB stacking order of graphite oxides. J Am Chem Soc 130:1362â1366Kim KS, Zhao Y, Jang H, Lee SY, Kim JM, Kim KS, Ahn JH, Kim P, Choi JY, Hong BH (2009) Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature 457:706â710Kuila T, Bose S, Mishra AK, Khanra P, Kim NH, Lee JH (2012) Chemical functionalization of graphene and its applications. Prog Mater Sci 57:1061â1105Kuilla T, Bhadra S, Yao D, Kim NH, Bose S, Lee JH (2010) Recent advances in graphene based polymer composites. Prog Polym Sci 35:1350â1375Kumar P, Subrahmanyam KS, Rao CNR (2011a) Graphene produced by radiation-induced reduction of graphene oxide. Intl J Nanosci 10:559â566Kumar P, Panchakarla LS, Rao CNR (2011b) Laser-induced unzipping of carbon nanotubes to yield graphene nanoribbons. Nanoscale 3:2127â2129Kumar P, Das B, Chitara B et al (2012) Novel radiation induced properties of graphene and related materials. Macromol Chem Phys 213:1146â1163Lee C, Wei X, Kysar JW, Hone J (2008) Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321:385â388Li D, Kaner RB (2008) Graphene-based materials. Science 320:1170â1171Li J, Liu CY (2010) Ag/Graphene heterostructures: synthesis, characterization and optical properties. Eur J Inorg Chem 8:1244â1248Li D, Muller MB, Gilje S, Kaner RB, Wallace GG (2008) Processable aqueous dispersions of graphene nanosheets. Nat Nanotechnol 3:101â105Li X, Cai W, An J et al (2009) Large-area synthesis of high-quality and uniform graphene films on copper foils. Science 324:1312â1314Maitra U, Matte HSRR, Kumar P, Rao CNR (2012) Strategies for the synthesis of graphene, graphene nanoribbons, nanoscrolls and related materials. Chimia 66:941â948Mei XG, Ouyang JY (2011) Ultrasonication-assisted ultrafast reduction of graphene oxide by zinc powder at room temperature. Carbon 49:5389â5397Mkhoyan K, Contryman A, Silcox J, Stewart D, Eda G, Mattevi C, Miller S, Chhowalla M (2009) Atomic and electronic structure of graphene-oxide. Nano Lett 9:1058â1063Nair RR, Blake P, Grigorenko AN et al (2008) Fine structure constant defines visual transparency of graphene. Science 320:1308Park S, Lee KS, Bozoklu G et al (2008) Graphene oxide papers modified by divalent ions enhancing mechanical properties via chemical cross-linking. ACS Nano 2:572â578Park S, An J, Jung I et al (2009) Colloidal suspensions of highly reduced graphene oxide in a wide variety of organic solvents. Nano Lett 9:1593â1597Park HJ, Meyer J, Roth S, SkĂĄkalovĂĄ V (2010) Growth and properties of few-layer graphene prepared by chemical vapor deposition. Carbon 48:1088â1094Park S, An J, Potts JR, Velamakanni A, Murali S, Ruoff RS (2011) Hydrazine-reduction of graphite- and graphene oxide. Carbon 49:3019â3023Patil AJ, Vickery JL, Scott TB, Mann S (2009) Aqueous stabilization and self-assembly of graphene sheets into layered bio-nanocomposites using DNA. Adv Mater 21:3159â3164Stankovich S, Piner RD, Chen X, Wu N, Nguyen SBT, Ruoff RS (2006) Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate). J Mater Chem 16:155â158Subrahmanyam KS, Panchakarla LS, Govindaraj A, Rao CNR (2009) Simple method of preparing graphene flakes by an arc-discharge method. J Phys Chem C 113:4257â4259SzabĂł T, Tombacz E, Illes E, DĂŠkĂĄny I (2006) Enhanced acidity and pH-dependent surface charge characterization of successively oxidized graphite oxides. Carbon 44:537â545Wu JS, Pisula W, Mullen K (2007) Graphenes as potential material for electronics. Chem Rev 107:718â747Wu H, Zhao WF, Hu HW, Chen GH (2011) One-step in situ ball milling synthesis of polymer-functionalized graphene nanocomposites. J Mater Chem 21:8626â8632Xu Y, Bai H, Lu G, Li C, Shi G (2008) Flexible graphene films via the filtration of water-soluble noncovalent functionalized graphene sheets. J Am Chem Soc 130:5856â5857Yin Z, Wu S, Zhou X et al (2010) Electrochemical deposition of ZnO nanorods on transparent reduced graphene oxide electrodes for hybrid solar cells. Small 6:307â312Zhang L, Liang J, Huang Y, Ma Y, Wang Y, Chen YS (2009) Size-controlled synthesis of graphene oxide sheets on a large scale using chemical exfoliation. Carbon 47:3365â3380Zhang J, Yang H, Shen G, Cheng P, Zhang J, Guo S (2010) Reduction of graphene oxide via l-ascorbic acid. Chem Comm 46:1112â1114Zhou Y, Bao Q, Tang LAL, Zhong Y, Loh KP (2009) Hydrothermal dehydration for the âgreenâ reduction of exfoliated graphene oxide to graphene and demonstration of tunable optical limiting properties. Chem Mater 21:2950â295
Orienting coupled quantum rotors by ultrashort laser pulses
We point out that the non-adiabatic orientation of quantum rotors, produced
by ultrashort laser pulses, is remarkably enhanced by introducing dipolar
interaction between the rotors. This enhanced orientation of quantum rotors is
in contrast with the behavior of classical paired rotors, in which dipolar
interactions prevent the orientation of the rotors. We demonstrate also that a
specially designed sequence of pulses can most efficiently enhances the
orientation of quantum paired rotors.Comment: 7 pages, 5 figures, to appear in Phys. Rev.
Higgs Boson in the 4DCHM: LHC phenomenology
Composite Higgs models provide an elegant solution to the hierarchy problem
present in the Standard Model (SM) and give an alternative pattern leading to
the mechanism of Electro-Weak Symmetry Breaking (EWSB). We present an analysis
of the Higgs boson production and decay within a recently proposed realistic
realization of this general idea: the 4D Composite Higgs Model (4DCHM).
Comparing our results with the latest Large Hadron Collider (LHC) data we show
that the 4DCHM could provide an alternative explanation with respect to the SM
of the LHC results pointing to the discovery of a Higgs-like particle at 125
GeV.Comment: Conference proceeding, EPS-HEP 2013, 18-24 July 2013, Stockholm. 3
pages, 2 figures, typo correcte
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