A search for single photon events in neutrino interactions

C. T. Kullenberg; S. R. Mishra; D. Dimmery; X. C. Tian; D. Autiero; S. Gninenko; A. Rubbia; S. Alekhin; P. Astier; A. Baldisseri; M. Baldo-Ceolin; M. Banner; G. Bassompierre; K. Benslama; N. Besson; I. Bird; B. Blumenfeld; F. Bobisut; J. Bouchez; S. Boyd; A. Bueno; S. Bunyatov; L. Camilleri; A. Cardini; P. W. Cattaneo; V. Cavasinni; A. Cervera-Villanueva; R. Challis; A. Chukanov; G. Collazuol; G. Conforto; C. Conta; M. Contalbrigo; R. Cousins; H. Degaudenzi; A. De Santo; T. Del Prete; L. Di Lella; E. do Couto e Silva; J. Dumarchez; M. Ellis; G. J. Feldman; R. Ferrari; D. Ferrère; V. Flaminio; M. Fraternali; J. M. Gaillard; E. Gangler; A. Geiser; D. Geppert; D. Gibin; A. Godley; J. J. Gomez-Cadenas; J. Gosset; C. Gößling; M. Gouanère; A. Grant; G. Graziani; A. Guglielmi; C. Hagner; J. Hernando; P. Hurst; N. Hyett; E. Iacopini; C. Joseph; F. Juget; N. Kent; O. Klimov; J. Kokkonen; A. Kovzelev; A. Krasnoperov; J. J. Kim; M. Kirsanov; S. Kulagin; S. Lacaprara; C. Lachaud; B. Lakić; A. Lanza; L. La Rotonda; M. Laveder; A. Letessier-Selvon; J. M. Levy; J. Ling; L. Linssen; A. Ljubičić; J. Long; A. Lupi; V. Lyubushkin; A. Marchionni; F. Martelli; X. Méchain; J. P. Mendiburu; J. P. Meyer; M. Mezzetto; G. F. Moorhead; D. Naumov; P. Nédélec; Yu Nefedov; C. Nguyen-Mau; D. Orestano; F. Pastore; L. S. Peak; E. Pennacchio; H. Pessard; R. Petti; A. Placci; G. Polesello; D. Pollmann; A. Polyarush; C. Poulsen; B. Popov; L. Rebuffi; J. Rico; P. Riemann; C. Roda; F. Salvatore; O. Samoylov; K. Schahmaneche; B. Schmidt; T. Schmidt; A. Sconza; A. M. Scott; M. B. Seaton; M. Sevior; D. Sillou; F. J.P. Soler; G. Sozzi; D. Steele; U. Stiegler; M. Stipčević; Th Stolarczyk; M. Tareb-Reyes; G. N. Taylor; V. Tereshchenko; A. Toropin; A. M. Touchard; S. N. Tovey; M. T. Tran; E. Tsesmelis; J. Ulrichs; L. Vacavant; M. Valdata-Nappi; V. Valuev; F. Vannucci; K. E. Varvell; M. Veltri; V. Vercesi; G. Vidal-Sitjes; J. M. Vieira; T. Vinogradova; F. V. Weber; T. Weisse; F. F. Wilson; L. J. Winton; Q. Wu; B. D. Yabsley; H. Zaccone; K. Zuber; P. Zuccon

doi:10.1016/j.physletb.2011.11.049

A search for single photon events in neutrino interactions

C. T. Kullenberg, S. R. Mishra, D. Dimmery, X. C. Tian, D. Autiero, S. Gninenko, A. Rubbia, S. Alekhin, P. Astier, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. BoydA. Bueno, S. Bunyatov, L. Camilleri, A. Cardini, P. W. Cattaneo, V. Cavasinni, A. Cervera-Villanueva, R. Challis, A. Chukanov, G. Collazuol, G. Conforto, C. Conta, M. Contalbrigo, R. Cousins, H. Degaudenzi, A. De Santo, T. Del Prete, L. Di Lella, E. do Couto e Silva, J. Dumarchez, M. Ellis, G. J. Feldman, R. Ferrari, D. Ferrère, V. Flaminio, M. Fraternali, J. M. Gaillard, E. Gangler, A. Geiser, D. Geppert, D. Gibin, A. Godley, J. J. Gomez-Cadenas, J. Gosset, C. Gößling, M. Gouanère, A. Grant, G. Graziani, A. Guglielmi, C. Hagner, J. Hernando, P. Hurst, N. Hyett, E. Iacopini, C. Joseph, F. Juget, N. Kent, O. Klimov, J. Kokkonen, A. Kovzelev, A. Krasnoperov, J. J. Kim, M. Kirsanov, S. Kulagin, S. Lacaprara, C. Lachaud, B. Lakić, A. Lanza, L. La Rotonda, M. Laveder, A. Letessier-Selvon, J. M. Levy, J. Ling, L. Linssen, A. Ljubičić, J. Long, A. Lupi, V. Lyubushkin, A. Marchionni, F. Martelli, X. Méchain, J. P. Mendiburu, J. P. Meyer, M. Mezzetto, G. F. Moorhead, D. Naumov, P. Nédélec, Yu Nefedov, C. Nguyen-Mau, D. Orestano, F. Pastore, L. S. Peak, E. Pennacchio, H. Pessard, R. Petti, A. Placci, G. Polesello, D. Pollmann, A. Polyarush, C. Poulsen, B. Popov, L. Rebuffi, J. Rico, P. Riemann, C. Roda, F. Salvatore, O. Samoylov, K. Schahmaneche, B. Schmidt, T. Schmidt, A. Sconza, A. M. Scott, M. B. Seaton, M. Sevior, D. Sillou, F. J.P. Soler, G. Sozzi, D. Steele, U. Stiegler, M. Stipčević, Th Stolarczyk, M. Tareb-Reyes, G. N. Taylor, V. Tereshchenko, A. Toropin, A. M. Touchard, S. N. Tovey, M. T. Tran, E. Tsesmelis, J. Ulrichs, L. Vacavant, M. Valdata-Nappi, V. Valuev, F. Vannucci, K. E. Varvell, M. Veltri, V. Vercesi, G. Vidal-Sitjes, J. M. Vieira, T. Vinogradova, F. V. Weber, T. Weisse, F. F. Wilson, L. J. Winton, Q. Wu, B. D. Yabsley, H. Zaccone, K. Zuber, P. Zuccon

Research output: Contribution to journal › Article › peer-review

28 Scopus citations

Abstract

We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e⁺e^- in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined in situ using control data samples prior to opening the 'signal-box'. In the signal region, we observe 155 events with a predicted background of 129.2±8.5±3.3. We interpret this as null evidence for excess of single photon events, and set a limit. Assuming that the hypothetical single photon has a momentum distribution similar to that of a photon from the coherent π⁰ decay, the measurement yields an upper limit on single photon events, <4.0×10^-4 per ν_μ charged current event. Narrowing the search to events where the photon is approximately collinear with the incident neutrino, we observe 78 events with a predicted background of 76.6±4.9±1.9 yielding a more stringent upper limit, <1.6×10^-4 per ν_μ charged current event.

Original language	English (US)
Pages (from-to)	268-275
Number of pages	8
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	706
Issue number	4-5
DOIs	https://doi.org/10.1016/j.physletb.2011.11.049
State	Published - Jan 5 2012
Externally published	Yes

Keywords

Coherent
Neutral current
Neutrino
Pion
Single photon

ASJC Scopus subject areas

Nuclear and High Energy Physics

Access to Document

10.1016/j.physletb.2011.11.049

Cite this

Kullenberg, C. T., Mishra, S. R., Dimmery, D., Tian, X. C., Autiero, D., Gninenko, S., Rubbia, A., Alekhin, S., Astier, P., Baldisseri, A., Baldo-Ceolin, M., Banner, M., Bassompierre, G., Benslama, K., Besson, N., Bird, I., Blumenfeld, B., Bobisut, F., Bouchez, J., ... Zuccon, P. (2012). A search for single photon events in neutrino interactions. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 706(4-5), 268-275. https://doi.org/10.1016/j.physletb.2011.11.049

Kullenberg, CT, Mishra, SR, Dimmery, D, Tian, XC, Autiero, D, Gninenko, S, Rubbia, A, Alekhin, S, Astier, P, Baldisseri, A, Baldo-Ceolin, M, Banner, M, Bassompierre, G, Benslama, K, Besson, N, Bird, I, Blumenfeld, B, Bobisut, F, Bouchez, J, Boyd, S, Bueno, A, Bunyatov, S, Camilleri, L, Cardini, A, Cattaneo, PW, Cavasinni, V, Cervera-Villanueva, A, Challis, R, Chukanov, A, Collazuol, G, Conforto, G, Conta, C, Contalbrigo, M, Cousins, R, Degaudenzi, H, De Santo, A, Del Prete, T, Di Lella, L, do Couto e Silva, E, Dumarchez, J, Ellis, M, Feldman, GJ, Ferrari, R, Ferrère, D, Flaminio, V, Fraternali, M, Gaillard, JM, Gangler, E, Geiser, A, Geppert, D, Gibin, D, Godley, A, Gomez-Cadenas, JJ, Gosset, J, Gößling, C, Gouanère, M, Grant, A, Graziani, G, Guglielmi, A, Hagner, C, Hernando, J, Hurst, P, Hyett, N, Iacopini, E, Joseph, C, Juget, F, Kent, N, Klimov, O, Kokkonen, J, Kovzelev, A, Krasnoperov, A, Kim, JJ, Kirsanov, M, Kulagin, S, Lacaprara, S, Lachaud, C, Lakić, B, Lanza, A, La Rotonda, L, Laveder, M, Letessier-Selvon, A, Levy, JM, Ling, J, Linssen, L, Ljubičić, A, Long, J, Lupi, A, Lyubushkin, V, Marchionni, A, Martelli, F, Méchain, X, Mendiburu, JP, Meyer, JP, Mezzetto, M, Moorhead, GF, Naumov, D, Nédélec, P, Nefedov, Y, Nguyen-Mau, C, Orestano, D, Pastore, F, Peak, LS, Pennacchio, E, Pessard, H, Petti, R, Placci, A, Polesello, G, Pollmann, D, Polyarush, A, Poulsen, C, Popov, B, Rebuffi, L, Rico, J, Riemann, P, Roda, C, Salvatore, F, Samoylov, O, Schahmaneche, K, Schmidt, B, Schmidt, T, Sconza, A, Scott, AM, Seaton, MB, Sevior, M, Sillou, D, Soler, FJP, Sozzi, G, Steele, D, Stiegler, U, Stipčević, M, Stolarczyk, T, Tareb-Reyes, M, Taylor, GN, Tereshchenko, V, Toropin, A, Touchard, AM, Tovey, SN, Tran, MT, Tsesmelis, E, Ulrichs, J, Vacavant, L, Valdata-Nappi, M, Valuev, V, Vannucci, F, Varvell, KE, Veltri, M, Vercesi, V, Vidal-Sitjes, G, Vieira, JM, Vinogradova, T, Weber, FV, Weisse, T, Wilson, FF, Winton, LJ, Wu, Q, Yabsley, BD, Zaccone, H, Zuber, K & Zuccon, P 2012, 'A search for single photon events in neutrino interactions', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 706, no. 4-5, pp. 268-275. https://doi.org/10.1016/j.physletb.2011.11.049

