It has been argued that the mixed Higgs-R 2 model acts as the UV extension of the Higgs inflation, pushing up its cut-off scale in the vacuum close up to the Planck scale. In this letter, we study the inflaton oscillation stage after inflation, focusing on the effective mass of the phase direction of the Higgs field, which can cause a violent preheating process. We find that the “spikes” in the effective mass of the phase direction observed in the Higgs inflation still appear in the mixed Higgs-R 2 model. While the spikes appear above the cut-off scale in the Higgs-only case, they appear below the cut-off scale when the model is extended with R 2 term though reheating cannot be completed in the violent particle production regime since the spikes get milder.
|Number of pages||7|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2019 Apr 10|
Bibliographical noteFunding Information:
We thank Y.-F. Cai, S. Pi, Y. Watanabe, and Y.-P. Wu for useful discussion. MH was supported by the Global Science Graduate Course (GSGC) program in the Graduate School of Science, the University of Tokyo . RJ and KK were supported by IBS under the project code, IBS-R018-D1 . KK thanks IBS-CTPU for kind hospitality during the completion of this work. The work of SCP was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (No. 2016R1A2B2016112 ) and ( NRF-2018R1A4A1025334 ). AS acknowledges RESCEU hospitality as a visiting professor. He was also partially supported by the RFBR grant 17-02-01008 . The work of JY was supported by JSPS KAKENHI, Grant-in-Aid for Scientific Research 15H02082 and Grant-in-Aid for Scientific Research on Innovative Areas 15H05888 .
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics