Jet Substructure as a New Higgs-Search Channel at the Large Hadron Collider

Physical Review Letters American Physical Society (APS) 100:24 (2008) 242001

Authors:

Jonathan M Butterworth, Adam R Davison, Mathieu Rubin, Gavin P Salam

Closed k-strings in SU(N) gauge theories: 2 + 1 dimensions

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 663:5 (2008) 429-437

Authors:

B Bringoltz, M Teper

Abstract:

We calculate the ground state energies of closed k-strings in (2 + 1)-dimensional SU(N) gauge theories, for N = 4, 5, 6, 8 and k = 2, 3, 4. From the dependence of the ground state energy on the string length, we infer that such k-strings are described by an effective string theory that is in the same bosonic universality class (Nambu-Goto) as the fundamental string. When we compare the continuum k-string tensions to the corresponding fundamental string tensions, we find that the ratios are close to, but typically 1-2% above, the Casimir scaling values favoured by some theoretical approaches. Fitting the N-dependence in a model-independent way favours an expansion in 1 / N (as in Casimir scaling) rather than the 1 / N2 that is suggested by naive colour counting. We also observe that the low-lying spectrum of k-string states falls into sectors that belong to particular irreducible representations of SU(N), demonstrating that the dynamics of string binding knows about the full gauge group and not just about its centre.

Volume Modulus Inflation and the Gravitino Mass Problem

ArXiv 0806.0809 (2008)

Authors:

Joseph P Conlon, Renata Kallosh, Andrei Linde, Fernando Quevedo

Abstract:

The Hubble constant during the last stages of inflation in a broad class of models based on the KKLT mechanism should be smaller than the gravitino mass, H <~ m_{3/2}. We point out that in the models with large volume of compactification the corresponding constraint typically is even stronger, H <~ m_{3/2}^{3/2}, in Planck units. In order to address this problem, we propose a class of models with large volume of compactification where inflation may occur exponentially far away from the present vacuum state. In these models, the Hubble constant during inflation can be many orders of magnitude greater than the gravitino mass. We introduce a toy model describing this scenario, and discuss its strengths and weaknesses.

Volume Modulus Inflation and the Gravitino Mass Problem

(2008)

Authors:

Joseph P Conlon, Renata Kallosh, Andrei Linde, Fernando Quevedo

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory.

Phys Rev Lett 100:21 (2008) 211101

Authors:

J Abraham, P Abreu, M Aglietta, C Aguirre, D Allard, I Allekotte, J Allen, P Allison, J Alvarez-Muñiz, M Ambrosio, L Anchordoqui, S Andringa, A Anzalone, C Aramo, S Argirò, K Arisaka, E Armengaud, F Arneodo, F Arqueros, T Asch, H Asorey, P Assis, BS Atulugama, J Aublin, M Ave, G Avila, T Bäcker, D Badagnani, AF Barbosa, D Barnhill, SLC Barroso, P Bauleo, JJ Beatty, T Beau, BR Becker, KH Becker, JA Bellido, S BenZvi, C Berat, T Bergmann, P Bernardini, X Bertou, PL Biermann, P Billoir, O Blanch-Bigas, F Blanco, P Blasi, C Bleve, H Blümer, M Bohácová, C Bonifazi, R Bonino, M Boratav, J Brack, P Brogueira, WC Brown, P Buchholz, A Bueno, RE Burton, NG Busca, KS Caballero-Mora, B Cai, DV Camin, L Caramete, R Caruso, W Carvalho, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, A Chiavassa, JA Chinellato, A Chou, J Chye, PDJ Clark, RW Clay, E Colombo, R Conceição, B Connolly, F Contreras, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, K Daumiller, BR Dawson, RM de Almeida, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I DeMitri, V de Souza, L del Peral, O Deligny, A Della Selva, C Delle Fratte, H Dembinski, C Di Giulio, JC Diaz, C Dobrigkeit, JC D'Olivo, D Dornic, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, MA DuVernois, R Engel, L Epele, M Erdmann, CO Escobar, A Etchegoyen, P Facal San Luis, H Falcke, G Farrar, AC Fauth, N Fazzini, F Ferrer, S Ferry, B Fick, A Filevich, A Filipcic, I Fleck, R Fonte, CE Fracchiolla, W Fulgione, B García, D García Gámez, D Garcia-Pinto, X Garrido, H Geenen, G Gelmini, H Gemmeke, PL Ghia, M Giller, H Glass, MS Gold, G Golup, F Gomez Albarracin, M Gómez Berisso, R Gómez Herrero, P Gonçalves, M Gonçalves do Amaral, D Gonzalez, JG Gonzalez, M González, D Góra, A Gorgi, P Gouffon, V Grassi, AF Grillo, C Grunfeld, Y Guardincerri, F Guarino, GP Guedes, J Gutiérrez, JD Hague, JC Hamilton, P Hansen, D Harari, S Harmsma, JL Harton, A Haungs, T Hauschildt, MD Healy, T Hebbeker, G Hebrero, D Heck, C Hojvat, VC Holmes, P Homola, J Hörandel, A Horneffer, M Horvat, M Hrabovský, T Huege, M Hussain, M Iarlori, A Insolia, F Ionita, A Italiano, M Kaducak, KH Kampert, T Karova, B Kégl, B Keilhauer, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, R Knapik, J Knapp, D-H Koang, A Krieger, O Krömer, D Kuempel, N Kunka, A Kusenko, G La Rosa, C Lachaud, BL Lago, D Lebrun, P Lebrun, J Lee, MA Leigui de Oliveira, A Letessier-Selvon, M Leuthold, I Lhenry-Yvon, R López, A Lopez Agüera, J Lozano Bahilo, R Luna García, MC Maccarone, C Macolino, S Maldera, G Mancarella, ME Manceñido, D Mandat, P Mantsch, AG Mariazzi, IC Maris, HR Marquez Falcon, D Martello, J Martínez, O Martínez Bravo, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurizio, PO Mazur, T McCauley, M McEwen, RR McNeil, MC Medina, G Medina-Tanco, A Meli, D Melo, E Menichetti, A Menschikov, Chr Meurer, R Meyhandan, MI Micheletti, G Miele, W Miller, S Mollerach, M Monasor, D Monnier Ragaigne, F Montanet, B Morales, C Morello, JC Moreno, C Morris, M Mostafá, MA Muller, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, C Newman-Holmes, D Newton, T Nguyen Thi, N Nierstenhoefer, D Nitz, D Nosek, L Nozka, J Oehlschläger, T Ohnuki, A Olinto, VM Olmos-Gilbaja, M Ortiz, F Ortolani, S Ostapchenko, L Otero, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, G Parente, E Parizot, S Parlati, S Pastor, M Patel, T Paul, V Pavlidou, K Payet, M Pech, J Pekala, R Pelayo, IM Pepe, L Perrone, S Petrera, P Petrinca, Y Petrov, Diep Pham Ngoc, Dong Pham Ngoc, TN Pham Thi, A Pichel, R Piegaia, T Pierog, M Pimenta, T Pinto, V Pirronello, O Pisanti, M Platino, J Pochon, P Privitera, M Prouza, EJ Quel, J Rautenberg, A Redondo, S Reucroft, B Revenu, FAS Rezende, J Ridky, S Riggi, M Risse, C Rivière, V Rizi, M Roberts, C Robledo, G Rodriguez, D Rodríguez Frías, J Rodriguez Martino, J Rodriguez Rojo, I Rodriguez-Cabo, G Ros, J Rosado, M Roth, B Rouillé-d'Orfeuil, E Roulet, AC Rovero, F Salamida, H Salazar, G Salina, F Sánchez, M Santander, CE Santo, EM Santos, F Sarazin, S Sarkar, R Sato, V Scherini, H Schieler, A Schmidt, F Schmidt, T Schmidt, O Scholten, P Schovánek, F Schüssler, SJ Sciutto, M Scuderi, A Segreto, D Semikoz, M Settimo, RC Shellard, I Sidelnik, BB Siffert, G Sigl, N Smetniansky De Grande, A Smiałkowski, R Smída, AGK Smith, BE Smith, GR Snow, P Sokolsky, P Sommers, J Sorokin, H Spinka, R Squartini, E Strazzeri, A Stutz, F Suarez, T Suomijärvi, AD Supanitsky, MS Sutherland, J Swain, Z Szadkowski, J Takahashi, A Tamashiro, A Tamburro, O Taşcău, R Tcaciuc, D Thomas, R Ticona, J Tiffenberg, C Timmermans, W Tkaczyk, CJ Todero Peixoto, B Tomé, A Tonachini, I Torres, D Torresi, P Travnicek, A Tripathi, G Tristram, D Tscherniakhovski, M Tueros, V Tunnicliffe, R Ulrich, M Unger, M Urban, JF Valdés Galicia, I Valiño, L Valore, AM van den Berg, V van Elewyck, RA Vázquez, D Veberic, A Veiga, A Velarde, T Venters, V Verzi, M Videla, L Villaseñor, S Vorobiov, L Voyvodic, H Wahlberg, O Wainberg, P Walker, D Warner, AA Watson, S Westerhoff, G Wieczorek, L Wiencke, B Wilczyńska, H Wilczyński, C Wileman, MG Winnick, H Wu, B Wundheiler, T Yamamoto, P Younk, E Zas, D Zavrtanik, M Zavrtanik, A Zech, A Zepeda, M Ziolkowski, Pierre Auger Collaboration

Abstract:

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.