@article{c927463499f348618523457eba37d5e6,

title = "A search for single photon events in neutrino interactions",

abstract = "We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e+e- in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined in situ using control data samples prior to opening the 'signal-box'. In the signal region, we observe 155 events with a predicted background of 129.2±8.5±3.3. We interpret this as null evidence for excess of single photon events, and set a limit. Assuming that the hypothetical single photon has a momentum distribution similar to that of a photon from the coherent π0 decay, the measurement yields an upper limit on single photon events, <4.0×10-4 per νμ charged current event. Narrowing the search to events where the photon is approximately collinear with the incident neutrino, we observe 78 events with a predicted background of 76.6±4.9±1.9 yielding a more stringent upper limit, <1.6×10-4 per νμ charged current event.",

keywords = "Coherent, Neutral current, Neutrino, Pion, Single photon",

author = "Kullenberg, {C. T.} and Mishra, {S. R.} and D. Dimmery and Tian, {X. C.} and D. Autiero and S. Gninenko and A. Rubbia and S. Alekhin and P. Astier and A. Baldisseri and M. Baldo-Ceolin and M. Banner and G. Bassompierre and K. Benslama and N. Besson and I. Bird and B. Blumenfeld and F. Bobisut and J. Bouchez and S. Boyd and A. Bueno and S. Bunyatov and L. Camilleri and A. Cardini and Cattaneo, {P. W.} and V. Cavasinni and A. Cervera-Villanueva and R. Challis and A. Chukanov and G. Collazuol and G. Conforto and C. Conta and M. Contalbrigo and R. Cousins and H. Degaudenzi and {De Santo}, A. and {Del Prete}, T. and {Di Lella}, L. and {do Couto e Silva}, E. and J. Dumarchez and M. Ellis and Feldman, {G. J.} and R. Ferrari and D. Ferr{\`e}re and V. Flaminio and M. Fraternali and Gaillard, {J. M.} and E. Gangler and A. Geiser and D. Geppert and D. Gibin and A. Godley and Gomez-Cadenas, {J. J.} and J. Gosset and C. G{\"o}{\ss}ling and M. Gouan{\`e}re and A. Grant and G. Graziani and A. Guglielmi and C. Hagner and J. Hernando and P. Hurst and N. Hyett and E. Iacopini and C. Joseph and F. Juget and N. Kent and O. Klimov and J. Kokkonen and A. Kovzelev and A. Krasnoperov and Kim, {J. J.} and M. Kirsanov and S. Kulagin and S. Lacaprara and C. Lachaud and B. Laki{\'c} and A. Lanza and {La Rotonda}, L. and M. Laveder and A. Letessier-Selvon and Levy, {J. M.} and J. Ling and L. Linssen and A. Ljubi{\v c}i{\'c} and J. Long and A. Lupi and V. Lyubushkin and A. Marchionni and F. Martelli and X. M{\'e}chain and Mendiburu, {J. P.} and Meyer, {J. P.} and M. Mezzetto and Moorhead, {G. F.} and D. Naumov and P. N{\'e}d{\'e}lec and Yu Nefedov and C. Nguyen-Mau and D. Orestano and F. Pastore and Peak, {L. S.} and E. Pennacchio and H. Pessard and R. Petti and A. Placci and G. Polesello and D. Pollmann and A. Polyarush and C. Poulsen and B. Popov and L. Rebuffi and J. Rico and P. Riemann and C. Roda and F. Salvatore and O. Samoylov and K. Schahmaneche and B. Schmidt and T. Schmidt and A. Sconza and Scott, {A. M.} and Seaton, {M. B.} and M. Sevior and D. Sillou and Soler, {F. J.P.} and G. Sozzi and D. Steele and U. Stiegler and M. Stip{\v c}evi{\'c} and Th Stolarczyk and M. Tareb-Reyes and Taylor, {G. N.} and V. Tereshchenko and A. Toropin and Touchard, {A. M.} and Tovey, {S. N.} and Tran, {M. T.} and E. Tsesmelis and J. Ulrichs and L. Vacavant and M. Valdata-Nappi and V. Valuev and F. Vannucci and Varvell, {K. E.} and M. Veltri and V. Vercesi and G. Vidal-Sitjes and Vieira, {J. M.} and T. Vinogradova and Weber, {F. V.} and T. Weisse and Wilson, {F. F.} and Winton, {L. J.} and Q. Wu and Yabsley, {B. D.} and H. Zaccone and K. Zuber and P. Zuccon",

