Physics Letters B 747 (2015) 365–372
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
Search for dark Higgsstrahlung in e
+
e
−
→ μ
+
μ
−
and missing energy
events with the KLOE experiment
KLOE-2 Collaboration
A. Anastasi
a,f
, D. Babusci
f
, G. Bencivenni
f
, M. Berlowski
s
, C. Bloise
f
, F. Bossi
f
,
P. Branchini
p
, A. Budano
o,p
, L. Caldeira Balkeståhl
r
, B. Cao
r
, F. Ceradini
o,p
, P. Ciambrone
f
,
F. Curciarello
g,b
, E. Czerwi
´
nski
e
, G. D’Agostini
k,l
, E. Danè
f
, V. De Leo
p
, E. De Lucia
f
,
A. De Santis
f
, P. De Simone
f
, A. Di Cicco
o,p
, A. Di Domenico
k,l
, R. Di Salvo
n
,
D. Domenici
f
, A. D’Uffizi
f
, A. Fantini
m,n
, G. Felici
f
, S. Fiore
q,l
, A. Gajos
e
, P. Gauzzi
k,l
,
G. Giardina
g,b
, S. Giovannella
f
, E. Graziani
p,∗
, F. Happacher
f
, L. Heijkenskjöld
r
,
W. Ikegami Andersson
r
, T. Johansson
r
, D. Kami
´
nska
e
, W. Krzemien
s
, A. Kupsc
r
,
S. Loffredo
o,p
, G. Mandaglio
g,b
, M. Martini
f,j
, M. Mascolo
f
, R. Messi
m,n
, S. Miscetti
f
,
G. Morello
f
, D. Moricciani
n
, P. Moskal
e
, F. Nguyen
p,∗,1
, A. Palladino
f
, A. Passeri
p
,
V. Patera
i,f
, E. Perez del Rio
f
, A. Ranieri
a
, P. Santangelo
f
, I. Sarra
f
, M. Schioppa
c,d
,
M. Silarski
f
, F. Sirghi
f
, L. Tortora
p
, G. Venanzoni
f
, W. Wi
´
slicki
s
, M. Wolke
r
a
INFN Sezione di Bari, Bari, Italy
b
INFN Sezione di Catania, Catania, Italy
c
Dipartimento di Fisica dell’Università della Calabria, Cosenza, Italy
d
INFN Gruppo collegato di Cosenza, Cosenza, Italy
e
Institute of Physics, Jagiellonian University, Cracow, Poland
f
Laboratori Nazionali di Frascati dell’INFN, Frascati, Italy
g
Dipartimento di Fisica e Scienze della Terra dell’Università di Messina, Messina, Italy
h
Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia
i
Dipartimento di Scienze di Base ed Applicate per l’Ingegneria dell’Università “Sapienza”, Roma, Italy
j
Dipartimento di Scienze e Tecnologie Applicate, Università “Guglielmo Marconi”, Roma, Italy
k
Dipartimento di Fisica dell’Università “Sapienza”, Roma, Italy
l
INFN Sezione di Roma, Roma, Italy
m
Dipartimento di Fisica dell’Università “Tor Vergata”, Roma, Italy
n
INFN Sezione di Roma Tor Vergata, Roma, Italy
o
Dipartimento di Matematica e Fisica dell’Università “Roma Tre”, Roma, Italy
p
INFN Sezione di Roma Tre, Roma, Italy
q
ENEA UTTMAT-IRR, Casaccia R.C., Roma, Italy
r
Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
s
National Centre for Nuclear Research, Warsaw, Poland
a r t i c l e i n f o a b s t r a c t
Article history:
Received
27 January 2015
Received
in revised form 9 June 2015
Accepted
9 June 2015
Available
online 10 June 2015
Editor: L.
Rolandi
Keywords:
Dark
matter
We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with
a dark photon U and a dark Higgs boson h
, with the KLOE detector at DANE. We investigated the case
of h
lighter than U , with U decaying into a muon pair and h
producing a missing energy signature.
We found no evidence of the process and set upper limits to its parameters in the range 2m
μ
< m
U
<
1000 MeV, m
h
< m
U
.
© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
3
.
*
Corresponding author.
E-mail
addresses: enrico.graziani@roma3.infn.it (E. Graziani), federico.nguyen@cern.ch (F. Nguyen).
1
Present address: ENEA UTMEA-TER, Casaccia R.C., Roma, Italy.
http://dx.doi.org/10.1016/j.physletb.2015.06.015
0370-2693/
© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by
SCOAP
3
.