Observation of photon polarization in the $b \to s\gamma$ transition
R. Aaij
,
Y. Amhis
(1)
,
S. Barsuk
(1)
,
O. Callot
(1)
,
J. He
(1)
,
O. Kochebina
(1)
,
J. Lefrançois
(1)
,
F. Machefert
(1)
,
A. Martin Sanchez
(1)
,
Marie Nicol
(1)
,
P. Robbe
(1)
,
M.-H. Schune
(1)
,
M. Teklishyn
(1)
,
A. Vallier
(1)
,
B. Viaud
(1)
,
E. Ben-Haim
(2)
,
M. Benayoun
(2)
,
P. David
(2)
,
L. del Buono
(2)
,
A. Martens
(2)
,
D.A. Milanes
(2)
,
F. Polci
(2)
,
Ziad Zj Ajaltouni
(3)
,
M. Baalouch
(3)
,
E. Cogneras
(3)
,
O. Deschamps
(3)
,
I. El Rifai
(3)
,
M. Grabalosa Gándara
(3)
,
Pierre Henrard
(3)
,
M. Hoballah
(3)
,
R. Lefèvre
(3)
,
J. Maratas
(3)
,
S. Monteil
(3)
,
V. Niess
(3)
,
Pascal Perret
(3)
,
Diego Alejandro Roa Romero
(3)
,
I. de Bonis
(4)
,
D. Decamp
(4)
,
N. Déléage
(4)
,
Ph. Ghez
(4)
,
J.-P. Lees
(4)
,
M.-N. Minard
(4)
,
B. Pietrzyk
(4)
,
W. Qian
(4)
,
S. t'Jampens
(4)
,
V. Tisserand
(4)
,
E. Tournefier
(4)
,
E. Aslanides
(5)
,
J. Cogan
(5)
,
W. Kanso
(5)
,
R. Legac
(5)
,
O. Leroy
(5)
,
G. Mancinelli
(5)
,
A. Mordà
(5, 6)
,
M. Perrin-Terrin
(5)
,
M. Sapunov
(5)
,
J. Serrano
(5)
,
A. Tsaregorodtsev
(5)
1
LAL -
Laboratoire de l'Accélérateur Linéaire
2 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
3 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
4 LAPP - Laboratoire d'Annecy de Physique des Particules
5 CPPM - Centre de Physique des Particules de Marseille
6 CPT - Centre de Physique Théorique - UMR 7332
2 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
3 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
4 LAPP - Laboratoire d'Annecy de Physique des Particules
5 CPPM - Centre de Physique des Particules de Marseille
6 CPT - Centre de Physique Théorique - UMR 7332
R. Aaij
- Function : Author
J. He
- Function : Author
- PersonId : 756138
- ORCID : 0000-0001-8179-417X
L. del Buono
- Function : Author
- PersonId : 742055
- IdHAL : luigi-del-buono
- IdRef : 253135834
A. Martens
- Function : Author
- PersonId : 738690
- IdHAL : aurelien-martens
Ziad Zj Ajaltouni
- Function : Author
- PersonId : 903794
E. Cogneras
- Function : Author
- PersonId : 743220
- IdHAL : eric-cogneras
- ORCID : 0000-0002-8933-9427
O. Deschamps
- Function : Author
- PersonId : 12089
- IdHAL : olivier-deschamps
- ORCID : 0000-0002-7047-6042
- IdRef : 161447368
Pierre Henrard
- Function : Author
- PersonId : 829303
M. Hoballah
- Function : Author
- PersonId : 1174785
- IdHAL : mostafa-adam-hoballah-hobart
Pascal Perret
- Function : Author
- PersonId : 739797
- IdHAL : pascal-perret
- ORCID : 0000-0002-5732-4343
Diego Alejandro Roa Romero
- Function : Author
- PersonId : 769524
- IdRef : 172096839
S. t'Jampens
- Function : Author
- PersonId : 736045
- IdHAL : stephane-tjampens
- ORCID : 0000-0003-4249-6641
J. Cogan
- Function : Author
- PersonId : 750510
- IdHAL : julien-cogan
- ORCID : 0000-0001-7194-7566
- IdRef : 078779014
O. Leroy
- Function : Author
- PersonId : 171866
- IdHAL : olivier-leroy
- ORCID : 0000-0002-2589-240X
- IdRef : 169871835
M. Perrin-Terrin
- Function : Author
- PersonId : 741779
- IdHAL : perrin-terrin
- ORCID : 0000-0002-3568-1956
- IdRef : 179269666
J. Serrano
- Function : Author
- PersonId : 175327
- IdHAL : justine-serrano
- ORCID : 0000-0003-2489-7812
- IdRef : 127525521
Abstract
This Letter presents a study of the flavor-changing neutral current radiative $B^{\pm} \to K^{\pm}\pi^{\mp}\pi^{\pm}\gamma$ decays performed using data collected in proton-proton collisions with the LHCb detector at $7$ and $8\,$TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of $3\,\text{fb}^{-1}$, nearly $14\,000$ signal events are reconstructed and selected, containing all possible intermediate resonances with a $K^{\pm}\pi^{\mp}\pi^{\pm}$ final state in the $[1.1, 1.9]\,$GeV/$c^{2}$ mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of $K^{\pm}\pi^{\mp}\pi^{\pm}$ mass and the asymmetry between the number of signal events found on each side of the plane is obtained. The first direct observation of the photon polarization in the $b \to s\gamma$ transition is reported with a significance of $5.2\,\sigma$.
Origin : Files produced by the author(s)