note = "Funding Information: We extend our grateful appreciations to the CERN SPS staff for the magnificent performance of the neutrino beam. We (C.T.K. and S.R.M.) warmly thank Bill Louis, Richard Hill, Chris Hill, James Jenkins and Terry Goldman for many stimulating discussions and insights. The experiment was supported by the following agencies: ARC and DIISR of Australia ; IN2P3 and CEA of France , BMBF of Germany , INFN of Italy , JINR and INR of Russia , FNSRS of Switzerland , DOE , NSF , Sloan , and Cottrell Foundations of USA, and VP Research Office of the University of South Carolina .",

year = "2012",

month = jan,

day = "5",

doi = "10.1016/j.physletb.2011.11.049",

language = "English (US)",

volume = "706",

pages = "268--275",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier",

number = "4-5",

}

TY - JOUR

T1 - A search for single photon events in neutrino interactions

AU - Kullenberg, C. T.

AU - Mishra, S. R.

AU - Dimmery, D.

AU - Tian, X. C.

AU - Autiero, D.

AU - Gninenko, S.

AU - Rubbia, A.

AU - Alekhin, S.

AU - Astier, P.

AU - Baldisseri, A.

AU - Baldo-Ceolin, M.

AU - Banner, M.

AU - Bassompierre, G.

AU - Benslama, K.

AU - Besson, N.

AU - Bird, I.

AU - Blumenfeld, B.

AU - Bobisut, F.

AU - Bouchez, J.

AU - Boyd, S.

AU - Bueno, A.

AU - Bunyatov, S.

AU - Camilleri, L.

AU - Cardini, A.

AU - Cattaneo, P. W.

AU - Cavasinni, V.

AU - Cervera-Villanueva, A.

AU - Challis, R.

AU - Chukanov, A.

AU - Collazuol, G.

AU - Conforto, G.

AU - Conta, C.

AU - Contalbrigo, M.

AU - Cousins, R.

AU - Degaudenzi, H.

AU - De Santo, A.

AU - Del Prete, T.

AU - Di Lella, L.

AU - do Couto e Silva, E.

AU - Dumarchez, J.

AU - Ellis, M.

AU - Feldman, G. J.

AU - Ferrari, R.

AU - Ferrère, D.

AU - Flaminio, V.

AU - Fraternali, M.

AU - Gaillard, J. M.

AU - Gangler, E.

AU - Geiser, A.

AU - Geppert, D.

AU - Gibin, D.

AU - Godley, A.

AU - Gomez-Cadenas, J. J.

AU - Gosset, J.

AU - Gößling, C.

AU - Gouanère, M.

AU - Grant, A.

AU - Graziani, G.

AU - Guglielmi, A.

AU - Hagner, C.

AU - Hernando, J.

AU - Hurst, P.

AU - Hyett, N.

AU - Iacopini, E.

AU - Joseph, C.

AU - Juget, F.

AU - Kent, N.

AU - Klimov, O.

AU - Kokkonen, J.

AU - Kovzelev, A.

AU - Krasnoperov, A.

AU - Kim, J. J.

AU - Kirsanov, M.

AU - Kulagin, S.

AU - Lacaprara, S.

AU - Lachaud, C.

AU - Lakić, B.

AU - Lanza, A.

AU - La Rotonda, L.

AU - Laveder, M.

AU - Letessier-Selvon, A.

AU - Levy, J. M.

AU - Ling, J.

AU - Linssen, L.

AU - Ljubičić, A.

AU - Long, J.

AU - Lupi, A.

AU - Lyubushkin, V.

AU - Marchionni, A.

AU - Martelli, F.

AU - Méchain, X.

AU - Mendiburu, J. P.

AU - Meyer, J. P.

AU - Mezzetto, M.

AU - Moorhead, G. F.

AU - Naumov, D.

AU - Nédélec, P.

AU - Nefedov, Yu

AU - Nguyen-Mau, C.

AU - Orestano, D.

AU - Pastore, F.

AU - Peak, L. S.

AU - Pennacchio, E.

AU - Pessard, H.

AU - Petti, R.

AU - Placci, A.

AU - Polesello, G.

AU - Pollmann, D.

AU - Polyarush, A.

AU - Poulsen, C.

AU - Popov, B.

AU - Rebuffi, L.

AU - Rico, J.

AU - Riemann, P.

AU - Roda, C.

AU - Salvatore, F.

AU - Samoylov, O.

AU - Schahmaneche, K.

AU - Schmidt, B.

AU - Schmidt, T.

AU - Sconza, A.

AU - Scott, A. M.

AU - Seaton, M. B.

AU - Sevior, M.

AU - Sillou, D.

AU - Soler, F. J.P.

AU - Sozzi, G.

AU - Steele, D.

AU - Stiegler, U.

AU - Stipčević, M.

AU - Stolarczyk, Th

AU - Tareb-Reyes, M.

AU - Taylor, G. N.

AU - Tereshchenko, V.

AU - Toropin, A.

AU - Touchard, A. M.

AU - Tovey, S. N.

AU - Tran, M. T.

AU - Tsesmelis, E.

AU - Ulrichs, J.

AU - Vacavant, L.

AU - Valdata-Nappi, M.

AU - Valuev, V.

AU - Vannucci, F.

AU - Varvell, K. E.

AU - Veltri, M.

AU - Vercesi, V.

AU - Vidal-Sitjes, G.

AU - Vieira, J. M.

AU - Vinogradova, T.

AU - Weber, F. V.

AU - Weisse, T.

AU - Wilson, F. F.

AU - Winton, L. J.

AU - Wu, Q.

AU - Yabsley, B. D.

AU - Zaccone, H.

AU - Zuber, K.

AU - Zuccon, P.

N1 - Funding Information: We extend our grateful appreciations to the CERN SPS staff for the magnificent performance of the neutrino beam. We (C.T.K. and S.R.M.) warmly thank Bill Louis, Richard Hill, Chris Hill, James Jenkins and Terry Goldman for many stimulating discussions and insights. The experiment was supported by the following agencies: ARC and DIISR of Australia ; IN2P3 and CEA of France , BMBF of Germany , INFN of Italy , JINR and INR of Russia , FNSRS of Switzerland , DOE , NSF , Sloan , and Cottrell Foundations of USA, and VP Research Office of the University of South Carolina .

PY - 2012/1/5

Y1 - 2012/1/5

N2 - We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e+e- in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined in situ using control data samples prior to opening the 'signal-box'. In the signal region, we observe 155 events with a predicted background of 129.2±8.5±3.3. We interpret this as null evidence for excess of single photon events, and set a limit. Assuming that the hypothetical single photon has a momentum distribution similar to that of a photon from the coherent π0 decay, the measurement yields an upper limit on single photon events, <4.0×10-4 per νμ charged current event. Narrowing the search to events where the photon is approximately collinear with the incident neutrino, we observe 78 events with a predicted background of 76.6±4.9±1.9 yielding a more stringent upper limit, <1.6×10-4 per νμ charged current event.

AB - We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e+e- in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined in situ using control data samples prior to opening the 'signal-box'. In the signal region, we observe 155 events with a predicted background of 129.2±8.5±3.3. We interpret this as null evidence for excess of single photon events, and set a limit. Assuming that the hypothetical single photon has a momentum distribution similar to that of a photon from the coherent π0 decay, the measurement yields an upper limit on single photon events, <4.0×10-4 per νμ charged current event. Narrowing the search to events where the photon is approximately collinear with the incident neutrino, we observe 78 events with a predicted background of 76.6±4.9±1.9 yielding a more stringent upper limit, <1.6×10-4 per νμ charged current event.

KW - Coherent

KW - Neutral current

KW - Neutrino

KW - Pion

KW - Single photon

UR - http://www.scopus.com/inward/record.url?scp=84155162866&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84155162866&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2011.11.049

DO - 10.1016/j.physletb.2011.11.049

M3 - Article

AN - SCOPUS:84155162866

SN - 0370-2693

VL - 706

SP - 268

EP - 275

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 4-5

ER -

A search for single photon events in neutrino interactions

Abstract

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